Adults Are the Primary Predator of Baby Blue Crabs in Chesapeake Bay

A 37-year study in Chesapeake Bay confirms that cannibalism by adult blue crabs is the main cause of death for juveniles, accounting for about 97% of injuries with over half lethal. Fish predation was negligible. Cannibalism varies with season and crab size—warmer months and smaller juveniles are most at risk—while crabs in shallower waters survive better. The findings, published in the Proceedings of the National Academy of Sciences, inform a stock-assessment model for sustainable management and highlight the need to protect juvenile shelters as climate-related changes threaten shallow, mid-salinity habitats.