Salmo,

Here's one I read about in some journal a couple of years ago. Unfortunately I don't have a clue which one it was in.

Overfishing of salmon in Alaska is actually causing the destruction of kelp beds, which are home, spawning and rearing habitat, to multitudes of fish and marine life.

Here's how it worked...

With diminishing salmon, the killer whales were consuming sea otters at a greatly elevated rate. Less sea otters meant many more sea urchins, one of their major foods. Sea urchins eat kelp.

A classic example of how overfishing a river fifty miles from the ocean can affect the ling cod population off shore, or many other fish and sea life.

Fish on...

Todd.