Comparison of Fishes Occurring in Alga and Seagrass Habitats on the East Coast of Florida

Abstract

I compare the distribution and abundance of fishes between macroalga and seagrass habitats in Indian River lagoon, Florida. I sampled fishes monthly (Oct. 1986 - Sept. 1987) for a year by placing seines 10 m apart and pulling them together. I used a 1 m2 throw net to sample during March, May, June, August and September 1987. There was no significant difference in temperature, salinity, dissolved oxygen, and pH between habitats. Water depth was significantly different between alga (mean = 0.80 m) and seagrass (mean = 0.52 m). Dominate species (Lucania parva, Menidia peninsulae, Gobiosoma robustum, Syngnathus scovelli, Microgobius gulosus, Eucinostomus lefroyi, Floridichthys carpio, and Strongylura notata) were similar between the two habitats. Mean abundance, biomass, juvenile abundance and richness per seine tow; and abundance and biomass per throw net throw were significantly greater for sea grass habitat (p <0.05). Multiple regression analysis indicated that habitat type accounted for the majority of the variation in abundance (37%) and biomass of fishes (31%) collected. Vegetation biomass, dissolved oxygen, pH, salinity, temperature, and water depth accounted for smaller amounts (<10%) of variation in abundance and biomass of fishes.