These were manatees, which belong to the order Sirenia, like the dugong and Steller's sea cow. Harmless and unaggressive, these fine animals were six to seven meters long and must have weighed at least 4,000 kilograms each. I told Ned Land and Conseil that farseeing nature had given these mammals a major role to play. In essence, manatees, like seals, are designed to graze the underwater prairies, destroying the clusters of weeds that obstruct the mouths of tropical rivers.

这些海牛像海马和大海马一样，属于人鱼目。这些美丽、安详、温顺的动物，长6至7米，体重至少有4000公斤。我告诉尼德·兰和康塞尔，有远见的造物主赋予这些哺乳动物一个重要的角色。的确，正是它们，像海豹一样，以海中的海草为食，把阻塞热带河流出海口的大面积海草消灭掉。

"And do you know," I added, "what happened since man has almost completely wiped out these beneficial races?Rotting weeds have poisoned the air, and this poisoned air causes the yellow fever that devastates these wonderful countries. This toxic vegetation has increased beneath the seas of the Torrid Zone, so the disease spreads unchecked from the mouth of the Rio de la Plata to Florida!"

“你们知道吗，”我补充说，“当人类差不多将这些有用的动物种类统统消灭光时，会有什么后果吗？那就是，腐烂了的海草就会毒化空气，而有毒的空气，会导致黄热病，使这个富饶的地区变得一片荒凉。而有害的植物就会蔓延滋长在这片酷热的海里，疾病就会不可抵制地从普拉塔的里约河口，一直蔓延到佛罗里达。”

And if Professor Toussenel is correct, this plague is nothing compared to the scourge that will strike our descendants once the seas are depopulated of whales and seals. By then, crowded with jellyfish, squid, and other devilfish, the oceans will have become huge centers of infection, because their waves will no longer possess "these huge stomachs that God has entrusted with scouring the surface of the sea."

但如果按杜斯耐尔的观点，这种灾难比起海里的鲸鱼和海豹数量减少而带给我们的后代的灾难来说，那还不算什么。因为现在海里不再存在着那些“上帝派来清扫海面的大胃口动物”，海洋里到处充斥着章鱼、水母和槍，乌贼，海洋将变成一个巨大的疾病传染源。

Meanwhile, without scorning these theories, the Nautilus's crew captured half a dozen manatees.In essence, it was an issue of stocking the larder with excellent red meat, even better than beef or veal.

然而，尽管明了这些道理，“鹦鹉螺号”船上的人还是捕捉了6只海牛。这其实是为了充实船上的食品储备，这种美味的海牛肉比牛肉和小牛肉还好吃。