Humans and Seagrasses in East Africa

A social-ecological systems approach

MARICELA DE LA TORRE-CASTRO

Doctoral Thesis in Natural Resource Management

Department of Systems Ecology Stockholm University

106 91 Stockholm, Sweden Stockholm 2006

Doctoral Dissertation 2006 Maricela de la Torre-Castro Department of Systems Ecology Stockholm University 106 91 Stockholm Sweden maricela@ecology.su.se

© Maricela de la Torre-Castro, Stockholm 2006

ISBN 91-7155-228-6 pp. 1-62. Printed in Sweden by Intellecta Docusys, Stockholm 2006 Distributor: Stockholm University Library Cover and papers’ sheet presentation design Jorge E. de la Torre Castro (Arte.Plastiko)

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“Yet unless it be thoroughly engrained in the mind, I am convinced that

the whole economy of nature, with every fact on distribution, rarity, abundance, extinction, and variation, will be dimly seen or quiet

misunderstood. We behold the face of nature bright with gladness, we often see superabundance of food; we do not see, or we forget, that the

birds which are idly singing round us mostly live on insects or seeds, and are thus constantly destroying life; or we forget how largely these

songsters or their eggs or their nestlings, are destroyed by birds and beasts of prey; we do not always bear in mind, that though food may be

now superabundant, it is not so at all seasons of each recurring year”

Charles Darwin, 1859 (1998: 49-50)

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To Mariam R., Mariam M., Zaudyart, Helef, Adila, Jaina, Rama, Ali, Erie, Sabina, Bisu

and all the other children whose lives depend on the sea… and whose existence and company made this journey worth to sail…

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ABSTRACT

The present study is one of the first attempts to analyze the societal importance of seagrasses (marine flowering plants) by investigating the linkages between humans and seagrass ecosystems from a Natural Resource Management perspective, using a social-ecological systems (SES) approach. The interdisciplinary study takes place in East Africa (Western Indian Ocean, WIO) and includes in-depth studies in Chwaka Bay, Zanzibar, Tanzania. Methods from natural and social sciences were used. Ecological sampling, fish landings analysis and seagrass characterization were used together with interviews, document/archive research and participant observation. The results are presented in six articles. The first shows that seagrass ecosystems are rich in seagrass species (13) and form an important part of the SES within the tropical seascape of the WIO, by increasing livelihoods opportunities as well as providing basic animal protein (seagrass associated fish, e.g. Siganidae and Scaridae). Research, management and education initiatives are, however, nearly non-existent. At local level in Chwaka Bay, seagrass meadows provide social-ecological resilience. The goods and services associated with seagrass ecosystems and also appreciated by locals were fishing and collection grounds as well as substrate for seaweed cultivation. Seagrasses are used as medicines and fertilizers and are associated with different beliefs and values. Dema (basket trap) fishery showed clear links to seagrasses (i.e. fishing grounds, bait provision and targeted fish) and provided the highest gross per capita income of all economic activities. Drag-net fishery seems to damage the substrate and hence seagrasses. Two ecological studies show that artisanal seaweed cultivation of red algae (Euchema denticulatum and Kappaphycus alvarezii), mainly done by women and pictured as sustainable in the WIO, has a thinning effect on seagrass beds, reduces associated macrofauna, affects sediments, changes fish catch composition and reduces diversity when sampled using dema basket traps. Furthermore, it has a negative effect on i.a. women’s health and on diversification. The two last papers are institutional analyses of the human-seagrass relationship. Regulative, normative and cultural-cognitive institutions were analyzed. The complex web of ecosystems and resource users present in Chwaka Bay are expressed in particular institutional frameworks. Ecological knowledge was investigated, showing to be heterogeneous and situated. Due to the abundance of resources and high internal control, the SES seems to be entangled in a rigidity trap with the risk of falling into a poverty trap. Cooperation and conflict take place between different institutions, interacting with their slow (e.g. culture) or fast (e.g. regulations) moving characteristics, and are thus fundamental in directing the system into sustainable/unsustainable paths. Regulations were found insufficient to understand SES dynamics. “Well” designed organizational structures for management were found insufficient for “good” institutional performance. The dynamics between individuals embedded in different social and cultural structures showed to be crucial. Bwana Dikos, monitoring officials, placed in villages or landing sites in Zanzibar experienced four dilemmas – kinship, loyalty, poverty and control – decreasing efficiency and affecting resilience. Mismatches between institutions themselves, and between institutions and cognitive capacities were identified. Some important practical implications of the study are the necessity to include seagrass meadows in management and educational plans, addressing a seascape perspective, livelihood diversification, subsistence value, impacts, social-ecological resilience, and a broad institutional approach. Key words: seagrasses, social-ecological systems, institutions, seaweed farming, artisanal fisheries, common-pool resources, natural resource management, Zanzibar, Tanzania, East Africa, Western Indian Ocean

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TABLE OF CONTENTS

LIST OF PAPERS 7

ABBREVIATIONS 8

INTRODUCTION 9

FRAMEWORK AND THEORETICAL CONCEPTS 11

SCOPE OF THE THESIS 16

SOME WORDS ON SEAGRASSES 17

STUDY SITE 20

SYNTHESIS OF RESULTS 22 Seagrass Ecosystems in the Western Indian Ocean (WIO) (Paper 1) 22

Ecosystem goods and services associated with seagrasses (Paper 2) 23

Seaweed farming, a sustainable livelihood? (Papers 3, 4) 25

Institutions and management (Paper 5) 27 The critical role of monitoring in a wider institutional context (Paper 6) 28

IMPLICATIONS OF MAJOR FINDINGS 30 Seagrass management in the WIO 30 Development and poverty 32 Social-ecological system shifts 33

MAIN CONCLUSIONS IN SHORT 35

APPENDIX A. Ecological goods and services associated with seagrass ecosystems 36

APPENDIX B. Interview guides 39

APPENDIX C. Questionnaires 48

APPENDIX D. Market and ecological data 49

ACKNOWLEDGMENTS 50

REFERENCES 52

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LIST OF PAPERS

Paper 1 Gullström M., de la Torre-Castro M., Bandeira S. O., Björk M., Dahlberg M., Kautsky N., Rönnbäck P. and Öhman M. C. (2002). Seagrass ecosystems in the Western Indian Ocean. Ambio 31(7-8): 588-596. Paper 2 de la Torre-Castro M. and Rönnbäck P. (2004). Links between humans and seagrasses – an example from tropical East Africa. Ocean & Coastal Management 47: 361-387. Paper 3 Eklöf J. S., de la Torre-Castro M., Adelsköld L., Jiddawi N. S. and Kautsky N. (2005). Differences in macrofaunal and seagrass assemblages in seagrass beds with and without seaweed farms. Estuarine, Coastal and Shelf Science 63: 385-396. Paper 4 Eklöf J. S. de la Torre-Castro M., Nilsson C. and Rönnbäck, P. (2006). How do seaweed farms influence fishery catches in a seagrass-dominated setting in Chwaka Bay, Zanzibar? Aquatic and Living Resources 19 (2). In press. Paper 5 de la Torre-Castro M. and Lindström L. Fishing for institutions – the institutionalization of the social-ecological web in Chwaka Bay, Zanzibar. Submitted to World Development. Paper 6 de la Torre-Castro M. Beyond regulations in fisheries management: The dilemmas of the “beach recorders” Bwana Dikos in Zanzibar, Tanzania. Submitted to Ecology and Society. As first author, work includes planning, field work, analysis and writing. As second author, I shared the main responsibility with the first author. In paper 1, I didn’t take part in the presented field case. Paper 3 is the result of a Minor Field Study, which I planned together with the first author and supervised both in the field and afterwards; less inputs were done in writing and no inputs in macrofauna identification. In paper 4, I didn’t participate in the field part of the sub-study “Microhabitat comparisons”. The published and accepted papers are reprinted with the kind permission of the publishers

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ABBREVIATIONS

CAS Complex Adaptive System

DFMR Department of Fisheries and Marine Resources (Zanzibar)

GEF Global Environmental Facility

IDA International Development Aid

MACEMP Marine and Coastal Environmental Management Project (The World Bank)

NRM Natural Resource Management

SES Social-Ecological System

UNRISD United Nations Research Institute for Social Development

WIO Western Indian Ocean

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INTRODUCTION

Humans are and have always been dependent on nature. This is particularly striking in rural communities where people strongly depend on natural resources to meet most of their material needs, through employment of diversified livelihoods strategies for survival (e.g. UNRISD 1995, Ellis 1998, Andersson and Ngazi 1998, Bryceson and Massinga 2002, Ellis and Allison 2004). Seagrass ecosystems constitute one of the natural resources that rural tropical communities benefit from. Seagrasses are marine flowering plants present along almost all coasts of our planet (e.g. den Hartog 1970, Green and Short 2003). They constitute an example of convergent evolution, and have independently evolved at different times (Les et al. 1997, Waycott et al. 2006). Extinction of seagrasses on the Earth would be equivalent to cutting four branches in the tree of life1. In the tropics, they normally co-exist with mangroves and coral reefs, forming the varied mosaic of interconnected ecosystems known as the seascape (e.g. Ogden and Gladfelter 1983, Moberg and Rönnbäck 2003). Seagrasses supply a wide range of ecological goods and services such as habitat for fish and invertebrates; nursery grounds; stabilization of sediments; recycling of nutrients; etc. (e.g. Costanza et al. 1997, Hemminga and Duarte 2000, Green and Short 2003). Especially important is the supply of protein (seagrass associated fish) for coastal communities. Despite the large number of ecosystem goods and services associated to seagrasses, few comprehensive and systematic studies of their societal importance have been done. This thesis analyzes the links between humans and the seagrass ecosystem, and it does so from a Natural Resource Management perspective, using a social-ecological systems approach (Folke 1998, Berkes and Folke 1998). Seagrass management studies are few (Duarte 1999) and, apart from general surveys, it is not until recently that research on seagrasses along the East African coasts has begun (e.g. Uku et al. 1995, Bandeira 1995, Gell 1999, Bandeira 2000, Bandeira and Björk 2001, Ochieng and Erftemeijer 2003, Uku 2005). Regardless of all the ecological and human benefits that seagrasses provide, they are seldom included in management and educational programs. Managers and donors have given much attention to corals and mangroves, while similar efforts focusing on seagrass ecosystems have been nearly non-existent. This thesis constitutes one of the first attempts to focus on seagrasses linking the ecosystem to humans, and addresses management and development. The general objective has been to analyze the relationships between humans and seagrasses and the significance of these habitats for livelihoods in East Africa taking into account management and institutions in a social-ecological framework. Regional and local scales have been considered as well as the main stakeholders and activities taken place in the meadows (basically artisanal fisheries and seaweed farming). Chwaka Bay on the east coast of Zanzibar, Tanzania has been the main research focus.

1 Seagrasses are a striking example of convergent evolution. Despite the fact that they occur nowhere outside of the monocotyledon subclass Alismatidae, they have evolved four separate times within that subclass of principally freshwater species (Les et al. 1997, Waycott et al. 2006).

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The major assumptions in the thesis are that i) societies are embedded in natural systems and thus the management of natural resources is not only an ecological issue (e.g. Jansson and Jansson 1994, Turner and Adger 1996, Folke 1998, Berkes and Folke 1998, Holling 2001), ii) humans and nature constitute a linked system and should be treated together (Folke et al. 2002), iii) social and ecological systems co-exist, and are subject to co-evolutionary processes (Norgaard 1994, Berkes and Folke 1998, Folke 1998, Futuyma 1998, Levin 1998 and 1999, Holling 2001), iv) since humans are biological organisms, human life and well-being is ultimately dependent on the ecosystem goods and services that nature provides (e.g. Daily 1997). Six articles (papers) form the core of the thesis. In each, particular aspects are analyzed and specific questions posed. The first paper addresses the question of the relevance of seagrass for the whole East African region, asking whether seagrass ecosystems are present along all coasts or are isolated features and whether there are signs of livelihood activities associated to them, as well as management initiatives. Having assessed the regional scale, a particular case, Chwaka Bay, Zanzibar, was chosen for in-depth studies. What are the goods and services provided by seagrass ecosystems? What are the links between humans and seagrasses? Which of these are identified and valued by the local population? What do the links look like in terms of use, economic importance and everyday praxis? What is the ecological knowledge of the local people about seagrass ecosystems? Do seagrasses increase social-ecological resilience (decrease livelihood vulnerability)? These questions are addressed in Paper 2. Papers 3 and 4 focus on the impacts of seaweed farming activities taking place over the seagrass meadows in Chwaka Bay. Preliminary studies and the results from Paper 2 suggest that the activity may have negative effects on seagrasses, and for these reasons, studies comparing seagrass meadows with and without seaweed farms were carried out. The benthic compartment (i.e. seagrasses, associated macrofauna, sediments) and associated fish catches, using a traditional fishing method (dema, basket trap fishery) were studied. Having identified the goods and services, the most important economic activities and the possible impacts of the different activities, the two last papers (5 and 6) consist of institutional analyses of the human-seagrass relationship. Institutions are approached considering a broad perspective accounting for regulative, normative and cultural-cognitive aspects for management and development. What are the institutions shaping the present state of the social-ecological system? What are the possible paths that the system might follow, given the institutional landscape? How does the praxis of resource users shape institutions? Are there any monitoring efforts taking place? Can institutions be the key to understand the status quo paradox at system level and every day action at actor level? In the next section, I will present the theoretical foundations and the major concepts on which the analysis is based. I continue with a presentation of the scope of the thesis, followed by some words on seagrasses. Finally, a synthesis of the work is provided, and I conclude with a discussion of the implications of the major findings.

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FRAMEWORK AND THEORETICAL CONCEPTS

Historically, two fundamental errors in Natural Resource Management have been identified (Folke et al. 2002). The first one is the belief that ecosystems behave in linear ways and are possible to predict and control (see also Holling and Meffe 1996). The second is the assumption that humans and nature are separated systems. Odum (1983) stressed the importance of including humans as part of ecosystems and considered human societies embedded in nature. This perspective has developed into the contemporary conceptualization of social-ecological systems. New frameworks in NRM linking the two, apparently separate systems have been developed based on empirical evidence from different systems (Berkes and Folke 1998, Folke 1998, Levin 1998 and 1999, Holling 2001, Folke 2006). The framework used in this thesis is based on previous work, mainly the pioneering paper by Folke (1998). This conceptual framework was developed to emphasize the linkages between ecology and society. It defines social and economic subsystems as part of the whole ecosphere. It stresses the importance of nature for human survival, identifies a wide spectrum of drivers of change and ecosystem degradation (population growth, economic and institutional factors, misguided development aid, power relations, worldviews, lifestyle, values, etc.) and considers scale issues from local to global (Folke 1998). Ecological knowledge and institutions are also highlighted as fundamental for an understanding of the human-nature relationship and management. This framework, and those developed afterwards (e.g. Berkes et al. 2003), stresses the need to give equal importance to the ecological and social components and the linkages between them. Scale issues are considered, since systems are not isolated but there are cross-scale interactions both temporally and spatially. The framework used in the thesis, has been modified for the Western Indian Ocean and to the particular characteristics of Chwaka Bay (see Scope of the thesis and Paper 2).

A social-ecological system (SES) can be defined as an integrated system of nature and society with reciprocal feedbacks (e.g. Berkes and Folke 1998, Carpenter and Folke 2006). Since human impact reaches the whole Globe, one might argue that the concept is useless and the whole planet is a large social-ecological system: the Earth is the largest scale of a SES. However, important differences exist depending on scale and the specific SES in question. In addition, the conventional management perspective of alienating humans from nature is a reason for integrating them, both practically and theoretically. Moreover, it may help to operationalize and set boundaries to related “open” concepts that are also scale independent like ecosystems. As long as there are organisms, abiotic-physical factors and interactions among them, ecosystems can be of any size. An ecosystem can be as small as a patch or as big as the Earth (see Pickett and Cadenasso 2002). In a social-ecological system not only plants, animals, etc. are present. Humans are endogenous to the system. I thus consider human societies embedded in nature. The concept of embeddedness is considered in two ways in the thesis. One is in the sense of Odum and refers to humans as part of nature (Paper 2). The other refers to the embeddedness of institutions in a wider cultural, social and

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historical context (Papers 5 and 6) (Evans 1996, Jentoft et al. 1998, McCay 2002). The concept of embeddedness has several implications. It acknowledges that humans are not isolated individuals, but are born and grown in specific cultural settings, while at the same time humans are considered unique individuals. Thus the concept is a way to handle theoretical extremes between agency and structural approaches (McCay 2002).

The concept of ecosystem services has during the last decades been developed to highlight the interactions between ecological functions and human well-being (e.g. Ehrlich and Mooney 1983, Costanza et al. 1997, Ehrlich et al. 1977, Daily 1997 and 2000). It is basically anthropocentric and value laden. It has been defined as “the conditions and processes through which natural ecosystems, and the species that make them up, sustain and fulfill human life” (Daily 1997, p.3) or “the benefits that human populations derive, directly or indirectly, from ecosystem functions” (Costanza et al. 1997, p. 253). de Groot et al. (2002, p. 395) state that “it is the presence of human beings as valuing agents that enables the translation of basic ecological structures and processes into value-laden identities.”

Evolution is the ultimate process that permeates changes in social-ecological systems. From the Latin evolvere, evolution means to “unfold, to unroll”, to manifest hidden potentialities. In its broadest sense evolution simply means change (Futuyma 1998). Organic evolution refers to the biological part of the system while cultural evolution refers to societal aspects (Futuyma 1998). Complex adaptive systems (CAS) theory acknowledges these features (Levin 1998 and 1999, Norberg and Cumming, forthcoming). Ecosystems, as biological interactive entities, are complex adaptive systems with different levels of organization with emergent properties, which are shaped by processes of self-organization and environmental pressure (e.g. Costanza et al. 1993, Levin 1998, Holling 2001). Social-ecological systems are thus subject to evolutionary processes which affect social, economic and cultural aspects and not only biological elements (e.g. Levin 1999). However, biological and cultural evolutionary processes take place in different ways and at fundamentally different paces. Selection forces clearly differ. Processes bringing novelty to the subsystems are also dissimilar. Take for instance biological speciation which requires isolation if new species are to be formed (Futuyma 1998)2 . Contrast this with knowledge production among humans which is mainly a cumulative and joint effort, many times a result of team work. Ecosystems are reactive, human systems are proactive. The capacity to communicate, create and of foresight are distinctive to human systems (Holling 2001). How the interactions in social-ecological systems and the particular dynamics in the subsystems can merge in a meta-theory is disputable and an emerging research field. Nevertheless, the interactions and links between the sub-sets (ecological and social components) are the focus of attention in attempts to tackle Natural Resource Management problems. History shows that there is a constant co-evolution between human activities and the environment (e.g. Redman 1999, McNeill 2000, Fagan 2000). In East Africa this is evident in the case of adaptation to climatic change and rainfall (Homberg and Öberg 2 See Futuyma (1998) Chapter 16, for a discussion. Allopatric speciation is the most common process of speciation and implies geographical separation. Other forms of speciation like sympatric speciation are subject of great debates in evolutionary biology.

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2006). The most important implication of the CAS perspective for management is that change is the rule and not the exception. Societies have been forced to tackle changes.

These ideas are linked to the adaptive cycle model (or the heuristic resilience model) developed by Holling (1986, 2001)3. Traditional ecology considers the phases of exploitation and conservation in ecosystem dynamics, while the adaptive cycle model adds two more phases of release and reorganization (e.g. Holling 1986, Holling and Sanderson 1996). The adaptive cycle embraces two opposites, namely growth and stability as well as change, variety and transformation. A key point of Holling’s ideas for management is the recognition that ecosystems behave in non-linear ways and that disturbance, surprise and change are inherent properties of ecosystem dynamics. In other words, there are seldom linear relations between cause and effect. The suppression of a disturbance might not lead to ecosystem recovery, a common belief in early management thought. Another implication is that ecosystems are not single equilibrium systems and might present different states. For example a lake might have clear waters vs. turbid water states, as a result of natural, for instance a heavy rain season, or anthropogenic disturbance, for instance a nutrient loading by sewage discharges.

The adaptive cycle is considered in this thesis as a metaphor to describe systems dynamics and not as testable hypothesis in the traditional positivist way. In science, metaphors play a creative role (Pickett 1999). The metaphor helps to address systems development and how the elements and resilience/vulnerability levels vary in the different stages of ecosystem development (Peterson 2000, Carpenter et al. 2001, Holling 2001). A highly resilient system has the capacity to withstand disturbance and can cope with changes because it has adaptive capacity and because the costs of failure are low in reorganization phases (the situation is already “chaotic”, there is not much to loose) (Holling 2001). The resilience approach emphasizes opportunities to change and capacity for development following disturbance (e.g. Holling 2001, Folke 2006). The panarchy metaphor (e.g. Gunderson and Holling 2001) linking several adaptive cycles emphasizes the point that the new system can be almost identical to the previous one or radically different. In other words there is no single adaptive cycle, but continuously linked dynamic cycles over time and at different scales.

Two specific situations in the adaptive cycle model are particularly important for developing countries. The first one is the risk to run into poverty traps. In these states, vulnerability is very high (and resilience low) and the internal control of the system is low as well as the potential for change. The second one is the rigidity trap state, in which there is a lot of wealth, but internal control is extremely high and the system is stable over time (no signs of reduced resilience). Rigidity traps are common in situations were natural resources are abundant but subjects to high rigid control (Holling 2001).

3 A large amount of literature explains Holling’s resilience model/theory; see for example Holling (1973, 1986, 1992, 1996, and 2001), Gunderson and Holling (2002). I choose to refer to Holling (2001), since this paper constitutes a review of the concepts and includes economic, ecological and social systems in the analysis, stressing adaptation as a result of disturbance.

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Adger (2000) argues that social and ecological resilience are related and define social resilience as “the ability of human communities to withstand external shocks to their social infrastructure, such as environmental variability or social, economic or political upheaval”. However, high social resilience might be at the cost of ecosystem degradation (Huitric 2004).

Resilience and changes of states are difficult to operationalize and measure (Carpenter et al. 2001, Carpenter et al. 2005). Normally, it is after a system has changed to another state that the thresholds and consequences can be identified. Up to date there are no ways to measure resilience and there is an active search for surrogates (Carpenter et al. 2005).

Nevertheless, the question “resilience of what to what” (Carpenter et al. 2001) is still crucial. Applying this to the analysis of seagrasses and humans, resilience can be seen as the ability of seagrass ecosystems to withstand disturbances including those caused by different human activities. In this thesis, one human activity was investigated, seaweed cultivation and its possible effect on seagrass ecosystems (Papers 3 and 4). Another application is the analysis of how resilient the social-ecological system is in the event of seagrass decrease or disappearance, i.e. if the ecological system can no longer provide ecosystem goods and services, which are crucial for these communities. This aspect is considered throughout the thesis by looking at seagrasses as one of the components of the system that provide ecosystems goods and services and allows the performance and diversification of essential livelihoods. The seagrass ecosystem adds variation and provides opportunities. This is especially relevant when other ecosystems like corals and mangroves have been degraded, as Paper 5 shows. Another issue is the consideration of resilience as a property of the system, resilience is not good/nor bad, it is an element of ecosystem dynamics. Systems considered maladaptive can, nevertheless, be very resilient e.g. the caste system in India and highly eutrophicated lakes (e.g. Levin et al. 1998). Different states or stability domains can, however, be more or less desirable for humans; there is always a value judgment associated. Humans might strive to maintain these desirable states. Normally, states that are more productive and hence provide a wider range of goods and services are most desirable.

Ecological knowledge is an important link between natural and human systems, and the combination of different kinds of knowledge has been considered a key factor for the design of better management schemes (e.g. Berkes and Folke 1998, Colding 2001, Olsson 2003). The terms local ecological knowledge (LEK) and traditional ecological knowledge (TEK) have dominated recent NRM literature4. Other authors have suggested other typologies like e.g. “folk knowledge” (Jentoft 1999). In this thesis, much reference is also simply done to “ecological knowledge”. LEK and TEK have predominantly been conceptualized as one general knowledge in a particular setting,

4 LEK is defined as “a more recently evolved cumulative body of knowledge applied and developed by stakeholders in a local context. This knowledge consists of externally and internally generated knowledge about resource and ecosystem dynamics” (Olsson and Folke 2001). Traditional ecological knowledge (TEK) is the cumulative body of knowledge, practices and beliefs about ecosystems developed by a society and handed down through generations (e.g. Berkes et al. 2003).

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associated to clear geographical scales and belonging to the whole population. This thesis shows that knowledge is not general or unified or shared by all members. Knowledge is heterogeneous and situated, associated with the everyday praxis of the resource users, or the goals, interests and access to information of the managers and other stakeholders. There is, for instance, no general “fishermen knowledge”; there is knowledge associated to what kind of fisher you are, what gear you use and what kind of ecosystems you fish in (Papers 2, 5, 6). Knowledge is not universal, but situated and related to activities and cultural frameworks (Sayer 2000).

Institutions have gained importance in NRM since they shape the way humans relate to nature and resource use. This field has been dominated by tragedies of the commons conceptions (Hardin 1968), common-pool resources approaches (e.g. Ostrom 1990, Baland and Platteau 1996, National Research Council 2002), and more recently analyses of traditional management systems (e.g. Berkes and Folke 1998, Colding 2001). Much of the focus has been on particular institutions like the regulation of property rights (e.g. Hanna et al. 1996, Becker and Ostrom 1995). Although many scholars use North’s (1990) broad definition of institutions as consisting of norms, rules and in general all constraints of human interaction, few had tackled a broad institutional perspective (Papers 5, 6).

The thesis applies a broad institutional approach. The focus is on understanding resource use in the broader context of social behavior. Previous work, pointing to the importance of considering these issues and widening the narrow perspectives of rational choice, which does not consider behavior in non-utilitarian ways (e.g. Ostrom 1998, Berkes and Folke 1998, Jentoft et al. 1998, Agrawal and Gibson 1999, McCay 2002, Young 2002, Folke 2003, Jentoft 2004, Folke et al. 2005) is used as well. The analysis is based on a broad concept of institutions to mean the structures and activities that provide stability and meaning to social behavior. Institutions provide stability, while they at the same time undergo change, gradual and/or discontinuous. Institutions are constituted in three pillars, the regulative, the normative and the cultural-cognitive (Scott 2001). The regulative pillar consists of rules and regulations. These are normally legally sanctioned through coercive mechanisms. The normative pillar refers to values and expectations, it acts trough social expectations and is morally binding. The normative pillar defines “what ought to be” and what is “good or bad”. The cultural-cognitive refers to the common share understanding in a particular cultural context. It deals with the things that are just taken for granted and that rest on an unconscious level, things that are so obvious that “they just are”. Routines are taken for granted as “the way we do things”. It’s about the interaction between the internal interpretative processes and the external cultural frameworks (Scott 2001). The cultural-cognitive pillar is thus related to the embeddedness concept.

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SCOPE OF THE THESIS

The empirical work of the thesis was done in the East Africa region or Western Indian Ocean. At the local scale it focuses on Chwaka Bay, Zanzibar, Tanzania. Two villages were mainly investigated, Chwaka and Marumbi, but contact with all the villages in the Bay was taken during the six field trips (duration varied from two weeks to three months). The social-ecological framework was adapted to the particular characteristics of the cases and is shown in the figure below. The figure also shows the main focus of the different papers in the thesis. Paper 1 addresses seagrass importance at a regional scale while Paper 2 addresses societal benefits from seagrasses to the local population of Chwaka village. Papers 3 and 4 are ecological field studies attempting to find out to what extent seaweed farms alter or impact seagrass meadows. Papers 5 and 6 are broad social-ecological systems analyses focusing on regulative, normative and cultural-cognitive institutions. Paper 5 analyses the complex web of interactions between different stakeholders and associated institutions as well as their slow/fast changing properties. Paper 6 addresses the importance of institutionalized monitoring and its relationship to organizational structures and nested institutions. The paper illustrates how individuals and structures may interact. The methods used varied from ecological sampling, interviews, questionnaires, document/archive research and participant observation. Appendix B, C and D includes the main interview forms and guides, questionnaires, etc. used in the studies.

Management Impacts

NATURE

Western Indian OceanChwaka Bay

Seagrass meadows

Ecosystemgoods and

services

HUMANSInstitutions & Ecological Knowledge

Fig. 1. Combined system of humans and nature, applied to seagrasses and local communities in Chwaka Bay, Zanzibar. Based on Folke (1998).

Fishersseaw

and eed farmers

/Tanzania

Villages Zanzibar

Social-ecological system SES

Paper 1

Paper 2

SUN

Papers 2-6

Papers 3, 4

Papers 5, 6

Papers 2, 5, 6

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SOME WORDS ON SEAGRASSES

Seagrasses are found along all coasts of the world (except in the Antarctic), thus having global influence on bio-geo-chemical cycles (den Hartog 1970). They are flowering plants (angiosperms) adapted to live their complete life-cycle in marine waters5. Some adaptations to the marine environment are the ribbon-like leaves that almost all species have, and the ability to take up nutrients both from the water column and the pore water in sediments (Hemminga and Duarte 2000). The structure of the plant, i.e. stems and leaves (above ground compartment), and rhizomes and roots (below ground compartment), forms numerous habitats for associated organisms. In seagrass systems, most phyla are represented (Williams and Heck 2001). den Hartog (1979) identifies nineteen structural groups in seagrass ecosystems, including phytoplankton and zooplankton in the water column, macroalgae (fleshy and coralline), epiphytes on blades and stems, micro-algal films, fungi, microbial groups, sessile fauna (e.g. hydroids, anemones and sponges), etc. Some specific taxa, e.g. crustaceans (e.g. lobsters and shrimps), echinoderms (e.g. sea-urchins and sea-cucumbers), molluscs (e.g. clams, oysters and cowries), and fishes which can have food (e.g. rabbit fish) or aquaria value (e.g. sea-horses) are particularly important from an anthropocentric point of view. Large charismatic species such as turtles, ducks, geese and marine mammals like dugongs and manatees (red listed in the IUCN 2001) are also found. Some species use seagrasses during their whole life-cycles, while others use them as feeding or refuge areas in some part of their lives; seagrasses are often nursery grounds for juveniles (Orth 1992, Jackson et al. 2001, Hemminga and Duarte 2000, but see Heck et al. 2003, Chittaro et al. 2005).

In general, the associated diversity is remarkably higher than the diversity of the seagrasses themselves, which is low compared to land flowering plants and other marine primary producers. The number of species reported varies from 48-66 (den Hartog 1970, Phillips and Meñez 1988, Short and Coles 2001, Green and Short 2003, den Hartog and Kuo 2006). Diversity is substantially higher in seagrasses than un-vegetated habitats such as sand or mudflats (e.g. Orth et al. 1984, Connolly 1994, Mattila et al. 1999) but not necessarily higher than similar vegetated habitats, such as salt marshes (e.g. Heck et al. 2003).

Seagrasses are plants, and thus get their primary energy from the sun. They are extremely productive and grow very fast6. They reproduce sexually and clonally. Their flexibility allows vertical and horizontal growth. They can grow linearly and are also able to branch, increasing space occupation (Marbà and Duarte 1998). They are thus able to cover large extensions, in intertidal and subtidal areas, commonly named 5 Seagrasses are adapted to the saline medium (but some of them can inhabit fresh water, e.g. Ruppia spp.). They grow submerged, have an anchoring system and hydrophilus pollination, with one exception Enhalus, which has surface pollination (den Hartog 1970, Les et al. 1997), and thus fulfill all the conditions for a marine water plant (Arber 1920). Seagrasses have special adaptations in their leaves, a very thin cuticle, well developed lacunae and lack stomata (Sculthorpe 1967, Kuo and McComb 1989). 6 Duarte and Chiscano (1999) reviewed the biomass and production showing a value as high as 1012 gDWm-2 yr-1 (average from all published data). Seagrass production has been reported in ranges of 5.5-18.5 gCday-1(Gelner 1959 in Knox 2001), 9–12 gC day-1 (Buesa 1975), and 8 gCday-1 (e.g. Zieman and Wetzel 1980). Leaves can grow up to 1 cm per day (e.g. Erftemeijer et al. 1993).

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seagrass meadows or beds. In temperate latitudes, meadows are normally mono-specific while in the tropics it is common to find many species co-existing, though one or two may dominate (Hemminga and Duarte 2000). Positive relationships between higher diversity and ecosystem services have been suggested, although difficult to test experimentally (Duarte 2000). The ecosystem goods and services generated by seagrasses are shown in the Appendix A, and are i.a. nursery and habitat provision, enhancement of biodiversity, coastal protection, nutrient recycling, etc.

Three main paths of matter and energy are present: direct herbivory (consumers of leaves or epiphytes), planktonic food webs (from phytoplankton to large carnivore fish) and detrital food webs (use of seagrass organic matter in sediments). Seagrasses are open systems connected to adjacent ecosystems (e.g. Ogden and Gladfelter 1983). Part of their net production is exported to adjacent systems (Duarte and Cebrián 1996), to land as beach cast (e.g. Ochieng and Erftemeijer 1999) and to the deep sea (Menzies et al. 1967).

Seagrasses are highly dynamic systems and change responding to natural disturbances like storms, especially in the tropics. However, other systems like the Mediterranean, with more than 4000 years old beds (Mateo et al. 1997), and lagoons, such as Izembek in Alaska, habitat for one of the largest Zostera marina beds in the world (Ward et al. 1997) are very stable over large time scales. Catastrophic events of seagrass loss have occurred. Notably, the seagrass loss due to the wasting disease in the 30’s affecting Zostera marina in most of its range (den Hartog 1987, Short and Wyllie-Echeverría 1996), the massive die-offs in Florida Bay (Roblee et al. 1991, Gunderson 2001) and in Chesapeake Bay (Orth and Moore 1983).

Global decrease in seagrass distribution has been reported with conservative estimations of 90,000 ha per decade (Short and Wyllie-Echeverría 1996). Although natural disturbances affect seagrasses (e.g. disease and weather), human activities are the main reasons for the reductions (e.g. Shepherd et al. 1989, Short and Wyllie-Echeverría 1996, Phillips and Durako 2000). Key potential stressors are reduction of light, nutrient enrichment, changes in sediment conditions, strong water motion and extreme grazing. In the tropics, light regimes are altered by pulsed sedimentation events, low nutrients in column water and grazing pressures (Dennison and Carruthers 2002). Water quality is a key parameter since light penetration allows for photosynthesis and is probably the most important factor affecting growth and distribution of seagrasses (e.g. Dennison et al. 1993). Eutrophication is identified as the major factor for seagrass loss worldwide (e.g. Short and Willie Echeverría 1996, Hemminga and Duarte 2000). Other activities that alter physical (waves, currents, tides and turbulence), geological (sediment grain size and organic matter) and geochemical (mainly sulphide) parameters may have an effect on seagrasses since all these parameters together determine the areas for seagrass establishment (Koch 2001). Filling and dredging, excess nutrient loading, industrial pollution, waste discharges, boats and harbour operations, and some fishing practices like trawling and digging are threats to seagrasses. Fishing activities may also alter seagrass food webs (Jackson et al. 2001, Jackson 2001, Valentine et al. 2002). Aquaculture practices may be negative to

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seagrasses due to organic overload, shading and trampling effects (e.g. Short and Wyllie-Echeverría 1996, Delgado et al. 1997, Duarte 2002).

Once seagrasses have been destroyed, rehabilitation is difficult and costs are extremely high (e.g. NOAA 1977). Recovery is normally slow (years/decades/centuries) and depends, among other factors, on the severity of the damage and on the species involved (e.g. Larkum et al. 1989, Fonseca et al. 2000, Kenworthy et al. 2000, González-Correa et al. 2005). While new methods have been developed, there is still a risk of failure (Calumpong and Fonseca 2001) and although recovery does occur in some cases, the general balance is still towards seagrass decline (Walker et al. 2006). Management of seagrass ecosystems has generally been conceived in terms of classic conservation, using legislation, marine protected areas, environmental impact assessments and access restriction to fishing and destructive gears (Coles and Fortes 2001). Human response is mainly triggered when threats are imminent, close and large, as the case of huge development plans (op. cit.), or rarely reported cases when livelihoods are at risk (de la Torre-Castro 2000).

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STUDY SITE

The study analyzes the East African (Western Indian Ocean) region. There are five mainland countries, i.e. Somalia, Kenya, Tanzania, Mozambique and South Africa, and the island states of the Seychelles, Comoros, Reunion, Mauritius and Madagascar. Diverse habitat types - from seagrasses, corals and mangroves to sand, mudflats and rocky beaches - fringe about 12,000 km coastline. The climate and oceanographic characteristics are driven by the monsoon cycles (Paper 1).

In-depth studies at local scale were carried out in Chwaka Bay on the east coast of Zanzibar. The bay is shallow (average 3.2 m) and has an area of about 50 km2. A mosaic of linked ecosystems, known as the seascape (Ogden and Gladfelter 1983) is present: mangroves are found in the south, large seagrass beds inside the bay and a patchy reef fringing the mouth. The tidal regime is semidiurnal (high and low peaks take place twice a day) and with wide ranges (from about 1m to about 3.5m). The bay constitutes an area of rich seagrass diversity and abundance. Eleven species of seagrasses form meadows in intertidal, subtidal and bank areas. Chwaka Bay is a well documented nursery ground of high economic importance (Subramaniam 1990, Muhando and Ngoile 1994, Lugendo et al. 2005).

The mangrove forest in the south is part of the Jozani-Chwaka Bay National Natural Reserve. Management, conservation and administration are however completely focused on the forest and not on the marine environment (Kitwana Makame et al. 2002).

The population is about 9,000 people (URT 2002). Seven villages surround the bay (Fig. 2). Islam is the dominating religion and the language is Kiswahili. The main livelihood activities are small scale fisheries and seaweed cultivation of red algae (mainly of Euchema denticulatum, previously E. spinosum followed by Kappaphycus alvarezii, previously E. cottonii), which is an export product 7 . Other activities like mangrove forestry, coral rag agriculture and invertebrate collection are also present. Diversification of activities and risk spreading strategies are common. Gear preference varies in the different villages. The study primarily focuses on two villages, Chwaka and Marumbi. Chwaka village is the largest in the area with about 3,000 inhabitants and has a considerable effect on the dynamics and resource use in the bay. The village is dominated (approx. 70%) by drag-net fisheries, followed by dema, i.e. basket trap (approx. 15%), and the remaining is divided between different kind of spears and handline fishing. In Marumbi village, which is situated close to the most diverse and dense seagrass meadows in the bay, about 1,000 people reside. Dema basket traps are used by about 85% of the fishers and the rest is distributed among large mesh size nets (jarife, soni), spears and handline. Detailed descriptions of the area are found in Papers 2 and 5. The following conceptual diagram shows the main features of the study site. Ponwge village is situated North of Uroa and doesn’t appear in the picture8. 7 The algae are used for the extraction of gel like sugars (carrageenans) used in the industry as thickeners, suspenders, binders. They are used in i.a. ice-cream, toothpaste, jelly and marshmallows such as bilar, etc. 8 Symbols are courtesy of the Integration and Application Network (www.ian.umces.edu), University of Maryland Center for Environmental Science.

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Fig. 2. Conceptual diagram of the social-ecological system in Chwaka Bay, Zanzibar, Tanzania.

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SYNTHESIS OF RESULTS

Seagrass Ecosystems in the Western Indian Ocean (WIO) (Paper 1) Seagrasses are important from a social-ecological point of view in the Region. They are widely distributed in all countries, thus constituting an important ecological element of the seascape. The total number of species in the region is high, with 13 different species reported, belonging to four families. The meadows of the WIO present high species richness with 8-10 species coexisting. The diversity and structural differences provided by the different species suggest that the associated animal communities, i.e. secondary productivity, can be quite high. We focused on fish communities and found, based on the different local studies and from our own case study in Mozambique, that the families associated with seagrass meadows in the WIO are varied and numerous (more than 50); many of the families are of commercial importance e.g. Gerreidae, Labridae, Lethrinidae, Lutjanidae, Scaridae, Siganidae, Teraponidae, Syngnathidae and Monacanthidae. This was also the case in Chwaka Bay (Paper 2).

The importance of seagrass associated products is significant at regional and local levels. A few published studies (e.g. Gell 1999, de Boer et al. 2001) and a large amount of unpublished reports suggest the importance for the local populations and that the value of traditional fisheries can be substantial. Gell (1999) reported for Mozambique a market value of 120,000 USD per year for a bay of about 35 km2 with high abundance of seagrasses. Paper 2 suggests that in Chwaka Bay the value might be even higher. Preliminary results from the local fish market in Chwaka show that the market value in Chwaka is higher, about 240,000 USD per year in a 50 km2 area (de la Torre-Castro and Jiddawi, in prep.).

The threats to seagrasses in the region are identified as both natural and human caused. Storms and disease are the main natural threats. Human threats were mainly associated with population increase and its associated changes, i.e. increase in effluent disposal, land-use patterns, agricultural activities, etc. Important is the increased tourism industry targeting the beaches in the region. Another important issue is the potential for aquaculture activities in the region. Seaweed cultivation has been promoted as a friendly sustainable alternative and is, in places such as Zanzibar, already well established (see Papers 2, 3, 4 and 5). However, it has negative effects on the social-ecological system, affecting the benthic compartment, fish community structure, women’s health and establishing semi-bonded relations with the transnational companies. This is presented in Papers 2 and 5.

A field study was carried out at Inhaca Island, Mozambique, showing that higher structural complexity of the seagrass plants contribute to higher density and biomass of fish (Paper 1). No direct management strategies were identified for seagrasses in the East Africa region (Paper 1). The plants seem to be “free riders” in programs related to corals and mangroves. A seascape approach making the role of seagrasses in coastal zones explicit is suggested as a starting point for management. Educational and other means is suggested as fundamental in order to highlight the links between welfare and

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seagrasses. Proper institutions with community participation have the likelihood to succeed based on previous experiences in the region. The research in the region turned out to be scarce, descriptive and concentrated on the states of Kenya, Mozambique, Tanzania and South Africa.

Having stated the importance of seagrasses on a regional basis and following the track of livelihood importance and seaweed farming promotion in the region, in depth studies were done in Chwaka Bay. Ecosystem goods and services associated with seagrasses (Paper 2) The ecosystem services concept has been widely used for tropical ecosystems like coral reefs (e.g. Moberg and Folke 1999) and mangrove forests (e.g. Rönnbäck 1999). It has, however, scarcely been used for seagrass ecosystems.

Seagrasses provide numerous goods and services linked to the structure and function of the whole ecosystem (e.g. Hemminga and Duarte 2000, Duarte 2002, Green and Short 2003). The capacity of seagrasses to provide habitat, refuge, foraging, nursery and spawning areas due to their morphological characteristics; their nutrient recycling abilities, their dual reproduction strategies (sexual and clonal) and their great plasticity (which give the plants the ability to stretch over vertical and horizontal space). Appendix A shows different classifications of ecosystem goods and services associated to seagrasses according to different authors and my own. These classifications were used as a guide to identify and analyze these aspects at the local scale in Chwaka village (Paper 2).

The most important stakeholders in the village, fishermen and seaweed farmers, considered seagrasses ecologically and economically important. Fishermen report their importance in terms of fishing grounds and associated marine products (fish, invertebrates and bait), and they report ecological services associated with seagrasses. Fishermen had extensive ecological knowledge. However, this knowledge differs depending on gear use. While dema “basket-trap” fishermen have a detailed knowledge of the seagrasses, net fishermen have a more shallow and asymmetrical knowledge. The reasons for this are found in the different fishing methods, ecosystem use and organizational structure (Papers 2, 5). Seaweed farmers considered seagrasses an important indicator for seaweed cultivation. However, the relationship between farmers and seagrasses is complex. Many farmers report a fertilizing effect of seagrasses on the growth of cultivated red algae. “Short” seagrass species (e.g. Thalassia hemprichii, Cymodocea spp.) are appreciated as good fertilizers while “long” seagrasses (e.g. Enhalus acoroides, Thalassodendron ciliatum) are generally uprooted and considered negative for cultivation. Many seaweed farmers had limited ecological knowledge about seagrasses but extensive knowledge of their farms. Seagrasses were used directly in the community, as fertilizers, medicines, and indicators of currents and seasonality. Social and cultural services were abundant in that seagrasses form part of the traditional beliefs and practices and some members of the population expressed religious values

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related to seagrasses. The main groups of identified values were instrumental, aesthetical and religious/spiritual (see table 3, Paper 2).

Seagrasses were a very important component of the local economy. Seagrass associated fisheries in the form of “dema”, basket trap fishery, gave the highest gross income per capita and showed direct links with seagrass ecosystems (fishing grounds, bait collection and target fish are seagrass related). Seagrass fish was highly valued in the local market and juveniles were directly consumed by the population, thus being an accessible fundamental protein source. Market data analysis reveals that seagrass meadows are the most frequented sites in the Bay, in spite of the presence of productive ecosystems like mangroves and corals (Fig. 2)(de la Torre-Castro and Jiddawi, in prep.). The reasons for this are explicated in Paper 5, and are clearly related to the historical development of the system, with sequential exploitation of ecosystems together with the social-ecological system and its evolving institutional setting.

0,0010,0020,0030,0040,0050,0060,0070,00

% o

f tot

al fi

shin

g tr

ips

Seagrass-Mangrove

Seagrass-Coral

Seagrass-Seagrass

Fishing trips to the different Bay Areas North and South East Monsoon and Dry seasons (n=4975)

Fig. 3. Fishing trips to the different areas of Chwaka Bay. Data collection during the research period, adjusted for area (de la Torre-Castro and Jiddawi, in prep.)

Invertebrate collection on intertidal areas and mainly performed by women benefits at least 10% of all households in the village (see also Håkansson 2006), providing extra income, adding variation to the diet and buffering when surprises affect the household.

During this phase of the research (Paper 2), key issues were identified leading the research into a number of specific issues namely, seaweed cultivation impacts on the seagrass environment, since all farms are confined to seagrass meadows, and the complex relation between women and the plants, both “protecting” and “degrading” seagrasses. In addition, the interviews suggest that seagrass fisheries play such an important role at present because other ecosystems like corals and mangroves have been heavily exploited during long periods of time (Papers 2, 5). Market data shows that large predators associated with coral environments are almost non-existing, which is confirmed by fishers and the Department of Fisheries and Marine Resources in Zanzibar (Paper 2, 5, de la Torre-Castro and Jiddawi in prep.). Mangrove shrimp fisheries were very weak. A shift in system exploitation seemed to have taken place, which eventually was confirmed by historical data from interviews and archives (Paper 5). The risk of falling into poverty traps in a rigidity trap situation was pointed to in Paper 2. All these findings and the apparent non-existence of institutions related to seagrasses lead the research into deeper seaweed impact studies (Papers 3, 4) and institutional analysis of the Chwaka Bay (Papers 5, 6)

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Seaweed farming, a sustainable livelihood? (Papers 3, 4) As identified in Paper 1, the major threats to seagrasses in the Western Indian Ocean are related to human activities. In the WIO, seaweed farming has been growing fast during the last years. The activity has been promoted as a viable ecologically harmless alternative livelihood. Nevertheless, negative effects from seaweed farming have been reported on meiofauna (Ólafsson et al. 1995), benthic microbial processes (Johnstone and Ólafsson 1995), fish assemblages (Bergman et al. 2001) as well as epifauna and macrophytes (Msuya et al. 1996, Semesi 2002). Collén et al. (1995) and Mtolera et al. (1995) found that the volatile halogenated compounds that the algae produces might damage seagrasses. Seaweed farmers report that seagrass decreases under the farms at time scales of months (Paper 2).

The results presented in Paper 2 confirm that even after the introduction of seaweed farming in Chwaka, fisheries are still the most important source of work and income. However seaweed farming follows, employing mainly women. The government of Tanzania, pressed by structural adjustment has supported algal cultivation as an environmental friendly alternative, which indeed provided large benefits to the locals when the activity was introduced (Petterson-Löfquist 1995). The thesis shows that this situation has changed.

To what extent does seaweed farming affect seagrass meadows? This is the question motivating Papers 3 and 4. The aim of these studies is to compare seagrass beds with and without seaweed farms. Paper 3 focuses on the effects of seaweed farms on the benthic compartment. Six sites in the bay were investigated: three seagrass beds proper, two seagrass beds with seaweed farms, and a sand bank. Three main elements are compared: seagrass, sediment and macrofauna. Seagrass characteristics were measured with standard methods (Short and Coles 2001). Data on shoot density, seagrass biomass, relative cover, canopy height and cores for sediment and macrofauna were taken in the selected areas. The results show that relative cover and canopy height were lower in the seaweed farms sites. Seagrass biomass was also lowest in one of the farms. In general, seagrass beds with farms had lower shoot density compared to seagrass beds proper 9 . Macrofauna biomass was lower under areas with seaweed farms, mainly due to the lack of bivalves in the farms sites. The macrofauna community under the seagrass beds with farms was more similar to a sand bank than to a seagrass meadow. The sediment was normally finer in the seagrass beds with farms than in seagrass beds proper. Organic matter content in the sediment was also lower under the seaweed farms. The conclusion of this study is that seaweed cultivation activities which take place over seagrasses seem to have an effect on basic functional groups of the ecosystem. It affects primary producers (seagrass itself) and filter feeders (absence of bivalves). The possible mechanisms explaining the seaweed

9 One of the seagrass beds with farms, Chwaka farm, showed no significant difference for shoot density with respect to one of the beds proper (Enhalus acoroides dominated). This site showed no differences in biomass when comparing with all the other seagrass beds. The reason for this might be the presence of one outlier in Chwaka farm, which contained a large sample of Enhalus acoroides. This sample had the highest level of biomass of all the study.

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farms effects are shading caused by algae, nutrient competition, the release of toxic substances by algae and mechanical damage through trampling and up-rooting.

Paper 4 is very similar in sampling design to Paper 3. In this paper, however, the focus was on associated fish catches from seagrass meadows and seaweed farms over the meadows. A between-site comparison was done in the Marumbi areas, since these represent the most dense seagrass beds in the Bay. The comparison was made between a seagrass bed (proper), an adjacent algal farm and a sand bank. A within site comparison was made on the farms in front of Chwaka village situated on a bank and exposed during low tides. Here, a short term experiment was carried out to see whether catches differ due to the presence of the farmed algae. The study was done using the local basket trap (dema) gear, since the “off-bottom” farming method (sticks and lines with attached algal seedlings, are placed directly over the meadows) does not allow for other sampling devices like trawls. The results show that seaweed farms affect fish catch composition (Siganus sutor, the herbivore seagrass rabbit fish was more common in the seaweed farms and Cheilinus chlororus, an invertebrate feeder was more common in the seagrass beds). The within site experiment shows that catches increase in numbers but decrease in diversity close to the algae. Non-random issues associated with sampling didn’t allow for an isolation of the seagrass factor as determinant for fish catches. Sampling was done following the traditional dema fishery method, which a priori selected sites with high seagrass cover. The overall conclusions of the study are that submerged aquatic vegetation is an important factor structuring catch composition. Seaweed farms are unlikely to be used as fishing grounds, due to ecological factors, difficulties for gear use, position of the farms in the intertidal sites, lower catches of economically important species than in “true” fishing grounds (Nilsson 2005, de la Torre-Castro and Jiddawi, in prep.) and important institutional issues associated with kinship and respect of the seaweed farms as women dominated areas (Paper 5).

The results of this research have fundamental implications for management; e.g. modification of farming methods, zonation and site selection, scale and intensity, working conditions, property rights regimes, and finally competition and conflicts with other activities in the coastal zone. The results of this study also suggest the application of the precautionary principle and to further analyze the conception of seaweed farming as a social and environmental friendly activity. Paper 5 illustrates, further, how these issues are related to the complex web of institutions present in the Bay.

Grave concerns were identified related to the global character of the activity including monopolistic control of transnational companies (Bryceson 2002), and an explicit exploitation policy from major transnational actors. Rönnbäck et al. (2002) illustrate how the companies advice to chose places with few livelihood options, degraded ecosystems and general poor conditions. The objective is to make seaweed farming the livelihood of last resort. Producers, naturally, do not account for negative impacts in terms of deterioration of women’s health, lack of organization, low educational levels and a shift from a diversity of economic activities to a single activity for all women in the towns.

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Institutions and management (Paper 5) As mentioned before, it is widely recognized that institutions play a central role in Natural Resource Management. Institutions will constrain and enable human behaviour and interactions (North 1990, Scott 2001), having large impacts for the way resources are used and managed. Institutions are part of the everyday life and they shape as well as are being shaped by human activities (Scott 2001).

The previous results of the research (Papers 2, 3, 4) showed that seagrasses were valued, used and part of the everyday life of the people in Chwaka Bay. Irrespective of being a fisher, a seaweed farmer, or a traditional doctor, seagrass seemed to play an important role for locals. In Paper 2, research on institutions was on its early phase and some hypotheses for the apparent absence of institutions directly related to seagrasses were formulated. These included group heterogeneity, kinship, resilience, time lag for institutional evolution and lack of incentives from the large group of drag-net fishermen. In Paper 5 the analysis shows that there is no single simple explanation to the institutional setting in the Bay and that all hypotheses are part of a broader explanation and not competing hypotheses. Moreover, it was found that institutions directly dealing with the existence of seagrasses do exist. Paper 5 also illustrates that the cultural-cognitive factors are so important in explaining the existence of institutions, their interaction and evolution that an approach seeking the reasons behind behavioural outcome in a wider perspective is needed. An approach using three types of institutions: regulative, normative and cultural-cognitive was followed (Scott 2001). Two main questions motivate this study, the first one how to explain the “seagrass paradox” (formulated after Paper 2 had been written) stating that, everybody acknowledges the importance of seagrass but there are no direct institutions dealing with the resource. Paper 5 shows that the “seagrass paradox” didn’t exist. The second question was what is the cause of the rigidity trap found in the social-ecological system (Paper 2)? Can explanations be found in the institutional setting? Why do clear regulations not apply and why do resource users seem to behave as they want?

Paper 5 identifies and analyzes the regulative, normative and cultural-cognitive institutions associated to dema fishery, drag-net fishery and seaweed farming. It also analyzes changes in ecosystem, resource use and regulations with a historical perspective. The case illustrates that the institutional dynamics in the system with cooperating and conflicting forces pulling in different directions were the reason for the rigidity trap observed. In addition, it was found that the dynamics of fast and slow moving institutions (Roland 2004) shape the situation in the Bay. It was also found that the institutions dealing with seagrasses were difficult to identify because they rest in the three different pillars (regulative, normative and cultural-cognitive. For example, the Chwaka By-Law (2001) is a regulative institution which prohibits nets in the Chwaka Bay area, and it was formulated after a conflict over seagrass fishing grounds. While the law regulates the use of gear and not seagrass, the historical development and the practical implications were actually directly related to the seagrass meadows. Normative and cultural-cognitive institutions were found, for instance, in the valuation of different seagrass species, and in the every day praxis up-rooting or choosing areas for

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cultivation. Cultural-cognitive institutions were also related to seagrasses and one of the clearest ones was the art of dema fishing. The findings from Paper 5 have several implications. A narrow institutional view in Natural Resource Management focusing on regulations is not sufficient to understand social-ecological system dynamics, nor as management instruments. Knowledge and understanding about what is actually happening in the system is a prerequisite for management. However, since management is also embedded in the wider social and cultural setting it is also influenced by it. Different actors with different interests and goals have different perspectives and “knowledge” and establish relations of both cooperation as well as contestation. Management outcome is open-ended. Conflicts between slow (e.g. culture and kinship) and fast (e.g. regulations) moving institutions are commonly present. Regulations are powerful tools to change path direction; however, great care should be taken to craft them considering other institutions and promote sustainable development. The critical role of monitoring in a wider institutional context (Paper 6) The dependence of the people of Chwaka Bay on goods and services and the importance of seagrasses to meet their needs was clear (Paper 2, 5). The importance of institutions shaping system trajectory was also clear from Paper 5. However, valuing and recognizing seagrasses is not a warranty assuring sustainability. It has been argued that three levels of analysis and understanding are needed for management towards sustaining the capacity of goods and services generation. The first one is to have knowledge of the ecosystem, in other words, the ecological dynamics in terms of structures, processes (including resilience) and links to other ecosystems (particularly relevant from a seascape perspective). The second one refers to how the system is managed, and how changes in the ecological system are incorporated to take actions and direct management. This requires monitoring systems of some kind; the important point is that the feedback triggers response. Listening and responding to feedback signals is closely related to the adaptive management and adaptive co-management concepts (e.g. Walters 1986, Olsson et al. 2004). The third level is the importance of the governance system and its associated institutions. Governance has been defined as all interactions “taken to solve societal problems and create societal opportunities” (Kooiman and Bavinck 2005, p. 17). Governance systems are constituted by the whole spectrum of actors in society, state, bureaucracies, organizations, civil society, etc. and the patterns that emerge from their interactions (see Dietz et al. 2003) and adaptive governance refers to these societal relationships to maintain ecosystem functioning and goods provision (Carpenter and Folke 2006). Paper 6 focuses on the interplay between the organizational structure and transfer of information. The paper looks into the key role of Bwana Dikos, local monitoring officials placed in different landing sites along the coast of Zanzibar. The Bwana Dikos constitute a key link between the social and ecological parts of the SES and in the organizational management structure (Fig. 1, Paper 6). The main question of this study

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is how a management system that has clear regulations and clear organizational structures presents poor performance? Why does a monitoring system that is “well” designed and formally institutionalized transmit fragmentary information? In other words, what is blocking feedback signals across the organizational structure? What happens to all “ecological knowledge” that the Bwana Dikos actually have, about people, resource use, problems and ecosystem state? The results show that the normative and cultural-cognitive pillars of institutions play a fundamental role affecting the performance of the Bwana Dikos. In addition psychological aspects were identified as important. Paper 6 identify four dilemmas that Bwana Dikos face in their every day praxis – kinship, loyalty, poverty and control -. The general poverty of the Zanzibar fishing villages was identified as the main driver of the dilemmas. Kinship is a deeply rooted cultural institution, expressed in extended families and multiple marriages. To care about kin in a poverty context leads to the “masking” of negative actions against ecosystems and regulations. The Bwana Dikos clearly know that the ultimate need of the people’s daily activities is to bring food home. The poverty of the Bwana Dikos pushes them to search for complementary economic activities making monitoring a discrete and not a continuous activity. The control dilemma is of a different nature than the other dilemmas, and refers to the mismatches between the institution and the ecosystem scale. Cognitive capacities of the human being and the complexity of the monitoring tasks in large areas produced a decrease in institutional performance and resilience of the whole organization. In this paper it is further discussed how embeddedness of the Bwana Diko in a wider social and cultural context and the presence of windows of opportunities, such as the revisions of laws and the encouragement of co-management, can be used to enhance performance and management. Cases from all over the world have shown that monitoring is more effective when formally institutionalized (Danielsen et al. 2005). Zanzibar has already a formalized monitoring system. Understanding the dilemmas of the Bwana Dikos and considering the windows of opportunities open up for a better organizational and institutional performance in Zanzibar. This in turn will lead to constant feedback and communication, which hopefully results in better management.

A major contribution of Papers 5 and 6 is the observation that different interest groups might create particular institutional frameworks. Humans might act in non-utilitarian ways. Regulations are important and powerful tools but not enough to understand and manage social-ecological systems. The dynamics between institutions can lead to different outcomes that may be either sustainable (desired states) or unsustainable (undesired states). Clear organizational structures and regulations are not sufficient to achieve good institutional performance, efficient management and facilitate flows of information. There are not only mismatches between institutions and ecosystems, institutions and scales, or institutions and feedback signals. There are also mismatches between institutions themselves expressed in cooperative or conflictive relationships, and according to different time scales (slow or fast moving institutions).

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IMPLICATIONS OF MAJOR FINDINGS

Seagrass management in the WIO The results of the thesis show that there is a sphere of visibility and invisibility regarding the recognition of goods and services associated with seagrasses. Direct and indirect goods, like medicines or fish, are well acknowledged, while other services like physical-structural and nutrient related services belong to “invisible services”. Managers have focused on corals and mangroves and the interviews reveal a general lack of awareness about seagrass ecosystems as resource suppliers and in terms of livelihood importance. Management alternatives can ultimately be decided politically, and spheres of conflict and cooperation will always be present (Paper 5). However, the framework of ecosystems goods and services can be a practical point of departure for management agencies in the region to acquire knowledge about the links between humans and seagrasses. Where are the seagrass meadows? What kind of meadows they are? What are the uses of the seagrass beds by the locals? What is their importance for livelihoods? What are the most valuable goods provided? What are the impacts and threats? What is the level of dependence on the resource in a particular location? And what kind of management initiatives and institutional frameworks are associated to them?

The impacts over the meadows are of great concern, since they might interfere with the flow of goods and services on which the population rely. Two main disturbances were identified, seaweed farming and drag-net fishing, and both representing chronic disturbance over the seagrass beds in Chwaka Bay (and probably in a similar way at a regional scale). Impact studies of the drag-nets are difficult to carry out, but there is a general consensus that the gear perturbs the substrate. It was also observed that nets up-rooted seagrass while sweeping over the fishing grounds and some fishers report cutting the canopies when they obstructed net use. To what extent drag-nets damage seagrass is an area for future research. The present knowledge about seaweed impact on the meadows is, on the other hand, well documented and the results point to negative effects on seagrass meadows (Papers 2, 3, 4 references therein, Eklöf et al. in press). Taking the results from the papers together it seems that seaweed farming represents, ecologically, a transition intermediate state between a “pure” seagrass meadow and a sand bank. The normative and cognitive institution of seagrass up-rooting is troublesome, especially in combination with drag-net use. The case study from Paper 1 and parallel studies of structural complexity in Chwaka and in other parts of the world show that higher structural complexity is associated with higher fish biomass (Orth et al. 1984, Hyndes et al. 2003, Nakamura and Sano 2003, Jackson et al. 2006, Gullström et al. in manus). In Chwaka Bay, both seaweed farmers and drag-net fishers remove large seagrass species (Thalassodendron ciliatum and Enhalus acoroides), which eventually might lead to a catch decrease. The scale issue is of importance here, since seaweed farms are localized and restricted to the nearest coasts of the villages, occupying a small area of the whole Bay (about 5%), although the impact on the intertidal areas encompasses kilometers of coastline. An expansion of

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the farms is unlikely at present due to the low income as well as problems of health and exploitation. On the other hand, drag-net impact is at Bay level and the consequences might be larger. The use of drag-nets may affect the meadows causing direct mechanical damage, which in turn may lead to lower structural complexity, higher fragmentation and higher turbidity with sediment destabilization. The effects of intensive fishing can have various environmental effects, including bottom up and top down mechanisms that might include growth and recruitment overfishing as well as changes in structural characteristics of the meadows that in turn can change dynamics. Overfishing causes a chain of events that may lead to loss of submerged aquatic vegetation. The decrease of large predators enables an increase of small predators which in turn reduce the numbers of meso-grazers which increases epiphytes and finally, this overload may lead the system into a seagrass loss (Heck and Valentine 2006). Other possible paths are an increase in urchins in the absence of their consumers, which eventually graze intensively on the beds leading to losses (Jackson 2001) (see also the discussion on effects of fishing Paper 2 and on catastrophic shifts Paper 5).

Paper 5 shows also that the institutional frameworks of net fishers seem to be very robust and likely to be reproduced by future generations. The abundance of resources and the high internal control in the absence of severe crisis, together with the conflicts between the different institutional frameworks constitute a rigidity trap (Paper 5). Given the failures to solve the situation, it seems that to unlock the rigidities, the presence of a third party or higher instances of decision making are needed. The efforts at Chwaka Bay level in combination with the Department of Fisheries and Marine Resources have yielded modest results so far. A more open and participative approach, including deliberation, at Bay level and not only in the particular villages might also succeed. The issues are urgent in the face of new projects and proposals from i.a. the World Bank. The Marine and Coastal Environmental Management Project (MACEMP) approved in 2005, includes 51 million dollars credit from the International Development Association (IDA) and a 10 million grant from the Global Environmental Facility (GEF) for Tanzania (www.web.worldbank.org). Part of the initiative for fisheries in Chwaka Bay is to provide larger vessels to fish in the grounds closer to the reef or outside the reef (decreasing fishing pressure inside the Bay) (Hamdan 2005, DFMR). The results of Paper 5 suggest that this will most probably contribute to the continuation of sequential exploitation of ecosystems (now shifting to the outer patchy reef) and new conflicts are likely to emerge between Chwaka and Uroa (situated closer to the reefs in the mouth of the bay). Uroa has traditional sea-tenure rights over those grounds. It is unlikely that seagrasses will be relieved from pressure, since the grounds are highly accessible and preferred, and since the monitoring system is not sufficient (Paper 6). Another management implication is that an intense exploitation of seagrass meadows may be a sign of degradation of adjacent ecosystems.

The Bwana Dikos’ (Paper 6) monitoring actions focus on fish stocks and not habitat condition. A general decoupling of stocks from habitat seems to dominate

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management thinking. It would be desirable to add report tasks on ecosystem state regularly and in a more routinized way, instead of reporting only unusual events.

There is a general belief in management agencies that locals have poor knowledge and understanding of resource and ecosystems. The results show that ecological knowledge is present, although heterogeneity makes its integration into management programs difficult. It is also clear that managers see fishers as a homogeneous group not only in terms of knowledge, but not taking diversification into account (see also Allison and Ellis 2001)

It is clear from the thesis that the diversification of coastal activities’ relies on the whole mosaic of ecosystems and not only on seagrasses. Exploitation levels and pressures might vary over time (Paper 5), but all ecosystems contribute to livelihoods. There has been a controversy about the value of seagrass habitats as nurseries for coral reef fishes and species ontogenic shifts between habitats in the seascape for the Indo-Pacific Region. Dorenbosch et al. (2005) studied mangrove, seagrass, corals, macroalgae and intertidal flats to evaluate the nursery value controversy all over the WIO. The results show that seagrass beds and corals were the most important nurseries and that seagrass beds greatly contributed to coral reef adult densities. A seascape approach is urgently needed although the difficulties of implementation are huge. Development and poverty The Millenium Ecosystem Assessment (2003) presents the linkages between ecosystem services and human well-being. The provision services of food, fresh water, fibers, etc. are closely related to the basic material needs for a good life (adequate livelihoods, sufficient nutritious food, shelter and access to goods). They are also related to basic health and access to clean air and water). The thesis shows that seagrass ecosystems are linked to most of these well-being components.

Seagrasses provide a diverse set of livelihood opportunities to the population and they have contributed to the social-ecological resilience of the system. The local population valued and recognized the goods and services closely related to well-being and survival. At present the most important economic activities, fishing, seaweed farming and invertebrate collection, are associated to the meadows, (Paper 2). Although almost the whole population in the Bay falls into the poverty or extreme poverty categories, the better offs have clear links with seagrass meadows. Seaweed farmers are worst off, earning about USD 1 per day (limit of extreme poverty), and an average fisherman is on the poverty line with about USD 2. The highest income per capita is earned by dema fishermen, with an average daily income of 2.7 USD (slightly over the poverty line) (Paper 2, de la Torre-Castro and Jiddawi in prep.). Of importance is that dema is institutionalized as a traditional and sustainable seagrass fishery (Paper 5). The thesis show, once again, that traditional systems seem to work in harmony with nature and that they might yield higher economic revenues. Some authors have argued that an approach to poverty problems should focus on what the

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poor have, instead on what the poor lack (Moser 1998, Ellis 2003 both in Ellis and Allison 2004). In this perspective it might be argued that seagrasses meadows are “supplier sources” for the poor. The contribution of seagrasses to food security in the form of animal protein from seagrass associated fish (Paper 2) is of significant importance. While fisheries contribute to food security and maintenance of health (clearly seen in child health), seaweed farming produces only cash-crops of low price and jeopardizes women’s health. Social-ecological system shifts While, ecologically, the seaweed farms seem to be transition intermediate states, between “pure” seagrasses and sand banks, a shift to a new social state seems to have taken place. The decrease of diversity of the complementary economic activities performed by women and the entrenchment of future women generations to algal farms (since they grow-up and learn only this activity under exploitative conditions) is probably the most important consequence of the shift. It is difficult to assess trade-offs between activities because losses and gains might be present in all options, as well as monetary and non-monetary values; but this study shows that the idea of seaweed farming as environmentally friendly and a good alternative for women does not hold as it is at present. How resilient are women to be able to shift into previous states of diversification and how desirable are these previous states, are questions for further research. The thesis shows that a majority of fishers in Chwaka village behave in non-utilitarian ways following their established institutional frameworks, which complicate the understanding of the situation and management or development initiatives (Paper 5). How resilient are fishermen to go back into traditional methods and how desirable this is, is a difficult question. Novel solutions, including re-organization, will most probably arise as a result of development. The challenge is to create possibilities for sustainable pathways creating positive synergetic effects (Paper 5 and 6).

The study also shows that the poverty situation has cross-scale effects on management which in turn affects monitoring, the information flow and general institutional performance. Paper 6 addresses possibilities to create synergetic effects, i.e. the state working together with the citizens through embeddedness, co-production and window of opportunities. Profound decentralization is not a solution since institutions at larger scales and infrastructure provision is needed. Neither are top-down approaches. Co-management and cross-scale considerations are needed (Folke et al. 2005). The study shows that institutional interplay is crucial not only in the vertical but also in the horizontal (Paper 6).

It is difficult to conceive of radical changes in livelihoods and survival strategies in the near future. Political agendas, international actors and donors play important roles. Pressures from the International Monetary Fund (IMF) and the World Bank include the formulation of Poverty Reduction Strategies Papers (PRSP). The fisheries sector is however commonly overseen, in spite of the strong food security aspects and improved livelihoods associated with fisheries. In Tanzania the fisheries sector is

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significant yet the programs do not reflect this point (Thorpe et al. 2004). The fisheries sector is subsumed under agricultural issues and given, relative to activities on land, little importance (PRSP 2000, ZPRP 2002).

Sustainable development would include considering the importance of seagrass meadows for livelihoods in a seascape perspective. Active management (adaptive when possible) and monitoring constitute a desirable start. Knowledge and understanding are needed for management. It is critical to identify the key drivers of the system. It is unlikely that the commonly use rapid appraisal methods disclose important variables. The results of this study show that middle and long term perspectives and continuity are needed, having tremendous implications for planning and donor fund administration.

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MAIN CONCLUSIONS IN SHORT

The major points of this thesis can be resumed at three levels: 1. Practical management implications

• Seagrass meadows are important ecosystems in the WIO and provide opportunities for basic livelihoods as well as food security

• Livelihoods with the closest links to the meadows in form of dema trap fishery provide the highest gross income per capita

• Seaweed farming and drag-net fishing seem to jeopardize a constant flow of goods and services

• Seaweed farms might be seen as intermediate states between “pure” seagrass meadows and sand banks

• Intertidal and subtidal meadows might experience chronic disturbances • Co-management and conservation for development are needed. The institutional

frameworks present as well as the seascape perspective should be considered 2. Development

• The seascape, and particularly seagrass meadows, are important elements for livelihood diversification, providing social-ecological resilience

• Seaweed farming status as desirable livelihood should be re-evaluated • The key drivers to understand social-ecological system dynamics (basically

institutional frameworks) are complex and difficult to identify. Rapid appraisals seem to be inappropriate as guides for development

• Rigidity traps may be present when natural resources are abundant and high internal control is present, rigidity traps might change into poverty traps

• Poverty at individual level may affect transfer of information in monitoring activities (vertically and horizontally), thus having consequences across scales

3. Natural Resource Management • The framework of ecosystems goods and services constitute a good starting point,

particularly when previous knowledge is scarce or non-existing • Broad institutional perspectives (addressing regulative, normative and cultural-

cognitive institutions) increase the understanding of the social-ecological system. Institutions are key drivers into sustainable or unsustainable paths

• Slow (e.g. culture, religion, kinship) and rapid (e.g. regulations according to presidential periods) institutions influence social-ecological system dynamics

• Regulations are important and powerful institutions, but insufficient to understand social-ecological systems and to create alternative management options leading to sustainable paths

• “Well” designed organizations and nested institutions for management are not sufficient for “good” institutional performance, other institutions affect performance

• Dynamics of conflict are as important as dynamics of cooperation • Humans may behave in non-utilitarian ways • Mismatches between institutions themselves and between institutions and

cognitive capacities were identified • Ecological knowledge tends to be heterogeneous, situated and rooted in different

interests and cultures

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APPENDIX A. ECOLOGICAL GOODS AND SERVICES ASSOCIATED WITH SEAGRASS ECOSYSTEMS

The association of the ecosystem goods and services with the corresponding ecological processes is a difficult task since there is no one to one correspondence (e.g. de Groot et al. 2002). The following table is an attempt at classifying these relationships. The first column of the table shows the primary values or basis for the provision of all goods and services (Gren et al. 1994). The second column shows some of the processes, factors or structures affecting the provision of goods and services. This column is meant to identify some of the ecological processes behind the provision of goods and services. The last column shows the list of goods and services, predominantly anthropocentric. The contents of this table should be considered in a context in which disturbance regimes and resilience are components of the ecosystem dynamics. Basis for the provision of all ecosystem services and goods

Set of processes, factors and/or structural attributes affecting each good/service

Goods and/or services

• Detritus chain • Planktonic chain • Direct herbivory • Species specific seagrass nutrient

contents (e.g. carbohydrates) Direct coupling to Biological services

Direct goods: Leaves Roots Fibers Medicinal resources Indirect goods: Fish Crustaceans Molluscs Equinoderms

• Hydrodynamics • Sediment dynamics • Degree of patchiness • Size of large seagrass beds • Species specific morphological

differences

Physical-structural services: Erosion and sediment control Improving water quality Provision of low energy areas (control of wave and tide energy) Flood mitigation Protection of the coastline Ecological corridor (support both mobile links and physical and biochemical interactions between adjacent ecosystems)

• Light regimes • Life history and ethology of

associated fauna • Larval dynamics • Degree of patchiness • Size of large seagrass beds • Combined clonal and sexual

reproduction • Hydrophilus pollination • Evolutionary and genetical

processes

Biological services: Conversion of light energy into biomass Habitat and substrate provision (both adult/juveniles and permanent/transient organisms) Provision of nursery, spawning, refuge and foraging areas Alternative reproduction systems Increase of biodiversity Preservation of genetic material

• Life history of the different

species • Physiological adaptations and

nutritional requirements of different species

Nutrient related services: Export of organic matter and nutrients (both in water column and in sediments) Burial of organic matter and nutrients Global carbon budget Production of O2 Sink of CO2

• Physiological, ecological and

evolutionary characteristics of seagrasses.

Information services: Physiology, Ecology and Evolutionary history of marine angiosperms Biomarkers and monitor control Responses to large climatic changes (CO2, Temperature and sea level increases)

• Primary

Productivity/nutrients recycling

• Three-dimensional structure: Canopy and root system

• Ecosystem dynamics, including resilience

• All

Social and cultural services: Aesthetic Tourism/ Education Coastal communities livelihoods Religious or spiritual values

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Ecosystems goods and services associated to seagrasses according to other authors.

de Groot (1992)

Daily (1997)

Costanza (1997)10

Rönnbäck (1999)11

Moberg and Folke (1999)

Duarte (2001)12

Green and Short (2003)

Regulation functions Prevention of soil erosion and sediment control Fixation of solar energy and biomass production Storage and recycling of organic matter Storage and recycling of nutrients Regulation of biological control mechanisms Maintenance of migration and nursery habitats Maintenance of biological and genetic diversity Carrier functions Providing space and substrate for: Energy conversion Recreation and tourism (snorkelling) Nature protection Production functions

Global materials cycling Global carbon cycle Other nutrients recycling Production of oxygen Transformation, detoxification and sequestration of wastes Nutrient absorption in rich environments, via both leaves and roots. Other values Recreation value: Ecotourism: Scuba diving and snorkelling. Cultural and historical value Scientific and information value

Only account for Nutrient regulation and raw materials A number of other services are given by seagrasses using his classification: Disturbance regulation Erosion control Pollination (hydrophilus pollination) Biological control Refugia Food production Raw materials Genetic resources Recreation Cultural

Natural products Leaves Seeds Roots Fish Crustaceans Molluscs Manure Animal fodder Traditional medicine Fibre materials Ecological services Protection against floods, tides and waves Control of erosion Biophysical support to other coastal systems Provision of nursery, breeding and feeding grounds Maintenance of biodiversity and genetic control Storage and recycling of organic matter, nutrients and pollutants Export of organic matter and nutrients

Goods provision Leaves and roots for construction of fishing traps, furniture, carpets, etc. Leaves for salad, manure, fodder Seeds for consumption Traditional medicine Physical structure services Shoreline protection Control of sediment fluxes Sediment bind Control of waves Control of water flows velocities and directions Biotic services Transforming solar energy into biomass Habitat and substrate provision Provision of nursery grounds Export of fish Maintenance of biodiversity at all

Ecosystems functions Primary production Carbon storage Carbon flow Nutrient recycling Ecosystem services Gas and climate regulation Disturbance regulation Erosion and sedimentation control Remineralisation Waste treatment Biological control Monitoring of global change and ecosystem health Recreation tourism and education Ecosystem goods Habitat and refuge Food resources Raw materials Genetic resources Natural heritage

Provision of commercial and artisanal fisheries Nursery habitat for offshore fisheries Food Fodder or bedding for animals Fibres Packing material Fertilizer and mulch Building dikes Coastal protection from erosion Stabilizing sediments Water purification Interaction with adjacent ecosystems Maintenance of biodiversity and threatened species Carbon dioxide sink Cultural, aesthetic and intrinsic values

10 Developed from Daily 1997. 11 Developed from Saenger et al. 1983, Hamilton and Snedaker 1984, Ruitenbeek 1994 and Costanza 1997. 12 Developed from Heip et al. 1998.

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Oxygen Food Genetic resources Raw materials Fodder and fertilizers Ornamental resources Information functions Aesthetic Spiritual Historical Cultural Educational and scientific

Biological regulation of ecosystem processes and functions Biological maintenance of resilience Production of oxygen Sink of carbon dioxide Influence on local and global climate Sustaining of livelihoods of coastal communities Heritage values Cultural, spiritual and religious values Artistic, educational and scientific information Recreation and tourism

levels Regulation of ecosystem processes and functions Influence over resilience processes Support to mobile links between adjacent ecosystems Function as an ecological corridor Export and burial of organic matter and nutrients Biogeochemical functions Global carbon budget Recycling of nutrients Waste assimilation Information services Evolutionary history angiosperms in the marine environment Social and cultural services Support recreation Aesthetic values Inspiration source Important for local communities Religious or spiritual values

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APPENDIX B. INTERVIEW GUIDES

HUMANS AND SEAGRASS PROJECT Date______ Interview series 1 #Int.______ Semi-structured interview guide Name of translator___

● FISHERMEN

Gear Type of fisherman

1. GENERAL INFORMATION Name___________________________________________ Age ________________________________Sex__________ Family: 1.1 Marital status 1.2 Wife or wives and occupation 1.3 Children in the family 1.4 Migration: Are you from Chwaka or come from another town? 1.5 Has anyone from the family left Chwaka to work in another place? 2. ECONOMIC ACTIVITIES Main economic activity

Other important Reason for choice What if ______ disappear

Are there any invertebrate collectors in the family

activities

1. Direct income No. of Children 2. Tradition Wife/wives 3. Friend advice 4. Easy job 5. Easy access 3. FISHERIES Property rights: Who has the right to fish? How are fishing areas allocated? What happens with newcomers? What happens when other villagers come into your territory? Has property rights changed over time? What system of property and fishing rights would you prefer or like? Do you have any contact with the government about fishing area allocation? Organization: Are you member of a fishermen organization? If yes, how does it work? Members/getting membership How are leaders elected? Fees How do the organizations work? How would you improve the organization?

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Parametric management (Based on Acheson and Wilson 1996) Parameter yes/no Short explanation

Existence of defined fishing areas Limited access (fishermen) Seasonal limits (rest from fishing one season of the year) Limits of technology (big boats, trawls, etc.) Protection of adults Protection of juveniles Size limits of catches Ethical principles (conservation) Protecting overcrowding Quotas Sacred Sites Taboo systems Sleeping territorialities Fisheries characteristics: Describe an ideal fishing ground Where is your favourite fishing ground? Where do you prefer to fish in vegetated (such as algal mats or seagrasses) or unvegetated areas? Boat type _________ gear__________ bait____________ Production per spring tide: weight of fresh fish ____________ Production per neap tide: weight fresh fish _______________ What do you catch during spring tides? What do you catch during neap tides? How many hours do fish per day? spring______ neap______ Seasonality: Working the whole year?_______ Best season________________ Historical context: When did you start fishing? Do you remember how the place was? At start Now Sediments Bottom vegetation Fish People behaviour (attitudes, etc) Have you noticed any changes in the fisheries in the Bay after the seaweed cultivation was introduced? Price Catches Size of the fish Do you want to expand your fisheries? Do you feel secure about the future? Conflict resolution: Do you have any problems with other fishermen? If yes, what kind of problems? Are there problems with fishing, gear types, production, etc? What do you do if there is a problem? Whom do you inform? Is there any punishment? What is your relationship with the seaweed farmers? Have the use of fishing grounds changed after seaweed introduction? Do you think that seaweed farms affect bait collection activities?

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Do you think that seaweed farms affect seagrass as habitat for the fish that you target? Revenues How much do you earn daily (min-max range)? Who buys your fish? How is your health status? 4. DIET What do you eat during a normal day? Breakfast: Lunch: Dinner: If fish, what fish….. If seashells, what seashells…. How many times a week do you eat beef, chicken or goat? How many times a week do you eat Mollusca? Do you consider fish important for your health? Do you consider seashells important for your health? Do you think that they are important for the growth of your children? What is the best food when you are ill? What is the best food when you have a celebration? What is the best food during Ramadhan? 5. LOCAL ECOLOGICAL KNOWLEDGE Choose the three most important habitats for fish

Habitat 3 best Reason

Sand flats Mangroves

Seagrasses Corals Seaweed farms Channels

Are there any differences between seagrasses and algae? What is the role of short seagrass …why? What is the role of long seagrass …why? What do you think about seagrass washed upon the beach? If seagrass is removed, does it come back?_________ Fastly or slowly? Have you noticed changes in seagrasses in the Bay? If yes, what changes and where Do you think that something happens to seagrasses when fishing? Do you think that something happens to seagrasses when collecting invertebrates? Do you think that something happens to seagrasses with algal cultivation? What bait is collected from seagrass meadows? What kind of fish can you catch in seagrasses? What kind of invertebrates can you catch in seagrasses? Do you use seagrasses…how, what for (direct use of seagrasses)? What is the benefit of seagrasses for the people in the Bay? What do you think will happen if seagrass disappears? To the environment __________________________ To the people________________________________ Have you snorkelled in seagrasses? Do you think they are beautiful? Do you think that we should care about them?

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Adaptations of the interview to seaweed farmers 1. GENERAL INFORMATION Same 2. ECONOMIC ACTIVITIES Same 3. ALGAL FARMS Property rights: How did you get your farm? Who has the right to cultivate? What happens with new farmers? What happens when other villagers come into your territory? Have there been changes over time (in the property rights system)? What system would you prefer or like? Do you have any contact with the government about farm allocation? Organization: Are you a member of a seaweed farmer’s organization? If, yes, how does it works? Members/getting membership How are leaders elected? Are there any fees? How do the organization works? How would you improve the organization? Parametric management: Farm characteristics: How is the best place to start a farm? Where do you prefer to farm in vegetated (such as algal mats or seagrasses) or unvegetated areas? How many plots do you have? Materials and duration? sticks_____ ropes_______ ties_____ Production per spring tide: Dry weight bags _______ What do you do in your farm during spring tides? What do you do during neap tides? How many hours do you work in your farm per day? spring______ neap______ Seasonality: Working the whole year?_______ Best season________________ Historical context: When did you start with the seaweed farm? Do you remember how the place was? Same Do you want to expand your farm? Do you feel secure about the future? Conflict resolution: Do you have any problem with other farmers? What kind of problem? What do you do if you have a problem? Whom do you inform? Is there any punishment when someone doesn’t respect the rules? What is your relationship with the fishers? Have fishers taken good places for seaweed farming? Do you think that fishermen affect your activities? Do you think that seaweed farms affect the seagrass as habitat for fish? Revenues: How much do you earn from the seaweed farm (min-max range)? Who is the buyer? How is your health status? 4. DIET Same 5. LOCAL ECOLOGICAL KNOWLEDGE Same

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Interview series 2 Semi-structured interview guide

Fishers 1. General information 2. Name, age, sex, demographic information, main economic activities contribution to household budget,

remittances, electricity if yes, costs 3. Village identity - How would you define Chwaka as a fishermen village or farmer or other? 4. Production and maintenance costs of economic activities 5. Fisheries gears and regulations – gear preference, no. gears, changes, places for fishing, presence of

seagrasses, gear regulation knowledge, license payment, knowledge about Department of Fisheries and Bwana diko

6. Problem of fisheries decline – reasons, fish and invertebrate species, own reflections 7. Informal organization – “company organization”, leadership, knowledge, financing and income division 8. Local ecological knowledge (Using photographs, herbarium and fresh seagrasses) 9. Ask for the local names and uses of seven common species of seagrasses (Enhalus acoroides, Thalassia

hemprichii, Halophila spp., Cymodocea spp., Halodule spp., Thalassodendron ciliatum and Syringodium isoetifolium). Discuss the use of conventional fertilizers.

10. Seagrass distribution and characterization – Ask for distribution and abundance of the same seven species in the most common fishing grounds and in intertidal subtidal areas.

11. Function and associated fauna – Description of species and their ecological functions, associated species of fish and invertebrates.

12. Threats to seagrasses and possible solutions. 13. Diet – specific protein items, e.g. eggs, ducks, milk for adults and babies, fish 14. Narratives of the Marumbi conflict

Adaptations of the interview to seaweed farmers 1. same 2. same 3. same 4. same 5. Seaweed production and regulations – farm regulations, knowledge about Department of Fisheries and

Bwana diko, place allocation, etc. 6. Problems associated to seaweed production decline - reasons, algal species, own reflections 7. Informal organization – same plus own thoughts about the seaweed farmers local organization 8. same 9. same 10. same 11. same 12. same 13. same 14. same

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Interview series 3 Semi-structured interview guide for fishermen Chwaka/Marumbi/Uroa

Generalities 1. Village 2. Gear 3. Age 4. Education 5. Do you belong to the fishermen committee? 6. How often do you meet? 7. Main discussion topic? 8. How many years have you been fishing? 9. Your father was a fisher? 10. Your grandfather was a fisher? 11. Your grand grandfather was a fisher? 12. Have you been in contact with Dept. of fisheries? 13. Have you been in contact with Bwana diko? 14. Have you gotten credit from Dept. of fisheries? 15. Have you gotten credit from someone from Zanzibar town? 16. Have you gotten credit from someone from other place?

Past issues (general changes the last 10 years)

17. Have you seen changes in seagrasses in the Bay? 18. If yes, what changes 19. Seagrass abundance increase/decrease/stable 20. Sea-urchin population increase/decrease/stable 21. Fish abundance increase/decrease/stable 22. Please name species that have decreased most 23. Please name the species that are abundant at present 24. Please name the species that have increased 25. Please name the species that have decreased 26. Size of the fish increase/decrease/stable 27. Dema fishers increase/decrease/stable 28. Net fishers increase/decrease/stable 29. Spear fishers increase/decrease/stable 30. Do you remember a situation in which there was a fishing crisis in the Bay? 31. When, what happened? 32. How did you solve the crisis?

Present issues/situation

33. What is your main problem at present? 34. How can you solve it? 35. With whom you discuss the problem? 36. Who can help you to solve the problem?

Future perspective

37. Will your children be fishers? 38. How will the catches be? 39. What fish species will be more abundant? 40. What fish species will disappear? 41. How will the seagrass meadows be? 42. Majani kumbi increase/decrease/stable 43. Majani Mtimbi increase/decrease/stable 44. Majani madogo increase/decrease/stable 45. What will be the role of Dept. of fisheries? 46. Name the most important economic alternatives in the future?

44

The role of organizations/actors (their work is good, their work is regular, their work is bad) 47. Dept. of Fisheries and Marine Resources 48. District office 49. Dept. of environment 50. Dept. of forestry 51. Dept. of tourism 52. Non-governmental organization’s projects 53. Projects and organizations related to the Jozani Park 54. Institute of Marine Sciences 55. Bwana Diko 56. Foreign scientists 57. Others

Statements of agreement (I do agree/relatively agree/disagree)

58. The problems will be solved in my lifetime 59. The problems will be solved through the fishermen committee 60. The problems will be solved by the Dept. of fisheries 61. We should respect and support traditional fishing grounds 62. We should change the traditional fishing grounds system to a modern one 63. Dema gear will gain support 64. Net gear will gain support 65. Spear gear will gain support 66. Tourism will gain support 67. I will stop fishing, if I get ____ shillings per day 500 , 600 , 800 , 1000 , 1,500, 2000 , 2500 , 3000

more or I cannot stop my fishing because... Choose only one statement that best reflects your opinion

68. Allah alone will solve the problems 69. Fishers alone will solve the problems 70. Dept. of fisheries and government alone will solve the problems 71. Dept. of fisheries together with Allah will solve the problems 72. Fishers together with Allah will solve the problems 73. Depart. Of fisheries, fishers and Allah, all together will solve the problems

Comments, additional information.

45

Interview series 4 Guide for semi-structured interview in Marumbi village (Dema basket trap fishers)

1. Name 2. Age 3. Civil status, wives, etc. 4. If married, wife (wives) occupation 5. Children, boys ( ) girls ( ) 6. Why are you a dema fisher? 7. Since when you are a dema fisher? 8. How many demas do you have? 9. Do you change gear during the year seasons? 10. Tell me about your life as a dema fisher, a normal day, advantages, disadvantages, etc. 11. Fishing group organization 12. Arenas for discussion: Who do you talk to, who should help to solve the problems, what is your

opinion about fisheries department and Bwana Dikos 13. Talk about power relations in the village and Bay 14. Talk about kinship relations in the village and Bay 15. Talk about traditional issues in the village and Bay 16. Fishing grounds rights 17. Seaweed farms rights 18. Changes in environment, fish and fisheries because of the farms 19. Organization, action in NRM management. Role of committees, Sheha, Bwana Diko, other? 20. Communication channels with other villages in the Bay 21. Trust between groups e.g. fisher-fisher, fisher-seaweed farmers, fisher-authorities, fisher-researchers, etc. 22. Rank 3 most important habitats for fish: sand flats, mangroves, corals, seaweed farms, channels, rocks 23. Rank 3 most important factors when you decide where to fish: tide, distance, weather, corals, seagrass,

mangroves 24. If seagrass important then discuss habitat short seagrass, habitat long seagrass, habitat seagrass diversity,

habitat seagrass patchiness 25. Can you describe the best fishing ground for dema? 26. Why is the best ground for dema? 27. Do you fish there? 28. How often? 29. If not, why not? 30. Are there other fishers there? 31. What is your relationship with those fishers? 32. What bait do you use? 33. Where do you collect it? 34. Do you have a cultivation plot? 35. Do you sell something? 36. Any other economic activities 37. Any family member sending money 38. How many times a week do you eat milk, meat, chicken, duck, eggs, fish 39. If fish, which fish 40. How many Tanzanian Shillings do you need everyday to sustain your family? 41. Do you own a boat? 42. How did you finance it? 43. How a young fisher can buy a boat now? 44. When the market established? 45. Who sells fish in the market? 46. Who buys fish in the market? 47. Do you need to go to Zanzibar town to sell your fish?

46

Interview series 5 Interview guide with different managers at different Departments in Zanzibar 1. What are the objectives in your department for Chwaka Bay management? 2. Is there any management plan at present addressing these objectives? 3. What are the difficulties in implementation? 4. Are seagrasses included in some management or regulative measures? 5. What is, in your opinion, the importance of seagrasses? 6. Are there any threats to seagrasses? If yes….what are they? 7. If no management, why do you think there are no specific management programs for seagrasses? 8. What can be done to manage and conserve seagrasses? 9. Why do you think that so far, the management in Chwaka Bay has been focused mainly on mangrove

forest? 10. What are, in your opinion, the functions of seagrass ecosystems? Are they resilient? 11. Can you tell me what happened in Chwaka-Marumbi during 1996?

Other discussion topics were artisanal fisheries, management of marine resources and projects (on-going and coming), fishermen knowledge and problems, laws and by-laws.

Interview series 6 Interview guide with Bwana Dikos (Beach recorders)

1. History of getting the job, job and working conditions 2. Job tasks and responsibilities 3. Marine Resource organization and management 4. Property rights issues 5. Generational issues 6. Fish market issues 7. Advantages of being a Bwana Diko 8. Disadvantages of being a Bwana Diko 9. Communication and authority issues (with the Department of Fisheries and villagers) 10. Fisheries and farmers problems experienced during his time as Bwana Diko 11. Marumbi conflict 12. Various, additional comments

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APPENDIX C. QUESTIONNAIRES

A. Questions to all boat captains in Chwaka village

1. Boat number 2. Name of the owner, living in 3. Name of the captain, living in 4. Gear 5. Fishing technique 6. How many fishers are in the boat? 7. How many times a week do you fish at day? 8. How many times a week do you fish at night? 9. How much of your income is from day? 10. How much of your income is from night? 11. Where do you mainly fish? 12. Boat, machine and gear type 13. Boat, machine and gear size 14. Boat, machine and gear financing

B. Questions to all dema (basket trap) fishermen in Chwaka village

1. Name 2. Age 3. No. of traps 4. Size of your traps 5. Bait used 6. Place of bait collection 7. Favorite fishing ground

C. Questions to all Marumbi captains

1. Date 2. Name skipper 3. Gear (dema, net, handline, spear) 4. No. Large demas 5. No. Medium demas 6. No. Small demas 7. Net pieces 8. Handline 9. Spear 10. Age 11. Boat owner (yes or no) 12. Type of ownership ( Individual, bank, family, fishing company, rent, businessman, cooperative) 13. Total Fishers in this boat 14. Other fishers age 15. Type of boat 16. Length 17. Equipment (such as paddle, sails, etc.) 18. Name of the owner 19. Owner's place of residence 20. Age 21. Capital cost vessel/sail/gear/machine/ 22. Year investment 23. Type of invest (friend, bank, individual, family, NGO, government, businessman) 24. Type investment 25. Bait mostly used 26. Education 27. Time fishing 28. Fishing knowledge (Government, parents, tradition) 29. Comments

48

APPENDIX D. MARKET AND ECOLOGICAL DATA

A. Market data daily recording sheet Village: Date: Lunar calendar: Tidal period:

Sampler's names: Weather:

Religious/cultural activities:

Fishing camps (Dago): Comments:

Tim

e

Boat

type

Gea

r

Bait

Wt (

kg)

Valu

e (T

ZS)

Mos

t com

mon

spec

ies

Oth

er sp

ecies

No.

Fish

ers

Fish

ing

Gro

und

Selli

ng p

lace

Batch 1 Batch 2 Batch 3 Batch n

B. Ecological data and sampling devices’ characteristics

Date Site Random selected sampling point within site GPS Identification (GPS-ID) Seagrass species composition in decreasing order Macroalgae main groups Halimeda presence/absence Canopy height (standard method, Short and Coles 2001) % Cover vegetation (total, seagrass, macroalgae, Halimeda spp., sand, sampled in a 0.25m2 steel frame) Shoot density (all shoots sub-sampled in a 0.0625m2 steel frame ) Sediment samples core dimensions: inside diameter 6 cm; depth 10 cm Macrofauna samples core dimensions: inside diameter 12 cm; depth 10 cm Dema traps dimensions: Hexagonal traps made of local material (Bambusoideae or Maetenus spp.) Approximate measures: 0.95 X 1.10 X 0.2 m; mesh size approx. 3 cm. Fishing grounds mapping was done delineating and demarcating the grounds using GPS with the assistance of local fishers. Accuracy of the map was gained after each field season and the contribution of related Minor Field Studies such as Bergstén (2004) and Hammar (2005).

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ACKNOWLEDGMENTS

The Ph.D. experience is a long and winding road and the good thing is that there is always a person taking care of you while you are in the roller-coaster. To all those people thanks! All my gratefulness goes to everybody in Chwaka and Marumbi! You are the most important people in my work; this period together with you is one of the best I have experienced! Special thanks to Mcha Manzi and his wonderful family, to Rashidi, Mr. Chonga, Daudi, Mr. Kipande, Salum, Mwadindi, and Mr. Ali Abdallah. Nils Kautsky, Nisse, Kan man önska sig en bättre handledare? You are amazing! I am so happy about our collaboration, your total trust in me, your openness to explore new subjects, your humbleness and your support. Nisse, thanks for giving me the chance to chose, to make me feel part of the team and to be there with me till the bitter end! Carl Folke, Calle thanks for all your valuable feedback, your enthusiasm, the wonderful laughs and all the music! For embracing all people that honestly want to make a contribution to a better world! Thanks for being such a driving force! Patrik Rönnbäck provided constant positive feedback and we had so many nice moments together! Thanks Pat for your optimism, for always reading carefully, for your inputs as co-author, your encouraging words and for taking this seriously. Narriman Jiddawi, you are a key person in this thesis, this work wouldn’t exist without your support, logistically, morally and scientifically. I really appreciate all the free time and energy that you have devoted to my project. Dr. Dubi, thanks for opening the IMS for me and my students and for always being supportive to our research ideas. All appreciation to Hamad Khatib, Saleh Yahya, Muhammed Nur, Salum S. Hamed, Ali M. Ussi, Rashid J. Rashid, Said and Omar Amir for your great work, guidance and company! The staff at the Institute of Marine Sciences (IMS), Zanzibar, has always received me with a smile! Thanks to all of you! Thank you Maggie! Thanks to the Department of Fisheries and Marine Resources, Zanzibar, for constant help and feedback. Julius Francis and all the staff at WIOMSA in Zanzibar facilitated my work in all ways. Thanks to all the good friends at Systems Ecology! Particularly Ragnar, Lasse G., Barbara, Birgitta, Bosse and Siw; and my room-mates Beatrice and Ninni. The Natural Resource Management group is an amazing creative force, to all of you thank you! Thanks Jon for your CAS courses. Maria T. and Maria Å., for sharing your thoughts and your personal libraries! Thanks Erik, Elin, Sara, Lisa and Henrik E. for your comments and support during the last writing hours! Fred Wulff means support and inspiration. Thanks Fred, for the San Quintín adventure, the nice photographs and the mobile telephones. You don’t have any idea of what they mean to “my” fishers! Thanks to all my co-authors; especially Martin Gullström who shared with me the first steps! I want to thank particularly, Johan Eklöf for all the team work, field adventures, laughter and writing! Johan, I really appreciate all the shared time!

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Thanks to all my master students, Lisa Adelsköld, Johan Eklöf, Maria Bergstén, Linus Hammar, Camilla Nilsson, Malin Andersson and Elin Håkansson. Lisa thanks also for your assisting with the workshop and for your friendship! Mats Björk has been a special person all the time. He opened the “seagrass door” to me and I am very happy for that. All these years, Mats has been positive, open and supportive. I hope that we can continue research cooperation! Thanks to all the other “seagrassers” for exchanges of ideas and inspiration, especially Jacqueline, Salomao, Thomas, Shaleena, Dr. Mtolera, Paul L., Jud K. and Don L. Max Troell and Johan Colding I am thankful for you thinking about me when there were opportunities and for all your support since earlier stages of my Master. Thanks to Ian Bryceson for support and comments all the way from planning to accomplishment! From our first dinner at “Blues” in Zanzibar, to our last meetings using Skype. Ian, it is great to discuss and learn from you, thanks for being so open, so warm and so tough! Tuija Hilding-Rydevik, my mentor, is an invaluable company, all conversations, advices and recommendations both professionally and privately have made my work better. There are few female role models in natural sciences, thank you Lena for being one! Thanks to the graphic designers. Jorge Eduardo for the art work and his patience to listen and change according to my wishes, Tim Carruthers and Tracey Saxby for help with the icons and to Robert Kautsky with all kind of pictures. A friend in need is a friend in deed… Aisha and Ma. Elena (in alphabetical order!) who listened endlessly during rainy and sunny days! My family has always been there. Mommy and Daddy (Bini) thank you for all you have given me always! Sigurd tack för författarstugan! Jorge E. (Yoryi), Leticia (Beans), Christian, Ines, Rafael, Isa, Andrea, Vicky, Esperanza…and the memory of my grandmas, two extraordinary women who have been an example of strength, perseverance, naughtiness, joyfulness and wisdom. I miss you so much! Lasse, shall I thank to you when your life is my life and my life is your life? Yes! I want to write it! You were the best “soul-mate” in this journey…and you made contributions in all possible fields: cleaning fish stomachs, repairing boats, constructing ngalawa ladders, sending pillows to Chwaka, taking care of our home, packing lunch-boxes, playing music, etc. You were also one of the most stimulating intellectual persons and sharp reviewer that enriched my work. I will keep an image of all these years with you by my side, with a pen, with a pan, with a smile (and sometimes even sleeping!)…It’s such a warm feeling! And there are so many other things that brought us closer during this journey! Mi vida, this one’s for you too! This research was supported by Sida/SAREC and Stiftelsen Lars Hiertas Minne.

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