VCR-LTER Student Conference, September 1996
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Craig Layman and Dave Smith
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VCR-LTER Student Conference, September 1996
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Craig Layman and Dave Smith
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There are many ponds on the barrier islands of the Virginia Coast Reserve that undergo seasonal fluctuations in water depth. Many of these ponds are small, but one of the larger ponds is found in the middle of North Hod Island. This pond is about two miles in length and up to 100 yards wide. Some areas of the pond can be up to six feet deep, while the shallower portions are an inch or less. In general, the pond gets deeper toward its southern end, therefore, during the relatively drier summer months the pond dries from north to south. This reduction of pond size can easily be followed as the the pond's northern edge dries toward the south. Through exploratory reserach over the past two summers, I have found four species of fish that inhabit this pond: the atlantic silverside, mummichog, sheepshead minnow and rainwater killifish. Over the course of the next year I intend to study the population dynamics of these four species and any other species that may be discovered in the pond. I will look at such variables as total numbers, biomass, size, location, and preferred depth of the fish species. An emphasis will be placed on how these factors change as the pond fills in the winter and dries throughout the summer months. Samples will be taken weekly or bi-weekly from five to eight designated sampling areas along the edge of the pond. These sampling sites will be chosen at different depths starting at the shallow northern end of the pond and running toward the deeper southern end.
Sampling is difficult due to the dense vegetation that thrives in the ponds. Therefore, of the numerous sampling methods, only a few specific methods are actually feasible. I have chosen to sample using a throw ring made from a metal trash can. The ring will be thrown so that it hits the water perfectly horizontal and can sink into the soft substrate on the pond's bottom. This ring will trap everything within its area and a sieve system will then be used to remove the fish.