Water Column Monitoring 2004. Summary Report

Abstract

This report presents results from the Water Column Monitoring 2004, carried out in collaboration between NIVA and RF-Akvamiljø, with sub-contractors. The objective of the survey was to assess the extent to which discharges from Statfjord B affect organisms living in the water column. The study was designed to monitor bioaccumulation and biomarker responses in organisms held in cages in the vicinity of the platform. Furthermore, feral saithe were caught at locations with increasing distance from the platform. The results from the survey indicate that caged organisms have been exposed to low levels of produced water components, compared to results from 2001 (BECPELAG). The reason for this is not clear, but several possible explanations are proposed. However, mussels accumulated PAHs, with levels following the expected gradient with distance from the platform. There was no clear signal from the biological effects, possibly with the exception of micronucleus formation in mussel haemocytes. Concentrations of PAH-metabolites in bile of caged cod and feral saithe were both low, suggesting low exposure levels. There were no differences between locations in the levels of hepatic DNA adducts in the saithe, but there were individuals at each of the locations that had elevated levels of adducts. There were no obviously contaminant-related effects on liver histology in the saithe.