Growth parameters of a benthic suspension feeder along a depth gradient across the pycnocline in the southern Kattegat

Comparative studies were made of somatic growth, condition and gut content of the filter feeding bivalve Arctica islandica and of gross community variables of total fauna at stations along a transect across the area where the pycnocline usually has contact with the bottom. Growth rates in terms of shell size of premature individuals were higher at intermedaite depths, immediately below pycnocline depth, suggesting enhanced growth conditions in this area. A part of the variation in shell size was apparently due to long-term variations in growth conditions. The data does not support the expectation of a direct simple relation between pycnocline production and A. islandica growth.