Context:
As per a new study, population swings in eastern North Pacific grey whales — some of which have resulted in recent mass mortality events — are driven by changing prey biomass and ice cover in the Arctic.
Relevance:
GS III: Environment and Ecology
Dimensions of the Article:
- About Grey Whales
- Conservation Status
About Grey Whales:
- Grey whales are fascinating marine mammals known for their unique characteristics and behaviors.
Here are some key points about them:
- Physical Features: Grey whales are recognized by their humpbacked appearance and the presence of a ridge of sharp bumps along their backs instead of a dorsal fin.
- Dietary Habits: They belong to the group of baleen whales, which means they use special bristly structures in their mouths (baleen plates) to filter food, such as small crustaceans, from the water.
- Habitat: Grey whales primarily inhabit shallow coastal waters in the North Pacific Ocean. While feeding, they stay close to the shore. During migration, they sometimes venture into deeper waters far from the coast.
- Geographic Distribution: There are two distinct populations of grey whales in the North Pacific:
- The eastern North Pacific stock or DPS, found along the west coast of North America.
- The western North Pacific stock or DPS, primarily found along the coast of eastern Asia.
Migration Journey:
- Grey whales are famous for their remarkable migrations, which can cover up to 12,000 miles round trip.
- Western grey whales migrate between their summer feeding grounds near Sahkalin Island, Russia, and their winter feeding grounds in the South China Sea.
- Eastern grey whales migrate from the Bering and Chukchi Seas in Alaska and Russia to the west coast of the United States and Mexico for breeding and calving during the winter.
Conservation Status:
- Grey whales have different conservation statuses based on their geographic populations.
- The western grey whale is classified as “Critically Endangered” by the IUCN (International Union for Conservation of Nature), while the eastern grey whale is categorized as “Least Concern.”
- This distinction reflects the varying population trends and threats faced by these two groups.
-Source: The Hindu
