Accession Number : ADA113215

Title :   Population Dynamics and Production of the Amphipod Corophium salmonis in Grays Harbor, Washington,


Personal Author(s) : Albright,Richard ; Armstrong,David A

PDF Url : ADA113215

Report Date : Sep 1981

Pagination or Media Count : 75

Abstract : The tube-dwelling amphipod Corophium salmonis is a dominant benthic organism and important food resource in the estuarine mudflats of Grays Harbor, Washington. Intertidal core samples were collected at two sites during the spring and summer of 1980 to determine the population structure, biomass, rate of growth and production of C. salmonis. Two elevations (+1.8 and +.6 meters relative to MLLW) were sampled at each site. C. salmonis abundance ranged from 0 to 49,700 individuals per sq m. Peak abundances occurred during July and August. Abundances at the 1.8 meter stations were higher than at the .6 meter stations. Male-female ratios were lower for sexually mature C. salmonis than for immature C. salmonis, apparently as a result of predation on sexually mature males which wander over the tideflats in search of females. Data from both natural populations and from cohorts artificially isolated inside in situ cages were used to obtain size-specific growth rate curves and production estimates from C. salmonis. Total Corophium production for each station between April 1 and September 30 varied from 3.6 to 10.7 grams dry wt. per sq m. Corophium production was higher at the upper intertidal stations. Turnover rates (the ratio of production to mean biomass) ranged from 7.2 to 8.6.

Descriptors :   *Crustacea, *Harbors, *Rivers, Productivity, Population, Washington(State), Growth(Physiology), Rates, Reproduction(Physiology), Breeding, Sampling, Males, Females, Ratios

Subject Categories : Civil Engineering

Distribution Statement : APPROVED FOR PUBLIC RELEASE