Huge Marine Heat wave Killed 4 Million Alaska Seabirds: Study

Why in the news?

  • Study Published: A new study in Science revealed the devastating impact of a marine heatwave on Alaskan seabirds.
  • Record-breaking Event: The heatwave, dubbed “The Blob,” occurred from 2014 to 2016, causing the largest documented die-off of a single wild bird species.

HUGE MARINE HEAT WAVE KILLED 4 MILLION ALASKA SEABIRDS: STUDY

Key Findings

  • Mass Die-off: Over 4 million common murres perished due to the marine heatwave.
  • Domino Effect: Warm waters disrupted the food chain, collapsing fish populations critical for murres’ survival.
  • Ongoing Impact: Eight years later, the murres show no signs of recovery, raising concerns about recurring events.

Significance of the Findings

  • Global Warming Link: Oceans have absorbed over 90% of excess heat from burning fossil fuels, severely impacting marine ecosystems like coral reefs and kelp forests.
  • Food Web Disruption: While some marine species survived, “pinch points” in the food web caused catastrophic effects on murres and other species.

Study Methodology

  • Data Analysis: Researchers compared bird counts at 13 breeding colonies in the Gulf of Alaska and Eastern Bering Sea.
  • Extrapolated Results: Declines observed across colonies highlighted widespread impacts of the heatwave.
  • Broader Implications: The study underscores the increasing frequency of such climate events and their devastating ecological consequences.

Marine Heatwave

  • Definition: Marine heatwaves are prolonged periods of abnormally high sea surface temperatures that exceed the seasonal average.
  • Causes:
  • Climate Change: Global warming due to greenhouse gas emissions is a major driver.
  • Ocean Currents: Changes or stagnation in currents can trap heat in certain regions.
  • Natural Phenomena: Events like El Niño intensify marine heatwaves.
  • Effects on Ecosystems:
  • Disrupted Food Chains: Affects plankton, fish, and larger predators, leading to ecological imbalances.
  • Mass Die-offs: Significant mortality in marine species such as seabirds, corals, and fish.
  • Habitat Degradation: Coral bleaching and loss of kelp forests are common impacts.

Sources Referred:

PIB, The Hindu, Indian Express, Hindustan Times