Fisheries Assessment and Management Synthesis: Lessons for Chesapeake Bay

Describes the basic approaches that are used for stock assessment of the fish and shellfish stocks of the Chesapeake Bay system. The authors summarize the principal methods of stock assessment and fisheries management that have been and are being-applied to Bay fisheries, with particular emphasis on data collection and the use of models. Three case studies of critical species are presented - the striped bass, the blue crab and the Eastern oyster.https://scholarworks.wm.edu/vimsbooks/1168/thumbnail.jp

Computational Decision Support for Socio-Technical Awareness of Land-Use Planning under Complexity—A Dam Resilience Planning Case Study

Land-use planning for modern societies requires technical competence as well as social competence. We therefore propose an integrative solution enabling better land-use planning and management through better-informed decision-making. We adapt a method developed for cross-disciplinary team building to identify the stakeholders and their various objectives and value systems. We use these results to populate artificial societies embedded into a dynamic data analytics framework as a tool to identify, explore, and visualize the challenges resulting from the different objectives and value systems in land-use planning and management. To prove the feasibility of the proposed solution, we present two use cases from the dam resilience planning domain, show how to apply the process and tools, and present the results. The solution is not limited to such use cases but can be generalized to address challenges in socio-technical systems, such as water resource evaluations or climate change effects

The value of applying commercial fishers' experience to designed surveys for identifying characteristics of essential fish habitat for adult summer flounder

Identifying the habitat requirements of marine fish is necessary to conserve and manage their populations, but these requirements are poorly understood for many species. One method of screening for important habitat characteristics is to identify differences in habitat features between areas of high and low fish abundance. We tested the association between abundance of adult summer flounder Paralichthys dentatus and benthic habitat features at two study areas in the Middle Atlantic Bight in summer 2004. The study included trawl and remote-sensing surveys that were designed and conducted with the assistance of commercial fishers. Within each area, a local commercial fisher designated specific locations a priori as productive or unproductive for fishing. Summer flounder abundance, as measured by mean catch per area swept, was significantly greater at sites designated as productive than at sites designated as unproductive (6.5 times greater in Maryland and 4.7 times greater in Rhode Island). These results indicate that summer flounder were attracted consistently to localized habitats that must have had different characteristics than other nearby locations. Habitat variables associated with the substrate (e.g., particle size, bottom shape, and presence of sessile organisms) were measured along trawl paths using underwater video imagery. The measured variables did not explain abundance well, suggesting that microscale characteristics of the substrate did not affect summer flounder distribution. Summer flounder were most abundant at depths of 10-20 m; however, both high and low catch rates occurred in this depth range, indicating that other factors also were important. These results suggest that additional localized variables merit further investigation to determine their importance to summer flounder. This study demonstrates the importance of combining fishers' knowledge and experience with planned surveys to identify essential habitat features for fish

Resilience indicators support valuation of estuarine ecosystem restoration under climate change

Economic valuation of ecological restoration most often encompasses only the most tangible ecosystem service benefits, thereby omitting many difficult‐to‐measure benefits, including those derived from enhanced reliability of ecosystem services. Because climate change is likely to impose novel ecosystem stressors, a typical approach to valuing benefits may fail to capture the contribution of ecosystem resilience to sustaining long‐term benefits. Unfortunately, we generally lack predictive probabilistic models that would enable measurement and valuation of resilience. Therefore, alternative measures are needed to complement monetary values and broaden understanding of restoration benefits. We use a case study of Chesapeake Bay restoration (total maximum daily load) to show that ecosystem service benefits that are typically monetized leave critical information gaps. To address these gaps, we review evidence for ecosystem services that can be quantified or described, including changes in harmful algal bloom risks. We further propose two integrative indicators of estuarine resilience—the extent of submerged aquatic vegetation and spatial distribution of fish. Submerged aquatic vegetation extent is indicative of qualities of ecosystems that promote positive feedbacks to water quality. Broadly distributed fish populations reduce risk by promoting diverse responses to spatially heterogeneous stresses. Our synthesis and new analyses for the Chesapeake Bay suggest that resilience metrics improve understanding of restoration benefits by demonstrating how nutrient and sediment load reductions will alleviate multiple sources of stress, thereby enhancing the system's capacity to absorb or adapt to extreme events or novel stresses