Sharks help keep climate change at bay

A boat trip from Walvis Bay or Lüderitz on the Atlantic Ocean is a highlight for tourists in Namibia. A champagne breakfast, watching dolphins and seals passing by is pure bliss. When lucky, even a whale or two can be spotted and a shark's fin is the only visible sign that one of these predators is also around.

Sharks are dangerous, yes, but they help keep the ecological balance in the oceans in check.

“Sharks play a crucial role in marine ecosystems, which has a previously overlooked impact on global climate change,” writes Generose Kaveruire Korukuve in the online magazine Conservation Namibia. „Sharks have a significant impact on the ocean's ability to produce oxygen, absorb carbon dioxide, and regulate acidity.  This efficient absorption is due to photosynthesizing plankton (known as phytoplankton)”, according to Korukuve.  Phytoplankton are microscopic organisms that produce a large amount of oxygen. Namibia has 52 shark species along its coastline.

Many fish species feed on plankton and this prevents excessive growth of phytoplankton, otherwise harmful algae blooms are caused, often called red tide.

The populations of these fish species increase unchecked, to avoid ''overgrazing'' on the phytoplankton.

Sharks again feed on these fish species and thus keep their populations from exploding.

In this way, sharks support the ocean's ability to absorb carbon dioxide from the atmosphere, produce oxygen via phytoplankton and slow down the rate of climate change.

But sharks face challenges due to climate change as ocean waters warm up. To gain more insight

into sharks and rays, the Namibia's Rays and Sharks (NaRaS) project was recently established under the auspices of the Namibia Nature Foundation.

Brigitte Weidlich