GLOUCESTER -- The Chesapeake Bay might have a new resident, thanks to warming waters and successful habitat restoration.
Blue crabs are the typical catch in local waters. But crabbers on the bay have reported adult stone crabs in their pots on Willoughby Spit, marking the first time the species has been spotted growing in Hampton Roads.
The find could mark an exciting addition to the crab industry in the Chesapeake Bay, according to Rom Lipcius, a researcher and professor at William & Mary's Batten School at the Virginia Institute of Marine Science.
Stone crabs are slow creatures. They're not as active as blue crabs, and their oversized claws are hard to ignore. When fished commercially, crabbers looking for stone crab do not harvest the entire body. Instead, they remove the larger claw (also called a crusher), and they will leave the smaller claw, or the "cutter." The stone crab is returned to the water, where it can regenerate its crusher claw. Since the crabs can regenerate crushers more than once, and the crabs can be returned to the water to reproduce.
In the past, crab larvae have floated into Hampton Roads, but they would not last until adulthood. Typically, the adult stone crabs would be found toward Florida and as far north as North Carolina, but their populations have had a hard stop before reaching Virginia.
"They're quite abundant (in North Carolina), but here? Never," Lipcius said. "This is really exciting and unique in having these -- and not just one or two, but several."
A handful of stone crabs now reside at VIMS's Seawater Research Laboratory in Gloucester County for research, passed over by a waterman who found them in the bay. The team is preparing a publication officially documenting their presence in the region.
Lipcius pointed to great improvements in oyster restoration as a potential reason the stone crabs might be thriving to adulthood in Virginia waters. Goals for all 10 tributaries in the Chesapeake Bay have met oyster restoration goals, and more than 2,000 acres have been restored.
Warmer waters also allow larvae coming in through the tides to continue to grow, and the higher salinity of the lower parts of the Chesapeake Bay make for a good habitat for the crabs.
"The combination of the warming waters and the provision of critical habitat, I think, is going to really promote the future," Lipcius said. "And I don't see this being a one time thing. I think what's going to happen is this is the start, and it's going to keep increasing. My sense is down the road, stone crabs will actually be part of the blue crab fisheries."
It's not the first time warmer waters have brought new critters to the Chesapeake Bay. Lipcius points to white shrimp as another species that didn't originally call the bay home, but it quickly grew into a fisheries success. Now, the small crustaceans are very popular in Hampton Roads.
Currently, only male stone crabs have been recorded in the bay, but if female stone crabs are identified, Lipcius said that will be the true test to see if stone crabs could become part of the ecosystem. Because there's been so few adults caught so far, it's still unclear why only males have been found. One reason could be that females may not be as active as males when going out to feed. It's also spawning season, so that could also be affecting female crabs' behavior.
At this point, stone crabs do not really pose a significant threat to blue crabs, Lipcius said. While they do have similar diets and habitat needs, crabbers are not reporting significant numbers of stone crabs to warrant concern, but Lipcius said more research may be needed if the stone crab population continues to rise. Because the native blue crabs are much faster, it's unlikely that they will end up the losers in the ecological fight.
Researchers at VIMS want to hear from crabbers who may have caught stone crabs in their pots. They can report their findings to Lipcius via email at rom@vims.edu.