Challenges, Opportunities, and Innovation in Crustacean Fisheries (hosted by AFS)

Crustaceans, especially shrimp, crabs, and lobsters, support valuable fisheries at local, regional, and global scales. These fisheries range from wild and farmed shrimp, the single most valuable global fishery commodity, to tropical and cold-water lobsters, krill in the waters off Antarctica, and freshwater crabs in China and elsewhere. Crustacean fisheries face many of the same challenges as finfish fisheries including overfishing, habitat loss, disease, and illegal and unreported fishing. Climate change increases uncertainty in our understanding of population dynamics and adds new challenges through thermal stress, range shifts, ocean acidification, and other factors. Crustacean fisheries also present unique challenges for management such as discontinuous growth and limited availability of techniques for aging. Adding to these challenges, most crustacean fisheries are considered “data-poor.” This symposium brings together experts from a wide range of crustacean fisheries to discuss current and emerging challenges, opportunities, and innovation in crustacean fisheries management. We especially encourage presentations on innovative approaches, comparative studies across species or regions, socioeconomic studies, and global perspectives. The symposium invites presentations on topics including but not limited to the following: fisheries management, socioeconomics, life history, stock assessment, population dynamics, trophic interactions, reproductive biology, fishing gear, impacts of climate change, habitat use, genetics and genomics, conservation.

10:10AM The Global Rise of Crustaceans in World Fisheries
  Robert Boenish, Jacob Kritzer, Robert Boenish, Robert Steneck, Wenbin Zhu, Frederick Schram, Doug Rader, Karl-Michael Werner, William Cheung, Jose Ingles, Yongjun Tian, John Mimikakis
Amidst widespread overfishing and climate change, global decapod crustacean (lobsters, crabs, and shrimp) fisheries are growing faster than any other major group. To date, little attention has been given to the socio-biological costs of a shift towards crustaceans. We address this knowledge gap using over six decades (1950-2016) of reported catch and nutrition data to examine spatial taxonomic and economic trends in global crustacean catches. We expand the existing view and suggest that direct and indirect enhancements are facultative to the global rise of crustaceans. Due to intrinsic biological qualities, high productivity, and inefficient capture methods, increased reliance on crustacean fisheries carries both ecological, and socioeconomic implications. Our results suggest there is strong potential for more employment and profit, but also largely unevaluated risks and costs including increased carbon emissions, reduced nutritional yield, weakened socioecological resilience through overdependence, and lower biodiversity. Most negative externalities will disproportionately affect developing countries.
10:30AM An Assessment of Vertical Line Use in Gulf of Maine Fixed Gear Fisheries for Conservation of the Endangered North Atlantic Right Whale
  Nathaniel Willse, Erin Summers, Caitlin Cleaver, Yong Chen
A large threat to the critically endangered North Atlantic right whale (Eubalaena glacialis) is entanglement in fixed gear fishery vertical lines, but the current spatial distribution and variability in vertical lines across the Gulf of Maine is poorly defined. Management measures limiting the strength of vertical lines used in the American Lobster fishery are likely to negatively impact fishing communities, however the line strength requirements of these communities are not well characterized. Analyzing the spatially explicit variables that affect vertical line strength requirements allows nimble management strategies that meet biological management goals while mitigating socio-economic disruption. We will model the breaking strength of lines used by commercial lobster fisheries spatially across the Gulf of Maine and create an index of risk to right whales inhabiting the area. We will measure the load put on lines used in typical American Lobster fishery operations to determine the minimum strength required to fish safely and effectively. We will highlight areas where rope strength reduction is beneficial for whales and provide guidelines for the minimum rope strength necessary for fishery operation to inform management decision goals that include a sustainable lobster fishery, and conservation of right whales.
10:50AM Migratory Movements of Spawning Female Blue Crabs in Louisiana
  Helen Olmi, Zachary Darnell
Blue crabs support one of our nation’s most valuable fisheries, and Louisiana has led national landings 8 of the last 11 years. Fishery-independent estimates of abundance have declined in recent years and in 2015, the Louisiana spawning stock biomass reached the lowest point ever recorded. Management efforts have been haphazard, hindered by incomplete knowledge of migration patterns and fishing mortality. In 2016, we began a mark-recapture study in three Louisiana estuaries to examine these trends. 7118 female blue crabs were tagged and released across the Terrebonne, Barataria, and Pontchartrain Basins. Together, these estuaries supply >80% of the state’s landings. Recapture information was used to examine spatial and temporal variation in the timing and route of the spawning migration. Postcopulatory females migrate down-estuary and seaward to higher salinity waters to spawn. This spawning migration occurs throughout the warmer months of the year, beginning late March and continuing through October. Active acoustic telemetry was utilized to better understand the fine-scale behavioral mechanisms underlying the spawning migration. Movement data will be directly applicable to Louisiana blue crab management plans and stock assessments.

Organizers: Zachary Darnell
Supported by: AFS Fish Habitat Section

Location: Reno-Sparks CC Date: October 2, 2019 Time: 10:10 am - 11:50 am