The trophic dynamics of summer flounder (Paralichthys dentatus) in Chesapeake Bay

Data on the trophic dynamics of fishes are needed for management of ecosystems such as Chesapeake Bay. Summer flounder (Paralichthys dentatus) are an abundant seasonal resident of the bay and have the potential to impact foodweb dynamics. Analyses of diet data for late juvenile and adult summer flounder collected from 2002−2006 in Chesapeake Bay were conducted to characterize the role of this flatfish in this estuary and to contribute to our understanding of summer flounder trophic dynamics throughout its range. Despite the diversity of prey, nearly half of the diet comprised mysid shrimp (Neomysis spp.) and bay anchovy (Anchoa mitchilli). Ontogenetic differences in diet and an increase in diet diversity with increasing fish size were documented. Temporal (inter- and intra-annual) changes were also detected, as well as trends in diet reflecting peaks in abundance and diversity of prey. The preponderance of fishes in the diet of summer flounder indicates that this species is an important piscivorous predator in Chesapeake Bay

Spatiotemporal trends and drivers of fish condition in Chesapeake Bay

Measures of condition in fishes are often used to assess the general well-being of fish populations since condition reflects the biotic and abiotic factors experienced by individuals over moderate time scales. Fish condition can also be used as an indicator of ecosystem suitability in the context of ecosystem-based management. From an ecosystem perspective, evaluation of fish condition is best described over multiple spatiotemporal scales and in a multi-species context. This study analyzed 14 yr (2002-2015) of fisheries-independent trawl survey data to evaluate trends in condition for 16 demersal fishes inhabiting Chesapeake Bay, the largest estuary in the USA. Seasonal and spatial variability in condition were inferred from linear mixed-effects models, while dynamic factor analysis (DFA) was used to reveal coherence among and drivers of annual trends in condition across all species and for 3 subgroups representing trophic guilds. Patterns of intra-annual condition varied among species, likely reflecting life history strategies and physiological responses to seasonal environmental conditions, while spatial patterns showed improved condition for both coastal and oligohaline species with increasing distance from their source. Annual trends in condition showed remarkable coherence for all fishes and for species within each trophic guild, suggesting that factors influencing condition-based indicators of ecosystem suitability operate at the community level. Spring mean surface chl a concentration was included in the selected DFA model for nearly all groups (exception: benthivores) and was statistically significant for several species, indicating the importance of bottom-up processes on bay-wide annual fish condition

Spatial differences in estuarine utilization by seasonally resident species in Mid-Atlantic Bight, USA

Climate-driven distributional shifts have been well-documented for fisheries resources along the East Coast of the United States, yet little attention has been given to adjacent estuarine systems. The Chesapeake Bay is the largest estuary in the continental United States and serves as important habitat for a diversity of fishes and invertebrates, many of which are seasonal residents. Survey data indicate that relative abundance of finfish in Chesapeake Bay has diminished substantially, while coastwide stock status has remained unchanged. In response to warming, seasonal estuarine residents may remain in coastal waters or inhabit a northerly estuary, but the extent to which changing environmental conditions may drive exchange between the coastal ocean and estuarine systems remains unresolved. This study analyzed data collected from 2008 to 2019 by three fisheries-independent trawl surveys to explore temporal patterns and associated environmental drivers of the estuarine–coastal ocean exchange in the Mid-Atlantic for eight economically and ecologically important species. Relative habitat utilization of Chesapeake Bay declined for most species, while utilization patterns for Delaware Bay were largely constant or increasing over time. Broad-scale, multispecies analyses of relative habitat utilization time series revealed that the North Atlantic Oscillation (NAO) was an important driver of Chesapeake Bay exchange, but that average Apr/May coastal ocean bottom temperature was significant for Delaware Bay. Collectively, the results demonstrate that several Mid-Atlantic species have altered their estuarine habitat use over time, climate drivers associated with estuarine–coastal ocean exchange operate on different time scales, and that the impacts of warming within the Mid-Atlantic vary spatially

ANNUAL PROGRESS REPORT - 2006 Data collection and analysis in support of single and multispecies stock assessments in Chesapeake Bay: The Chesapeake Bay Multispecies Monitoring and Assessment Program

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

Evaluation of Striped Bass Stocks in Virginia: Monitoring and Tagging Studies, 2022 Progress Report

This report presents the results of striped bass (Morone saxatilis) tagging and monitoring activities in Virginia during the period 1 December 2020 through 30 November 2021. It includes an assessment of the biological characteristics of striped bass taken from the 2021 spring spawning run and estimates of annual survival and fishing mortality based on annual spring tagging. The information contained in this report is required by the Atlantic States Marine Fisheries Commission and is used to implement a coordinated management plan for striped bass in Virginia, and along the eastern seaboard

Evaluation of Striped Bass Stocks in Virginia: Monitoring and Tagging Studies, 2019 Progress Report - 1 December 2018 - 31 November 2019

This report presents the results of striped bass (Morone saxatilis) tagging and monitoring activities in Virginia during the period 1 December 2018 through 31 November 2019. It includes an assessment of the biological characteristics of striped bass taken from the 2019 spring spawning run and estimates of annual survival and fishing mortality based on annual spring tagging. The information contained in this report is required by the Atlantic States Marine Fisheries Commission and is used to implement a coordinated management plan for striped bass in Virginia, and along the eastern seaboard. This report includes 2018 striped bass Benchmark Assessment data

Northeast Area Monitoring and Assessment Program (NEAMAP) Mid-Atlantic Nearshore Trawl Program Pilot Survey Completion Report

Concerns regarding the status of fishery-independent data collection from the continental shelf waters between Cape Hatteras, North Carolina and the U.S. / Canadian border led the Atlantic States Marine Fisheries Commission’s (ASMFC) Management and Science Committee (MSC) to draft a resolution in 1997 calling for the formation the Northeast Area Monitoring and Assessment Program (NEAMAP) (ASMFC 2002). NEAMAP is a cooperative state-federal program modeled after the Southeast Area Monitoring and Assessment Program (SEAMAP), which had been coordinating fishery-independent data collection south of Cape Hatteras since the mid-1980s (Rester 2001). The four main goals of this new program directly address the deficiencies noted by the MSC for this region and include 1) developing fishery-independent surveys where current sampling is either inadequate or absent 2) coordinating data collection amongst existing surveys as well as any new surveys 3) providing for efficient management and dissemination of data and 4) establishing outreach programs (ASMFC 2002). The NEAMAP Memorandum of Understanding was signed by all partner agencies by July 2004

FINAL REPORT - 2007 Data collection and analysis in support of single and multispecies stock assessments in Chesapeake Bay: The Chesapeake Bay Multispecies Monitoring and Assessment Program

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

Response of An Electronic Sensor To Binary Solvent Mixtures in A Simulated Charcoal Bed

A study was performed which evaluated the ability of a charcoal bed breakthrough detector to be utilized under conditions where a binary mixture of solvents was passed through a bed. A Taguchi Gas Sensor (TGS 812) was used. Acetone and toluene were tested in a simulated charcoal bed system both singly and in binary mixtures over a range of concentrations. TGS response to acetone was much greater than to toluene. In addition, acetone achieved the charcoal service life endpoint (ie. 10% of the challenge concentration) more quickly. Toluene concentrations at the 10% breakthrough times for the acetone were insufficient to appreciably affect sensor response. It would thus appear that this detector can be utilized for the detection of a mixture of acetone and toluene if the alarm signal on the detector is preset for acetone. Sensor sensitivities were much weaker than found in a previous study with the same sensor.Master of Science in Public Healt