According to a report by the animal protection organization Whale and Dolphin Conservation (WDC), the consequences of climate change are increasingly threatening whales and dolphins. The warming of the seas is having a dramatic impact on a variety of species, according to the report “Whales in Hot Water”, which was published on the occasion of the UN Climate Change Conference (COP28) meeting in Dubai.
The habitats of whales and dolphins are changing so quickly that species compete with each other – and sometimes fight each other. As temperatures rise, algae blooms that release toxins are increasing.
The consequences
According to the WDC, they are increasingly being found in dead whales and dolphins. The poisons could also slow down the ability of marine mammals to react. This put them at even greater risk of colliding with ships.
According to the report, at least 343 baleen whales died in Chile in 2015 – extremely high concentrations of the paralyzing toxins were detected in more than two thirds of the animals (69 percent). “The sudden mass extinction is most likely due to an algae bloom,” writes the organization.
The animals are also increasingly moving into new and sometimes heavily used waters, not least of which increases the risk of collisions with ships. According to the WDC, the marine mammals can also become more susceptible to disease.
Almost two-thirds of disease outbreaks in whales and dolphins (61 percent) occurred during periods of increased sea surface temperatures, which are expected to become longer and more frequent with climate change.
Sometimes there are fights between related species. Increasing heat events caused bottlenose dolphins to relocate to areas with California harbor porpoises. There, bottlenose dolphins increasingly attacked their smaller relatives, often with fatal outcomes.
According to the WDC, the decline of krill as one of the most important food sources for baleen whales is also a problem. It is being decimated by industrial fishing and warmer sea temperatures. In the Southern Ocean, where whales migrate in the polar summer, krill abundance has declined by 30 percent since the 1980s.
A decline of 16 to 19 percent is forecast for the Pacific and Atlantic by 2100. With the food shortage, marine mammals would be able to store less fat and would no longer have enough energy for their seasonal migrations. It has also been observed that many animals no longer migrate to warmer waters to mate. Result: fewer young animals.
This way the animals could still be saved
The Paris Agreement’s goal of limiting global temperature rise to 1.5 degrees, if possible, must be pushed forward, the organization said. Effective protected areas should also be established that are of particular importance for the animals: areas in which they can feed, reproduce and migrate.
Fishing equipment is also a major threat to whales and dolphins. Governments and industry must ban destructive fishing practices. There must be catch limits and alternative fishing gear that reduce bycatch.
