Sharks May Lose Their Hunting Abilities and Sense of Smell with Climate Change
Climate change may drastically impact the hunting ability of sharks. As CO2 levels increase and as ocean waters warm, researchers have found that sharks may be unable to meet their energy demands.
In this latest study, the researchers conducted experiments in large tanks with natural habitat and prey. They found that embryonic development was faster under elevated temperatures. However, the combination of warmer water and high CO2 increased the sharks' energy requirement, reduced metabolic efficiency and removed the sharks' ability to located food through their sense of smell. This, in particular, led to marked reductions in growth rates of sharks.
"In warmer water, sharks are hungrier but with increased CO2 they won't be able to find their food," said Ivan Nagelkerken, one of the researchers, in a news release. "With a reduced ability to hunt, sharks will no longer be able to exert the same top-down control over the marine food webs, which is essential for maintaining healthy ocean ecosystems."
Sharks are already facing environmental threats from humans. Shark fins are regularly harvested in order to meet growing demands in Asia. With the impacts of climate change, though, it's more important than ever to put conservation policies into place.
"One-third of shark and ray species are already threatened worldwide because of overfishing," said Sean Connell, one of the researchers. "Climate change and ocean acidification are going to add another layer of stress and accelerate those extinction rates."
The findings are published in the journal Scientific Reports.
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