Jenssen B M
Department of Zoology, Norwegian University of Science and Technology, NTNU-Rosenborg, Trondheim, Norway.
Sci Total Environ. 1996 Jul 16;186(1-2):109-18. doi: 10.1016/0048-9697(96)05089-9.
Most incidences involving oil pollution of grey seals (Halichoerus grypus) seem to have occurred at the breeding sites. Because of the high concentration of animals at this time, even small oil spills will pollute many animals. As a result of chronic low-level pollution from coastal ship traffic and discharges from offshore petroleum activity in the North Sea, approximately 50% of the grey seal pups at the largest breeding colony in Norway are polluted each year by oil. In this case, as well as in other similar cases of spills at breeding colonies, oil has produced little visible disturbance to the seals behaviour and there has been little mortality. The effects and mortality may, however, be more serious following a spill of crude oil, where animals may be affected by inhalation of toxic volatile compounds. High body burdens of PCBs and DDTs seem to have caused skull-bone lesions and occlusions of the uteri in grey seals in the Baltic Sea. Exposure to these persistent compounds has also been suspected to be the cause of reduction in the population of Baltic grey seals. There are indications that thyroid hormone and vitamin A status of grey seal pups are affected by the low exposure concentrations experienced at the Norwegian coast (approximately 1/20 of the concentration detected in grey seal pups from the Baltic Sea). This gives serious cause for concern about the effects that chronic low-level exposure to persistent organochlorine pollutants may have on individuals and on populations of grey seals.
大多数涉及灰海豹（Halichoerus grypus）油污事件似乎都发生在繁殖地。由于此时动物高度集中，即使是小面积的石油泄漏也会污染许多动物。由于北海沿海船舶交通的长期低水平污染以及近海石油活动的排放，挪威最大繁殖群体中约50%的灰海豹幼崽每年都会被石油污染。在这种情况下，以及在繁殖群体发生的其他类似泄漏事件中，石油对海豹行为几乎没有造成明显干扰，死亡率也很低。然而，原油泄漏后影响和死亡率可能更严重，动物可能会因吸入有毒挥发性化合物而受到影响。多氯联苯和滴滴涕在体内的高负荷似乎导致了波罗的海灰海豹的颅骨病变和子宫堵塞。接触这些持久性化合物也被怀疑是波罗的海灰海豹数量减少的原因。有迹象表明，挪威海岸灰海豹幼崽所经历的低暴露浓度（约为波罗的海灰海豹幼崽检测浓度的1/20）会影响其甲状腺激素和维生素A水平。这令人严重担忧长期低水平接触持久性有机氯污染物可能对灰海豹个体和种群产生的影响。
