Biodiversity Loss and (What is Not) Rocket Science

It’s the habitat, stupid!

Such a well-worn phrase – or something close to it – could serve as a tag line for the alarming report on biodiversity loss released in summary form this week by the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES).

The report doesn’t mince words about the fact that human impacts on marine and terrestrial landscapes are creating an ecological and biological armageddon. Decreasing organic carbon in soils, collapsing populations of pollinators, the shrinking of coral reefs and coastal habitats, and the replacement of native species with scrappy invaders are some of the signature indicators of this calamity. A giant blenderizing is occurring as biotic communities the world over are losing both their vitality and their distinctiveness.

In a single line that caught most of the headlines, the report noted how a million species are heading towards extinction within decades. This is highly distressing news on its own. It gets worse when you realize how much humanity depends on these co-inhabitants for our economies, our health, and perhaps also our psychological well-being.

I used to be a part-time commercial fisherman in Alaska. For a couple of decades, I seined, trolled, and packed salmon for several weeks each summer in Prince William Sound, Bristol Bay, and among islands cloaked by the deep green hues of the Tongass forest. There was lots to love about those summers. The native and immigrant working cultures in which I was immersed, the cetaceans and pinnipeds who graciously shared the marine environment with me, the ravens and bald eagles presiding over foot-thick carpets of moss on the forest floor…each of these elements of the experience was deeply enlivening.

Amongst the mind-bending array of life on display, it was perhaps the sheer profusion of the salmon that was most eye-opening. Alaskan salmon fisheries are generally well-managed. The length of the openers and the permitted harvest sizes are strictly determined by careful aerial observations of the returning fish. Living and working in the midst of this profusion, it was not uncommon to see tens of thousands of salmon making the water boil in a purse seine net, to walk a footbridge over a throbbing creek filled bank to bank with fish laboring towards spawning grounds, or to watch hundreds of salmon a day succumb to the claws of bears, the talons of eagles, or the sheer exhaustion of converting their bodies to fresh water as they left the ocean and headed up the creeks on their final journey.

While good management is important, it was obvious to even to a non-expert like me that good habitat is even more essential. The abundance of uncompromised wetlands, clear-flowing creeks, cold inland lakes, and near-pristine waterways are what make the salmon fisheries of Alaska so fertile. Without these sanctuaries, the returning salmon would have nowhere to go to lay their precious cargo of several thousand eggs. There would be no place for the newly hatched fry to spend their early months nourishing themselves. The developing smolts would lack a clear migration passage out to the ocean to attain their full size and vigor in the competitive marine environment.

Put quite simply….no quality habitat, no stable salmon returns.

The planet has just a few more decades of human population growth before declining fertility rates will open up the possibility of large scale restoration of land no longer needed for agriculture. Of course there is no need to wait out those decades. In addition to constraining consumption, limiting growth, and increasing production efficiencies now, the restoration and rewilding of suitable spaces on current landscapes has startling potential for stemming the tide of species loss.

The IPBES report made clear that “prompt ecological restoration emphasizing the use of native species can offset current degradation and save many endangered species.” This can occur on scales that range from hundreds of thousands of acres in a watershed to a few square feet of a back yard garden plot.

On a rewilded farm in southern England, all five species of UK owls, rare purple emperor butterflies and migrating black storks have found their way back onto habitat recently freed from the yoke of agriculture. In a river whose dam has been removed in coastal Washington State, thousands of chinook salmon have started swimming towards spawning grounds they had not visited in nearly a century. In a backyard filled with native plants where chemical treatments have been banished, pollinators of all kinds are rapidly regaining a toe-hold. As naturally forgiving creatures, these returning organisms will eagerly spread their good work across any landscape they are permitted to re-claim. From the multi-billion dollar Everglades Restoration Plan to volunteer efforts to revegetate a few feet of an urban stream, recreating habitat is a key strategy for reversing the tide of species loss.

The IPBES report was a timely reminder that climate change has a companion crisis of equally significant scale. As much, and perhaps even more than is the case with the climate challenge, the biodiversity crisis has solutions available now that will bring real results. At each step taken to address this challenge, humans will have natural allies in the form of tens of millions of swimming, flying, and leaping fellow denizens of this earth eager to resume their role in a rebuilt ecosystem.

It is here we can find some much needed comfort and optimism. For us and our fellow creatures, a simple but adequate place to live, a reliable food supply, and the conviviality of a few fellow-members of our clan can be enough for us to flourish. The rebound in biodiversity could be dramatic.

The word ‘habitat’ has its roots in the idea of a ‘dwelling place.’ The word is also connected through proto-Indo-European languages to the idea of ‘giving’ and ‘receiving.’

In the face of the IPBES report, many high-consuming members of our species are clearly going to need to do some giving. If this can be made to happen, just think for a moment about what we stand to receive.

 

Coral image by Milos Prelevic
Salmon image by Katmai National Park and Preserve