The invation of the planktonic algae Chrysochromulina polylepsis along the coast of southern Norway in May-June 1988 Acute effects on coastal biota. Summary report

Abstract

This report describes the extent of damage to rocky bottom and soft bottom communities as well as to littoral fish. Damage has been registered along the whole of the coastline from the west coast of Sweden to the Haugesund area inclusive. Hardest hit were stretches from Grimstad to Kristiansand and from Farsund to Flekkefjord. Depths between 3 and 16 were affected along the most of the coastal region. In some localities depths of between 0 and 30 m were affected. The acute effects on rocky bottom organisms have been severe. Soft bottom organisms were less affected than rocky bottom organisms. The common dog whelk Nucella lapillus was almost completely exterminated. Wrasse showed the greatest mortality among wild fish. The year's cod fry were more or less wiped out. In addition, mortality among farmed salmon was high. New surveys should be conducted to observe any later effect as well as the process of recolonization.