A participatory integrated assessment of seagrass meadows ecosystem services in the Gulf of Morbihan

Denis Bailly

UMR-AMURE, European Institute for Marine StudiesUniversity of Brest

VALMER project

Apply the ecosystem services framework (MEA) to assess ecological, economic and social values of ecosystems services

to support the development of public policies (nature conservation, resources exploitation management, planning of offshore or impacting on-shore activities development)

With an integrative and participatory approach engaging regulators, managers, stakeholders, the public and scientists from social and natural sciences

Partnership between research, management and regulatory bodies (6 in South West England and 5 in France)

6 study sites (coastal areas of Western Channel and South Brittany)

Funding : France-England transboundary inter-regional fund (Interreg IVA)

The ecosystem services ‘cascade’ Adapted from Haines-Young, R. and Potschin M., in Raffaelli, D. and Frid C. (Eds.): Ecosystem Ecology: a new synthesis, Cambridge U. Press, 2010

Valmer perspective on assessment of ecosystem services values

Ecosystem services translate into :

easy to identify wellbeing benefits derived from natural capital (commercial or not, reflecting market structures and cultural preferences)

known benefits that are difficult to quantify, others that are highly hypothetical and claims based on moral values

Such different values cannot be resumed and aggregated as monetary equivalents, they rather call for extensive documentation and multidimensional metrics

They are useful only if communicable in policy-making arenas and for awareness raising, including uncertainties

VALMER study sites

South West England

Brittany - France

The Gulf of Morbihan is part of a Regional Natural Park project covering an area of 500 km², 35 communes, 170 km² of coastal waters, 500 km of coastline

Gulf of Morbihan study site

Zostera meadows : key habitats for the ecosystem of the Gulf ?

Two species in the Gulf of Morbihan : Zostera marina and Zostera noltei

Zostera beds are remarkable habitats protected under the OSPAR convention and the Habitat Directive of the EU.

A global degradation trend is observed but locally high temporal variability in coverage, density and plant condition leading to contradictory conclusions.

Pressures and impacts that influence the ecological status of zostera beds are not all clearly understood. So the policy commitment to protect seagrass beds is not straightforward

Seagrass beds are not emblematic habitats but they have their “natural” defenders like bird conservation NGOs

Seagrass beds functional roles are rather well recognized but not much quantified (they support productivity and biological diversity of coastal seas, they contribute to water quality, they stabilize the sediment,...)

To be cared about

The Good Ecological Status of a seagrass bed is difficult to attest as there is much spatial and temporal variability in the distribution and density of seagrass beds. Monitoring observation vs modelling can help to determine the potential for seagrass develop in a given place, but such information not available

There are many direct extractive and non extractive uses of seagrass beds and associated resources (commercial and recreational wild shellfish gathering, bird watching, shellfish farming, boat mooring, ...)

Contradictory observations about interactions between seagrass and oyster culture (bags on trestles) are not known : negative, positive, neutral ? But regulations says that aquaculture permit should not be renewed when they end to protect seagras

Mooring on seagrass bed has clear impacts, but temporary mooring by recreational boats is very difficult to control

Bird (bernacles feeding on seagrass beds) is the main argument calling for seagrass bed protection, sea horse is an emblematic species of the area, mainly seen in seagrass but almost extincted

Other functional roles in depuration processes, trophic chain, biodiversity , recruitment for main fishing stocks (commercial and recreational use), water depuration as the ecosystem is under strong pressure from land (nutriment, microbiology, chemicals,...) are for most of them recognized. But none is quantified

So need to develop a coherent management and monitoring strategy under any kind of applicable planning or regulatory instrument (SMVM, WFD, MSFD, Natura 2000)

Engaging scientists and stakeholder in the development of a Knowledge Sharing Platform

Gathering of scientific knowledge (and knowledge gaps)

Interviews with stakeholders (people knowledge)

Sorting of socio-ecological system components (uses, pressures, ecosystem services)

Mapping of interactions (impacting and benefiting uses)

Mapping of interactions (ecosystem services cascade)

Populating the knowledge base (narrative, drawings, resources)

ZOSTÈRES MARINE ET NAINE DES ESPÈCES SENSIBLES

Marine flowering plants in the world They are not algea About 60 species in the world including 10 Zostera

UNEP-WCMC, 2004, document from Canadian Secrétariate for Scientific Consultation

1979 1986 1989 1998 2000 2003 2006 2012 2013

Coastal Law

NAT

ION

AL

EU

ROPE

AN

INTE

RNAT

ION

AL

Bern convention

OSPARConvention

SCANatura 2000

SMVMLand

planning code

Red ListIUCN

REBENTnetwork

Water Framework

Directive

REGULATIONSSUIVI

Habitat Directive

Existing maps of seagrass beds in the Gulf

Source: R. Mahéo, d’après l’observatoire départemental de l’environnement (56)

« Sources diverses 2002-2007; Produit numérique REBENT multi-source Bernard & Chauvaud, TBM et CEVA »

Cette carte est une compilation de données !

Il existe des limites techniques d’acquisition et de traitement des données

Plus des coûts humains et financiers importants

Gathering people knowledge about Seagrass in the Gulf of Morbihan (representations from cognitive maps)

Plantbiology/ecology

Interactions with fishing (cuttlefish,

eel, seabass,…)

A system view of interactions

Location of seagrass beds in

the gulf

Gathering people knowledge about Seagrass Ecosystem Services in the Gulf of Morbihan (representations from discourse analysis)

bernacles eat seagrass from octobre to décembre

We see juveniles in the seagrass… so zostera serves as nursery grounds

(seabass, eel and cutlefish mentioned)

Cuttlefish and other molluscs lay their eggs on seagrass

Seagrass beds probably have different function : hatchery, nursery, water oxygenation,

stability of sediment

If seagrass disappear then we’ll see less things in the water

It is difficult to say how much seabass and cutlefish fisheries in the Gulf and outside depend on

seagrass beds

In the seagrass we find periwinkle, shrimps, eels, anemons, littorina snail, …

Mapping of the socio-ecological system (brown paper, Cmap)

Producing and organizing knowledge (narratives, drawings)

ZOSTERA IN THE GULFThere are two types of zostera. They are flowering plants living in the marine environment and more specifically on soft grounds...

[ know more …]

SENSITIVE SPECIESZostera are vegetal species very sensitive to variations of their environment originating from human action or natural.

[ know more …]

ZOSTÈRES MARINE ET NAINE DES ESPÈCES SENSIBLES

Sorting the components of the socio-ecosystem

18

→ Choix d’une représentation détaillée des sous-systèmes par usages

→ Difficulté de mettre en avant des services ecosystémiques assez indirects et de ne pas être toujours en représentation d’impacts des usages sur les zostères

→ Les deux zostères, marine et naine, fonctionnent différemment (haut et bas de l’estran, interactions différentes avec les usages) d’où un dédoublement des représentations

Mapping interactions in sub-systems

Next steps

Stakeholder group discussions (focus group), introduction to ecosystem services and need for protection, scenario building

Survey of public preferences for conservation (choice experiment)

Synthesis of scenarios and multiple stakeholder group discussion, setting of the “vision”

Feeding the policy processes (revision of planning document and regulation setting) with the outcomes

The VALMER team in the Gulf of Morbihan

Monique Cassé, Ronan Pasco, Juliette Herry, Matthias Urien, David Lédan

Intercommunal Syndicate for the Management of the Gulf of Morbihan (SIAGM)

Denis Bailly, Manuelle Philippe, Johanna Ballé-Béganton, Bérengère Angst, Michel Lample, Louinord Voltaire,

Julien Hay, Jean BoncoeurUMR-AMURE / University of Brest

Merci de votre attentionMerci de votre attention

www.valmer.eu