A paper published by the National Academy of Sciences in 2003 hypothesized that overfishing of great baleen and sperm whales in the North Pacific Ocean triggered one of the longest and most complex ecological chain reactions ever described, beginning in the open oceans 50 years ago, and leading to the decimation of Alaska’s kelp forest ecosystems today.

It started with the capture of hundreds of thousands of great whales from the North Pacific Ocean from 1946 to 1979. The paper’s eight authors argue that this removal of prey forced some killer whales to seek alternative sources of food. Beginning with harbor seals (populations collapsed early 70’s - early 80’s) then fur seals (mid 70’s - mid 80’s), then sea lions (late 70’s - 90 ‘s), the killer whales targeted populations of small, coastal marine mammals.

As the seals and sea lions became comparatively rare, some killer whales expanded their diet to include sea otters with rippling ecosystem effects. By the late 1990’s low numbers of sea otters allowed an explosion of sea urchins  - the otters' favorite prey species - and decimation of the kelp forests due to the urchins' over grazing, (For the complete report see http://www.compassonline.org/pdf_files/PR_2003_9_22.pdf )