Climate Change Is Killing Dolphins, According To New Study

A heatwave caused a significant drop in the survival rate of dolphins.

A bottlenose dolphin swims in Key Largo, Florida
Joe Raedle / Getty Images

A heatwave caused a significant drop in the survival rate of dolphins.

People love dolphins, but according to a new science report published in Current Biology, the global effects of climate change could have a catastrophic impact on dolphin populations.

As USA Today reports, Western Australia’s Shark Bay experienced a heat wave in 2011, with temperatures that rose as much as 7 degrees Fahrenheit above the average levels. This damaged the local seagrass population, resulting in the survival rate of local dolphins decreasing to a shocking 12 percent. It also caused a significant drop in dolphin birth rates, which did not recover in the years following the 2011 warming. According to Sonja Wild, a lead author of the study, “It is particularly unusual that the reproductive success of females appears to have not returned to normal levels, even after six years.”

CNN reports that while the negative consequences of the heatwave are clear, studies still need to be done to further determine the cause of the lowered birth and survival rates. While the decline in seagrass — which provides shelter and food to many Shark Bay inhabitants — is a key factor, other ones require more research. It’s possible that the hotter climate made it more challenging for young dolphins to survive, or delayed their sexual maturity. It has also been speculated that the unexpected heat may have caused dolphin parents to neglect their children in a way they wouldn’t have otherwise.

Many more heat waves, like the one that occurred in 2011, are likely to happen in the future, and climate change is predicted to have a particularly devastating impact on the world’s oceans. The oceans have been heating up at a hastening rate since the 1960s, and dolphins are far from the only life form impacted, as recent studies have shown a decline in the fish population.

Loading...

Dolphins are beloved by many people around the world. When asked how to save the intelligent mammals, study author Michael Krützen —also the director of the Department of Anthropology at the University of Zurich — puts it bluntly, “Stop using fossil fuels.”

Though all Shark Bay dolphins suffered consequences from the heatwave, some groups managed to get by better than others. Dolphins who used sponges as hunting tools were less severely impacted than others, in the short term, but further studies will be necessary to indicate longterm effects within this population. Regardless, the University of Zurich notes that this study shows the devastating impact that marine heat waves can — and will — have on animals at the top of the food chain, such as dolphins, as well as those on lower levels.