The Risk of Extinction Cascades

Samantha Zeitz

Researchers from the University of Exeter say that the risk of extinction cascades is increasing. They have seen that the loss of one species can cause damage to a species that doesn’t have a direct link.

An extinction cascade is when there is a secondary extinction that is triggered from an indirect primary extinction. Without another species to fall in line in the food chain after extinction, other species are put in jeopardy.

Extinction rates are higher than ever, with many more at risk. Ecological experts insist that human activity is the leading cause of extinction and continues to limit biodiversity. Doctor Dirk Sanders of the Centre for Ecology and Conservation at the University of Exeter says research has been conducted to narrow down which food webs are at high risk.

According to experiments conducted by University of Exeter researchers, simple communities can be more vulnerable to extinction cascades than a complex food web. They tested their theory by removing one species of wasp that resulted in a secondary extinction that was indirectly linked. That species was at the same level on the food web as the wasp. More complex food webs might not face the same impact because it’s more likely that another species could fill the void in the web.

Some species have already faced the reality of extinction including the Caribbean Monk Seal Nasal Mite. It was declared extinct after it’s host, the Caribbean Monk Seal met the cruel fate first, less than 100 years ago. The Lake Pedder Earthworm also bit the dust after being faced with human activity. These earthworms lived in Lake Pedder, which was purposely flooded in 1972 during construction of a hydroelectric facility.