Giving Compass' Take:

•  According to new research, the impacts of climate change on dolphins and marine life are more severe than scientists previously thought. 

• After collecting data for 10 years, researchers found that dolphins' survival rates decreased by 12 percent after the heat wave of 2011 and female dolphins gave birth less often. How are environmental philanthropists responding?

• Read about how climate change affects fisheries.

Climate change may have more far-reaching consequences for the conservation of marine mammals than previously thought, according to new research.

In Shark Bay in Western Australia in early 2011, a heat wave caused the water temperatures to rise to more than four degrees above the annual average. The extended period caused a substantial loss of seagrass, which drives the Shark Bay ecosystem, in this coastal area, a UNESCO world heritage site.

Researchers investigated how this environmental damage has affected survival and reproduction of dolphins using used long-term data on hundreds of animals collected over a 10-year period from 2007 to 2017. Their analyses revealed that the dolphins’ survival rate had fallen by 12 percent following the heat wave of 2011. Moreover, female dolphins were giving birth to fewer calves—a phenomenon that lasted at least until 2017.

“The extent of the negative influence of the heat wave surprised us,” says first author Sonja Wild, former PhD candidate at the University of Leeds. “It is particularly unusual that the reproductive success of females appears to have not returned to normal levels, even after six years.”

There are several possible explanations for this phenomenon, for instance neglect of calves, increased newborn mortality, delayed sexual maturity, or a combination thereof, but researchers have not yet been able to investigate them in detail.

Interestingly, the heat wave did not have the same effect on all dolphin groups. Dolphins that use sponges as tools—a socially learned foraging technique that helps dolphins locate food in deep water—were not as badly affected as those that do not use this technique.

The researchers show in their study for the first time that marine heat waves not only affect organisms at lower levels of the food chain, but also might have considerable long-term consequences for the animals at the top, such as dolphins.

Read the full article about climate change impact on dolphins at Futurity.