Britt-Marie Bäcklin, Sara Persson, Suzanne Faxneld, Frank Rigét F, Anna Roos M
Department of Environmental Research and Monitoring, Swedish Museum of Natural History, P.O. Box 50007, SE 104 05 Stockholm, Sweden.
Department of Ecoscience, Danish Centre for Environment and Energy, Arctic Research Centre, Aarhus University, Frederiksborgvej 399, 4000 Roskilde, Denmark.
Animals (Basel). 2021 Oct 15;11(10):2968. doi: 10.3390/ani11102968.
The prevalence of intestinal ulcers and parasites was investigated in 2172 grey seals () collected in the Baltic Sea and 49 grey seals collected outside the Baltic Sea (i.e., the Atlantic). An increase in frequency of ileocaeco-colonic ulcers was observed in the early 1980s, followed by a decrease in the mid-1990s. At the same time, there was an increase followed by a decrease in brominated flame retardants, Perfluorooctanesulfonic acid (PFOS) and cadmium levels in herring (), the most common prey item in Baltic grey seal diet, as well as in another top predator in the Baltic, the common guillemot (). The frequency of intestinal ulcers was significantly related to the intensity of acanthocephalan parasites, the age of the seal and the region of the Baltic Sea. Perforation of the intestinal wall was the cause of death in 26 of the investigated Baltic grey seals. In contrast, none of the investigated Atlantic grey seals had intestinal ulcers. They showed a thin colonic wall and very few acanthocephalan parasites. The high prevalence of intestinal ulcers and the high parasite intensity appear to be unique to the Baltic population of grey seals.
对在波罗的海采集的2172只灰海豹以及在波罗的海以外（即大西洋）采集的49只灰海豹的肠道溃疡和寄生虫患病率进行了调查。在20世纪80年代初观察到回盲结肠溃疡的频率增加，随后在20世纪90年代中期下降。与此同时，波罗的海灰海豹饮食中最常见的猎物鲱鱼以及波罗的海另一种顶级捕食者普通海雀体内的溴化阻燃剂、全氟辛烷磺酸（PFOS）和镉含量先增加后减少。肠道溃疡的频率与棘头虫寄生虫的感染强度、海豹的年龄以及波罗的海的区域显著相关。在所调查的波罗的海灰海豹中，有26只因肠壁穿孔而死亡。相比之下，所调查的大西洋灰海豹均无肠道溃疡。它们的结肠壁很薄，棘头虫寄生虫很少。肠道溃疡的高患病率和高寄生虫感染强度似乎是波罗的海灰海豹种群所特有的。
