서산 연안간석지에서 두토막눈썹참갯지렁이(청충), Perinereis aibuhitensis의 분포밀도와 현존자원량의 추정

Abstract

A study on the estimation of the stock density and biomass of Perinereis aibuhitensis in the tidal zone in Sosan, Chungchongnam-do, Korea was carried out from June to July 1988. A preliminary survey was conducted to determine the distribution pattern of the species and the optimum sample size for setting up the sampling design. The stock densities of the species by stratum and by subarea were estimated using the stratified random sampling method, based upon the results of preliminary survey. The differences in density between strata as well as among subareas were tested to decide whether they can be combined together for estimating the overall stock biomass or not. The results of the survey showed that p. aibuhitensis were randomly distributed(Poisson distribution) and the number of quadrats which satisfies a reasonable level of precision was determined to be five by stratum. The densities between strata were not significantly different, while densities among subareas were different. Subarea C showed the highest density with the mean of 53.9g/m2 and followed by subarea B. The density of subarea A was the lowest with the mean of 18.2g/m2. The overall mean density from the study area was 32.4g/m2 with the coefficient of variance(CV) of 6.8% The overall stock biomass was estimated to be 147.5mt in this area.