Surf clams reappear and rebound on Virginia coast

Rutgers University scientists point to improved environmental conditions as possible reason

Atlantic surf clams, an economically valuable species that is a staple in clam chowder and fried clam chips, are returning in large numbers to Virginia waters, reversing an extinction trend that began more than two decades ago.

Rutgers University scientists conducted a comprehensive study of surf clams collected from an area about 45 miles due east of the mouth of the Chesapeake Bay and found that the clam population in the area is thriving and growing. Scientists say one possible reason could be improved environmental conditions, and another could be the clam’s adaptation.The report was published in the scientific journal estuaries and coastsDetailed description of the characteristics of a population of healthy-sized mussels of varying ages living beneath the sandy seafloor surface.

It’s all a bit surprising.

Said this was unexpected good news Daphne Monroeis an associate professor in the Department of Marine and Coastal Sciences in the School of Environmental and Biological Sciences at Rutgers University and one of the study’s authors. They disappeared a while ago and we thought they were gone. But we discovered there were more clams there than we thought. They are thriving.

Munroe said northern clams began disappearing from waters off the Virginia coast in the late 1990s due to warming waters. By the turn of the 21st century, there were too few people there to fish these waters.

One day in 2021, Munroe received a call from a fishing buddy she often worked with.

He said, Daphne, you know, I have five ships sailing on Cape Charles [off Virginias Eastern Shore] Now? Munro said they are catching surf clams and loading them into trucks.

She added, I said, what is that? what are they doing? How can this be?

She was told that the refrigerated truck carrying the seafood was headed to Port Norris, New Jersey, home to one of the major northern clam processing plants on the East Coast. Munro works at the Haskin Shellfish Research Laboratory of the New Jersey Agricultural Experiment Station in Port Norris, near the processing plant.

I told him: I have to see those clams. too crazy.

Munroe, an expert in coastal and marine ecosystem dynamics, examined surf clams and a new study was born.She received funding from the National Science Foundation Marine Fisheries Science Center This led Monroe to hire MSU undergraduate Brynne Wisner as an intern. Wiesner, who led the collection, preparation and measurement of the clams, became the study’s first author.

The Atlantic surf clam, well known to beach surfers in the northeastern United States, is one of the most common bivalves in the Western Atlantic. Surf clams can live up to 40 years and their shells can grow to 8 or 9 inches long.

Although its habitat ranges from the Gulf of St. Lawrence in Canada to Cape Hatteras in North Carolina, the main population of surf clams lives off the coast of New Jersey. There, the relatively shallow northeastern U.S. continental shelf provides ideal, vast breeding habitat, extending for about 100 miles before descending into deep-sea canyons. The animals also thrive in the Cold Pool, a strip of near-seafloor cold water that flows through the lower portion of this part of the New York-New Jersey Sound.

The researchers used the New Jersey northern clam population as a comparison standard in the study, which sits perfectly in the middle of the species’ range. In samples collected from Virginia waters, scientists recorded the age of each North Sea clam shell (like trees, the successive growth rings on the shell correspond to lifespan), its size, growth rate and whether the clam contained a lot of meat. . They also collected tissue samples for genetic analysis.

Munro said clams are in good condition in the southern region. They are still young and growing as we would expect them to.

The study found that multiple generations existed in the collected clams, a sign of a healthy and expanding population.

Munro said the discovery suggests environmental conditions may have improved for southern surf clams, or that the population has adapted to changed conditions.

Munro said knowing how many populations exist at the southern edge of the mussel’s range can help researchers better understand changes in the species’ range and possible adaptation and recovery.

Genetic analysis shows that in the northern mussel population, Snaila smaller subspecies known for preferring warmer climates, Similar to Spisula Solidissima similis, was also found living there.

Munro said further research will investigate the possibility of mating between these species.This phenomenon is called subspecies hybridization and may be an important pathway Allowing species to adapt to changing environments.

In addition to Munro and Wisner, other Rutgers scientists involved in the study include Ximing Guo, distinguished professor in the Department of Marine and Coastal Sciences; Zhenwei Wang, a doctoral student; and Ailey Sheehan, a laboratory technician. From Haskin Shellfish Research Laboratory.