1·Wildlife like polar bears and walruses that depend on sea ice to live is also in danger.
像北极熊和海象这样依靠海冰生存的野生动物也处于危险之中。
2·Each spring, thousands of walruses return to the Walrus Islands in northern Bristol Bay to feed, rest, and sometimes die.
每年春天，成千上万只海象返回到布里斯托尔湾北部的海象群岛觅食、休憩、有时死亡。
3·Moreover, walruses and seals drive themselves through the water with thrusts of their hind flippers, but sea lions use their front flippers.
此外，海象和海豹用它们的后鳍推动自己在水中运动，而海狮用它们的前鳍。
4·Biologists have long maintained that two groups of pinnipeds, sea lions and walruses, are descended from response to similar environmental pressures.
生物学家们长期认为，两类鳍脚亚目动物，即海狮和海象，都是从一种陆地上的类似于熊的动物繁衍而来的。
5·Each spring thousands of walruses return to the walrus Islands in northern Bristol Bay to feed, rest, and sometimes die.
每年春天，成千上万的海象返回到布里斯托尔海湾北部的海象群岛，喂养、休憩、有时死亡。