Title of article :
Structure of the population and secondary production of Hediste diversicolor (O.F. Müller, 1776), (Polychaeta, Nereidae) in the Loire estuary, Atlantic Coast, France
Author/Authors :
P Gillet، نويسنده , , S Torresani، نويسنده ,
Issue Information :
روزنامه با شماره پیاپی سال 2003
Abstract :
A survey was carried out from April 1998 to June 2000 to study the structure of the population and the secondary production of
Hediste diversicolor (Copenhagen 32 (1776) 274) in the Loire estuary, Atlantic coast of France. Each month, samples were collected
in the intertidal zone of the Mindin harbour. In 1999, the mean annual density was 900 594 individuals (ind.) m 2 with a
minimum of 304 ind.m 2 in February and a maximum of 2560 ind.m 2 in April. The mean annual biomass (dry weight) was
B ¼ 9:1gm 2 with a minimum of 1.2 gm 2 in January and a maximum of 26.0 gm 2 in July 1999. The density and the biomass of
the population of H. diversicolor decreased during winter and increased during spring/summer. Size frequency histograms allowed
the analysis of cohorts and gave the growth curves. Two recruitment periods were detected each year, in June/July and October. The
secondary production was estimated by the method of Crisp (Methods for the study of marine benthos, Blackwell, Oxford, 1971).
From June 1998 to May 1999, P ¼ 5:1 g m 2 with B ¼ 4:6 g m 2 and the ratio P=B ¼ 1:1 and from June 1999 to May 2000,
P ¼ 34:4 g m 2 with B ¼ 9:6 g m 2 and P=B ¼ 3:6. The annual secondary production in 1999 was P ¼ 32:5 g m 2 with B ¼
9:1 g m 2 and P=B ¼ 3:6. The differences observed between the 1986–1988 and 1998–2000 populations of H. diversicolor in the Loire
estuary are discussed and could be explained by environmental changes, as competition or by migration of individuals.
Keywords :
Hediste diversicolor , Population dynamics , Secondary production , Loire estuary
Journal title :
Estuarine, Coastal and Shelf Science
Journal title :
Estuarine, Coastal and Shelf Science