Ecology of native fishes and crayfishes
Laboratory personnel conduct field surveys to determine the distribution of fishes and crayfishes in streams and lakes in the Northeast. With information on where species occur, we refine the search to identify microhabitat use. Techniques include traditional methods of capture: electroshocking, seines, traps and trawls. Depending on the conditions, microhabitat information can be gathered while snorkeling or by electroshocking and marking the exact capture site. A surprising amount of life history information can be obtained by looking at collections. My research depends heavily upon the records of capture over the past century and on specimens that have been captured in the past. The collection records and specimens are ideal for comparative work and can yield information on growth rates, condition, reproduction and feeding.
Ecology of exotic fishes and crayfishes
Although there are relatively few extralimital exotic fishes in New York, many fishes that are native to drainages in New York have been introduced into other drainages where they are not native. Exotic crayfish species probably outnumber native species, but there are relatively few species involved. The rate of introductions is accelerating. A few species were introduced over a century ago and populations have become naturalized. Others are relatively recent and have the potential to affect the distribution and abundance of native species. Recent work has examined the overall change in species composition in Adirondack lakes, where native species have declined in number and range. With colleagues, I have also been monitoring the expansion of northern snakehead and Chinese mitten crab into the Hudson River. Although species like the snakehead and mitten crab attract wide attention, they represent a small part of the total number of exotics within any aquatic system in New York. Our goal is to monitor the rate of expansion and document it with voucher specimens that ultimately are accessioned into the collection.
Largemouth bass (M_salmoides)
Largemouth bass (M_salmoides)
As part of the Adirondack Effects Assessment Program, a program funded by the Environmental Protection Agency to document changes in Adirondack biota resulting from the Clean Air Act, I studied fish assemblages is a selected group of lakes. The interest was in change in fish populations, so we assessed abundance and composition. The research team found that fish were not particularly responsive to small changes in environmental condition, but we did discover several other aspects of fish biology that were interesting. We monitored fish movement among lakes, in situ growth rates, interactions between native and exotic species, and overall change in species composition. We also rediscovered a species that was described in the 19th century but that had been largely ignored since. Rediscovering the biology of Catostomus utawana, the summer sucker, became the doctoral dissertation research of Dr. Rick Morse, the collection manager.
The crayfishes of New York are an understudied group. Perhaps it is because there are only about 12 species of crayfish in the state. Nonetheless, over the last several decades, several species have been introduced and the ranges of native and long-established species have been affected. In addition, there are about a dozen species of shrimps and crabs that are found in inland waters, mostly the tidal Hudson River. Two of the exotic crabs have the potential to severely alter the species composition of the Hudson River. This work focuses on the distribution of crayfishes, shrimps and crabs in New York’s inland waters.