An Analysis of the Variability of Fish Populations Taken by Otter Trawl in Biscayne Bay, Florida
Roessler MA. 1965. An Analysis of the Variability of Fish Populations Taken by Otter Trawl in Biscayne Bay, Florida. Transactions of the American Fisheries Society. 94(4):311-318
This document reports the results of a fish sampling survey in Biscayne Bay. It compares the variability of the gear, the changes between sampling areas, the differences between night and day sampling, and estimates the most efficient sampling size necessary for valid comparisons. Tables present the data. Journal abstract: Three bottom habitats in Biscayne Bay were sampled by 120 trawl samples taken during both day and night from April to August 1963. Daylight samples contained 1,391 fishes representing 41 species. Night samples contained 1,440 fishes and 49 species. The number of species per sample followed a Poisson distribution, the number of individuals per sample followed a negative binomial distribution, and the number of individuals per species followed Fisher's logarithmic series. The following generalizations apply to both number of species and number of individuals. More fishes were taken in the Thalassia area than in the Thalassia-sand area, which in turn had more than the mud-sand area. More were taken at night than during the day. Tidal direction had no significant effect. Analysis of data on the sample variance for paired 2-minute samples showed that seven to eight replicates are needed to detect a difference of five species and 10 samples are needed to detect a 10% change in the number of individuals with 95% confidence. Abstract provided by author.
- Type
- Journal Article
- Authors
- Roessler, Martin
- Units
- BISC
- Keywords
- Animal Studies, Bear Cut Channel, Biscayne Bay, comparisons, Distribution, Fish, Poisson, Research Methods, Seine Survey, Trawl