Are we in a sixth extinction? That’s the question that can be raised as the outcome of a new Stanford-led study that reveals that the larger marine animals would mostly likely be the first ones to go extinct during the next mass extinction event.
Any why will this happen? Scientists believe that it is humans who are driving the larger marine animals towards extinction due to extensive fishing with larger animals being targeted for consumption purpose. In the study published yesterday [September 16] in the journal Science, scientists examined the association between extinction threat level and ecological traits including body size for mollusks and vertebrates over the past 500 years. Further they compared these with the long history of these marine animals over a period of 445 million years.
The team found that in current times and recent past, humans are targeting larger marine animals for food. In quantitative terms, scientists explain that for every factor of 10 increase in body mass the odds of the animal being at risk of extinction go up by a factor of 13 or so meaning that the larger you are, the greater the risk of going extinct.
Scientists add that this particular selective extinction of larger marine animals could have serious consequences for the health of marine ecosystems primarily because these larger marine animals are at the top of the food chain and their movements through the water column and the seafloor help cycle nutrients through the oceans.
The team didn’t directly examine why large modern marine animals are at higher risk of extinction; however, their findings are consistent with a growing body of scientific literature that point to humans as the main culprits. Comparing with land based extinction there is evidence that ancient humans were responsible for the massacre of mammoths and other megafauna across the globe.
This effectively means that as soon as humans enter a particular ecosystem, the largest of animals are the first targets. This effect will be seen in marine ecosystem as well and with technological advancements that allow us to carry out fishing in some of the deepest of oceans, the day is not far when the repercussions will be huge.