Tidal and diurnal periodicity in macrocrustaceans and demersal fish of an exposed sandy beach, with special emphasis on juvenile plaice Pleuronectes platessa

Abstract

Macrocrustaceans and juvenile demersal fish were sampled in spring of 1997 in the surf zone of an exposed sandy beach on the Belgian coast. Three consecutive 24 h cycles were sampled to investigate tidal, diurnal and semi-lunar distribution patterns within the epibenthic community. Multivariate statistical techniques and 3-way ANOVA were used to evaluate the effects of the environmental variables measured. The most important variable correlated with the variation in epibenthic catch density was the state of the tide (ebb and flood), but light intensity (day and night) was also important. The individual catch density of several species differed significantly over the three 24 h cycles. Despite the strong turbulent conditions of the site studied, clear tidal (e.g. the brown shrimp Crangon crangon, juvenile plaice Pleuronectes platessa) and diurnal (e.g. juvenile sole Solea solea and clupeids, caught mainly during the night/day respectively) periodicities of many macrocrustacean and demersal fish species were observed. Nevertheless, the extremely turbulent conditions of the surf zone possibly affect the behaviour of many species (e.g. juvenile brown shrimp are not able to bury themselves as the water retreats). To investigate whether the high dynamics of the surf zone suppress the ability of juvenile plaice to actively search for food, stomach contents were analysed. Also, the interaction with potential prey was investigated: the hyperbenthic fauna was sampled simultaneously and macrobenthic data were available from the literature. Clearly, the Belgian sandy beaches are used as a feeding ground by I-group plaice. An opportunistic utilisation of available food resources is suggested. I-group plaice migrate high up the beach during the flood tide to profit from the rich macrobenthic intertidal area, while the 0-group feeds mainly on the most abundant hyperand macrobenthic organisms from somewhat deeper water. The presence of the 0-group in the intertidal area is possibly linked to refuge for predators or influenced by the strong surf zone currents.

Tidal influence on a fringing mangrove intertidal fish community as observed by in situ video recording: implications for studies of tidally migrating nekton

“…Alternatively, these species may have entered at positions in the intertidal zone that were unfortuitously undersampled due to the limited field of view and placement of video cameras. Like plaice and sole in the sandy surf zone of Belgium, these fish may be concentrated as they are forced to retreat from the more shallow portions of the intertidal zone by the retreating tide (Beyst et al 2002). For a more complete interpretation of this and other FM patterns, however, further research is required to elucidate the influence of tide stage on predation pressure and food availability in mangrove systems.…”

Spring-neap cycle as a major driver of temporal variations in feeding of intertidal fishes: Evidence from the sea catfish Sciades herzbergii (Ariidae) of equatorial west Atlantic mangrove creeks

“…The influence of the day-night cycle on feeding activity of intertidal fishes is speciesspecific and can interact with the tide (e.g. Kleypas and Dean, 1983;Beyst et al, 2002). In contrast to the two previous temporal cycles, the influence of the spring-neap tide cycle on feeding of fishes has rarely been studied.…”

Ecological aspects of the surf-zone ichthyofauna of Itamambuca Beach, Ubatuba, SP

“…According to Beyst et al (2002), this zone also acts as a foraging place for some species, such as planktivores, insectivores, piscivores and opportunists, the latter of which accounts for the majority of species (McLachlan & Erasmus 1983, Lasiak & McLachlan 1987, Layman 2000. Fish assemblages in the surf zone are generally composed of species that live only part of their life cycles in this area and only a few species are considered residents (McLachlan & Erasmus 1983, Ramos & Vieira 2001.…”