|Temporal and spatial variation of macrobenthic communities along the Belgian coast, and population dynamics of the bivalves Spisula subtruncata and Macoma balthica|
Arellano, N.L. (1995). Temporal and spatial variation of macrobenthic communities along the Belgian coast, and population dynamics of the bivalves Spisula subtruncata and Macoma balthica. MSc Thesis. RUG: Gent. 93 pp.
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This thesis presents the temporal and spatial variation of macrobentbic communities, and population dynamics of two bivalves Spisula subtruncata and Macoma balthica along the Belgian coast. Macrobenthic samples were collected in between sandbanks of 3 sampling stations located near the Westerschelde estuary, Ostend coast and the Belgian and French border from March 1994 to February 1995. The taxa composition, relative abundances and densities of the total macrobenthic samples were calculated. Nineteen taxa were recorded for the overall study area. The macrobenthic community is dominated by Polychaeta, Nematoda and Bivalvia. The bivalve population is dominated by Spisula subtruncata and Abra alba. The population dynamics of Spisula subtruncata and Macoma balthica were discussed. The growth parameters of the von Bertalanffy growth function for Macoma balthica were estimated with the use of Ford-Walford Plot and Gulland-Holt Plot using the age-length data established from the winter ring counts. The production of Spisula subtruncata was estimated by the growth increment method and removal summation method. The spatial and temporal structures have been analyzed by two multivariate statistical techniques: the Two Way Indicator Species Analysis (TWINSPAN) and the Correspondence Analysis (CA). The two methods for estimating the production of Spisula subtruncata yielded a very close estimate. The growth increment method yielded a production (5 months) of 19574 mg AFDW m-2y-1 with a P/B ratio of about 0.38. The removal summation method yielded 13727 mg AFDW m-2y-1 with a P/B ratio of 0.27. The maximum winter rings counted for Macoma balthica is 6. The growth parameters derived from Gulland-Holt Plot are similar to Ford-Walford plot. The growth parameters of Macoma balthica are 20.29 mm MSL and 0.48.