When it rains, it floods. But what about our species? When they decline, do they also collapse?

The confluence of a few events has made me worry about this lately.

First, there was my series of posts about the collapse of Chinook salmon. In the Central Valley, only 90,000 adult Chinook returned last year, and scientists predict that as few as 58,000 will return this year. The numbers are even lower on the Klamath. Commercial fishing in these areas has been banned as a result.

Yesterday, there was a similar story concerning Chesapeake Bay blue crabs. The governors of both Virginia and Maryland pledged to cut back on the harvest of this struggling species which continued to be over-fished.

These are only two examples. There are many others. American bee populations are dying from what Elizabeth Kolbert described as an AIDS-like epidemic. Monarch butterflies are threatened by deforestation. Polar bears are starving to death. Our oceans are being bulldozed by bottom trawlers. The list goes on.

After years of inaction, people are waking up to the problem. The Washington Post quoted Virginia's Governor Tim Kaine as saying: "The price of inaction is greater than the price of action. We do not want to wake up in five or 10 years and realize we've lost this very important part of who we are."

As drastic as the cuts are, the decision hinges on the belief that these species can recover. Kaine said the cuts would only be in place for two to three years until the population rebounds.

But what if this belief in short-term species recovery is unreasonable? What if we've past the tipping point?

In Gus Speth's new and powerful book, The Bridge at the End of the World, Stephen Meyer offers this grim forecast.

Over the next 100 years or so as many as half of the earth's species, representing a quarter of the planet's genetic stock, will functionally if not completely disappear... Nothing - not national or international laws, global bioreserves, local sustainability schemes, or even ‘wildlands' fantasies - can change the current course. The broad path for biological evolution is now set for the next several million years. And in this sense the extinction crisis - the race to save the composition, structure, and organization of biodiversity as it exists today-is over, and we have lost.

Is this accurate? I don't know.

But we do know that the Chinook, the Chesapeake blue crab, and American bee colonies, are all collapsing. We know that this is threatening the continued vitality of local, state and national economies, and of coastal ways of life. And we know that it is largely our fault.

Despite all of this, I remain optimistic. Small as the environmental movement remains, I'm reminded of Margaret Mead's famous words, in which she urged us to believe that a "small, dedicated group could change the world. Indeed, it is the only thing that ever has."

Let us hope she was right.