By Adam Vaunghan
Humanity is driving an unprecedented extinction of sealife (click here) unlike any in the fossil record, hunting and killing larger species in a way that will disrupt ocean ecosystems for millions of years, scientists have found.
A new analysis of the five mass extinction events millions of years ago discovered there was either no pattern to which marine species were lost, or smaller species were the ones that disappeared.
But today’s “sixth extinction” is unique in the way that the largest species, such as great white sharks, blue whales and southern bluefin tuna, are being pushed to the brink, due to humans’ tendency to fish for larger species more often than smaller ones....
...The danger is disproportionate to the percentage of threatened species, with the authors warning the loss of giants would “disrupt ecosystems for millions of years even at levels of taxonomic loss far below those of previous mass extinctions”.
The loss of larger species in the oceans could have knock-on effects on ecosystems, Payne said, citing the loss of very large predatory seasnails (Triton) from coral reefs, which appears to be one of the reasons behind the explosive growth in numbers of crown of thorns starfish, which eat coral.
Humans would be affected by such trends too, he said, as communities rely on coral reefs to attract tourism. He also pointed to the examples of tuna and cod, whose extinction would deprive people of an important source of income and protein....
