Rocky bottom fauna in a submarine gulley at Loppkalven, Finnmark, Northern Norway

Abstract

Vertical and horizontal distribution of macrobenthic flora and fauna were investigated on the vertical, rocky walls of a submarine gulley at Loppkalven (70 °18′N, 21 °22′E) in Northern Norway. The length of the gulley was 55 m at the water surface, and the water depth 12 m near the opening. Less than 1 % of the surface light at the opening was recorded near the bottom (6−8 m depth) in the inner parts. Brown algae and non-calcareous red algae were absent, even in the tidal zone, at the terminal end of the gulley. Porifera, anthozoans, hydrozoans, and bryozoans were the most common sessile animals, and showed clear vertical and horizontal gradients in their distributions. The amphipods Ischyrocerus anguipes, Sympleustes glaber and Stenothoe monoculoides, the bivalve Hiatella arctica, and the polychaete Eulalia viridis, were the most abundant solitary animals. The distribution of these amphipods and M. helicinus seemed to have the same distribution pattern as either non-calcareous algae or tuft-like bryozoans.