A group of University of Zurich researchers has found a link between heatwaves and declining birth rates in dolphins. Dolphins, like polar bears, sea turtles, countless reptile species and marine flora, are now included species vulnerable to a warming planet.
The report, released on April 1st, 2019, showed that a severe 2011 heatwave in Western Australia caused birth rates in dolphins to decline for 6 years following the event, and increased the death rate by 12%. They used aggregate data from a 10-year period from 2007 – 2017.
“Marine heatwaves are likely to occur more frequently in the future due to climate change,” says study leader Michael Krützen, a professor at the Department of Anthropology at the University of Zurich. “This is worrying not only for the long-term prospects of marine mammal populations but also for the entire oceanic ecosystems.”
Lead author, Sonja Wild, a former Ph.D. candidate at the University of Leeds adds, ”The extent of the negative influence of the heatwave surprised us…It is particularly unusual that the reproductive success of females appears to have not returned to normal levels, even after six years.” The study adds that there are several scientific and/or social explanations for this phenomenon, for instance, neglect of calves, increased newborn mortality, and/or delayed sexual maturity.
Read more from the Study, here.