North Atlantic right whales have become critically endangered as a result of climate change-induced warming in the oceans, a new study says.
Researchers said temperatures in the Gulf of Maine have driven the species from its traditional and protected habitat and into more lethal and unsafe waters.
Warming in the Gulf of Maine has been rising faster than 99 per cent of the global oceans over the past decade, reducing the abundance of copepods – tiny fatty crustaceans that make up the whale’s main food source.
As a result, the whales now travel north-east to the Gulf of St Lawrence in Canada to forage for food. Since 2015, scientists have seen an increased number of right whales feeding in the region.
But the Gulf of St Lawrence, an area with significant ship traffic and fishing, did not have protections in place to prevent ship strikes and fishing gear entanglement.
In 2017, 17 right whale carcasses were discovered, 12 of which were found in the Gulf of St Lawrence.
The number of female whales reproducing has also declined at the same time. In 2009, 39 right whale calves were born – a record-high for the species. But birthrates have since dropped significantly and in the beginning of 2018, no calves were born.
At the beginning of the decade, the population numbered more than 500. Now, the North Atlantic Right Whale Consortium estimates the population at just 356 whales. The species is considered critically endangered.
The study, published this week in the journal Oceanography, is based on a years-long analysis of plankton, right whale sightings and ocean temperatures fluctuations.
At its current course, the right whale populations will decline and potentially become extinct in the coming decades, scientists believe.
Senior study author and professor in the Department of Earth and Atmospheric Sciences at Cornell, Charles Greene, said: “Due to a warming climate, the Atlantic Meridional Overturning Circulation is slowing down, causing the Gulf Stream to move North, injecting warmer and saltier slope water into the Gulf of Maine.”