Marine Predators Key for Keeping Climate Change in Check

It's no secret that greenhouse gas levels across the globe are approaching worrying levels, trapping heat and warming our seas. Marine habitats full of vegetation are some of the best 'carbon-sinks' out there, naturally mitigating greenhouse gas emissions. New research has found however, that if ocean predators decline, so will these essential seagrass beds, salt marshes, and mangroves.

"People typically think of predators and people as being in conflict," marine scientists Mike Heithaus, a researcher with Florida International University, said in a statement.

Like wolves on land, some people see sharks and other infamous marine predators as frightening threats. The fewer, they would say, the better. However, much like the apex predators of land, marine predators are responsible for keeping our delicate habitats in order.

"The presence of marine predators is good for us in many ways. They help to preserve ecosystems that support human uses like fisheries," Heithaus explained. "And the evidence continues to stack up that their contributions to the long-term stability of these ecosystems can help mitigate climate change through preserving carbon stores." (Scroll to read on...)

So what exactly is he talking about? The researcher and his colleagues recently set out to explore just how much costal habitats - known to bury carbon up-to 40 times faster than tropical forests - are maintained by ocean predators.

They quickly identified a strong correlation between habitat health and predator populations. The more predators there were to keep grazing sea-creatures in check, the more efficient a carbon sink a region could become.

Likewise, regions that were overfished -- meaning there wasn't enough food around to help sustain a strong predator population -- absorbed very little carbon.

"Scientists and policy makers around the world are just beginning to understand the importance of carbon stored in coastal vegetated habitats to climate policy," added James Fourqurean, an international advocate for the Blue Carbon initiative - which plants seagrass meadows to battle humanity's carbon footprint. "This new study highlights how fisheries practices have a surprising and strong impact of the stability of the coastal carbon stores. In effect, fishing activities can influence the rate of global climate change."

The results were recently published in the journal Nature Climate Change.

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