A study from Canada says fish farms are a threat to some populations of wild salmon. It says the danger is from sea lice, which are small organisms that feed on fish.

The researchers say these parasites commonly infect salmon raised in farms, but also attack young wild pink salmon that swim nearby. Their research suggests that if these outbreaks continue, local populations of wild pink salmon will all but disappear.

Experts are debating the study, published in Science magazine. The Canadian government and some American experts say no direct link has been found between sea lice and salmon deaths.

Martin Krkosek of the University of Alberta in Edmonton led the study team. The researchers relate the growth of fish farming off British Columbia to losses in young wild salmon. The number of fish farms in the area has increased sharply. The researchers say lice commonly kill more than eighty percent of pink salmon in the areas they studied. The fish in these coastal areas swim past many fish farms before entering the open ocean.

参考译文:

一项来自加拿大的研究宣称鱼场对野生鲑鱼的一些种群来说是一种威胁。该研究称危险源于海虱，它们是食鱼为生的微小生物体。

研究人员说这些海虱一般会感染养殖场饲养的鲑鱼，但是它们也会侵袭到在附近游动的野生粉鲑（细鳞鲑鱼）鱼苗。 他们的研究显示，如果（海虱）爆发继续，当地的野生粉鲑种群将几近消失。

该项研究发表在《科学》杂志上，专家们正就此展开讨论。加拿大政府和一些美国专家说仍未发现海虱和鲑鱼死亡之间的直接关系。

埃德蒙顿市阿尔伯塔大学的Martin Krkosek 主持该研究小组。研究人员把不列颠哥伦比亚省附近鱼场的发展和野生粉鲑鱼苗的死亡联系起来。该区域的鱼场数目已大幅上升。研究者说在他们所研究的地区，海虱导致80%以上的野生粉鲑死亡。这些沿海区域的鱼进入辽阔的海域之前游经很多渔场。

TAG: voa,voa下载,voa慢速英语,voa英语,voa news,voa english,voa special,voa听力 ,美国之音