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Abstract Blue crab (Callinectes sapidus) supports lucrative Mid‐Atlantic crustacean fisheries and plays an important role in estuarine ecology, so their larval transport and recruitment dynamics in the Maryland Coastal Bays system were investigated using simulated and observed surface drifters. Relative contributions of winds, tides, density gradients, and waves to larval recruitment success were identified during the spawning season, particularly under hurricane conditions in 2014. Based on temperature (e.g., 19–29°C) and salinity conditions (e.g., 23–33 PSU), particles representing virtual blue crab larvae were released into the model domain from early June to late October 2014. During the spawning season, variations in the larval recruitment success caused by wind speed and direction, tides (e.g., affecting through inlets), density gradients (e.g., salinity variations), and surface gravity waves were 17%, 4%, −9%, and 17%, respectively. During Hurricane Arthur (2014), variability of self‐recruitment success caused by density gradients are negligible while by other three factors are comparable at 3%–4%. Surface drifter experiments support the modeling results that larval recruitment success is strongly associated with the coastal circulation. The high (low) self‐recruitment success in the Assawoman and Chincoteague Bays (Sinepuxent Bay) is related to the locally weak (strong) circulation; released larvae escape from inlets are likely recruited to southern Fenwick and northern Assateague Islands, and the coastal regions outside the Chincoteague Inlet. Understanding physical factors influencing larval recruitment success helps resource managers make informed decisions about habitat restoration and harvest regulations, in addition to seafood‐related food security.
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Drivers of bitter crab disease occurrence in eastern Bering Sea snow crab ( Chionoecetes opilio )
Abstract A recent population collapse of eastern Bering Sea (EBS) snow crab (Chionoecetes opilio) led to the first-ever closure of the snow crab fishery in 2022. The population collapse, caused, in part, by unprecedented warming, was preceded by peaks in juvenile snow crab density (2018) and bitter crab disease (BCD, Hematodinium sp.; 2016), a fatal crustacean disease. Annual bottom trawl surveys in the EBS show high year-to-year spatiotemporal variation in BCD-infected crab, yet it remains unclear what ecological drivers might explain the variation. We used statistical models of BCD presence/absence to examine the relative importance of intrinsic and extrinsic factors as drivers of BCD. We found a dome-shaped relationship between temperature and BCD presence, and results suggest that 2–4°C bottom temperatures are more likely to support BCD. Matching with past work across the globe, we find that stations with high population density of small, new shell crab are most likely to be BCD-positive. While our work highlights the challenges of disease monitoring in the EBS, our results indicate that indirect management measures related to snow crab rebuilding and recruitment may be more appropriate than directed fisheries management in mitigating BCD impacts.
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- Award ID(s):
- 1734999
- PAR ID:
- 10516241
- Publisher / Repository:
- Oxford University Press
- Date Published:
- Journal Name:
- ICES Journal of Marine Science
- Volume:
- 81
- Issue:
- 6
- ISSN:
- 1054-3139
- Format(s):
- Medium: X Size: p. 1073-1083
- Size(s):
- p. 1073-1083
- Sponsoring Org:
- National Science Foundation
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