Drifting algae are fundamental in terms of the ecological significance which they serve for birds and associated fishes. The occurrence of floating algal clumps and the associated fish and avifauna were investigated off the Belgian coastal zone in the North Sea. The most commonly encountered algal species were Fucus vesiculosus, Himanthalia elongata and Ascophyllum nodosum. Sixteen fish species were caught mainly during summer and autumn and the catch was dominated by four species: Chelon labrosus, Ciliata mustella, Trachurus trachurus and Cyclopterus lumpus. The highest abundance of seabird association was observed in July. The most common species encountered were mainly plunge diving species. Most of the behavioral associations with the floating seaweed were observed by terns. An unexpected outcome of this study was the numerical dominance of seaducks, however this is most likely explained by the presence of sandbanks in the Belgian part of the North Sea where their prey can be found in abundance. |
