Potential for environmental impact from leaking World War II shipwrecks due to the relative bioavailability and toxicity of their fuel oils

Abstract

ABSTRACT The Norwegian Authorities have classified 30 World War II (WWII) shipwrecks to have a considerable potential for pollution to the local environment, based on the location and condition of the wreck and the types and amount of fuel on board. Oil thus far has been removed from eight of these WWII shipwrecks. The water accommodated fractions (WAFs) of oils from the British sloop HMS “Bittern”, the British carrier tanker RFA “Boardale”, the German destroyer “Erich Giese”, and the German cargo ship MS “Nordvard” have been studied with special emphasis on chemistry and biological effects (algae growth (Skeletonema costatum) and copepod mortality (Calanus finmarchicus)). WAF is of special interest because components dissolved from an oil slick or from rising oil droplets in the water column are known to be bioavailable to marine organisms and therefore have a potential for causing toxic effects. The total WAF concentration in the oils from the shipwrecks varied, and the highest concentrations are quantified in the WAFs from “Erich Giese”. These WAFs were also the most toxic for both algae and copepods, and it is suggested that the high content of phenols and other polar compounds have impact on the toxicity. WAFs from “Nordvard” were also more toxic than the WAFs from “Bittern” and “Boardale”. The results from these studies show that the more “synthetic” oils from German WWII shipwrecks seem to have higher toxicity to marine organisms than the “mineral” oils from the British shipwrecks studied. This observation has resulted in an altering of the priority list for oil recovery from WWII wrecks by the Norwegian Authorities.