Researchers study fish to learn impact on environment

Photo by Marny Malin-Ryan Saylor, technician, Virginia Tech Fisheries and Wildlife Sciences; John Odenkirk, certified fisheries scientist, Virginia Department of Game and Inland Fisheries; and Nick LaPointe, doctoral student, Virginia Tech Fisheries and Wildlife sciences; comb Dogue Creek with nets, electrofishing for snakeheads.

Nick LaPointe and Ryan Saylor have spent almost every day for the past year in the waters of the Potomac that surround Fort Belvoir and in its tributaries tracking the snakehead fish, a predatory species that is illegal to possess. With a grant from the U.S. Geological Survey, authorized by Congress, they are studying the invasive fish. The researchers are interested in its spawning behavior, habitat, diet and its unique ability to migrate distances, in an effort to understand its impact on the river and native fish species.
LaPointe, a Virginia Tech doctoral student in fisheries and wildlife services; and Saylor, a Virginia Tech technician, have caught more than 200 snakeheads, shocking them and netting them for study. Launching their boat daily from the Fort Belvoir Marina or walking through the creeks in chest-high waders they have radio-tagged snakeheads and released a few for further research; while most have been used to gather data, tracing the population for its genetics, health and habits.
"I became interested in introduced species because second to habitat loss, they are the greatest threat to fish diversity," LaPointe stated. Having always been interested in nature, ecology and the outdoors, LaPointe began fishing at 5 years old and began to pursue it seriously as a teenager after he got his first car and went fishing at every opportunity.
So far, they have found snakeheads to have an unusual ability to disburse, finding their way past the Pentagon to a tributary of the Anacostia River about 24 miles away from its original location. They also have found it likes to spend its time in very shallow water eating the juveniles and adults of white and yellow perch, sunfish, goldfish, eels and minnows. They are able to survive in a variety of water conditions, preferring highly vegetated areas while prolifically reproducing: schools of over several thousand have been sighted.
"The real threat with this species is transporting it to inland waters where it will affect the game fish," according to LaPointe. All of the thousands of snakeheads in this area, have been genetically traced to one ancestral mother. Most conclude that fish was dumped by someone emptying the fish from an aquarium. It was an act that threatens to have a tremendous effect on the native fish species, sport fishing and the river's ecosystem. Severe penalties, five years in jail and fines up to $250,000 are imposed on individuals caught for introducing non-native species into bodies of water.
"North American anglers prefer the native fish that are easy to catch, because of their habitats and their elusive ability, snakeheads are not easily caught," said LaPointe. LaPointe will report his data to the USGS and hopes to publish his findings in scientific journals. Anyone who catches a snakehead should kill it, and report it at 800-770-4951, to the Department of Game and Inland Fisheries. For more information visit www.dgif.virginia.gov/fishing/snakeheads.html.