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USE OF VIDEO TO ACCESS JUVENILE WINTER FLOUNDER DENSITIES AND HABITATS
Citation:
Meng, L, G Cicchetti, AND S. Raciti. USE OF VIDEO TO ACCESS JUVENILE WINTER FLOUNDER DENSITIES AND HABITATS. Presented at NOAA International Flatfish Conference, Westbrook, CT, December 10, 2002.
Description:
We used a digital video camera mounted to a 1-m beam trawl together with an attached continuous recording YSI sonde and a GPS unit to quantify juvenile winter flounder (Pseudopleuronectes americanus) densities and fish habitat in Narragansett Bay, RI. The YSI sonde measured temperature, salinity, dissolved oxygen, depth, turbidity, and chlorophyll a. We hypothesized that human-induced habitat alteration would correlate with a decrease in juvenile winter flounder densities. We sampled true-random points derived from digitization of the entire shoreline of the West Passage of Narragansett Bay and the Providence River. At each random point, the camera/beam trawl/YSI unit was deployed at the water's edge, then towed out perpendicular to shore for 50-100 m, depending on the amount of macroalgae present. We sampled 80 transects from June-July 2002 and captured 603 fish representing 23 species. Winter flounder made up 60% of the catch, followed by grubby (Myoxocephalus aenaeus) at 22%. Contrary to our expectations, juvenile winter flounder densities were greater at sites with more anthropogenic influence. Densities were highest at the head of the bay, near the city of Providence and in other semi-enclosed areas with high chlorophyll a values. When random locations were broken down into eight habitat types (beach, marsh, cobble beach, rip-rap, rock, industrial, marina and macroalgae), densities were highest near rip-rap, industrial areas, and marinas. These areas tended to be near the head of the bay or near harbors with high levels of nutrients and chlorophyll a.