2 June 2016
A fashion for otter fur in the 19th Century has given researchers insight into how social changes can be a warning for ecosystems on the brink of collapse.

In a new paper published today in the journal Frontiers in Ecology and the Environment, scientists argue that environmental managers need to broaden their focus from routine ecological monitoring to include social and economic factors if we are to protect ecosystems before it is too late.

As part of the study, the team at Lancaster University, Stanford University, Conservation International, and the ARC Centre of Excellence for Coral Reef Studies at James Cook University looked back into history to examine four iconic marine ecosystems that collapsed, investigating the social changes that preceded their demise.

From the dramatic decline in Canadian cod populations to the decimation of Jamaican coral reefs, they found social factors from fashion to technological advances had a strong influence in driving environmental collapses.

For example, in the North Pacific, otter populations had been harvested by native hunters for thousands of years but were driven close to extinction by commercial hunting in the 1800s due to lucrative foreign markets for otter fur, which saw the value of otter pelts leap from a mere $15 to over $28,000 for a single pelt at the height of the market. The near extinction of otter populations created an explosion in urchin densities that diminished kelp forests and associated fish and invertebrates.

“Sometimes ecosystems can undergo major changes in species composition, known as a regime shift, and although these shifts appear to unfold quickly, it often takes decades to get to that point. Undoing the damage is not easy,” said lead author Christina Hicks of Lancaster University Environment Centre.

“By examining these four iconic marine regime shifts, we found that in all cases a range of social factors set the scene for the ecosystem shift, ultimately driving them towards collapse.”

Researchers say their new study underlines the importance of looking beyond ecological systems for clues, to understanding the root social causes that may forewarn when and where we are heading into dangerous waters.

“If we can tune into these social drivers we could potentially use them as an early warning signal of ecosystems at risk. This is really important if we want to spot these changes before they happen and take action,” explained co-author Larry Crowder of Stanford University.

“Without knowing the root social drivers, we can get caught in a trap of treating the symptoms, rather than the underlying causes of the disease – this is critical for saving ecosystems before they are irreversibly lost.”