Christopher F. BonzekRobert J. Latour, Ph.DJames Gartland

June 2007

School of Marine ScienceCollege of William and MaryVirginia Institute of Marine ScienceGloucester Point, VA 23062

ANNUALPROGRESS REPORT

Data collection and analysis in support of single and multispecies stock assessments in Chesapeake Bay:

The Chesapeake Bay Multispecies Monitoring and Assessment Program

ANNUAL PROGRESS REPORT

Data collection and analysis in support of single and multispecies stock assessments in Chesapeake Bay:

The Chesapeake Bay Multispecies Monitoring and Assessment Program

U.S. Fish and Wildlife Service Sportfish Restoration Project F-130-R-2

April 2006 – March 2007

Submitted June 2007

Prepared by:

Christopher F. Bonzek Robert J. Latour, Ph.D

James Gartland

School of Marine Science College of William and Mary

Virginia Institute of Marine Science Gloucester Point, VA 23062

Submitted to:

Virginia Marine Resources Commission United States Fish and Wildlife Service

ChesMMAP Staff:

Principal Investigators: Robert J. Latour, Ph.D. Christopher F. Bonzek Project Manager: James Gartland Field and Laboratory Staff: Eric Brasseur

Melanie Chattin RaeMarie Johnson

Graduate Students: Andre Buchheister Andrij Horodysky Patrick Lynch Kathleen McNamee

Introduction Historically, fisheries management has been based on the results of single-species stock assessment models that focus on the interplay between exploitation level and sustainability. There currently exists a suite of standard and accepted analytical frameworks (e.g., virtual population analysis (VPA), biomass dynamic production modeling, delay difference models, etc.) for assessing the stocks, projecting future stock size, evaluating recovery schedules and rebuilding strategies for overfished stocks, setting allowable catches, and estimating fishing mortality or exploitation rates. A variety of methods also exist to integrate the biological system and the fisheries resource system, thereby enabling the evaluation of alternative management strategies on stock status and fishery performance. These well-established approaches have specific data requirements involving biological (life history), fisheries-dependent, and fisheries-independent data (Table 1). From these, there are two classes of stock assessment or modeling approaches used in fisheries: partial assessment based solely on understanding the biology of a species, and full analytical assessment including both biological and fisheries data. Table 1. Summary of biological, fisheries-dependent and fisheries-independent data requirements for single-species analytical stock assessment models. Data Category Assessment Type Data Description

Growth (length / weight) Maturity schedule Fecundity Partial recruitment schedules Longevity

Biological / Life History Partial

Life history strategies (reproductive and behavioral) Catch, landings, and effort Biological characterization of the harvest (size, sex, age) Gear selectivity

Fishery-Dependent Data Analytical

Discards/bycatch Biological characterization of the population (size, sex, age)

Mortality rates

Fishery-Independent Data Analytical

Estimates of annual juvenile recruitment

Although single-species assessment models are valuable and informative, a primary shortcoming is that they generally fail to consider the ecology of the species under management (e.g., habitat requirements, response to environmental change), ecological interactions (e.g., predation, competition), and technical interactions (e.g.,

1

discards, bycatch) (NMFS 1999, Link 2002a,b). However, inclusion of ecological processes into fisheries management plans is now strongly recommended (NMFS 1999, NRC 1999, Pew Commission 2003, U.S. Oceans Commission 2004) and in some cases even mandated (NOAA 1996). Multispecies assessment models have been developed to move towards an ecosystem-based approach to fisheries management (Hollowed et al. 2000, Whipple et al. 2000, Link 2002a,b). Although such models are still designed to yield information about sustainability, they are structured to do so by explicitly incorporating the effects of ecological processes among interacting populations. Over the past several years, the number and type of multispecies models designed to provide insight about fisheries questions has grown significantly (Hollowed et al. 2000, Whipple et al. 2000). This growth has been fueled by the need to better inform fisheries policy makers and managers, however, recent concerns about effects of fishing on the structure of ecosystems have also prompted research activities on multispecies modeling and the predator-prey relationships that are implied. From a theoretical perspective, basing fisheries stock assessments on multispecies rather than single-species models certainly appears to be more appropriate, since multispecies approaches allow a greater number of the processes that govern population abundance to be modeled explicitly. However, this increase in realism leads to an increased number of model parameters, which in turn, creates the need for additional types of data. In the Chesapeake Bay region, there has been a growing interest in ecosystem-based fisheries management, as evidenced by the recent development of fisheries steering groups (e.g., ASMFC multispecies committee), the convening of technical workshops (Miller et al. 1996; Houde et al. 1998), publication of the Fisheries Ecosystem Planning document (Chesapeake Bay Fisheries Ecosystem Advisory Panel 2006), and the goals for ecosystem-based fisheries management set by the Chesapeake Bay 2000 (C2K) Agreement. In many respects, it can be argued that the ecosystem-based fisheries mandates inherent to the C2K Agreement constitute the driving force behind this growing awareness. The exact language of the C2K agreement, as it pertains to multispecies fisheries management, reads as follows:

1. By 2004, assess the effects of different population levels of filter feeders such as menhaden, oysters and clams on Bay water quality and habitat.

2. By 2005, develop ecosystem-based multispecies management plans for targeted

species.

3. By 2007, revise and implement existing fisheries management plans to incorporate ecological, social and economic considerations, multispecies fisheries management and ecosystem approaches.

If either single-species or ecosystem-based management plans are to be developed, they must be based on sound stock assessments. In the Chesapeake Bay region,

2

however, the data needed to perform single and multispecies assessments is either partially available or nonexistent. The Chesapeake Bay Multispecies Monitoring and Assessment Program (ChesMMAP) was developed to assist in filling these data gaps, and ultimately to support bay-specific stock assessment modeling activities at both single and multispecies scales. While no single gear or monitoring program can collect all of the data necessary for both types of assessments, ChesMMAP was designed to maximize the biological and ecological data collected for several recreationally, commercially, and ecologically important species in the bay. In general, ChesMMAP is a large-mesh bottom trawl survey designed to sample late juvenile-to-adult fishes in Chesapeake Bay. This field program currently provides data on relative abundance, length, weight, age, and trophic interactions for several important fish species seasonally inhabiting the bay. This report summarizes the field, laboratory, and preliminary data. Among the research agencies in the Chesapeake Bay region, only VIMS has a program focused on multispecies issues involving the adult/harvested components of the exploited fish species that seasonally inhabit the bay. The multispecies research program at VIMS is comprised of three main branches: field data collection (ChesMMAP and the VIMS Seagrass Trammel Net Survey), laboratory processing (The Chesapeake Trophic Interactions Laboratory Services – CTILS, and ChesMMAP), and data analysis and multispecies modeling (The Fisheries Ecosystem Modeling and Assessment Program - FEMAP). In this report, we summarize the field, laboratory, and data analysis activities associated with the 2006 sampling year. The following Jobs are addressed in this report:

• Job 1 – Conduct research cruises • Job 2 – Synthesize data for single species analyses • Job 3 – Quantify trophic interactions for multispecies analyses • Job 4 – Estimate abundance

Methods Job 1 – Conduct research cruises In 2006, five research cruises were conducted bimonthly from March to November in the mainstem of Chesapeake Bay. The timing of the cruises was chosen to adequately characterize the seasonal abundances of fishes in the bay. The R/V Bay Eagle, a 19.8m aluminum hull, twin diesel vessel owned and operated by VIMS, served as the sampling platform for this survey. The trawl net is a 13.7m (headrope length) 4-seam balloon trawl manufactured by Reidar’s Manufacturing Inc. of New Bedford, MA. The wings and body of the net are constructed of #21 cotton twine (15.2cm mesh), and the codend is constructed of #48 twine (7.6cm mesh). The legs of the net are 6.1m and connected directly to 1.3m x 0.8m steel-V trawl doors weighing 83.9kg each. The trawl

3

net is deployed with a single-warp system using 9.5mm steel cable with a 37.6m bridle constructed of 7.9mm cable. For each cruise, the goal was to sample 80 stations distributed in a stratified random design throughout the mainstem of Chesapeake Bay. The Bay was stratified by dividing the mainstem into five regions of 30 latitudinal minutes each (the upper and lower regions being slightly smaller and larger than 30 minutes, respectively). Within each region, three depth strata ranging from 3.0m-9.1m, 9.1m-15.2m, and >15.2m were defined. A grid of 1.9km2 cells was superimposed over the mainstem, where each cell represented a potential sampling location. The number of stations sampled in each region and in each stratum was proportional to the surface area of water represented. Stations were sampled without replacement and those north of Pooles Island (latitude 39o 17’) have not been sampled since July 2002 due to repeated loss of gear. In the future, sidescan sonar will be used to identify potential sampling locations in this area. Tows were conducted in the same general direction as the tidal current (pilot tows conducted using the net monitoring gear in November 2001 indicated that the gear performed most consistently when deployed with the current rather than against the current). The net was generally deployed at a 4:1 scope, which refers to the amount of cable deployed relative to depth. For shallow stations, however, the bridle was always deployed beyond the vessel’s tow-point, implying that the scope ratio could be quite high. The target tow speed was 6.5 km/h but occasionally varied depending on wind and tidal conditions. Based on data collected from the net monitoring gear, tow speed and scope were also adjusted occasionally to ensure that the gear was deployed properly. Tows were 20 minutes in duration, unless obstructions or other logistical issues forced a tow to be shortened (if the duration of a tow was at least 10 minutes, it was considered complete). Computer software was used to record data from the net monitoring gear (i.e., wingspread and headrope height) as well as a continuous GPS stream during each tow. On occasions when the monitoring gear failed, the trawl geometry was assumed to follow cruise averages and beginning and ending coordinates were taken from the vessel’s GPS system. Job 2 – Synthesize data for single species analyses Once onboard, the catch from each tow is sorted and measured by species or size-class if distinct classes within a particular species are evident. A subsample of each species or size-class is further processed for weight determination, stomach contents, ageing, and determination of sex and maturity stage. In addition, surface and bottom temperature, salinity, and dissolved oxygen readings are also recorded at each sampling location. Single-species assessment models typically require information on (among others) age- length-, and weight-structure, sex ratio, and maturity stage. Data were synthesized to characterize age-, length-, and weight-frequency distributions across a variety of spatial

4

and temporal scales (e.g., by year, season, or region of the bay) for each species. Sex ratio and maturity data are also be available to support sex-specific analyses. Job 3 – Quantify trophic interactions for multispecies analyses In addition to the population-level information described under Task 3, multispecies assessment models require information on predator-prey interactions across broad seasonal and spatial scales. In general, these procedures involve identifying each prey item to the lowest possible taxonomic level (Hyslop 1980). Several diet indices were calculated to identify the main prey types for each species: %weight, %number, and %frequency-of-occurrence. These indices were coupled with the information generated from Task 3 and age-, length-, and sex-specific diet characterizations were developed for each species. Efforts also focused on characterizing spatial and temporal variability in these diets. Diet index values were calculated to identify the main prey in the diet of predators in the mainstem Chesapeake Bay. Since trawl collections essentially yield a cluster of fish at each sampling location, the aforementioned indices were calculated using a cluster sampling estimator (Buckel et al. 1999). The contribution of each prey type to the diet (%Qk, where Qk is any of the aforementioned index types) is given by:

∑

∑

=

== n

ii

ik

n

ii

k

M

qMQ

1

1% , (1)

where

100*i

ikik w

wq = ,

and where n is the number of trawls containing the predator of interest, Mi is the number of that predator collected at sampling site i, wi is the total weight, number, or frequency of all prey items encountered in the stomachs of that predator collected from sampling location i, and wik is the total weight, number, or frequency of prey type k in those stomachs. Accordingly, stomachs collected in the field were processed following standard diet analysis procedures (Hyslop 1980).

5

Job 4 – Estimate abundance Time-series of relative abundance information can easily be generated from the basic catch data of a monitoring survey. For each species, a variety of relative abundance trends can be generated according to year, season, and location within the Bay. Absolute abundance estimates can be generated for each species by combining relative abundance data with area swept and gear efficiency information. Area swept was calculated for each tow by multiplying tow distance (provided by GPS equipment) by average wingspread (provided by net monitoring gear). Gear efficiency estimates are being derived by comparing the number of fish that encounter the gear (from the hydroacoustic data) with the fraction captured (from the catch data). To develop species-specific efficiency estimates, the hydroacoustic data will be partitioned according to the target strength distribution for each species. These distributions will be determined through ongoing cage experiments. ChesMMAP utilizes two types of hydroacoustic gear in an effort to convert relative indices of abundance into estimates of total abundance. The equation necessary for this conversion is:

ea

cA N = , (1)

where N is total population size measured in numbers (or biomass), c is the mean number (or weight) of fish captured per tow, a is the area swept by one trawl tow, A is the total survey area, and e is the net efficiency (dimensionless). Given that c is observed and A is easily determined, the hydroacoustic equipment is used to derive estimates of a and e. Estimation of the parameter e for a variety of species is a mid-to-long term goal. Until then, removal of that parameter from Equation 1 results in relative estimates of ‘minimum trawlable abundance.’ These estimates represent the smallest number (or biomass) of fish present within the sampling area that are susceptible to the sampling gear. Results Job 1 – Conduct Research Cruises Throughout the five years of sampling, the number of fish collected each year by the ChesMMAP survey was fairly consistent and ranged from approximately 31,000 (in 2003) to 48,000 (in 2004 – Table 1). Each year, between 3,900 and 6,000 pairs of otoliths have been collected, the majority of which have been processed for age determination. Similar numbers of stomach have been collected and processed for diet composition information annually.

6

Table 1. The number of specimens collected, measured and processed for age determination and diet composition information from ChesMMAP 2002 – 2006.

Year Fish collected

Fish measured

Otoliths collected

Otoliths processed

Stomachs collected

Stomachs processed

2002 32,018 23,605 5,487 4,382 4,555 2,638 2003 30,925 20,828 3,913 2,934 3,250 2,220 2004 47,623 31,245 5,169 3,431 4,271 3,137 2005 45,206 36,906 6,064 4,694 5,064 3,170 2006 43,959 31,239 5,412 In process 4,391 2,640

Jobs 2-4 – Data Summaries The data summaries in this report essentially represent biological and ecological profiles of those species well sampled by the ChesMMAP survey. Our intent with these profiles is to maximize the amount of information available to fishery managers. The profiles that follow are organized first by species and then by type of analysis (‘Task’). Each Task element (single-species stock parameter summarizations, trophic interaction summaries, and estimates of abundance) is included but is not labeled with a Task number and is not necessarily shown in Task number order (note also that not all analysis types are available for all species). The species profiles contain the following information (note that some data/analyses may not be available for all species):

1) estimates of abundance, both in numbers and biomass, by year, month, and region within the bay

2) site-specific abundance maps (number per area swept) for each cruise, overlaid on depth strata

3) length-frequency data by year 4) age-class distributions by year (for those species where appreciable numbers

have been captured and otoliths have been processed) 5) sex-ratio by year and where appropriate, by region, month, and/or by age. 6) statistically determined length-weight relationships for sexes combined and

separately 7) sex-specific maturity ogives along with a single diet summary

Following the species profiles figures are a series of figures for each cruise containing data describing the following water quality parameters:

1) Water temperature at the surface and at the bottom. 2) Salinity at the surface and at the bottom. 3) Dissolved oxygen at the surface and at the bottom.

7

List of Figures Atlantic Croaker (pages 17 – 27) Figure 1. Atlantic croaker minimum trawlable abundance estimates in Chesapeake Bay, 2002-2006. Figures 2 – 6. Site-specific Atlantic croaker abundance figures, 2002-2006. Figure 7. Atlantic croaker length-frequency distribution in Chesapeake Bay, 2002-2006. Figure 8. Atlantic croaker age-frequency distribution in Chesapeake Bay, 2002-2005 (2006 ages not yet assigned). Figure 9. Atlantic croaker sex-ratios in Chesapeake Bay, 2002-2006, by (A) region, and (B) age. Figure 10. Atlantic croaker length-weight relationships in Chesapeake Bay, 2002-2006 for (A) sexes combined, and (B) males and females separated. Figure 11. Atlantic croaker maturity schedule in Chesapeake Bay, 2002-2006 for sexes combined. Figure 12. Atlantic croaker diet composition in Chesapeake Bay, 2002-2006. Black Seabass (pages 29 – 35) Figure 13. Black seabass minimum trawlable abundance estimates in Chesapeake Bay, 2002-2006. Figure 14. Black seabass length-frequency distribution in Chesapeake Bay, 2002-2006. Figure 15. Black seabass age-frequency distribution in Chesapeake Bay, 2002-2003. Figure 16. Black seabass sex-ratios in Chesapeake Bay, 2002-2006, by (A) year and (B) month. Figure 17. Black seabass length-weight relationships in Chesapeake Bay, 2002-2006 for (A) sexes combined and (B) males and females separated. Figure 18. Black seabass maturity schedule for females in Chesapeake Bay, 2002-2006. Figure 19. Black seabass diet composition in Chesapeake Bay 2002-2006.

8

Bluefish (pages 37 – 47) Figure 20. Bluefish minimum trawlable abundance estimates in (A) numbers and (B) biomass in Chesapeake Bay, 2002-2006. Figures 21 – 25. Site-specific bluefish abundance figures, 2002-2006. Figure 26. Bluefish length-frequency distribution in Chesapeake Bay 2002-2006. Figure 27. Bluefish age-frequency distribution in Chesapeake Bay, 2002-2004 (2005-2006 ages not yet assigned). Figure 28. Bluefish sex-ratios in Chesapeake Bay 2002-2006, by year. Figure 29. Bluefish length-weight relationships in Chesapeake Bay, 2002-2006 for (A) sexes combined and (B) males and females separated. Figure 30. Bluefish maturity schedule in Chesapeake Bay, 2002-2006, for sexes combined. Figure 31. Bluefish diet composition in Chesapeake Bay, 2002-2006. Butterfish (pages 49 – 56) Figure 32. Butterfish minimum trawlable abundance estimates in (A) numbers and (B) biomass in Chesapeake Bay, 2002-2006. Figures 33 – 37. Site-specific butterfish abundance figures, 2002-2006. Figure 38. Butterfish length-frequency distribution in Chesapeake Bay, 2002-2006. Figure 39. Butterfish length-weight relationship in Chesapeake Bay, 2002-2006. Figure 40. Butterfish diet composition in Chesapeake Bay, 2002-2006. Northern Kingfish (pages 57 – 66) Figure 41. Northern kingfish minimum trawlable abundance estimates in (A) numbers and (B) biomass in Chesapeake Bay, 2002-2006. Figures 42 – 46. Site-specific northern kingfish abundance figures, 2002-2006. Figure 47. Northern kingfish length-frequency distribution in Chesapeake Bay 2002-2006. Figure 48. Northern kingfish sex-ratios in Chesapeake Bay, 2002-2006, by (A) year and (B) month.

9

Figure 49. Northern kingfish length-weight relationships in Chesapeake Bay, 2002-2006, for (A) sexes combined and (B) males and females separated. Figure 50. Northern kingfish maturity schedule in Chesapeake Bay, 2002-2006, for sexes combined. Figure 51. Northern kingfish diet composition in Chesapeake Bay, 2002-2006. Northern Puffer (pages 68 – 73) Figure 52. Northern puffer minimum trawlable abundance estimates in (A) numbers and (B) biomass (B) in Chesapeake Bay, 2002-2006. Figure 53. Northern puffer length-frequency distribution in Chesapeake Bay, 2002-2006. Figure 54. Northern puffer sex-ratios in Chesapeake Bay, 2002-2006, by (A) year and (B) month. Figure 55. Northern puffer length-weight relationships in Chesapeake Bay, 2002-2006, for (A) sexes combined and (B) males and females separated. Figure 56. Northern puffer maturity schedule in Chesapeake Bay, 2002-2006, for sexes combined. Figure 57. Northern puffer diet composition in Chesapeake Bay, 2002-2006. Scup (pages 75 – 84) Figure 58. Scup minimum trawlable abundance estimates in (A) numbers and (B) biomass in Chesapeake Bay, 2002-2006. Figures 59 – 63. Site-specific scup abundance figures, 2002-2006. Figure 64. Scup length-frequency distribution in Chesapeake Bay, 2002-2006. Figure 65. Scup sex-ratios in Chesapeake Bay, 2002-2006, by (A) year and (B) month. Figure 66. Scup length-weight relationships in Chesapeake Bay, 2002-2006, for (A) sexes combined and (B) males and females separated. Figure 67. Scup maturity schedule in Chesapeake Bay, 2002-2006, for sexes combined. Figure 68. Scup diet composition in Chesapeake Bay, 2002-2006.

10

Spot (pages 85 – 95) Figure 69. Spot minimum trawlable abundance estimates in (A) numbers and (B) biomass in Chesapeake Bay, 2002-2006. Figures 70 – 74. Site-specific spot abundance figures, 2002-2006. Figure 75. Spot length-frequency distribution in Chesapeake Bay, 2002-2006. Figure 76. Spot age-frequency distribution in Chesapeake Bay, 2002-2006. Figure 77. Spot sex-ratios in Chesapeake Bay, 2002-2005, by (A) year and (B) month. Figure 78. Spot length-weight relationships in Chesapeake Bay 2002-2006 for (A) sexes combined and (B) males and females separated. Figure 79. Spot maturity schedule in Chesapeake Bay, 2002-2006, for sexes combined. Striped Bass (pages 97 – 107) Figure 80. Striped bass minimum trawlable abundance estimates in (A) numbers and (B) biomass in Chesapeake Bay, 2002-2006. Figures 81 – 85. Site-specific striped bass abundance figures, 2002-2006. Figure 86. Striped bass length-frequency distribution in Chesapeake Bay, 2002-2006. Figure 87. Striped bass age-frequency distribution in Chesapeake Bay. 2002-2006. Figure 88. Striped bass sex-ratios in Chesapeake Bay. 2002-2006, by (A) year, (B), month, and (C) age. Figure 89. Striped bass length-weight relationships in Chesapeake Bay, 2002-2006, for (A) sexes combined and (B) males and females separated. Figure 90. Striped bass maturity schedule in Chesapeake Bay, 2002-2006, for sexes combined. Figure 91. Striped bass diet composition in Chesapeake Bay, 2002-2006.

11

Summer Flounder (pages 109 – 119) Figure 92. Summer flounder minimum trawlable abundance estimates in (A) numbers and (B) biomass in Chesapeake Bay, 2002-2006. Figures 93 – 97. Site-specific summer flounder abundance, 2002-2006. Figure 98. Summer flounder length-frequency distribution in Chesapeake Bay, 2002-2006. Figure 99. Summer flounder age-frequency distribution in Chesapeake Bay, 2002-2006. Figure 100. Summer flounder sex-ratios in Chesapeake Bay, 2002-2006, by (A) month, (B) region and (C) age. Figure 101. Summer flounder length-weight relationships in Chesapeake Bay, 2002-2005 for (A) sexes combined and (B) males and females separated. Figure 102. Summer flounder maturity schedule in Chesapeake Bay, 2002-2006, for sexes combined. Figure 103. Summer flounder diet composition in Chesapeake Bay 2002-2006. Weakfish (pages 121 – 131) Figure 104. Weakfish minimum trawlable abundance estimates in (A) numbers and (B) biomass (B) in Chesapeake Bay, 2002-2006. Figures 105 – 109. Site-specific weakfish abundance, 2002-2006. Figure 110. Weakfish length-frequency distribution in Chesapeake Bay, 2002-2006. Figure 111. Weakfish age-frequency distribution in Chesapeake Bay, 2002-2006. Figure 112. Weakfish sex-ratios in Chesapeake Bay, 2002-2005, by (A) year, (B) region and (C) age. Figure 113. Weakfish length-weight relationships in Chesapeake Bay, 2002-2006, for (A) sexes combined and (B) males and females separated. Figure 114. Weakfish maturity schedule in Chesapeake Bay, 2002-2006, for sexes combined. Figure 115. Weakfish diet composition in Chesapeake Bay, 2002-2006.

12

White Perch (pages 133 – 143) Figure 116. White perch minimum trawlable abundance estimates in (A) numbers and (B) biomass in Chesapeake Bay, 2002-2006. Figures 117 – 121. Site-specific white perch abundance, 2002-2006. Figure 122. White perch length-frequency distribution in Chesapeake Bay, 2002-2006. Figure 123. White perch age-frequency distribution in Chesapeake Bay, 2002-2005. Figure 124. White perch sex-ratios in Chesapeake Bay 2002-2005, by (A) year and (B) age. Figure 125. White perch length-weight relationships in Chesapeake Bay, 2002-2006 for (A) sexes combined and (B) males and females separated. Figure 126. White perch maturity schedule in Chesapeake Bay, 2002-2006, for sexes combined. Figure 127. White perch diet composition in Chesapeake Bay, 2002-2006. Water Temperature (pages 144 – 153) Figure 128. Surface temperature in Chesapeake Bay, 2002. Figure 129. Bottom temperature in Chesapeake Bay, 2002. Figure 130. Surface temperature in Chesapeake Bay, 2003. Figure 131. Bottom temperature in Chesapeake Bay, 2003. Figure 132. Surface temperature in Chesapeake Bay, 2004. Figure 133. Bottom temperature in Chesapeake Bay, 2004. Figure 134. Surface temperature in Chesapeake Bay, 2005. Figure 135. Bottom temperature in Chesapeake Bay, 2005. Figure 136. Surface temperature in Chesapeake Bay, 2006. Figure 137. Bottom temperature in Chesapeake Bay, 2006.

13

Salinity (pages 154 – 163) Figure 138. Surface salinity in Chesapeake Bay, 2002. Figure 139. Bottom salinity in Chesapeake Bay, 2002. Figure 140. Surface salinity in Chesapeake Bay, 2003. Figure 141. Bottom salinity in Chesapeake Bay, 2003. Figure 142. Surface salinity in Chesapeake Bay, 2004. Figure 143. Bottom salinity in Chesapeake Bay, 2004. Figure 144. Surface salinity in Chesapeake Bay, 2005. Figure 145. Bottom salinity in Chesapeake Bay, 2005. Figure 146. Surface salinity in Chesapeake Bay, 2006. Figure 147. Bottom salinity in Chesapeake Bay, 2006. Dissolved Oxygen (pages 164 – 173) Figure 148. Surface dissolved oxygen in Chesapeake Bay, 2002. Figure 149. Bottom dissolved oxygen in Chesapeake Bay, 2002. Figure 150. Surface dissolved oxygen in Chesapeake Bay, 2003. Figure 151. Bottom dissolved oxygen in Chesapeake Bay, 2003. Figure 152. Surface dissolved oxygen in Chesapeake Bay, 2004. Figure 153. Bottom dissolved oxygen in Chesapeake Bay, 2004. Figure 154. Surface dissolved oxygen in Chesapeake Bay, 2005. Figure 155. Bottom dissolved oxygen in Chesapeake Bay, 2005. Figure 156. Surface dissolved oxygen in Chesapeake Bay, 2006. Figure 157. Bottom dissolved oxygen in Chesapeake Bay, 2006.

14

Additional Work Performed – Serve as sampling platform for bay studies Since its inception, ChesMMAP has strived to be not just a state-of-the-art monitoring survey, but equally, a research platform from which numerous projects can benefit. We have participated in fish disease, tagging, and habitat related studies that otherwise either could not have been conducted, or would have had very substantially increased costs. For example, since 2003 ChesMMAP personnel have been collecting additional samples from striped bass to support a mycobacteriosis prevalence study conducted by scientists in the Fisheries and Environmental and Aquatic Animal Health (EAAH) Departments at VIMS. Specifically, spleen samples from these striped bass were analyzed histologically for the presence of granulomas, which are evident in diseased fish. The apparent prevalence data set derived from these samples is the most comprehensive apparent prevalence data set collected for striped bass in the bay. Subsequent modeling of those prevalence data has shown 1) the force-of-infection (rate of which disease-negative fish become disease positive) is age-dependent, 2) covariates sex and season are significant explanatory variables, and 3) that there is appreciable disease-associated mortality. In 2006, ChesMMAP personnel collected 536 striped bass tissue samples to support a trophic ecology project led by members of the Center for Quantitative Fisheries Ecology (CQFE) at Old Dominion University. Stable isotope analysis is being used to investigate the trophic interactions and position of striped bass; ultimately these data will be compared to data from traditional stomach content analysis to provide a more comprehensive description of the predatory impacts of striped bass. The costs associated with conducting both the disease monitoring and stable isotope studies in the absence of a sampling platform such as the ChesMMAP trawl survey would likely have been prohibitive. In addition to the aforementioned striped bass projects, ChesMMAP also supported the Environmental Protection Agency’s National Coastal Assessment (NCA) program by sampling 11 additional sites during the September 2006 survey. At each of these stations, up to 10 specimens of each of a number of species of interest were sacrificed for chemical and pathological analysis. Overall, 96 specimens were taken for this effort. Again, by contracting the ChesMMAP survey to conduct this relatively small amount of sampling, the cost of obtaining the resulting information was reduced substantially. And finally, ChesMMAP’s sampling efforts supported four master’s theses and a doctoral dissertation in 2006. Literature Cited Buckel, J.A., D.O. Conover, N.D. Steinberg, and K.A. McKown. 1999a. Impact of age-0

bluefish (Pomatomus saltatrix) predation on age-0 fishes in Hudson River Estuary: evidence for density-dependant loss of juvenile striped bass (Morone saxatilis). Canadian Journal of Fisheries and Aquatic Sciences 56:275-287.

15

Chesapeake Bay Fisheries Ecosystem Advisory Panel. 2006. Fisheries ecosystem planning for Chesapeake Bay. American Fisheries Society, Trends in Fisheries Science and Managemen 3, Bethesda, Maryland.

Hollowed, A.B., N. Bax, R. Beamish, J. Collie, M. Fogarty, P. Livingston, J. Pope, and

J.C. Rice. 2000. Are multispecies models an improvement on single-species models for measuring fishing impacts on marine ecosystems? ICES Journal of Marine Science 57:707-719.

Houde, E.D., M.J. Fogarty and T.J. Miller (Convenors). 1998. STAC Workshop Report: Prospects for Multispecies Fisheries Management in Chesapeake Bay.

Chesapeake Bay Program, Scientific Technical Advisory Committee. Hyslop, E.J. 1980. Stomach content analysis – a review of methods and their application. Journal of Fish Biology 17:411-429. Link, J.S. 2002a. Ecological considerations in fisheries management: when does it matter? Fisheries 27(4):10-17. Link, J.S. 2002b. What does ecosystem-based fisheries management mean? Fisheries

27:18-21.

NMFS (National Marine Fisheries Service). 1999. Ecosystem-based fishery management. A report to Congress by the Ecosystems Principles Advisory Panel. U. S. Department of Commerce, Silver Spring, Maryland.

Miller, T.J., E.D. Houde, and E.J. Watkins. 1996. STAC Workshop Report: Prospectives

on Chesapeake Bay fisheries: Prospects for multispecies fisheries management and sustainability. Chesapeake Bay Program, Scientific Technical Advisory Committee.

NOAA (National Oceanic and Atmospheric Administration). 1996. Magnuson-Stevens Fishery Management and Conservation Act amended through 11 October 1996.

NOAA Technical Memorandum NMFS-F/SPO-23. U. S. Department of Commerce.

Pew Oceans Commission. 2003. America’s Living Oceans: Charting a Course for Sea

Change. A Report to the Nation. May 2003. Pew Oceans Commission, Arlington, Virginia.

U.S. Commission on Ocean Policy. An Ocean Blueprint for the 21st Century. Final Report. Washington, DC, 2004

Whipple, S. J., J. S. Link, L. P. Garrison, and M. J. Fogarty. 2000. Models of predation and fishing mortality in aquatic ecosystems. Fish and Fisheries 1:22-40.

16

Figure 1. Atlantic croaker minimum trawlable abundance estimates in numbers (A) and biomass (B) in ChesapeakeBay 2002-2006.

R e g io n Va-Lo w Va-U p p M d -Lo w M d-M id M d -U p p

Min

imum

Tra

wla

ble

Num

ber

0

10,000,000

20,000,000

30,000,000

40,000,000

50,000,000

M o n th

Y e ar2002 2003 2004 2005 2006

M ar M ay Ju l Se p No v M ar M ay Ju l Se p No v M ar M ay Ju l Se p No v M ar M ay Ju l Se p No v M ar M ay Ju l Se p No v

A.

R e g io n V a - L o w V a - U p p M d - L o w M d - M id M d - U p p

Min

imum

Tra

wla

ble

Bio

mas

s (k

g)

0

1 ,0 0 0 ,0 0 0

2 ,0 0 0 ,0 0 0

3 ,0 0 0 ,0 0 0

4 ,0 0 0 ,0 0 0

5 ,0 0 0 ,0 0 0

6 ,0 0 0 ,0 0 0

7 ,0 0 0 ,0 0 0

8 ,0 0 0 ,0 0 0

9 ,0 0 0 ,0 0 0

1 0 ,0 0 0 ,0 0 0

1 1 ,0 0 0 ,0 0 0

1 2 ,0 0 0 ,0 0 0

1 3 ,0 0 0 ,0 0 0

1 4 ,0 0 0 ,0 0 0

1 5 ,0 0 0 ,0 0 0

1 6 ,0 0 0 ,0 0 0

1 7 ,0 0 0 ,0 0 0

1 8 ,0 0 0 ,0 0 0

1 9 ,0 0 0 ,0 0 0

M o n t h

Y e a r2 0 0 2 2 0 0 3 2 0 0 4 2 0 0 5 2 0 0 6

M a r M a y J u l S e p N o v M a r M a y J u l S e p N o v M a r M a y J u l S e p N o v M a r M a y J u l S e p N o v M a r M a y J u l S e p N o v

B.

17

Mar

chJu

lySe

ptem

ber

Nov

embe

rM

ay

Figu

re 2

. Ab

unda

nce

(num

ber p

er h

ecta

re s

wep

t) of

Atla

ntic

cro

aker

in C

hesa

peak

e Ba

y, 2

002.

18

Mar

chJu

lySe

ptem

ber

Nov

embe

rM

ay

Figu

re 3

. Ab

unda

nce

(num

ber p

er h

ecta

re s

wep

t) of

Atla

ntic

cro

aker

in C

hesa

peak

e Ba

y, 2

003.

19

Mar

chJu

lySe

ptem

ber

Nov

embe

rM

ay

Figu

re 4

. Ab

unda

nce

(num

ber p

er h

ecta

re s

wep

t) of

Atla

ntic

cro

aker

in C

hesa

peak

e Ba

y, 2

004.

20

Mar

chJu

lySe

ptem

ber

Nov

embe

rM

ay

Figu

re 5

. Ab

unda

nce

(num

ber p

er h

ecta

re s

wep

t) of

Atla

ntic

cro

aker

in C

hesa

peak

e Ba

y, 2

005.

21

Mar

chJu

lySe

ptem

ber

Nov

embe

rM

ay

Figu

re 6

. Ab

unda

nce

(num

ber p

er h

ecta

re s

wep

t) of

Atla

ntic

cro

aker

in C

hesa

peak

e Ba

y, 2

006.

22

Figure 7. Atlantic croaker length-frequency in Chesapeake Bay 2002-2006.

2 0 0 2

02 0 04 0 06 0 08 0 0

1 0 0 01 2 0 01 4 0 01 6 0 0

T o t a l L e n g t h ( m m )0 5 0 1 0 0 1 5 0 2 0 0 2 5 0 3 0 0 3 5 0 4 0 0 4 5 0

2 0 0 3

0

5 0 0

1 0 0 0

1 5 0 0

2 0 0 0

T o t a l L e n g t h ( m m )0 5 0 1 0 0 1 5 0 2 0 0 2 5 0 3 0 0 3 5 0 4 0 0 4 5 0

2 0 0 4

0

1 0 0 0

2 0 0 0

3 0 0 0

4 0 0 0

T o t a l L e n g t h ( m m )0 5 0 1 0 0 1 5 0 2 0 0 2 5 0 3 0 0 3 5 0 4 0 0 4 5 0

2 0 0 5

02 0 04 0 06 0 08 0 0

1 0 0 01 2 0 01 4 0 01 6 0 0

T o t a l L e n g t h ( m m )0 5 0 1 0 0 1 5 0 2 0 0 2 5 0 3 0 0 3 5 0 4 0 0 4 5 0

2 0 0 6

02 0 04 0 06 0 08 0 0

1 0 0 01 2 0 0

T o t a l L e n g t h ( m m )0 5 0 1 0 0 1 5 0 2 0 0 2 5 0 3 0 0 3 5 0 4 0 0 4 5 0

Exp

ande

d N

umbe

r

23

Figure 8. Atlantic croaker age-structure in Chesapeake Bay 2002-2005 (2006 ages not yet assigned).2002

0

3030

487 555

1819

3993

1330

84174

77 111 46 23 1 0 0 00

1000

2000

3000

4000

Age (Year Class)

0 (20

02)

1 (20

01)

2 (20

00)

3 (19

99)

4 (19

98)

5 (19

97)

6 (19

96)

7 (19

95)

8 (19

94)

9 (19

93)

10 (1

992)

11 (1

991)

12 (1

990)

13 (1

989)

14 (1

988)

15 (1

987)

16 (1

986)

2003

51 208

6521

672

30

1494

1983

46798 43 135 65 21 8 0 0 00

1000

2000

3000

4000

5000

6000

7000

Age (Year Class)

0 (20

03)

1 (20

02)

2 (20

01)

3 (20

00)

4 (19

99)

5 (19

98)

6 (19

97)

7 (19

96)

8 (19

95)

9 (19

94)

10 (1

993)

11 (1

992)

12 (1

991)

13 (1

990)

14 (1

989)

15 (1

988)

16 (1

987)

2004

57

1199

232

10726

716 495

2352

1741

665202 223 71 146 239 70 0 00

1000

20003000

40005000

60007000

80009000

10000

11000

Age (Year Class)

0 (20

04)

1 (20

03)

2 (20

02)

3 (20

01)

4 (20

00)

5 (19

99)

6 (19

98)

7 (19

97)

8 (19

96)

9 (19

95)

10 (1

994)

11 (1

993)

12 (1

992)

13 (1

991)

14 (1

990)

15 (1

989)

16 (1

988)

2005

1

640

2857

2135

3955

477

193

553

965

287

4 5 10111

1 0 00

1000

2000

3000

4000

Age (Year Class)

0 (20

05)

1 (20

04)

2 (20

03)

3 (20

02)

4 (20

01)

5 (20

00)

6 (19

99)

7 (19

98)

8 (19

97)

9 (19

96)

10 (1

995)

11 (1

994)

12 (1

993)

13 (1

992)

14 (1

991)

15 (1

990)

16 (1

989)

Exp

ande

d N

umbe

r

24

Figure 9. Atlantic croaker sex-ratios in Chesapeake Bay 2002-2006, by region (A), age (B).

Sex FMU

63.8

32.3

100.0

45.8

44.6

9.6

100.0

44.9

53.3

100.1

44.9

54.3

100.1

58.7

40.7

100.1

Perc

ent

0

10

20

30

40

50

60

70

80

90

100

Region1 Md-Upp 2 Md-Mid 3 Md-Low 4 Va-Upp 5 Va-Low

n = 93 209 386 1710 1450 P

erce

nt

A.

Sex FMU

97.2

99.9

45.0

53.3

100.0

60.5

38.4

100.0

50.3

48.6

100.0

54.5

44.8

100.0

41.7

58.3

100.0

65.1

34.8

100.0

54.1

45.9

100.0

70.6

29.4

100.0

50.0

50.0

100.0

75.0

25.0

100.0

52.4

47.6

100.0

77.1

22.9

100.0

68.3

31.7

100.0

98.1

100.0Percent SUM

0

10

20

30

40

50

60

70

80

90

100

AGE0 1 2 3 4 5 6 7 8 9 10 11 12 13 14

B.

n = 72 475 427 335 391 349 284 214 152 61 38 25 15 12 2

Per

cent

25

Figure 10. Atlantic croaker length-weight relationships in Chesapeake Bay 2002-2006 as calculated by power regressionfor sexes combined (A) and separately (B).

W e i g h t ( g ) = 0 .0 0 6 6 * L e n g t h ( c m ) * * 3 .1 8 3 4 ( n = 3 9 5 5 )

Wei

ght(

g)

0

1 0 0 0

2 0 0 0

3 0 0 0

T o t a l L e n g t h ( c m )

0 1 0 2 0 3 0 4 0 5 0

A.

Females - Weight(g) = 0.0067 * Length(cm)**3.1818 (n = 2117)Males - Weight(g) = 0.0072 * Length(cm)**3.1573 (n = 1674)

Wei

ght(g

)

0

1000

2000

3000

Total Length(cm)

0 10 20 30 40 50

B.

26

Figure 11. Atlantic croaker maturity schedule in Chesapeake Bay 2002-2006 combined, by sex.

50% m atur ity

99% m atur ity

S E X FM

Prob

abili

ty o

f Mat

urity

0 .0

0 .1

0 .2

0 .3

0 .4

0 .5

0 .6

0 .7

0 .8

0 .9

1 .0

T o ta l Length (c m )0 10 20 30 40 50

Figure 12. Atlantic croaker diet in Chesapeake Bay 2002-2006 combined*.

*All samples not analyzed.

27

28

Figure 13. Black seabass minimum trawlable abundance estimates in numbers (A) and biomass (B) in ChesapeakeBay 2002-2006 (Note: abundance estimates for this species not considered reliable).

R e g io n V a - L o w V a - U p p M d - L o w M d - M id M d - U p p

Min

imum

Tra

wla

ble

Num

ber

0

1 0 ,0 0 0

2 0 ,0 0 0

3 0 ,0 0 0

4 0 ,0 0 0

5 0 ,0 0 0

6 0 ,0 0 0

7 0 ,0 0 0

8 0 ,0 0 0

9 0 ,0 0 0

1 0 0 ,0 0 0

1 1 0 ,0 0 0

1 2 0 ,0 0 0

M o n t h

Y e a r2 0 0 2 2 0 0 3 2 0 0 4 2 0 0 5 2 0 0 6

M a r M a y J u l S e p N o v M a r M a y J u l S e p N o v M a r M a y J u l S e p N o v M a r M a y J u l S e p N o v M a r M a y J u l S e p N o v

A.

R e g io n V a - L o w V a - U p p M d - L o w M d - M id M d - U p p

Min

imum

Tra

wla

ble

Bio

mas

s (k

g)

0

1 0 ,0 0 0

2 0 ,0 0 0

3 0 ,0 0 0

4 0 ,0 0 0

5 0 ,0 0 0

6 0 ,0 0 0

7 0 ,0 0 0

8 0 ,0 0 0

M o n t h

Y e a r2 0 0 2 2 0 0 3 2 0 0 4 2 0 0 5 2 0 0 6

M a r M a y J u l S e p N o v M a r M a y J u l S e p N o v M a r M a y J u l S e p N o v M a r M a y J u l S e p N o v M a r M a y J u l S e p N o v

B.

29

Note: This species is not captured in enough abundance to create meaningful abundance maps.

30

Figure 14. Black seabass length-frequency in Chesapeake Bay 2002-2006.

2 0 0 2

012345678

T o ta l L e n g th (m m )0 5 0 1 0 0 1 5 0 2 0 0 2 5 0 3 0 0

2 0 0 3

01234567

T o ta l L e n g th (m m )0 5 0 1 0 0 1 5 0 2 0 0 2 5 0 3 0 0

2 0 0 4

0

1

2

3

4

T o ta l L e n g th (m m )0 5 0 1 0 0 1 5 0 2 0 0 2 5 0 3 0 0

2 0 0 5

0

1

2

3

T o ta l L e n g th (m m )0 5 0 1 0 0 1 5 0 2 0 0 2 5 0 3 0 0

2 0 0 6

0

1

2

3

T o ta l L e n g th (m m )0 5 0 1 0 0 1 5 0 2 0 0 2 5 0 3 0 0

Exp

ande

d N

umbe

r

31

Figure 15. Black seabass age-structure in Chesapeake Bay 2002-2003 (2004-2006 ages not yet assigned).

2 0 0 2

2

3 5

6

0 0 00

1 0

2 0

3 0

4 0

A g e ( Y e a r C l a s s )

0 (2002 )

1 (2001 )

2 (2000 )

3 (1999 )

4 (1998 )

5 (1997 )

2 0 0 3

1

2 7

20 0 0

0

1 0

2 0

3 0

A g e ( Y e a r C l a s s )

0 (2003 )

1 (2002 )

2 (2001 )

3 (2000 )

4 (1999 )

5 (1998 )

32

Figure 16. Black seabass sex-ratios in Chesapeake Bay 2002-2006, by year (A), month (B).

Sex FMU

77.1

18.8

100.1

96.9

100.0

57.1

14.3

28.6

100.0

84.6

7.7

7.7

100.0

90.9

99.9

Perc

ent

0

10

20

30

40

50

60

70

80

90

100

Year2002 2003 2004 2005 2006

n = 48 32 14 13 17

A.

Sex FMU

100

100.0

83

17

100.0

72

8

20

100.0

81

19

100.0

876

799.9

Perc

ent

0

10

20

30

40

50

60

70

80

90

100

Month03-Mar 05-May 07-Jul 09-Sep 11-Nov

n = 1 6 25 21 71

B.

33

Figure 17. Black seabass length-weight relationships in Chesapeake Bay 2002-2006 as calculated by power regressionfor sexes combined (A) and separately (B).

W e ig h t(g ) = 0 .0 2 0 9 * L e n g th (c m )**2 .9 2 8 1 (n = 1 2 4 )

Wei

ght(g

)

0

1 0 0

2 0 0

3 0 0

4 0 0

T o ta l L e n g th (c m )

7 8 9 1 0 1 1 1 2 1 3 1 4 1 5 1 6 1 7 1 8 1 9 2 0 2 1 2 2 2 3 2 4 2 5 2 6 2 7

F e m a le s - W e ig h t(g ) = 0 .0 1 9 8 * L e n g th (c m )**2 .9 5 0 3 (n = 1 0 2 )

M a le s - W e ig h t(g ) = 0 .0 4 8 4 * L e n g th (c m )**2 .6 5 6 (n = 6 )

Wei

ght(g

)

0

1 0 0

2 0 0

3 0 0

4 0 0

T o ta l L e n g th (c m )

7 8 9 1 0 1 1 1 2 1 3 1 4 1 5 1 6 1 7 1 8 1 9 2 0 2 1 2 2 2 3 2 4 2 5 2 6 2 7

A.

B.

34

Figure 18. Black seabass maturity schedule in Chesapeake Bay 2002-2006 combined (females only).

50% m atu r ity

99% m atu r ity

S E X F

Prob

abili

ty o

f Mat

urity

0 .0

0 .1

0 .2

0 .3

0 .4

0 .5

0 .6

0 .7

0 .8

0 .9

T o ta l L e n g th (c m )8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27

Figure 19. Black seabass diet in Chesapeake Bay 2002-2006 combined.

35

36

Figure 20. Bluefish minimum trawlable abundance estimates in numbers (A) and biomass (B) in Chesapeake Bay2002-2006 (Note: abundance estimates for this species not considered reliable).

R e g io n V a - L o w V a - U p p M d - L o w M d - M id M d - U p p

Min

imum

Tra

wla

ble

Num

ber

0

1 0 0 ,0 0 0

2 0 0 ,0 0 0

3 0 0 ,0 0 0

4 0 0 ,0 0 0

5 0 0 ,0 0 0

M o n t h

Y e a r2 0 0 2 2 0 0 3 2 0 0 4 2 0 0 5 2 0 0 6

M a r M a y J u l S e p N o v M a r M a y J u l S e p N o v M a r M a y J u l S e p N o v M a r M a y J u l S e p N o v M a r M a y J u l S e p N o v

A.

R e g io n V a - L o w V a - U p p M d - L o w M d - M id M d - U p p

Min

imum

Tra

wla

ble

Bio

mas

s (k

g)

0

1 0 0 ,0 0 0

2 0 0 ,0 0 0

3 0 0 ,0 0 0

4 0 0 ,0 0 0

M o n t h

Y e a r2 0 0 2 2 0 0 3 2 0 0 4 2 0 0 5 2 0 0 6

M a r M a y J u l S e p N o v M a r M a y J u l S e p N o v M a r M a y J u l S e p N o v M a r M a y J u l S e p N o v M a r M a y J u l S e p N o v

B.

37

Mar

chJu

lySe

ptem

ber

Nov

embe

rM

ay

Figu

re 2

1. A

bund

ance

(num

ber p

er h

ecta

re s

wep

t) of

blu

efis

h in

Che

sape

ake

Bay,

200

2.

38

Mar

chJu

lySe

ptem

ber

Nov

embe

rM

ay

Figu

re 2

2. A

bund

ance

(num

ber p

er h

ecta

re s

wep

t) of

blu

efis

h in

Che

sape

ake

Bay,

200

3.

39

Mar

chJu

lySe

ptem

ber

Nov

embe

rM

ay

Figu

re 2

3. A

bund

ance

(num

ber p

er h

ecta

re s

wep

t) of

blu

efis

h in

Che

sape

ake

Bay,

200

4.

40

Mar

chJu

lySe

ptem

ber

Nov

embe

rM

ay

Figu

re 2

4. A

bund

ance

(num

ber p

er h

ecta

re s

wep

t) of

blu

efis

h in

Che

sape

ake

Bay,

200

5.

41

Mar

chJu

lySe

ptem

ber

Nov

embe

rM

ay

Figu

re 2

5. A

bund

ance

(num

ber p

er h

ecta

re s

wep

t) of

blu

efis

h in

Che

sape

ake

Bay,

200

6.

42

Figure 26. Bluefish length-frequency in Chesapeake Bay 2002-2006.

2 0 0 2

0123456

F o rk L e n g th (m m )0 5 0 1 0 0 1 5 0 2 0 0 2 5 0 3 0 0 3 5 0 4 0 0 4 5 0 5 0 0 5 5 0

2 0 0 3

0

1 0

2 0

F o rk L e n g th (m m )0 5 0 1 0 0 1 5 0 2 0 0 2 5 0 3 0 0 3 5 0 4 0 0 4 5 0 5 0 0 5 5 0

2 0 0 4

0

1

2

3

4

F o rk L e n g th (m m )0 5 0 1 0 0 1 5 0 2 0 0 2 5 0 3 0 0 3 5 0 4 0 0 4 5 0 5 0 0 5 5 0

2 0 0 5

0

1 0

2 0

3 0

F o rk L e n g th (m m )0 5 0 1 0 0 1 5 0 2 0 0 2 5 0 3 0 0 3 5 0 4 0 0 4 5 0 5 0 0 5 5 0

2 0 0 6

0

1

2

3

F o rk L e n g th (m m )0 5 0 1 0 0 1 5 0 2 0 0 2 5 0 3 0 0 3 5 0 4 0 0 4 5 0 5 0 0 5 5 0

Exp

ande

d N

umbe

r

43

Figure 27. Bluefish age-structure in Chesapeake Bay 2002-2004 (2005-2006 ages not yet assigned).

2002

15

19

0 0 0 002468

101214161820

Age (Year Class)

0 (20

02)

1 (20

01)

2 (20

00)

3 (19

99)

4 (19

98)

5 (19

97)

2003

96

10 60 0 0

0102030405060708090

100

Age (Year Class)

0 (2003

)

1 (20

02)

2 (20

01)

3 (2000

)

4 (19

99)

5 (19

98)

2004

19

6

20 0 0

02468

101214161820

Age (Year Class)

0 (20

04)

1 (20

03)

2 (20

02)

3 (20

01)

4 (20

00)

5 (19

99)

44

Figure 28. Bluefish sex-ratios in Chesapeake Bay 2002-2006, by year.

Se x FMU

41.2

41.2

17.6

100

46.8

36.6

16.6

100

58.6

27.1

14.3

100

45.8

44.2

10.0

100

56.5

34.8

8.7

100

Perc

ent

0

10

20

30

40

50

60

70

80

90

100

Year2002 2003 2004 2005 2006

n = 34 68 27 71 23

45

Figure 29. Bluefish length-weight relationships in Chesapeake Bay 2002-2006 as calculated by power regressionfor sexes combined (A) and separately (B).

Weight(g) = 0.0044 * Length(cm )**3 .3433 (n = 229)

Wei

ght(g

)

0

1000

2000

3000

Fork Length(cm )

10 20 30 40 50 60

A.

Females - W eight(g) = 0.0049 * Length(cm)**3.3166 (n = 111)

Males - W eight(g) = 0.0039 * Length(cm)**3.3846 (n = 86)

Wei

ght(g

)

0

1000

2000

3000

Fork Length(cm )

10 20 30 40 50 60

B.

46

Figure 30. Bluefish maturity schedule in Chesapeake Bay 2002-2006 combined, by sex.

50% maturity

99% maturity

SEX FM

Prob

abili

ty o

f Mat

urity

0 .0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1.0

Fork Le ngth (cm )10 20 30 40 50 60

Figure 31. Bluefish diet in Chesapeake Bay 2002-2006 combined.

47

48

Figure 32. Butterfish minimum trawlable abundance estimates in numbers (A) and biomass (B) in Chesapeake Bay 2002-2006.

R e g io n V a - L o w V a - U p p M d - L o w M d - M id M d - U p p

Min

imum

Tra

wla

ble

Num

ber

0

1 ,0 0 0 ,0 0 0

2 ,0 0 0 ,0 0 0

3 ,0 0 0 ,0 0 0

M o n t h

Y e a r2 0 0 2 2 0 0 3 2 0 0 4 2 0 0 5 2 0 0 6

M a r M a y J u l S e p N o v M a r M a y J u l S e p N o v M a r M a y J u l S e p N o v M a r M a y J u l S e p N o v M a r M a y J u l S e p N o v

A.

R e g io n V a - L o w V a - U p p M d - L o w M d - M id M d - U p p

Min

imum

Tra

wla

ble

Bio

mas

s (k

g)

0

1 0 0 ,0 0 0

2 0 0 ,0 0 0

3 0 0 ,0 0 0

M o n t h

Y e a r2 0 0 2 2 0 0 3 2 0 0 4 2 0 0 5 2 0 0 6

M a r M a y J u l S e p N o v M a r M a y J u l S e p N o v M a r M a y J u l S e p N o v M a r M a y J u l S e p N o v M a r M a y J u l S e p N o v

B.

49

Mar

chJu

lySe

ptem

ber

Nov

embe

rM

ay

Figu

re 3

3. A

bund

ance

(num

ber p

er h

ecta

re s

wep

t) of

but

terfi

sh in

Che

sape

ake

Bay,

200

2.

50

Mar

chJu

lySe

ptem

ber

Nov

embe

rM

ay

Figu

re 3

4. A

bund

ance

(num

ber p

er h

ecta

re s

wep

t) of

but

terfi

sh in

Che

sape

ake

Bay,

200

3.

51

Mar

chJu

lySe

ptem

ber

Nov

embe

rM

ay

Figu

re 3

5. A

bund

ance

(num

ber p

er h

ecta

re s

wep

t) of

but

terfi

sh in

Che

sape

ake

Bay,

200

4.

52

Mar

chJu

lySe

ptem

ber

Nov

embe

rM

ay

Figu

re 3

6. A

bund

ance

(num

ber p

er h

ecta

re s

wep

t) of

but

terfi

sh in

Che

sape

ake

Bay,

200

5.

53

Mar

chJu

lySe

ptem

ber

Nov

embe

rM

ay

Figu

re 3

7. A

bund

ance

(num

ber p

er h

ecta

re s

wep

t) of

but

terfi

sh in

Che

sape

ake

Bay,

200

6.

54

Figure 38. Butterfish length-frequency in Chesapeake Bay 2002-2006.

2 0 0 2

01 02 03 04 05 06 0

T o t a l L e n g t h ( m m )0 5 0 1 0 0 1 5 0 2 0 0 2 5 0 3 0 0

2 0 0 3

0

1 0 0

2 0 0

3 0 0

T o t a l L e n g t h ( m m )0 5 0 1 0 0 1 5 0 2 0 0 2 5 0 3 0 0

2 0 0 4

0

1 0 0

2 0 0

3 0 0

T o t a l L e n g t h ( m m )0 5 0 1 0 0 1 5 0 2 0 0 2 5 0 3 0 0

2 0 0 5

0

2 0

4 0

6 0

8 0

1 0 0

T o t a l L e n g t h ( m m )0 5 0 1 0 0 1 5 0 2 0 0 2 5 0 3 0 0

2 0 0 6

01 02 03 04 05 06 07 08 0

T o t a l L e n g t h ( m m )0 5 0 1 0 0 1 5 0 2 0 0 2 5 0 3 0 0

Exp

ande

d N

umbe

r

55

Figure 39. Butterfish length-weight relationship in Chesapeake Bay 2002-2006 as calculated by power regression.

Weight(g) = 0.0146 * Length(cm )**3.1672 (n = 1408)

Wei

ght(

g)

0

100

200

300

Fork Length(cm )

3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22

Figure 40. Butterfish diet in Chesapeake Bay 2002-2006 combined (Note: nearly all samples from 2002).

56

Figure 41. Northern kingfish minimum trawlable abundance estimates in numbers (A) and biomass (B) in ChesapeakeBay 2002-2006.

R e g io n V a - L o w V a - U p p M d - L o w M d - M id M d - U p p

Min

imum

Tra

wla

ble

Num

ber

0

1 0 0 ,0 0 0

2 0 0 ,0 0 0

3 0 0 ,0 0 0

4 0 0 ,0 0 0

5 0 0 ,0 0 0

M o n t h

Y e a r2 0 0 2 2 0 0 3 2 0 0 4 2 0 0 5 2 0 0 6

M a r M a y J u l S e p N o v M a r M a y J u l S e p N o v M a r M a y J u l S e p N o v M a r M a y J u l S e p N o v M a r M a y J u l S e p N o v

A.

R e g io n V a - L o w V a - U p p M d - L o w M d - M id M d - U p p

Min

imum

Tra

wla

ble

Bio

mas

s (k

g)

0

1 0 ,0 0 0

2 0 ,0 0 0

3 0 ,0 0 0

4 0 ,0 0 0

5 0 ,0 0 0

6 0 ,0 0 0

7 0 ,0 0 0

8 0 ,0 0 0

9 0 ,0 0 0

1 0 0 ,0 0 0

1 1 0 ,0 0 0

1 2 0 ,0 0 0

1 3 0 ,0 0 0

1 4 0 ,0 0 0

1 5 0 ,0 0 0

1 6 0 ,0 0 0

1 7 0 ,0 0 0

1 8 0 ,0 0 0

M o n t h

Y e a r2 0 0 2 2 0 0 3 2 0 0 4 2 0 0 5 2 0 0 6

M a r M a y J u l S e p N o v M a r M a y J u l S e p N o v M a r M a y J u l S e p N o v M a r M a y J u l S e p N o v M a r M a y J u l S e p N o v

B.

57

Mar

chJu

lySe

ptem

ber

Nov

embe

rM

ay

Figu

re 4

2. A

bund

ance

(num

ber p

er h

ecta

re s

wep

t) of

nor

ther

n ki

ngfis

h in

Che

sape

ake

Bay,

200

2.

58

Mar

chJu

lySe

ptem

ber

Nov

embe

rM

ay

Figu

re 4

3. A

bund

ance

(num

ber p

er h

ecta

re s

wep

t) of

nor

ther

n ki

ngfis

h in

Che

sape

ake

Bay,

200

3.

59

Mar

chJu

lySe

ptem

ber

Nov

embe

rM

ay

Figu

re 4

4. A

bund

ance

(num

ber p

er h

ecta

re s

wep

t) of

nor

ther

n ki

ngfis

h in

Che

sape

ake

Bay,

200

4.

60

Mar

chJu

lySe

ptem

ber

Nov

embe

rM

ay

Figu

re 4

5. A

bund

ance

(num

ber p

er h

ecta

re s

wep

t) of

nor

ther

n ki

ngfis

h in

Che

sape

ake

Bay,

200

5.

61

Mar

chJu

lySe

ptem

ber

Nov

embe

rM

ay

Figu

re 4

6. A

bund

ance

(num

ber p

er h

ecta

re s

wep

t) of

nor

ther

n ki

ngfis

h in

Che

sape

ake

Bay,

200

6.

62

Figure 47. Northern kingfish length-frequency in Chesapeake Bay 2002-2006.

2 0 0 2

02468

1 01 21 41 6

T o t a l L e n g t h ( m m )0 5 0 1 0 0 1 5 0 2 0 0 2 5 0 3 0 0 3 5 0 4 0 0 4 5 0

2 0 0 3

0

2

4

6

8

1 0

T o t a l L e n g t h ( m m )0 5 0 1 0 0 1 5 0 2 0 0 2 5 0 3 0 0 3 5 0 4 0 0 4 5 0

2 0 0 4

02468

1 01 21 4

T o t a l L e n g t h ( m m )0 5 0 1 0 0 1 5 0 2 0 0 2 5 0 3 0 0 3 5 0 4 0 0 4 5 0

2 0 0 5

0

2

4

6

8

1 0

T o t a l L e n g t h ( m m )0 5 0 1 0 0 1 5 0 2 0 0 2 5 0 3 0 0 3 5 0 4 0 0 4 5 0

2 0 0 6

0

5

1 0

1 5

2 0

T o t a l L e n g t h ( m m )0 5 0 1 0 0 1 5 0 2 0 0 2 5 0 3 0 0 3 5 0 4 0 0 4 5 0

Exp

ande

d N

umbe

r

63

Figure 48. Northern kingfish sex-ratios in Chesapeake Bay 2002-2006, by year (A), month (B).

Sex FMU

51.0

39.4

9.7

100.1

64.2

34.3

100.0

55.6

35.5

9.0

100.1

58.1

21.7

20.2

100.0

49.2

49.7

100.0

Per

cent

0

10

20

30

40

50

60

70

80

90

100

Year2002 2003 2004 2005 2006

Per

cent

n = 73 55 55 71 66

A.

Sex FMU

57.3

42.7

100

45.2

53.7

100

61.0

33.0

6.0

100

52.0

20.7

27.3

100

Per

cent

0

10

20

30

40

50

60

70

80

90

100

Month05-May 07-Jul 09-Sep 11-Nov

Per

cent

B.

n = 51 63 130 76

64

Figure 49. Northern kingfish length-weight relationships in Chesapeake Bay 2002-2006 as calculated by power regressionfor sexes combined (A) and separately (B).

W eight(g ) = 0.0068 * Length(cm)* *3.145 (n = 339)

Wei

ght(g

)

0

100

200

300

400

500

600

700

Total Length(cm )0 10 20 30 40

A.

Females - W eight(g ) = 0.0064 * Length(cm)* *3.166 (n = 179)Males - W eight(g ) = 0.0109 * Length(cm)* *2.999 (n = 110)

Wei

ght(g

)

0

100

200

300

400

500

600

700

Total Length(cm )10 20 30 40

B.

65

Figure 50. Northern kingfish maturity schedule in Chesapeake Bay 2002-2006 combined, by sex.

Figure 20. Northern kingfish diet in Chesapeake Bay 2002-2005 combined*.

5 0 % m a tu r ity

9 9 % m a tu r ity

S E X FM

Prob

abili

ty o

f Mat

urity

0 .0

0 .1

0 .2

0 .3

0 .4

0 .5

0 .6

0 .7

0 .8

0 .9

1 .0

T o ta l L e n g th (c m )10 20 3 0 40

Figure 51. Northern kingfish diet in Chesapeake Bay 2002-2006 combined.

66

67

Figure 52. Northern puffer minimum trawlable abundance estimates in numbers (A) and biomass (B) in ChesapeakeBay 2002-2006.

R e g io n V a - L o w V a - U p p M d - L o w M d - M id M d - U p p

Min

imum

Tra

wla

ble

Num

ber

0

1 0 0 ,0 0 0

2 0 0 ,0 0 0

3 0 0 ,0 0 0

4 0 0 ,0 0 0

5 0 0 ,0 0 0

6 0 0 ,0 0 0

M o n t h

Y e a r2 0 0 2 2 0 0 3 2 0 0 4 2 0 0 5 2 0 0 6

M a r M a y J u l S e p N o v M a r M a y J u l S e p N o v M a r M a y J u l S e p N o v M a r M a y J u l S e p N o v M a r M a y J u l S e p N o v

A.

R e g io n V a - L o w V a - U p p M d - L o w M d - M id M d - U p p

Min

imum

Tra

wla

ble

Bio

mas

s (k

g)

0

1 0 ,0 0 0

2 0 ,0 0 0

3 0 ,0 0 0

4 0 ,0 0 0

5 0 ,0 0 0

6 0 ,0 0 0

7 0 ,0 0 0

8 0 ,0 0 0

9 0 ,0 0 0

1 0 0 ,0 0 0

1 1 0 ,0 0 0

1 2 0 ,0 0 0

1 3 0 ,0 0 0

1 4 0 ,0 0 0

1 5 0 ,0 0 0

1 6 0 ,0 0 0

M o n t h

Y e a r2 0 0 2 2 0 0 3 2 0 0 4 2 0 0 5 2 0 0 6

M a r M a y J u l S e p N o v M a r M a y J u l S e p N o v M a r M a y J u l S e p N o v M a r M a y J u l S e p N o v M a r M a y J u l S e p N o v

B.

68

Note: This species is not captured in enough abundance to create meaningful abundance maps.

69

Figure 53. Northern puffer length-frequency in Chesapeake Bay 2002-2006.

2 0 0 2

0

1 0

2 0

3 0

T o t a l L e n g t h ( m m )0 5 0 1 0 0 1 5 0 2 0 0 2 5 0 3 0 0

2 0 0 3

0

1 0

2 0

3 0

4 0

T o t a l L e n g t h ( m m )0 5 0 1 0 0 1 5 0 2 0 0 2 5 0 3 0 0

2 0 0 4

01234567

T o t a l L e n g t h ( m m )0 5 0 1 0 0 1 5 0 2 0 0 2 5 0 3 0 0

2 0 0 5

0

1 0

2 0

3 0

T o t a l L e n g t h ( m m )0 5 0 1 0 0 1 5 0 2 0 0 2 5 0 3 0 0

2 0 0 6

02468

1 01 2

T o t a l L e n g t h ( m m )0 5 0 1 0 0 1 5 0 2 0 0 2 5 0 3 0 0

Exp

ande

d N

umbe

r

70

Figure 54. Northern puffer sex-ratios in Chesapeake Bay 2002-2006, by year (A), month (B).

S e x FMU

4 9 .7

3 6 .9

1 3 .3

9 9 .9

6 7 .9

3 1 .6

1 0 0 .1

6 3 .1

3 4 .5

1 0 0 .0

5 5 .0

2 7 .0

1 8 .01 0 0 .0

4 0 .4

4 6 .2

1 3 .51 0 0 .1

Perc

ent

0

1 0

2 0

3 0

4 0

5 0

6 0

7 0

8 0

9 0

1 0 0

Y e a r2 0 0 2 2 0 0 3 2 0 0 4 2 0 0 5 2 0 0 6

n = 134 97 31 84 51

A.

Per

cent

S e x FMU

5 0 .0

2 8 .6

2 1 .41 0 0 .0

3 6 .0

6 2 .3

1 0 0 .1

4 2 .6

3 6 .7

2 0 .71 0 0 .0

6 9 .1

2 2 .9

8 .01 0 0 .0

Perc

ent

0

1 0

2 0

3 0

4 0

5 0

6 0

7 0

8 0

9 0

1 0 0

M o n th0 5 -M a y 0 7 -J u l 0 9 -S e p 1 1 -N o v

Per

cent

n = 14 76 105 202

B.

71

Figure 55. Northern puffer length-weight relationships in Chesapeake Bay 2002-2006 as calculated by powerregression for sexes combined (A) and separately (B).

W e i g h t ( g ) = 0 .0 3 7 * L e n g t h ( c m ) * * 2 .8 8 5 8 ( n = 4 4 3 )

Wei

ght(

g)

0

1 0 0

2 0 0

3 0 0

4 0 0

5 0 0

6 0 0

T o t a l L e n g t h ( c m )

0 1 0 2 0 3 0

A.

F e m a l e s - W e i g h t ( g ) = 0 .0 5 5 7 * L e n g t h ( c m ) * * 2 .7 5 6 9 ( n = 2 2 1 )

M a l e s - W e i g h t ( g ) = 0 .0 3 3 2 * L e n g t h ( c m ) * * 2 .9 0 3 9 ( n = 1 3 7 )

Wei

ght(

g)

0

1 0 0

2 0 0

3 0 0

4 0 0

5 0 0

6 0 0

T o t a l L e n g t h ( c m )

0 1 0 2 0 3 0

B.

72

Figure 56. Northern puffer maturity schedule in Chesapeake Bay 2002-2006 combined, by sex.

50 % m atu r ity

99 % m atu r ity

S E X FM

Prob

abili

ty o

f Mat

urity

0 .0

0 .1

0 .2

0 .3

0 .4

0 .5

0 .6

0 .7

0 .8

0 .9

1 .0

T o ta l L e n g th (c m )0 10 20 30

Figure 57. Northern puffer diet in Chesapeake Bay 2002-2006 combined.

73

74

Figure 58. Scup minimum trawlable abundance estimates in numbers (A) and biomass (B) in Chesapeake Bay2002-2006.

R e g io n V a - L o w V a - U p p M d - L o w M d - M id M d - U p p

Min

imum

Tra

wla

ble

Num

ber

0

1 ,0 0 0 ,0 0 0

2 ,0 0 0 ,0 0 0

3 ,0 0 0 ,0 0 0

4 ,0 0 0 ,0 0 0

M o n t h

Y e a r2 0 0 2 2 0 0 3 2 0 0 4 2 0 0 5 2 0 0 6

M a r M a y J u l S e p N o v M a r M a y J u l S e p N o v M a r M a y J u l S e p N o v M a r M a y J u l S e p N o v M a r M a y J u l S e p N o v

A.

R e g io n V a - L o w V a - U p p M d - L o w M d - M id M d - U p p

Min

imum

Tra

wla

ble

Bio

mas

s (k

g)

0

1 0 ,0 0 0

2 0 ,0 0 0

3 0 ,0 0 0

4 0 ,0 0 0

5 0 ,0 0 0

6 0 ,0 0 0

7 0 ,0 0 0

8 0 ,0 0 0

9 0 ,0 0 0

1 0 0 ,0 0 0

1 1 0 ,0 0 0

1 2 0 ,0 0 0

1 3 0 ,0 0 0

1 4 0 ,0 0 0

1 5 0 ,0 0 0

1 6 0 ,0 0 0

1 7 0 ,0 0 0

1 8 0 ,0 0 0

1 9 0 ,0 0 0

2 0 0 ,0 0 0

M o n t h

Y e a r2 0 0 2 2 0 0 3 2 0 0 4 2 0 0 5 2 0 0 6

M a r M a y J u l S e p N o v M a r M a y J u l S e p N o v M a r M a y J u l S e p N o v M a r M a y J u l S e p N o v M a r M a y J u l S e p N o v

B.

75

Mar

chJu

lySe

ptem

ber

Nov

embe

rM

ay

Figu

re 5

9. A

bund

ance

(num

ber p

er h

ecta

re s

wep

t) of

scu

p in

Che

sape

ake

Bay,

200

2.

76

Mar

chJu

lySe

ptem

ber

Nov

embe

rM

ay

Figu

re 6

0. A

bund

ance

(num

ber p

er h

ecta

re s

wep

t) of

scu

p in

Che

sape

ake

Bay,

200

3.

77

Mar

chJu

lySe

ptem

ber

Nov

embe

rM

ay

Figu

re 6

1. A

bund

ance

(num

ber p

er h

ecta

re s

wep

t) of

scu

p in

Che

sape

ake

Bay,

200

4.

78

Mar

chJu

lySe

ptem

ber

Nov

embe

rM

ay

Figu

re 6

2. A

bund

ance

(num

ber p

er h

ecta

re s

wep

t) of

scu

p in

Che

sape

ake

Bay,

200

5.

79

Mar

chJu

lySe

ptem

ber

Nov

embe

rM

ay

Figu

re 6

3. A

bund

ance

(num

ber p

er h

ecta

re s

wep

t) of

scu

p in

Che

sape

ake

Bay,

200

6.

80

Figure 64. Scup length-frequency in Chesapeake Bay 2002-2006.

2 0 0 2

0

1 0

2 0

3 0

4 0

F o r k L e n g t h ( m m )0 5 0 1 0 0 1 5 0 2 0 0 2 5 0 3 0 0 3 5 0

2 0 0 3

01 02 03 04 05 06 07 0

F o r k L e n g t h ( m m )0 5 0 1 0 0 1 5 0 2 0 0 2 5 0 3 0 0 3 5 0

2 0 0 4

02 04 06 08 0

1 0 01 2 01 4 01 6 0

F o r k L e n g t h ( m m )0 5 0 1 0 0 1 5 0 2 0 0 2 5 0 3 0 0 3 5 0

2 0 0 5

0

1 0 0

2 0 0

3 0 0

F o r k L e n g t h ( m m )0 5 0 1 0 0 1 5 0 2 0 0 2 5 0 3 0 0 3 5 0

2 0 0 6

01 02 03 04 05 06 07 08 0

F o r k L e n g t h ( m m )0 5 0 1 0 0 1 5 0 2 0 0 2 5 0 3 0 0 3 5 0

Exp

ande

d N

umbe

r

81

Figure 65. Scup sex-ratios in Chesapeake Bay 2002-2005, by year (A) and month (B).

Se x FMU

2 9 .9

4 6 .8

2 3 .3

1 0 0 .0

4 0 .7

2 7 .5

3 1 .8

1 0 0 .0

3 9 .9

1 0 .7

4 9 .5

1 0 0 .1

3 3 .5

2 9 .5

3 7 .0

1 0 0 .0

1 4 .6

8 .5

7 6 .8

9 9 .9

Perc

ent

0

10

20

30

40

50

60

70

80

90

100

Year2002 2003 2004 2005 2006

n = 40 97 155 85 115

A.

Per

cent

Se x FMU

1 3 .8

8 6 .2

1 0 0

3 0 .05 .6

6 4 .4

1 0 0

3 2 .0

2 8 .0

4 0 .0

1 0 0

5 5 .8

2 8 .8

1 5 .4

1 0 0

Perc

ent

0

10

20

30

40

50

60

70

80

90

100

M on th05-M ay 07-Ju l 09-Sep 11-N ov

n = 34 124 255 79

B.

Per

cent

82

Figure 66. Scup length-weight relationships in Chesapeake Bay 2002-2006 as calculated by powerregression for sexes combined (A) and separately (B).

W eight(g ) = 0 .0236 * Length (cm )**2 .9806 (n = 496 )

Wei

ght(

g)

0

100

200

300

Tota l Length (cm )6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23

A.

Fem ales - W e igh t(g ) = 0 .0243 * Length (cm )**2 .9746 (n = 184 )M a les - W e igh t(g ) = 0 .0401 * Length (cm )**2 .799 (n = 104 )

Wei

ght(

g)

0

100

200

300

Tota l Length (cm )8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23

B.

83

Figure 67. Scup maturity schedule in Chesapeake Bay 2002-2006 combined, by sex.

50 % m atu r ity

99 % m atu r ity

S E X FM

Prob

abili

ty o

f Mat

urity

0 .0

0 .1

0 .2

0 .3

0 .4

0 .5

0 .6

0 .7

0 .8

0 .9

1 .0

F o rk L e n g th (c m )8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23

Figure 68. Scup diet in Chesapeake Bay 2002-2006 combined.

84

Figure 69. Spot minimum trawlable abundance estimates in numbers (A) and biomass (B) in Chesapeake Bay2002-2006.

R e g io n V a - L o w V a - U p p M d - L o w M d - M id M d - U p p

Min

imum

Tra

wla

ble

Num

ber

0

1 ,0 0 0 ,0 0 0

2 ,0 0 0 ,0 0 0

3 ,0 0 0 ,0 0 0

4 ,0 0 0 ,0 0 0

5 ,0 0 0 ,0 0 0

6 ,0 0 0 ,0 0 0

7 ,0 0 0 ,0 0 0

8 ,0 0 0 ,0 0 0

9 ,0 0 0 ,0 0 0

1 0 ,0 0 0 ,0 0 0

1 1 ,0 0 0 ,0 0 0

1 2 ,0 0 0 ,0 0 0

1 3 ,0 0 0 ,0 0 0

1 4 ,0 0 0 ,0 0 0

1 5 ,0 0 0 ,0 0 0

1 6 ,0 0 0 ,0 0 0

1 7 ,0 0 0 ,0 0 0

1 8 ,0 0 0 ,0 0 0

1 9 ,0 0 0 ,0 0 0

M o n t h

Y e a r2 0 0 2 2 0 0 3 2 0 0 4 2 0 0 5 2 0 0 6

M a r M a y J u l S e p N o v M a r M a y J u l S e p N o v M a r M a y J u l S e p N o v M a r M a y J u l S e p N o v M a r M a y J u l S e p N o v

A.

R e g io n V a - L o w V a - U p p M d - L o w M d - M id M d - U p p

Min

imum

Tra

wla

ble

Bio

mas

s (k

g)

0

1 0 0 ,0 0 0

2 0 0 ,0 0 0

3 0 0 ,0 0 0

4 0 0 ,0 0 0

5 0 0 ,0 0 0

6 0 0 ,0 0 0

7 0 0 ,0 0 0

8 0 0 ,0 0 0

9 0 0 ,0 0 0

1 ,0 0 0 ,0 0 0

1 ,1 0 0 ,0 0 0

1 ,2 0 0 ,0 0 0

1 ,3 0 0 ,0 0 0

1 ,4 0 0 ,0 0 0

1 ,5 0 0 ,0 0 0

1 ,6 0 0 ,0 0 0

1 ,7 0 0 ,0 0 0

1 ,8 0 0 ,0 0 0

1 ,9 0 0 ,0 0 0

2 ,0 0 0 ,0 0 0

M o n t h

Y e a r2 0 0 2 2 0 0 3 2 0 0 4 2 0 0 5 2 0 0 6

M a r M a y J u l S e p N o v M a r M a y J u l S e p N o v M a r M a y J u l S e p N o v M a r M a y J u l S e p N o v M a r M a y J u l S e p N o v

B.

85

Mar

chJu

lySe

ptem

ber

Nov

embe

rM

ay

Figu

re 7

0. A

bund

ance

(num

ber p

er h

ecta

re s

wep

t) of

spo

t in

Che

sape

ake

Bay,

200

2.

86

Mar

chJu

lySe

ptem

ber

Nov

embe

rM

ay

Figu

re 7

1. A

bund

ance

(num

ber p

er h

ecta

re s

wep

t) of

spo

t in

Che

sape

ake

Bay,

200

3.

87

Mar

chJu

lySe

ptem

ber

Nov

embe

rM

ay

Figu

re 7

2. A

bund

ance

(num

ber p

er h

ecta

re s

wep

t) of

spo

t in

Che

sape

ake

Bay,

200

4.

88

Mar

chJu

lySe

ptem

ber

Nov

embe

rM

ay

Figu

re 7

3. A

bund

ance

(num

ber p

er h

ecta

re s

wep

t) of

spo

t in

Che

sape

ake

Bay,

200

5.

89

Mar

chJu

lySe

ptem

ber

Nov

embe

rM

ay

Figu

re 7

4. A

bund

ance

(num

ber p

er h

ecta

re s

wep

t) of

spo

t in

Che

sape

ake

Bay,

200

6.

90

Figure 75. Spot length-frequency in Chesapeake Bay 2002-2006.

2 0 0 2

0

1 0 0

2 0 0

3 0 0

4 0 0

5 0 0

F o r k L e n g t h ( m m )0 5 0 1 0 0 1 5 0 2 0 0 2 5 0 3 0 0 3 5 0

2 0 0 3

01 0 02 0 03 0 04 0 05 0 06 0 07 0 0

F o r k L e n g t h ( m m )0 5 0 1 0 0 1 5 0 2 0 0 2 5 0 3 0 0 3 5 0

2 0 0 4

01 0 02 0 03 0 04 0 05 0 06 0 07 0 0

F o r k L e n g t h ( m m )0 5 0 1 0 0 1 5 0 2 0 0 2 5 0 3 0 0 3 5 0

2 0 0 5

02 0 04 0 06 0 08 0 0

1 0 0 01 2 0 01 4 0 0

F o r k L e n g t h ( m m )0 5 0 1 0 0 1 5 0 2 0 0 2 5 0 3 0 0 3 5 0

2 0 0 6

02 0 04 0 06 0 08 0 0

1 0 0 01 2 0 01 4 0 01 6 0 0

F o r k L e n g t h ( m m )0 5 0 1 0 0 1 5 0 2 0 0 2 5 0 3 0 0 3 5 0

Exp

ande

d N

umbe

r

91

Figure 76. Spot age-structure in Chesapeake Bay 2002-2006.2 0 0 2

1 6 5 1

9 5 4

8 4 2 4 1 00

2 0 0

4 0 0

6 0 0

8 0 0

1 0 0 0

1 2 0 0

1 4 0 0

1 6 0 0

1 8 0 0

A g e ( Y e a r C l a s s )

0 (200 2 )

1 (200 1 )

2 (200 0 )

3 (199 9 )

4 (199 8 )

5 (199 7 )

2 0 0 3

2 2 8 0

1 2 7 2

3 1 0 2 00

1 0 0 0

2 0 0 0

3 0 0 0

A g e ( Y e a r C l a s s )

0 (200 3 )

1 (200 2 )

2 (200 1 )

3 (200 0 )

4 (199 9 )

5 (199 8 )

2 0 0 4

2 6 2 2

1 2 6 5

1 8 62 0 0

0

1 0 0 0

2 0 0 0

3 0 0 0

A g e ( Y e a r C l a s s )

0 (200 4 )

1 (200 3 )

2 (200 2 )

3 (200 1 )

4 (200 0 )

5 (199 9 )

Exp

ande

d N

umbe

r

2 0 0 5

7 1 2 3

4 0 7 2

1 5 3 2 0 2 00

1 0 0 0

2 0 0 0

3 0 0 0

4 0 0 0

5 0 0 0

6 0 0 0

7 0 0 0

8 0 0 0

A g e ( Y e a r C l a s s )

0 (200 5 )

1 (200 4 )

2 (200 3 )

3 (200 2 )

4 (200 1 )

5 (200 0 )

92

2 0 0 6

3 8 6 5

2 8 3 5

8 9 0 0 00

1 0 0 0

2 0 0 0

3 0 0 0

4 0 0 0

A g e (Y e a r C la s s )

0 (2006)

1 (2005)

2 (2004)

3 (2003)

4 (2002)

5 (2001)

Figure 77. Spot sex-ratios in Chesapeake Bay 2002-2005, by year (A), month (B).

S e x FMU

4 1 .4

4 4 .8

1 3 .81 0 0

4 5 .2

4 8 .3

6 .51 0 0

4 4 .4

3 8 .2

1 7 .41 0 0

4 7 .1

3 9 .3

1 3 .61 0 0

5 5 .3

4 0 .9

1 0 0

Perc

ent

0

1 0

2 0

3 0

4 0

5 0

6 0

7 0

8 0

9 0

1 0 0

Y e a r2 0 0 2 2 0 0 3 2 0 0 4 2 0 0 5 2 0 0 6

n = 672 380 617 1023 680

A.

Per

cent

S e x FMU

1 0 01 0 0

4 3

3 9

1 91 0 0

4 7

4 2

1 11 0 0

4 7

4 6

71 0 0

5 1

3 4

1 51 0 0

Perc

ent

0

1 0

2 0

3 0

4 0

5 0

6 0

7 0

8 0

9 0

1 0 0

M o n th0 3 -M a r 0 5 -M a y 0 7 -J u l 0 9 -S e p 1 1 -N o v

n = 4 433 802 1304 829

B.

Per

cent

93

Figure 78. Spot length-weight relationships in Chesapeake Bay 2002-2006 as calculated by powerregression for sexes combined (A) and separately (B).

W e ig h t(g ) = 0 .0 0 8 * L e n g th (c m )**3 .2 5 8 (n = 3 4 1 3 )

Wei

ght(g

)

0

1 0 0

2 0 0

3 0 0

4 0 0

5 0 0

6 0 0

F o r k L e n g th (c m )

0 1 0 2 0 3 0 4 0

A.

F em ales - W eig h t (g ) = 0 .0076 * L en g th (cm )* * 3 .2742 (n = 1579)

M ales - W eig h t (g ) = 0 .0087 * L en g th (cm )* *3 .2296 (n = 1299)

Wei

ght(g

)

0

1 0 0

2 0 0

3 0 0

4 0 0

5 0 0

6 0 0

F o r k L e n g th (c m )

0 1 0 2 0 3 0 4 0

B.

94

Figure 79. Spot maturity schedule in Chesapeake Bay 2002-2006 combined, by sex.

5 0 % m a tu r ity

9 9 % m a tu r ity

S E X FM

Prob

abili

ty o

f Mat

urity

0 .0

0 .1

0 .2

0 .3

0 .4

0 .5

0 .6

0 .7

0 .8

0 .9

1 .0

F o rk L e n g th (c m )0 1 0 2 0 3 0 4 0

95

96

Figure 80. Striped bass minimum trawlable abundance estimates in numbers (A) and biomass (B) in Chesapeake Bay2002-2006.

R e g io n V a - L o w V a - U p p M d - L o w M d - M id M d - U p p

Min

imum

Tra

wla

ble

Num

ber

0

1 ,0 0 0 ,0 0 0

2 ,0 0 0 ,0 0 0

3 ,0 0 0 ,0 0 0

4 ,0 0 0 ,0 0 0

M o n t h

Y e a r2 0 0 2 2 0 0 3 2 0 0 4 2 0 0 5 2 0 0 6

M a r M a y J u l S e p N o v M a r M a y J u l S e p N o v M a r M a y J u l S e p N o v M a r M a y J u l S e p N o v M a r M a y J u l S e p N o v

A.

R e g io n V a - L o w V a - U p p M d - L o w M d - M id M d - U p p

Min

imum

Tra

wla

ble

Bio

mas

s (k

g)

0

1 ,0 0 0 ,0 0 0

2 ,0 0 0 ,0 0 0

3 ,0 0 0 ,0 0 0

M o n t h

Y e a r2 0 0 2 2 0 0 3 2 0 0 4 2 0 0 5 2 0 0 6

M a r M a y J u l S e p N o v M a r M a y J u l S e p N o v M a r M a y J u l S e p N o v M a r M a y J u l S e p N o v M a r M a y J u l S e p N o v

B.

97

Mar

chJu

lySe

ptem

ber

Nov

embe

rM

ay

Figu

re 8

1. A

bund

ance

(num

ber p

er h

ecta

re s

wep

t) of

stri

ped

bass

in C

hesa

peak

e Ba

y, 2

002.

98

Mar

chJu

lySe

ptem

ber

Nov

embe

rM

ay

Figu

re 8

2. A

bund

ance

(num

ber p

er h

ecta

re s

wep

t) of

stri

ped

bass

in C

hesa

peak

e Ba

y, 2

003.

99

Mar

chJu

lySe

ptem

ber

Nov

embe

rM

ay

Figu

re 8

3. A

bund

ance

(num

ber p

er h

ecta

re s

wep

t) of

stri

ped

bass

in C

hesa

peak

e Ba

y, 2

004.

100

Mar

chJu

lySe

ptem

ber

Nov

embe

rM

ay

Figu

re 8

4. A

bund

ance

(num

ber p

er h

ecta

re s

wep

t) of

stri

ped

bass

in C

hesa

peak

e Ba

y, 2

005.

101

Mar

chJu

lySe

ptem

ber

Nov

embe

rM

ay

Figu

re 8

5. A

bund

ance

(num

ber p

er h

ecta

re s

wep

t) of

stri

ped

bass

in C

hesa

peak

e Ba

y, 2

006.

102

Figure 86. Striped bass length-frequency in Chesapeake Bay 2002-2006.

2 0 0 2

0

1 0

2 0

3 0

F o r k L e n g t h ( m m )0 5 0 1 0 0 1 5 0 2 0 0 2 5 0 3 0 0 3 5 0 4 0 0 4 5 0 5 0 0 5 5 0 6 0 0 6 5 0 7 0 0 7 5 0 8 0 0 8 5 0 9 0 0 9 5 0 1 0 0 0

2 0 0 3

0

1 0

2 0

3 0

4 0

5 0

F o r k L e n g t h ( m m )0 5 0 1 0 0 1 5 0 2 0 0 2 5 0 3 0 0 3 5 0 4 0 0 4 5 0 5 0 0 5 5 0 6 0 0 6 5 0 7 0 0 7 5 0 8 0 0 8 5 0 9 0 0 9 5 0 1 0 0 0

2 0 0 4

0

1 0

2 0

3 0

4 0

5 0

F o r k L e n g t h ( m m )0 5 0 1 0 0 1 5 0 2 0 0 2 5 0 3 0 0 3 5 0 4 0 0 4 5 0 5 0 0 5 5 0 6 0 0 6 5 0 7 0 0 7 5 0 8 0 0 8 5 0 9 0 0 9 5 0 1 0 0 0

2 0 0 5

0

5 0

1 0 0

1 5 0

2 0 0

F o r k L e n g t h ( m m )0 5 0 1 0 0 1 5 0 2 0 0 2 5 0 3 0 0 3 5 0 4 0 0 4 5 0 5 0 0 5 5 0 6 0 0 6 5 0 7 0 0 7 5 0 8 0 0 8 5 0 9 0 0 9 5 0 1 0 0 0

2 0 0 6

01 02 03 04 05 06 07 0

F o r k L e n g t h ( m m )0 5 0 1 0 0 1 5 0 2 0 0 2 5 0 3 0 0 3 5 0 4 0 0 4 5 0 5 0 0 5 5 0 6 0 0 6 5 0 7 0 0 7 5 0 8 0 0 8 5 0 9 0 0 9 5 0 1 0 0 0

Exp

ande

d N

umbe

r

103

Figure 87. Striped bass age-structure in Chesapeake Bay 2002-2006.2 0 0 2

0

1 6 31 5 7

3 4 2 8

4

5 1

1 33

91 2 2 0 0 0 0

01 02 03 04 05 06 07 08 09 0

1 0 01 1 01 2 01 3 01 4 01 5 01 6 01 7 0

A g e ( Y e a r C l a s s )

0 ( 20 02 )

1 ( 20 01 )

2 ( 20 00 )

3 ( 19 99 )

4 ( 19 98 )

5 ( 19 97 )

6 ( 1996 )

7 ( 1995 )

8 ( 1994 )

9 ( 1993 )

10 (199 2)

11 (199 1)

12 (199 0)

1 3 (1989)

1 4 (1988)

1 5 (1987)

1 6 (1986)

2 0 0 3

2 5

2 5 4

1 6 7

7 6

1 8 2 24 2

2 11 0

2 51 0 3 0 0 0

0

1 0 0

2 0 0

3 0 0

A g e ( Y e a r C l a s s )

0 ( 20 03 )

1 ( 20 02 )

2 ( 20 01 )

3 ( 20 00 )

4 ( 19 99 )

5 ( 19 98 )

6 ( 1997 )

7 ( 1996 )

8 ( 1995 )

9 ( 1994 )

10 (199 3)

11 (199 2)

12 (199 1)

1 3 (1990)

1 4 (1989)

1 5 (1988)

1 6 (1987)

2 0 0 4

2

2 7 3

9 3

2 9 0

9 6

1 9 1 8 2 1 2 58 7 9 1 0 1 2 2

0

1 0 0

2 0 0

3 0 0

A g e ( Y e a r C l a s s )

0 ( 20 04 )

1 ( 20 03 )

2 ( 20 02 )

3 ( 20 01 )

4 ( 20 00 )

5 ( 19 99 )

6 ( 1998 )

7 ( 1997 )

8 ( 1996 )

9 ( 1995 )

10 (199 4)

11 (199 3)

12 (199 2)

1 3 (1991)

1 4 (1990)

1 5 (1989)

1 6 (1988)

2 0 0 5

1

7 3

1 7 3 4

9 9

1 4 9

5 0

61 4

41 4 7 2 4 0 0 0 0

0

2 5

5 0

7 5

1 0 0

1 2 5

1 5 0

1 7 5

2 0 0

1 7 0 0

1 8 0 0

A g e ( Y e a r C l a s s )

0 (200 5 )

1 (200 4 )

2 (2003 )

3 (200 2 )

4 (200 1 )

5 (200 0 )

6 (199 9 )

7 (199 8 )

8 (1997 )

9 (1996 )

10 (199 5)

1 1 (19 9 4)

1 2 (19 9 3)

13 (19 92)

1 4 (19 91)

1 5 (19 90)

16 (198 9)

2 0 0 6

0

5 0

1 5 0

5 5 1

1 3

4 7

1 9 1 3 5 1 01 9

6 9 4 1 0 00

2 5

5 0

7 5

1 0 0

1 2 5

1 5 0

1 7 5

2 0 0

5 0 0

6 0 0

A g e ( Y e a r C l a s s )

0 (200 6 )

1 (200 5 )

2 (2004 )

3 (200 3 )

4 (200 2 )

5 (200 1 )

6 (2000 )

7 (1999 )

8 (1998 )

9 (199 7 )

10 (19 9 6)

11 (19 95)

1 2 (199 4)

1 3 (199 3)

1 4 (199 2)

1 5 (19 91)

1 6 (19 90)

Exp

ande

d N

umbe

r

104

Figure 88. Striped bass sex-ratios in Chesapeake Bay 2002-2006, by year (A), month (B), age (C).

Sex FMU

31.9

63.34.8

100.0

39.2

59.3

100.0

40.9

53.0

6.0

99.9

45.2

53.2

100.0

31.6

67.3

100.0

Perc

ent

0

10

20

30

40

50

60

70

80

90

100

Year

2002 2003 2004 2005 2006

n = 337 467 584 724 535

A.

Per

cent

Sex FMU

48.3

48.1

100.0

19.3

77.0

100.0

27.6

68.2

99.9

32.4

66.0

100.1

38.5

60.9

100.0

Perc

ent

0

10

20

30

40

50

60

70

80

90

100

Month

03-Mar 05-May 07-Jul 09-Sep 11-Nov

n = 1137 350 211 149 800

B.

Per

cent

Sex FMU

19

23

58

100.0

40

41

19

100.0

48

52

100.1

48

52

100.0

23

77

100.0

12

88

100.0

7

93

100.0

19

81

100.0

28

72

100.0

15

83

100.0

22

78

100.0

36

64

100.0

29

71

100.0

100

100.0

100

100.0

50

50

100.0

50

50

100.0Percent SUM

0

10

20

30

40

50

60

70

80

90

100

AGE

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16

n = 5 263 725 363 256 83 57 73 44 38 30 14 7 3 1 2 2

C.

Per

cent

105

Figure 89. Striped bass length-weight relationships in Chesapeake Bay 2002-2006 as calculated by power regression forsexes combined (A) and separately (B).

W e ig h t(g ) = 0 .0 0 9 3 * L e n g th (c m )**3 .0 6 6 2 (n = 2 6 8 9 )

Wei

ght(g

)

0

1 0 0 0

2 0 0 0

3 0 0 0

4 0 0 0

5 0 0 0

6 0 0 0

7 0 0 0

8 0 0 0

9 0 0 0

1 0 0 0 0

1 1 0 0 0

1 2 0 0 0

1 3 0 0 0

1 4 0 0 0

1 5 0 0 0

1 6 0 0 0

F o rk L e n g th (c m )

0 1 0 2 0 3 0 4 0 5 0 6 0 7 0 8 0 9 0 1 0 0 1 1 0

A.

F e m a le s - W e ig h t(g ) = 0 .0 0 8 5 * L e n g th (c m )**3 .0 8 5 5 (n = 9 6 6 )

M a le s - W e ig h t(g ) = 0 .0 0 9 3 * L e n g th (c m )**3 .0 6 8 1 (n = 1 6 2 4 )

Wei

ght(g

)

0

1 0 0 0

2 0 0 0

3 0 0 0

4 0 0 0

5 0 0 0

6 0 0 0

7 0 0 0

8 0 0 0

9 0 0 0

1 0 0 0 0

1 1 0 0 0

1 2 0 0 0

1 3 0 0 0

1 4 0 0 0

1 5 0 0 0

1 6 0 0 0

F o rk L e n g th (c m )

0 1 0 2 0 3 0 4 0 5 0 6 0 7 0 8 0 9 0 1 0 0 1 1 0

B.

106

Figure 40. Striped bass diet in Chesapeake Bay 2002-2005 combined.

Figure 90. Striped bass maturity schedule in Chesapeake Bay 2002-2006 combined, by sex.

50% matur ity

99% matur ity

S E X FM

Prob

abili

ty o

f Mat

urity

0 .0

0 .1

0 .2

0 .3

0 .4

0 .5

0 .6

0 .7

0 .8

0 .9

1 .0

F o rk L e n g th (c m )

0 10 20 30 40 50 60 70 80 90 100 110

Figure 91. Striped bass diet in Chesapeake Bay 2002-2006 combined.

107

108

Figure 92. Summer flounder minimum trawlable abundance estimates in numbers (A) and biomass (B) in ChesapeakeBay 2002-2006.

R e g io n V a - L o w V a - U p p M d - L o w M d - M id M d - U p p

Min

imum

Tra

wla

ble

Num

ber

0

1 0 0 ,0 0 0

2 0 0 ,0 0 0

3 0 0 ,0 0 0

4 0 0 ,0 0 0

5 0 0 ,0 0 0

6 0 0 ,0 0 0

7 0 0 ,0 0 0

8 0 0 ,0 0 0

9 0 0 ,0 0 0

1 ,0 0 0 ,0 0 0

1 ,1 0 0 ,0 0 0

1 ,2 0 0 ,0 0 0

1 ,3 0 0 ,0 0 0

1 ,4 0 0 ,0 0 0

1 ,5 0 0 ,0 0 0

1 ,6 0 0 ,0 0 0

M o n t h

Y e a r2 0 0 2 2 0 0 3 2 0 0 4 2 0 0 5 2 0 0 6

M a r M a y J u l S e p N o v M a r M a y J u l S e p N o v M a r M a y J u l S e p N o v M a r M a y J u l S e p N o v M a r M a y J u l S e p N o v

A.

R e g io n V a - L o w V a - U p p M d - L o w M d - M id M d - U p p

Min

imum

Tra

wla

ble

Bio

mas

s (k

g)

0

1 0 0 ,0 0 0

2 0 0 ,0 0 0

3 0 0 ,0 0 0

4 0 0 ,0 0 0

5 0 0 ,0 0 0

6 0 0 ,0 0 0

7 0 0 ,0 0 0

8 0 0 ,0 0 0

9 0 0 ,0 0 0

1 ,0 0 0 ,0 0 0

M o n t h

Y e a r2 0 0 2 2 0 0 3 2 0 0 4 2 0 0 5 2 0 0 6

M a r M a y J u l S e p N o v M a r M a y J u l S e p N o v M a r M a y J u l S e p N o v M a r M a y J u l S e p N o v M a r M a y J u l S e p N o v

B.

109

Mar

chJu

lySe

ptem

ber

Nov

embe

rM

ay

Figu

re 9

3. S

ite-s

peci

fic s

umm

er fl

ound

er a

bund

ance

(num

ber p

er h

ecta

re s

wep

t), 2

002.

110

Mar

chJu

lySe

ptem

ber

Nov

embe

rM

ay

Figu

re 9

4. S

ite-s

peci

fic s

umm

er fl

ound

er a

bund

ance

(num

ber p

er h

ecta

re s

wep

t), 2

003.

111

Mar

chJu

lySe

ptem

ber

Nov

embe

rM

ay

Figu

re 9

5. S

ite-s

peci

fic s

umm

er fl

ound

er a

bund

ance

(num

ber p

er h

ecta

re s

wep

t), 2

004.

112

Mar

chJu

lySe

ptem

ber

Nov

embe

rM

ay

Figu

re 9

6. S

ite-s

peci

fic s

umm

er fl

ound

er a

bund

ance

(num

ber p

er h

ecta

re s

wep

t), 2

005.

113

Mar

chJu

lySe

ptem

ber

Nov

embe

rM

ay

Figu

re 9

7. S

ite-s

peci

fic s

umm

er fl

ound

er a

bund

ance

(num

ber p

er h

ecta

re s

wep

t), 2

007.

114

Figure 98. Summer flounder length-frequency in Chesapeake Bay 2002-2006.

2 0 0 2

01 02 03 04 05 06 0

T o ta l L e n g th (m m )0 5 0 1 0 0 1 5 0 2 0 0 2 5 0 3 0 0 3 5 0 4 0 0 4 5 0 5 0 0 5 5 0 6 0 0 6 5 0 7 0 0 7 5 0 8 0 0

2 0 0 3

0

1 0

2 0

3 0

4 0

5 0

T o ta l L e n g th (m m )0 5 0 1 0 0 1 5 0 2 0 0 2 5 0 3 0 0 3 5 0 4 0 0 4 5 0 5 0 0 5 5 0 6 0 0 6 5 0 7 0 0 7 5 0 8 0 0

2 0 0 4

02 04 06 08 0

1 0 01 2 0

T o ta l L e n g th (m m )0 5 0 1 0 0 1 5 0 2 0 0 2 5 0 3 0 0 3 5 0 4 0 0 4 5 0 5 0 0 5 5 0 6 0 0 6 5 0 7 0 0 7 5 0 8 0 0

2 0 0 5

01 02 03 04 05 06 0

T o ta l L e n g th (m m )0 5 0 1 0 0 1 5 0 2 0 0 2 5 0 3 0 0 3 5 0 4 0 0 4 5 0 5 0 0 5 5 0 6 0 0 6 5 0 7 0 0 7 5 0 8 0 0

2 0 0 6

02 04 06 08 0

1 0 01 2 0

T o ta l L e n g th (m m )0 5 0 1 0 0 1 5 0 2 0 0 2 5 0 3 0 0 3 5 0 4 0 0 4 5 0 5 0 0 5 5 0 6 0 0 6 5 0 7 0 0 7 5 0 8 0 0

Exp

ande

d N

umbe

r

115

Figure 99. Summer flounder age-structure in Chesapeake Bay 2002-2006.

2 0 0 2

3 7 7

1 1 58 6 9 1

2 6 2 2 2 01 1 2 0 0 0

0

1 0 0

2 0 0

3 0 0

4 0 0

A g e ( Y e a r C l a s s )

0 (2002)

1 (2001)

2 (2000)

3 (1999)

4 (1998)

5 (1997)

6 (1996)

7 (1995)

8 (1994)

9 (1993 )

10 (1992 )

11 (1991 )

12 (1990 )

2 0 0 3

1 5 0 1 5 3

4 53 2

6 9

1 3 9 5 2 0 0 0 00

1 02 03 04 05 06 07 08 09 0

1 0 01 1 01 2 01 3 01 4 01 5 01 6 0

A g e ( Y e a r C l a s s )

0 (2003)

1 (2002)

2 (2001)

3 (2000)

4 (1999)

5 (1998)

6 (1997)

7 (1996)

8 (1995)

9 (1994 )

10 (1993 )

11 (1992 )

12 (1991 )

2 0 0 4

4 1 1

1 1 4 1 0 0

2 7

7 13 6

1 3 2 6 1 0 0 20

1 0 0

2 0 0

3 0 0

4 0 0

5 0 0

A g e ( Y e a r C l a s s )

0 (2004)

1 (2003)

2 (2002)

3 (2001)

4 (2000)

5 (1999)

6 (1998)

7 (1997)

8 (1996)

9 (1995 )

10 (1994 )

11 (1993 )

12 (1992 )

2 0 0 5

2 0 2

2 9 3

8 87 8

2 8 2 4 2 14 2 5 0 0 0

0

1 0 0

2 0 0

3 0 0

A g e ( Y e a r C l a s s )

0 (2005)

1 (2004)

2 (2003)

3 (2002)

4 (2001)

5 (2000)

6 (1999)

7 (1998)

8 (1997)

9 (1996 )

10 (1995 )

11 (1994 )

12 (1993 )

2 0 0 6

4 4 6

1 4 9

9 76 0 7 0

2 4 1 5 1 7 3 1 2 1 00

1 0 0

2 0 0

3 0 0

4 0 0

5 0 0

A g e ( Y e a r C la s s )

0 (2006)

1 (2005)

2 (2004)

3 (2003)

4 (2002)

5 (2001)

6 (2000)

7 (1999)

8 (1998)

9 (1997 )

10 (1996 )

11 (1995 )

12 (1994 )

Exp

ande

d N

umbe

r

116

Figure 100. Summer flounder sex-ratios in Chesapeake Bay 2002-2006, by month (A), region (B), age (C).

Sex FMU

76.9

15.7

7.4

100

77.2

20.1

100

76.3

20.6

100

68.0

29.0

100

58.9

37.9

100P

erce

nt

0

10

20

30

40

50

60

70

80

90

100

M onth03-M ar 05-M ay 07-Jul 09-Se p 11-Nov

n = 242 336 473 959 1028

A.P

erce

nt

Sex FMU

51.1

48.9

100.0

58.3

36.84.9

100.0

61.3

37.1

100.1

67.1

27.85.0

99.9

68.7

28.8

100.0

Per

cent

0

10

20

30

40

50

60

70

80

90

100

Re gion1 M d-Upp 2 M d-M id 3 M d-Low 4 Va-Upp 5 Va-Low

B.

n = 14 163 285 1012 1564

Per

cent

Sex FMU

48

47

5

100.0

64

32

4

100.1

93

7

100.0

964

100.0

95

5

100.0

96

4

100.0

92

8

100.0

100

100.0

93

7

100.0

89

11

100.0

100

100.0

100

100.0

50

50

100.0Percent SUM

0

10

20

30

40

50

60

70

80

90

100

AGE0 1 2 3 4 5 6 7 8 9 10 11 12

C.

n = 1114 716 354 276 194 114 78 28 14 9 2 1 2

Per

cent

117

Figure 101. Summer flounder length-weight relationships in Chesapeake Bay 2002-2005 as calculated by power regressionfor sexes combined (A) and separately (B).

Weight(g) = 0.004 * Length(cm)**3.2528 (n = 3078)

Wei

ght(g

)

0

1000

2000

3000

4000

5000

6000

Fork Length(cm)

10 20 30 40 50 60 70 80

A.

Females - W eight(g) = 0.0038 * Length(cm)**3.2678 (n = 2115)

Males - W eight(g) = 0.006 * Length(cm)**3.1414 (n = 854)

Wei

ght(g

)

0

1000

2000

3000

4000

5000

6000

Fork Length(cm)

10 20 30 40 50 60 70 80

B.

118

Figure 102. Summer flounder maturity schedule in Chesapeake Bay 2002-2006 combined, by sex.

Figure 47. Summer flounder diet in Chesapeake Bay 2002-2005 combined.

50% maturity

99% maturity

SEX FM

Prob

abili

ty o

f Mat

urity

0 .0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1.0

Total Length (cm )10 20 30 40 50 60 70 80

Figure 103. Summer flounder diet in Chesapeake Bay 2002-2006 combined.

119

120

Figure 104. Weakfish minimum trawlable abundance estimates in numbers (A) and biomass (B) in Chesapeake Bay2002-2006.

R e g io n V a - L o w V a - U p p M d - L o w M d - M id M d - U p p

Min

imum

Tra

wla

ble

Num

ber

0

1 ,0 0 0 ,0 0 0

2 ,0 0 0 ,0 0 0

3 ,0 0 0 ,0 0 0

4 ,0 0 0 ,0 0 0

5 ,0 0 0 ,0 0 0

M o n t h

Y e a r2 0 0 2 2 0 0 3 2 0 0 4 2 0 0 5 2 0 0 6

M a r M a y J u l S e p N o v M a r M a y J u l S e p N o v M a r M a y J u l S e p N o v M a r M a y J u l S e p N o v M a r M a y J u l S e p N o v

A.

R e g io n V a - L o w V a - U p p M d - L o w M d - M id M d - U p p

Min

imum

Tra

wla

ble

Bio

mas

s (k

g)

0

1 0 0 ,0 0 0

2 0 0 ,0 0 0

3 0 0 ,0 0 0

4 0 0 ,0 0 0

5 0 0 ,0 0 0

6 0 0 ,0 0 0

7 0 0 ,0 0 0

8 0 0 ,0 0 0

9 0 0 ,0 0 0

1 ,0 0 0 ,0 0 0

M o n t h

Y e a r2 0 0 2 2 0 0 3 2 0 0 4 2 0 0 5 2 0 0 6

M a r M a y J u l S e p N o v M a r M a y J u l S e p N o v M a r M a y J u l S e p N o v M a r M a y J u l S e p N o v M a r M a y J u l S e p N o v

B.

121

Mar

chJu

lySe

ptem

ber

Nov

embe

rM

ay

Figu

re 1

05. S

ite-s

peci

fic w

eakf

ish

abun

danc

e (n

umbe

r per

hec

tare

sw

ept),

200

2.

122

Mar

chJu

lySe

ptem

ber

Nov

embe

rM

ay

Figu

re 1

06. S

ite-s

peci

fic w

eakf

ish

abun

danc

e (n

umbe

r per

hec

tare

sw

ept),

200

3.

123

Mar

chJu

lySe

ptem

ber

Nov

embe

rM

ay

Figu

re 1

07. S

ite-s

peci

fic w

eakf

ish

abun

danc

e (n

umbe

r per

hec

tare

sw

ept),

200

4.

124

Mar

chJu

lySe

ptem

ber

Nov

embe

rM

ay

Figu

re 1

08. S

ite-s

peci

fic w

eakf

ish

abun

danc

e (n

umbe

r per

hec

tare

sw

ept),

200

5.

125

Mar

chJu

lySe

ptem

ber

Nov

embe

rM

ay

Figu

re 1

09. S

ite-s

peci

fic w

eakf

ish

abun

danc

e (n

umbe

r per

hec

tare

sw

ept),

200

6.

126

Figure 110. Weakfish length-frequency in Chesapeake Bay 2002-2006.

2 0 0 2

02 04 06 08 0

1 0 01 2 01 4 0

T o ta l L e n g th (m m )0 5 0 1 0 0 1 5 0 2 0 0 2 5 0 3 0 0 3 5 0 4 0 0 4 5 0 5 0 0 5 5 0 6 0 0 6 5 0 7 0 0

2 0 0 3

0

1 0 0

2 0 0

3 0 0

T o ta l L e n g th (m m )0 5 0 1 0 0 1 5 0 2 0 0 2 5 0 3 0 0 3 5 0 4 0 0 4 5 0 5 0 0 5 5 0 6 0 0 6 5 0 7 0 0

2 0 0 4

0

1 0 0

2 0 0

3 0 0

4 0 0

5 0 0

T o ta l L e n g th (m m )0 5 0 1 0 0 1 5 0 2 0 0 2 5 0 3 0 0 3 5 0 4 0 0 4 5 0 5 0 0 5 5 0 6 0 0 6 5 0 7 0 0

2 0 0 5

0

1 0 0

2 0 0

3 0 0

T o ta l L e n g th (m m )0 5 0 1 0 0 1 5 0 2 0 0 2 5 0 3 0 0 3 5 0 4 0 0 4 5 0 5 0 0 5 5 0 6 0 0 6 5 0 7 0 0

2 0 0 6

02 04 06 08 0

1 0 01 2 01 4 01 6 01 8 0

T o ta l L e n g th (m m )0 5 0 1 0 0 1 5 0 2 0 0 2 5 0 3 0 0 3 5 0 4 0 0 4 5 0 5 0 0 5 5 0 6 0 0 6 5 0 7 0 0

Exp

ande

d N

umbe

r

127

Figure 111. Weakfish age-structure in Chesapeake Bay 2002-2006.

2 0 0 2

5 1 9

6 2 9

2 9 1

1 3 2

6 29 3

0

1 0 0

2 0 0

3 0 0

4 0 0

5 0 0

6 0 0

7 0 0

A g e ( Y e a r C la s s )

0 (2002)

1 (2001 )

2 (2000)

3 (1999)

4 (1998)

5 (1997)

6 (1996 )

2 0 0 3

7 0 9

4 4 1

5 7 7

1 0 3

6 0 00

1 0 0

2 0 0

3 0 0

4 0 0

5 0 0

6 0 0

7 0 0

8 0 0

A g e ( Y e a r C la s s )

0 (2003)

1 (2002 )

2 (2001 )

3 (2000 )

4 (1999 )

5 (1998 )

6 (1997 )

2 0 0 4

4 0 5

1 9 6 1

8 8 6

3 9 5

1 0 00

2 0 0

4 0 0

6 0 0

8 0 0

1 0 0 0

1 2 0 0

1 4 0 0

1 6 0 0

1 8 0 0

2 0 0 0

A g e ( Y e a r C la s s )

0 (2004)

1 (2003 )

2 (2002 )

3 (2001 )

4 (2000 )

5 (1999 )

6 (1998 )

2 0 0 5

6 6 1 6 9 4

1 1 4 2

1 8 5

8 0 00

1 0 02 0 0

3 0 04 0 05 0 0

6 0 07 0 08 0 0

9 0 01 0 0 01 1 0 0

1 2 0 0

A g e ( Y e a r C la s s )

0 (2005)

1 (2004)

2 (2003 )

3 (2002 )

4 (2001 )

5 (2000 )

6 (1999)

Exp

ande

d N

umbe

r

2 0 0 6

5 0 6 5 2 8

3 2 5

9 8

4 0 00

1 0 0

2 0 0

3 0 0

4 0 0

5 0 0

6 0 0

A g e ( Y e a r C la s s )

0 (2006)

1 (2005)

2 (2004)

3 (2003)

4 (2002)

5 (2001)

6 (2000)

128

Figure 112. Weakfish sex-ratios in Chesapeake Bay 2002-2005, by year (A), region (B), age (C).

Sex FMU

47.8

43.5

8.6

99.9

49.8

42.7

7.5

100.0

55.9

40.7

100.0

54.7

38.0

7.3

100.0

52.6

37.0

10.4

100.0

Perc

ent

0

10

20

30

40

50

60

70

80

90

100

Year

2002 2003 2004 2005 2006

A.

n = 803 626 1108 1115 728P

erce

nt

Sex FMU

32.6

47.0

20.4

100.0

43.1

35.9

20.9

99.9

43.5

40.1

16.5

100.1

55.8

39.24.9

99.9

53.5

41.74.8

100.0

Perc

ent

0

10

20

30

40

50

60

70

80

90

100

Region

1 Md-Upp 2 Md-Mid 3 Md-Low 4 Va-Upp 5 Va-Low

B.

n = 90 264 532 1830 1664

Per

cent

Sex FMU

42.5

33.0

24.5

100.0

59.2

40.6

100.1

55.4

44.5

100.0

44.6

55.4

100.0

38.1

61.9

100.0

66.7

33.3

100.0

33.3

66.7

100.0Percent SUM

0

10

20

30

40

50

60

70

80

90

100

AGE

0 1 2 3 4 5 6

n = 1112 1170 964 231 34 9 3

C.

Per

cent

129

Figure 113. Weakfish length-weight relationships in Chesapeake Bay 2002-2006 as calculated by power regressionfor sexes combined (A) and separately (B).

Weight(g) = 0.0056 * Length(cm)**3.1662 (n = 4459)

Wei

ght(g

)

0

1000

2000

3000

T otal Length(cm)

0 10 20 30 40 50 60 70

A.

Females - W eight(g) = 0.0053 * Length(cm)**3.1854 (n = 2355)

Males - W eight(g) = 0.007 * Length(cm)**3.1006 (n = 1630)

Wei

ght(g

)

0

1000

2000

3000

T otal Length(cm)

0 10 20 30 40 50 60 70

B.

130

Figure 53. Weakfish diet in Chesapeake Bay 2002-2005 combined.

50% maturity

99% maturity

SEX FM

Prob

abili

ty o

f Mat

urity

0 .0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1.0

T otal Length (cm)0 10 20 30 40 50 60 70

Figure 114. Weakfish maturity schedule in Chesapeake Bay 2002-2006 combined, by sex.

Figure 115. Weakfish diet in Chesapeake Bay 2002-2006 combined.

131

132

Figure 116. White perch minimum trawlable abundance estimates in numbers (A) and biomass (B) in Chesapeake Bay2002-2006.

R e g io n V a - L o w V a - U p p M d - L o w M d - M id M d - U p p

Min

imum

Tra

wla

ble

Num

ber

0

1 0 ,0 0 0 ,0 0 0

2 0 ,0 0 0 ,0 0 0

3 0 ,0 0 0 ,0 0 0

4 0 ,0 0 0 ,0 0 0

M o n t h

Y e a r2 0 0 2 2 0 0 3 2 0 0 4 2 0 0 5 2 0 0 6

M a r M a y J u l S e p N o v M a r M a y J u l S e p N o v M a r M a y J u l S e p N o v M a r M a y J u l S e p N o v M a r M a y J u l S e p N o v

A.

R e g io n V a - L o w V a - U p p M d - L o w M d - M id M d - U p p

Min

imum

Tra

wla

ble

Bio

mas

s (k

g)

0

1 ,0 0 0 ,0 0 0

2 ,0 0 0 ,0 0 0

3 ,0 0 0 ,0 0 0

4 ,0 0 0 ,0 0 0

5 ,0 0 0 ,0 0 0

6 ,0 0 0 ,0 0 0

3 0 ,0 0 0 ,0 0 0

3 5 ,0 0 0 ,0 0 0

M o n t h

Y e a r2 0 0 2 2 0 0 3 2 0 0 4 2 0 0 5 2 0 0 6

M a r M a y J u l S e p N o v M a r M a y J u l S e p N o v M a r M a y J u l S e p N o v M a r M a y J u l S e p N o v M a r M a y J u l S e p N o v

B.

133

Mar

chJu

lySe

ptem

ber

Nov

embe

rM

ay

Figu

re 1

17. F

igur

es 1

17.

Site

-spe

cific

whi

te p

erch

abu

ndan

ce (n

umbe

r per

hec

tare

sw

ept),

2002

.

134

Mar

chJu

lySe

ptem

ber

Nov

embe

rM

ay

Figu

re 1

18. S

ite-s

peci

fic w

hite

per

ch a

bund

ance

(num

ber p

er h

ecta

re s

wep

t),20

03.

135

Mar

chJu

lySe

ptem

ber

Nov

embe

rM

ay

Figu

re 1

19. S

ite-s

peci

fic w

hite

per

ch a

bund

ance

(num

ber p

er h

ecta

re s

wep

t),20

04.

136

Mar

chJu

lySe

ptem

ber

Nov

embe

rM

ay

Figu

re 1

20. S

ite-s

peci

fic w

hite

per

ch a

bund

ance

(num

ber p

er h

ecta

re s

wep

t),20

05.

137

Mar

chJu

lySe

ptem

ber

Nov

embe

rM

ay

Figu

re 1

21. S

ite-s

peci

fic w

hite

per

ch a

bund

ance

(num

ber p

er h

ecta

re s

wep

t),20

06.

138

Figure 122. White perch length-frequency in Chesapeake Bay 2002-2006.

2 0 0 2

0

2 0 0

4 0 0

6 0 0

8 0 0

1 0 0 0

1 2 0 0

F o rk L e n g th (m m )0 5 0 1 0 0 1 5 0 2 0 0 2 5 0 3 0 0 3 5 0 4 0 0

2 0 0 3

0

1 0 0

2 0 0

3 0 0

4 0 0

5 0 0

6 0 0

F o rk L e n g th (m m )0 5 0 1 0 0 1 5 0 2 0 0 2 5 0 3 0 0 3 5 0 4 0 0

2 0 0 4

02 0 04 0 06 0 08 0 0

1 0 0 01 2 0 01 4 0 01 6 0 0

F o r k L e n g th (m m )0 5 0 1 0 0 1 5 0 2 0 0 2 5 0 3 0 0 3 5 0 4 0 0

2 0 0 5

0

2 0 0

4 0 0

6 0 0

8 0 0

1 0 0 0

1 2 0 0

F o r k L e n g th (m m )0 5 0 1 0 0 1 5 0 2 0 0 2 5 0 3 0 0 3 5 0 4 0 0

2 0 0 6

0

5 0 0

1 0 0 0

1 5 0 0

2 0 0 0

F o r k L e n g th (m m )0 5 0 1 0 0 1 5 0 2 0 0 2 5 0 3 0 0 3 5 0 4 0 0

Exp

ande

d N

umbe

r

139

Figure 123. White perch age-structure in Chesapeake Bay 2002-2005 (2006 ages not yet assigned).2 0 0 2

01 0 02 0 03 0 04 0 05 0 06 0 07 0 08 0 09 0 0

1 0 0 01 1 0 01 2 0 01 3 0 01 4 0 01 5 0 01 6 0 01 7 0 0

A g e ( Y e a r C la s s )

0 (2002)

1 (2001)

2 (2000)

3 (1999)

4 (1998)

5 (1997)

6 (19 96)

7 (19 95)

8 (19 94)

9 (19 93)

10 (1992)

11 (1991)

12 (1990)

13 (1989)

14 (1988)

15 (1987)

16 (1986)

2 0 0 3

4 3

2 3 3

4 3 33 8 4

2 6 2 2 6 1

6 4 7

2 5 8 2 9 0

8 4 0

1 6 4 2 8 4 0 00

1 0 0

2 0 0

3 0 0

4 0 0

5 0 0

6 0 0

7 0 0

8 0 0

9 0 0

A g e (Y e a r C la s s )

0 (2003)

1 (2002)

2 (2001)

3 (2000)

4 (1999)

5 (1998)

6 (1997)

7 (1996)

8 (1995)

9 (1994)

10 (1993)

11 (1992)

12 (1991)

13 (1990)

14 (1989)

15 (1988)

16 (1987)

2 0 0 4

0

1 0 0 0

2 0 0 0

3 0 0 0

A g e ( Y e a r C la s s )

0 (20 04)

1 (2003)

2 (20 02)

3 (20 01)

4 (2000)

5 (1999)

6 (19 98)

7 (19 97)

8 (1996)

9 (1995)

10 (1994)

11 (1993)

12 (1992)

13 (1991)

14 (1990)

15 (1989)

16 (1988)

2 0 0 5

0 2 7

9 1 3

7 0 8

8 2 4

9 2 4

5 3 86 1 6

7 2 2

9 2 5

9 1

1 9 6

5 1 7

4 2 8 2 00

1 0 0

2 0 0

3 0 0

4 0 0

5 0 0

6 0 0

7 0 0

8 0 0

9 0 0

1 0 0 0

A g e ( Y e a r C la s s )

0 (20 05)

1 (20 04)

2 (20 03)

3 (20 02)

4 (20 01)

5 (20 00)

6 (1999)

7 (1998)

8 (1997)

9 (1996)

10 (1995)

11 (1994)

12 (1993)

13 (1992)

14 (1991)

15 (1990)

16 (1989)

Exp

ande

d N

umbe

r

140

Figure 124. White perch sex-ratios in Chesapeake Bay 2002-2005, by year (A), age (B).

Sex FMU

70.5

28.9

100.0

68.5

31.2

100.0

79.3

20.5

99.9

74.9

24.8

100.0

68.2

31.8

100.0

Per

cent

0

10

20

30

40

50

60

70

80

90

100

Year2002 2003 2004 2005 2006

n = 551 177 356 419 385

A.

Per

cent

Sex FMU

11

84

5

100.1

55

34

12

100.0

76

23

100.0

58

42

100.0

76

24

100.0

72

28

100.0

81

19

100.0

73

27

100.0

70

31

100.0

70

30

100.0

69

31

100.0

92

8

100.0

85

15

100.0

100

100.0

100

100.0

100

100.0Percent SUM

0

10

20

30

40

50

60

70

80

90

100

AGE0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15

n = 6 33 95 79 118 114 219 132 136 248 72 103 68 8 8 2

B.

Per

cent

141

Figure 125. White perch length-weight relationships in Chesapeake Bay 2002-2006 as calculated by power regressionfor sexes combined (A) and separately (B).

Weight(g ) = 0 .0089 * Length(cm )**3 .2231 (n = 1886)

Wei

ght(g

)

0

100

200

300

400

500

600

700

800

Fork Length(cm )

0 10 20 30 40

A.

Females - W eight(g) = 0.0097 * Length(cm)**3.1949 (n = 1403)

Males - W eight(g) = 0.0087 * Length(cm)**3.2227 (n = 464)

Wei

ght(g

)

0

100

200

300

400

500

600

700

800

Fork Length(cm )

0 10 20 30 40

B.

142

Figure 126. White perch maturity schedule in Chesapeake Bay 2002-2006 combined, by sex.

50% maturity

99% maturity

SEX FM

Prob

abili

ty o

f Mat

urity

0 .0

0 .1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1.0

Fork Length (cm )0 10 20 30 40

Figure 127. White perch diet in Chesapeake Bay 2002-2006 combined.

143

Mar

ch

Figu

re 1

28.

Surfa

ce te

mpe

ratu

re in

Che

sape

ake

Bay,

200

2.

July

Sept

embe

rN

ovem

ber

144

Mar

ch

Figu

re 1

29.

Botto

m te

mpe

ratu

re in

Che

sape

ake

Bay,

200

2.

July

Sept

embe

rN

ovem

ber

145

Mar

ch

Figu

re 1

30.

Surfa

ce te

mpe

ratu

re in

Che

sape

ake

Bay,

200

3.

July

Sept

embe

rN

ovem

ber

May

146

Mar

ch

Figu

re 1

31.

Botto

m te

mpe

ratu

re in

Che

sape

ake

Bay,

200

3.

July

Sept

embe

rN

ovem

ber

May

147

Mar

ch

Figu

re 1

32.

Surfa

ce te

mpe

ratu

re in

Che

sape

ake

Bay,

200

4.

July

Sept

embe

rN

ovem

ber

May

148

Mar

ch

Figu

re 1

33.

Botto

m te

mpe

ratu

re in

Che

sape

ake

Bay,

200

4.

July

Sept

embe

rN

ovem

ber

May

149

Mar

ch

Figu

re 1

34.

Surfa

ce te

mpe

ratu

re in

Che

sape

ake

Bay,

200

5.

July

Sept

embe

rN

ovem

ber

May

150

Mar

ch

Figu

re 1

35.

Botto

m te

mpe

ratu

re in

Che

sape

ake

Bay,

200

5.

July

Sept

embe

rN

ovem

ber

May

151

Mar

ch

Figu

re 1

36.

Surfa

ce te

mpe

ratu

re in

Che

sape

ake

Bay,

200

6.

July

Sept

embe

rN

ovem

ber

May

152

Mar

ch

Figu

re 1

37.

Botto

m te

mpe

ratu

re in

Che

sape

ake

Bay,

200

6.

July

Sept

embe

rN

ovem

ber

May

153

Mar

ch

Figu

re 1

38.

Surfa

ce s

alin

ity in

Che

sape

ake

Bay,

200

2.

July

Sept

embe

rN

ovem

ber

154

Mar

ch

Figu

re 1

39.

Botto

m s

alin

ity in

Che

sape

ake

Bay,

200

2.

July

Sept

embe

rN

ovem

ber

155

Mar

chJu

lySe

ptem

ber

Nov

embe

rM

ay

Figu

re 1

40.

Surfa

ce s

alin

ity in

Che

sape

ake

Bay,

200

3.

156

Mar

chJu

lySe

ptem

ber

Nov

embe

rM

ay

Figu

re 1

41.

Botto

m s

alin

ity in

Che

sape

ake

Bay,

200

3.

157

Mar

chJu

lySe

ptem

ber

Nov

embe

rM

ay

Figu

re 1

42.

Surfa

ce s

alin

ity in

Che

sape

ake

Bay,

200

4.

158

Mar

chJu

lySe

ptem

ber

Nov

embe

rM

ay

Figu

re 1

43.

Botto

m s

alin

ity in

Che

sape

ake

Bay,

200

4.

159

Mar

chJu

lySe

ptem

ber

Nov

embe

rM

ay

Figu

re 1

44.

Surfa

ce s

alin

ity in

Che

sape

ake

Bay,

200

5.

160

Mar

chJu

lySe

ptem

ber

Nov

embe

rM

ay

Figu

re 1

45.

Botto

m s

alin

ity in

Che

sape

ake

Bay,

200

5.

161

Mar

chJu

lySe

ptem

ber

Nov

embe

rM

ay

Figu

re 1

46.

Surfa

ce s

alin

ity in

Che

sape

ake

Bay,

200

6.

162

Mar

chJu

lySe

ptem

ber

Nov

embe

rM

ay

Figu

re 1

47.

Botto

m s

alin

ity in

Che

sape

ake

Bay,

200

6.

163

Mar

ch

Figu

re 1

48.

Surfa

ce d

isso

lved

oxy

gen

in C

hesa

peak

e Ba

y, 2

002. Ju

lySe

ptem

ber

Nov

embe

r

164

Mar

ch

Figu

re 1

49.

Botto

m d

isso

lved

oxy

gen

in C

hesa

peak

e Ba

y, 2

002. Ju

lySe

ptem

ber

Nov

embe

r

165

Mar

chJu

lySe

ptem

ber

Nov

embe

rM

ay

Figu

re 1

50.

Surfa

ce d

isso

lved

oxy

gen

in C

hesa

peak

e Ba

y, 2

003.

166

Mar

chJu

lySe

ptem

ber

Nov

embe

rM

ay

Figu

re 1

51.

Botto

m d

isso

lved

oxy

gen

in C

hesa

peak

e Ba

y, 2

003.

167

Mar

chJu

lySe

ptem

ber

Nov

embe

rM

ay

Figu

re 1

52.

Surfa

ce d

isso

lved

oxy

gen

in C

hesa

peak

e Ba

y, 2

004.

168

Mar

chJu

lySe

ptem

ber

Nov

embe

rM

ay

Figu

re 1

53.

Botto

m d

isso

lved

oxy

gen

in C

hesa

peak

e Ba

y, 2

004.

169

Mar

chJu

lySe

ptem

ber

Nov

embe

rM

ay

Figu

re 1

54.

Surfa

ce d

isso

lved

oxy

gen

in C

hesa

peak

e Ba

y, 2

005.

170

Mar

chJu

lySe

ptem

ber

Nov

embe

rM

ay

Figu

re 1

55.

Botto

m d

isso

lved

oxy

gen

in C

hesa

peak

e Ba

y, 2

005.

171

Mar

chJu

lySe

ptem

ber

Nov

embe

rM

ay

Figu

re 1

56.

Surfa

ce d

isso

lved

oxy

gen

in C

hesa

peak

e Ba

y, 2

006.

172

Mar

chJu

lySe

ptem

ber

Nov

embe

rM

ay

Figu

re 1

57.

Botto

m d

isso

lved

oxy

gen

in C

hesa

peak

e Ba

y, 2

006.

173