Accession Number : ADA115530

Title :   Benthic Macro-Invertebrates of Rocky Creek, Eglin Air Force Base, Florida.

Descriptive Note : Final rept. Jul 78-Jun 79,

Corporate Author : AIR FORCE ARMAMENT LAB EGLIN AFB FL

Personal Author(s) : Scheiring,Joseph F ; Crews,Richard C ; Lefstad,Sandra M

PDF Url : ADA115530

Report Date : Oct 1981

Pagination or Media Count : 54

Abstract : A baseline study of benthic macro-invertebrates was conducted in Rocky Creek, a stream draining several test ranges used for the testing and evaluation of conventional munitions. The purpose of this study was to determine the numbers and kinds of benthic macro-invertebrates inhabiting the stream. This included an analysis of community composition, trophic structure, and seasonal and annual diversity patterns. A total of 85 taxa (mostly genera) was collected from July 1978 to June 1979. Sixty-five taxa were collected by quantitative methods (ponar grab) and 20 additional taxa were collected by qualitative methods (light trap and/or kick sample). Aquatic insects made up 89 percent of the total macro- invertebrates collected. The annual diversity values ranged from 3.063 to 1.836 while the evenness ranged from 0.597 to 0.382. The annual richness ranged from 35 to 27. The mean monthly diversity varied between 2.283 to 1.444 while the mean monthly evenness varied from 0.741 to 0.510. The seasonal changes in community composition and richness were due primarily to drift and life histories of the taxa. The community trophic analysis showed that collectors and predators were the dominant groups and had fairly constant abundances in all sites. The number of shredders decreased with increasing stream order while filters and scrapers increased. Functional group abundance and composition changed seasonally at each site due to the life histories of the individual insects and to stream conditions. The results of this study conform, very generally, to the River Continuum model.

Descriptors :   *Aquatic insects, *Marine biology, Invertebrates, Benthonic zones, Environmental protection, Indexes

Subject Categories : Biological Oceanography

Distribution Statement : APPROVED FOR PUBLIC RELEASE