Climate change’s deadly impact on marine life in South Africa

The climate crisis has various faces and its effects continue to alarm the scientific community. The subject of a new study is the upwelling of deep water, a phenomenon responsible for a massacre of marine animals in South Africa

Climate change spares nothing and no one. It has dramatic impacts on global fauna and flora, and off the coast of South Africa, it has led to a massive die-off of marine animals from 81 different species.

Dozens of sharks, rays, and other specimens died in the year 2021, and researchers can now explain exactly what happened to the marine megafauna in these waters. A new scientific study published in the journal Nature Climate Change reports on this.

A group of scientists analyzed this terrible mass mortality event that occurred in 2021 and discovered that the climate crisis is responsible for an increase in the upwelling of deep waters, leaving no escape for sea inhabitants.

The phenomenon is known as upwelling and is a process that occurs due to the action of the wind which, by “pushing away” the surface water, promotes the rise of deeper, colder, and nutrient-rich ocean waters.

It’s a trap that can prove fatal for marine fauna. Many marine animals have died in these upwelling currents, with no possibility of escape. Their carcasses were recovered on African beaches.

The researchers documented the event in detail, initially monitoring a bull shark, Carcharhinus leucas, and subsequently other sharks. The study’s findings show that the intensity and frequency of the upwelling of deep ocean waters have increased locally between 1981 and 2022.

The data are disturbing, according to the researchers, as they highlight the further pressures on an already extremely fragile biodiversity. These are consequences upon consequences, a formidable chain reaction, where everything is attributable to the climate crisis.

This highlights the potential impacts of increasing cold events and also the complexity of climate change on marine ecosystems as the oceans are generally warming, but climate change can simultaneously shift currents and winds to produce short but intense cold spells, explained Dr. Lubitz, the lead author of the study.

We know that climate change and abnormal water temperatures push subtropical species to explore new regions, expanding their range of distribution. But it is in these territories that they can fall victim to mass mortality events caused by upwelling.

Unlike other phenomena, the effects of these “cold waves” are still poorly studied. The scholars sound the alarm.

Source: Nature Climate Change

Condividi su Whatsapp Condividi su Linkedin