Distribution and density of goldsinny wrasse (Ctenolabrus rupestris) (Labridae) in the Risør and Arendal areas along the Norwegian Skagerrak coast

Abstract

Samples of fish were collected in the Arendal and Risør areas on the Norwegian Skagerrak coast during the period 1986 to 1990 using a beach seine at 36 different locations. In the Risør area, 131 out of 254 hauls yielded goldsinnies, and in the Arendal area 66 out of 100 hauls. The density of fish estimated for the summer period (June-September) was as follows: Sandnesfjorden 0.9, Sørfjorden 2.8, Nordfjorden 9.8, Risør Skerries 2.0 and Arendal 12.7 fish 1000 m-². The best catches of goldsinny were taken at stations with medium exposure, but the difference in mean catches between stations with different exposure was not significant. The average number of goldsinny taken at stations was not significantly related to freshwater influence, liS inferred from the distance to river outlets. The presence of rock in the substratum significantly increased the average number of goldsinny at a station compared to stations without rock. No similar effect was found for the presence or absence of sand or mud. Bottom with vegetation is highly preferred compared to barren bottom .