Potential influence of effluents from Longyearbyen on the benthic fauna in Adventfjorden, Svalbard

Abstract

Benthic macrofaunal communities,sampled in 1998 and 2005 in Adventfjorden, a small sidearm to the Isfjord-complex, were compared. The samples were collected in various distance from the main sewage discharge point from the settlement of Longyearbyen. There has been a huge population increase in Longyearbyen the recent years. From about 1000 residents in the early 90s to almost 2000 in 2006. In addition, there has been a huge increase in overnight stays due to increased tourism. Four locations were sampled each year in order to investigate if the increased organic effluents from Longyearbyen had effected benthic community structure. Univariate (Shannon-Wiener, Pielou, and hurlbert ES 100)and multivariate (Bray- Curtis, MDS,Correspondence analysis and Canonical Correspondence analysis) were conducted. The results showed that diversity indexes were generally low with the lowest values at the innermost locality in 2005. An inner community was recognised with high abundance of especially the opportunistic polychaetes Capitella capitata and Chaetozone sp..Capitella capitata disappear and the abundance of opistobranch Cylichna sp., the polychaete Thyasira gouldi and the contaminant sensitive polychaete maldane sarsi increases towards the fjord mouth. The innermost station in 2005 showed higher influence of organic pollution compared to 1998 indicated by the considerably higher abundance of Capitella capitata.