洄游路线

这片海域也是弓头鲸和海象等海洋哺乳动物的重要洄游路线。

The sea is also a major migration route and feeding area for marine mammals , including bowhead whales and walruses .

鱼类行为的研究是搞清鱼类洄游路线、提高捕捞效率、保护渔业资源的重要基础。

The purpose of studying fish behavior is to find out fish migration routes and improve capture efficiency , which gives an important foundation for the protection of fishery resources .

物理环境适合度与鳀鱼的分布有着良好的匹配，适合度由低到高的负梯度方向决定了鳀鱼的越冬洄游路线，适合度高值区恰是越冬鳀鱼的密集区；

The physical environmental fitness matches very well with the distribution of anchovy . The negative gradient direction of the fitness determines the route of the wintering migration of anchovy , as the areas with highest fitness just coincide with the areas with highest density of wintering anchovy .

上世纪，商业性捕鱼和阻挡洄游产卵路线的水坝建设导致其数量骤减。

Its population was decimated in the past century by commercial fishing and dams that sealed off its migratory spawning routes .