Food limitation in epibenthic species in temperate intertidal systems in summer: Analysis of 0-group plaice Pleuronectes platessa

Abstract

The Balgzand intertidal is an important nursery area for early life stages of various epibenthic crustacean and fish species. Especially in summer, extremely high numbers of individuals occur. This study analyses whether these high densities in summer lead to food limitation using 0-group plaice Pleuronectes platessa L. as a model species. Between 1975 and 2007, this species was quantitatively monitored during 20 yr. The aim of this study is twofold: (1) a statistical analysis of field growth in relation to density, whereby negative density-dependent growth is considered as an indication of intraspecific competition, and (2) a comparison of observed field growth with predicted maximum growth according to the dynamic energy budget (DEB) model, to detect whether growth reduction occurs during the growing season as an indication of interspecies competition. The statistical analysis indicated no negative density-dependent growth during the whole growing season, suggesting the absence of intraspecies competition for food. The comparison of observed growth with DEB-predicted maximum growth showed that field growth was lower than the possible maximum, and that the difference increased over time until about the end of July, suggesting interspecies competition for food in summer. The stabilization in growth rate from July onwards might be related to a change in food quality: a shift from small bivalve siphons as main food items to larger tail tips of the lugworm Arenicola marina. These findings illustrate that not only food quantity but also food quality affects growth rates, at least in 0-group plaice. © Inter-Research 2010.