For the third year in a row, the levels of organic environmental contaminants in Greenland halibut from the areas along the continental shelf slope (Eggakanten) south of Vesterålen in the Norwegian Sea, have been found to be significantly lower than in previous studies. NIFES therefore believes that there is no longer a scientific basis for maintaining the closure of the two fishing grounds that have been closed since 2012.
‘Lower levels of organic environmental contaminants three years in a row indicate that this is probably a consistently lower level and not only random variation,’ says Bente Nilsen, scientist at NIFES.
No positions exceeded the maximum limit
The new report from NIFES shows that no positions had levels exceeding the EU maximum level for dioxins and dioxin-like PCBs in 2015.
Levels of dioxins and dioxin-like PCBs in Greenland halibut from the continental shelf slope south of Vesterålen have varied considerably from year to year, and the average level is still relatively high in these areas, both compared with the levels found in Greenland halibut from other areas further north and compared with the levels found in other fish species. Despite this, NIFES believes that the levels in Greenland halibut are now consistently lower than the maximum level in the areas within and around the closed fishing grounds.
Baseline and follow-up studies
From 2006 to 2008, NIFES conducted a baseline study of a number of contaminants in Greenland halibut. The study revealed that the levels of dioxin and dioxin-like PCBs were higher than the maximum level for these substances along the area Eggakanten between 66 degrees and 69 degrees north. Eggakanten is an area where the continental shelf slopes down to the deep part of the Norwegian Sea.
Two follow-up studies were conducted in 2011 and 2012. The results led the Directorate of Fisheries to close two areas along the continental shelf slope, prohibiting Greenland halibut fisheries in these areas. Two more follow-up surveys were conducted in 2013 and 2014. The results of these surveys showed lower levels of dioxin and dioxin-like PCBs, and no positions had values exceeding the maximum levels. The fishing grounds nevertheless remained closed in 2015, to obtain data from one additional year.
Although the average levels are below the maximum level, some individual fish have values above the maximum level. In order to keep abreast of developments, NIFES recommends continued monitoring in the area with a more limited number of samples. Further monitoring of Greenland halibut should also include the northern fishing areas that haves not been studied in recent years.