How global warming affects whales?

Fekla Derbinet

Table of Contents:What do scientists predict?Forced Whale MigrationWhales are an important part of the marine ecosystemThe role of Whales in climate processes

The earth's climate is changing and global warming is affecting human life, but it is having a greater impact on plant and animal life.

Climate change is making life difficult for the whales, the great inhabitants of polar waters. The warming of the world's oceans and melting of glaciers change the composition of ocean plankton, causing the habitat of large whales to shrink. They have to change their feeding grounds and compete with each other for food, which prevents them from reproducing successfully.

What do scientists predict?

In 2018, Australian scientists predicted, based on one of the effects of global warming (decline in the crustacean population), that the number of baleen whales in the Southern Ocean will also decline.

Another example of the impact of climate on whale demography is the decline in the birth rate of North Atlantic humpback whales (Megaptera novaeangliae). The fact is that herring have all but disappeared from the warming Gulf of St. Lawrence off the coast of Canada in the past decade; it was the main prey of humpback whales, which migrate there every summer.

Forced Whale Migration

Climate change negatively affects the period and ways of animal migration. For several years now, the population of polar whales (Balaena mysticetus) has been skipping the migration cycle and wintering off the coast of Canada, Amundsen Bay and the Beaufort Sea. Instead of returning to the Bering Sea in the fall, the whales remain in areas that were usually only used for feeding in the summer.

Biologists explain this unusual behavior by two factors: an increase in water temperature (polar whales are no longer comfortable to return to southern waters) and the desire to avoid encounters with predatory killer whales, whose habitat is constantly expanding, again due to the warming of the world ocean.

Whales are an important part of the marine ecosystem

It is difficult to overestimate the importance of whales for the marine ecosystem: the life of all its inhabitants is built around these "ocean engineers". For example, when this link in the food chain is weakened, killer whales prey on small mammals like sea otters; declining numbers of sea otters lead to an invasion of sea urchins, which destroy algae colonies in the North Atlantic, limiting the ocean's ability to sequester carbon from the atmosphere.

The role of Whales in climate processes

Whales produce large quantities of iron-rich excrement, creating ideal conditions for phytoplankton, which absorbs up to 40% of the carbon dioxide we produce.

The life cycle of whales plays an important role in climate processes: their enormous bodies store tons of carbon, which sinks to the ocean floor after the animal's death. Thus, carbon is removed from the carbon cycle and stored in the form of bottom sediments. When a whale is killed and cut up on land, all the carbon stored in its carcass is sooner or later released into the atmosphere.

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