Biomass Size Spectra of Near-Shore Shallow-Water Benthic Communities in the Gulf of Gdańsk Southern Baltic Sea

The concept of size spectra, developed by S heldon & P arsons 1967 and S heldon et al. 1972, seeks to describe community structure by evoking the distribution of biomass over a sequence of equal intervals of the logarithm of body size. In this study, biomass size spectra were prepared for benthic macro- and meiobenthos communities at 5 stations, differing in their sediment characteristics, located in the shallow, coastal area of the Gulf of Gdańsk Southern Baltic Sea. The purpose of this study was to determine whether the community spectra would allow distinct separation of ecological categories of the benthos and whether habitat differences between stations would significantly affect benthic size spectra.
Benthic biomass at the stations sampled depended mainly on nematodes and oligochaetes among the meiobenthos and on hydrobiid snails and M. edulis among the macrobenthos. Regardless of habitat, size spectra peaked initially at the meiofaunal range weight class 25 1. 19–501.19 ng C, identical to that reported in other studies. The separation between meio- and macrobenthic peaks, however, was not as pronounced as that found in other studies. Normalized size spectra demonstrated that most of the variations in the spectra between stations was introduced by macrobenthos, which differed between the coarse- and fine-grained sediments. Nonetheless, those differences were not strong enough to significantly affect the spectra. In consequence, the benthic biomass spectra of all the stations were found to conform to a common pattern and could be represented by a single, average spectrum.