Researchers at North Carolina State University have published a study examining the decline of blue crab populations in North Carolina’s Albemarle-Pamlico Estuarine System (APES). The study, led by Ph.D. candidate Erin Voigt, compared juvenile blue crab numbers across three nursery habitats in Pamlico Sound before and after a major decline in the fishery.
The APES provides essential nursery habitat for most of North Carolina’s blue crabs. Blue crab larvae are released by mature females from inlets along the Outer Banks and return to the estuary as juveniles, settling in near-shore environments such as seagrass beds and marsh peat habitats.
“These juveniles hang out in the nurseries until they’re basically big enough to pick a fight and win, then they move into the rest of the estuary,” said Voigt.
The state’s blue crab fishery experienced a significant drop in adult crab populations during the early 2000s. In response, protective measures were implemented that cut crab fishing by half. Despite these efforts, adult populations have not recovered.
“The normal explanation for situations like these is recruitment overfishing, which just means that adults have been overfished to the point that they cannot produce enough young to get back to pre-collapse numbers,” Voigt said. “We wanted to determine if that was the case here.”
Voigt analyzed juvenile crabs—those with carapace widths between 2.2 and 20 millimeters—in three types of nursery habitats: patchy western shore seagrass beds, western shallow detrital marsh peat mats, and eastern seagrass beds. She compared data from two periods: before the fisheries decline (1996–1999) and after (2017–2019).
The results showed that juvenile numbers remained stable across both periods. Notably, western seagrass habitats supported nearly four times more juveniles than eastern ones, which had previously been considered primary nurseries.
“The main takeaway here is that the decline in adult populations isn’t directly due to recruitment problems,” Voigt said. “Even if some of these juveniles are coming down from the Chesapeake or up from the Gulf populations, the numbers indicate that there should be significantly more adult crabs in the area.
“There is most likely a bottleneck we aren’t aware of that’s happening somewhere between their arrival in the habitats and reaching adulthood. If we can find that bottleneck it may help the numbers improve.”
The research was published on September 10, 2025, in Fisheries Oceanography. It received support from several organizations including North Carolina Sea Grant; Southeastern Climate Adaptation Science Center; Albemarle-Pamlico National Estuarine Partnership; Curtis and Edith Munson Foundation; North Carolina Division of Marine Fisheries; and NC State University’s Center for Marine Sciences and Technology. David Eggleston, professor at NC State University, served as corresponding author alongside former Ph.D. student Lisa Etherington.
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