Methods for determining the age of whales improved.
In theory, such a framework should have guaranteed not only the survival of the world's great whales but their sustainable use for human benefit.
Work began on the 10 blue whales, and the catchers brought a further seven during the day: prospects were improving.
By that time, however, the local stocks of whales were becoming depleted.
If this were so elephants and whales would have language.
The examination of culture in whales and dolphins is not self-contained.
They then use these low standards to argue that some whales have unique cultures only matched by humans.
Size might be an obstacle to captive study of the large cetaceans, but the majority of toothed whales can be studied in captive settings.