Experts say this is why farmed salmon may have been fed food containing a man-made substance to make the flesh pinker.

专家指出，这就是为什么养殖的三文鱼可能被喂食含人造物质的饲料，以便让鱼肉变粉红。

Farmed salmon, by contrast, are bred exclusively for size.

相比之下，养殖鲑鱼则完全是为了增大尺寸而养殖的。

When they first started farming salmon, it could take as many as six pounds of wild fish to make a single pound of salmon.

当人们刚开始养殖鲑鱼时，要消耗六磅的野生鱼类 才能产出一磅鲑鱼。

And then we import farmed salmon from Chile, from Norway.

然后我们从智利、挪威进口养殖鲑鱼。

Escapes are also a concern as interbreeding threatens wild salmon populations and farmed salmon can pass parasites to the wild fish.

逃逸也是一个问题，因为杂交威胁到野生鲑鱼种群，而养殖鲑鱼可以将寄生虫传染给野生鱼类。

In salmon, a bright pink color is a sign of freshness to those buying the fish. Experts say this is why farmed salmon may have been fed food containing a man-made substance to make the flesh pinker.

对于购买三文鱼的人来说，亮粉色是新鲜的标志。专家说，这就是为什么养殖的三文鱼可能被喂食含有人造物质的食物，以使鱼肉变粉红。

) Even in Norway, where about half the country's salmon farms use RAS, it is limited to the first stage of the fish's life.

）即使在挪威， 该国大约一半的鲑鱼养殖场都使用 RAS，但它也仅限于鱼生命的第一阶段。

To keep the genetic pool intact, any farmed salmon that swim upstream there get clubbed to death with an offcut two-by-four (the club-wielder, Henrik Weiss, explains that the official salmon stick was chewed to pieces by a dog).

为了保持基因库的完整，任何逆流而上的养殖鲑鱼都会被一根 2×4 的木板碎片打死（挥舞木棒的人亨利克·韦斯 (Henrik Weiss) 解释说，官方的鲑鱼棒是被狗咬碎的）。