But many marine biologists worry that politicians lack the will to sacrifice jobs for cod.

But he also says that most biologists would not worry about commercial whaling of minkes and perhaps other populous species so long as quotas were set at a level that would sustain populations.

And biologists worry that the Missouri is only the latest river to get the disease, not the last.

And even after the Cambrian, the chain of events leading to man appears to be so special, so chancy, that biologists worry it might never have happened.

Since the 1930s, wildlife management and biologists have worried that artificial feeding spreads disease among animals.

Some biologists have worried that such encounters - increasingly frequent with a rise in ecotourism - may harm the penguins and other animals whose habitats are invaded by human visitors.

Why don't evolutionary biologists worry about the Cambrian Explosion, when invertebrates showed up on earth as if out of nowhere?

Having reached saturation point on the main island of the archipelago, the beavers have swum to several outlying islands and that makes biologists worry about an eventual continental invasion.

But biologists worry that any reduction in the diversity of life in the river could disrupt its ecology.

But for a few years, biologists and government officials have worried that if the record-breaking hauls continue, lobsters may go the way of the cod - fished to the brink of extinction - if they are not protected.