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How Marine Heatwaves are Changing Ocean Ecosystems

What we learned from a massive seabird die-off in the north Pacific


In order to protect park resources, we need to understand them. Monitoring allows us to track changes over time and identify when resources might be in trouble. Often the changes we detect are small, but sometimes they are large.

Between 2014 and 2016, there were two historically unprecedented events that coincided: an extreme marine heatwave and a massive seabird die-off. We knew that warm temperatures can stress marine life and we knew the seabirds starved to death. We didn't fully understand the connections between the heatwave and the seabird die-off until we looked more closely at monitoring data for the marine ecosystem. Those investigations revealed the many ways in which the food web was altered by the marine heatwave and the changes that followed contributed to the seabird die-off.

The National Park Service Southwest Alaska Network is part of a larger community of agencies and organizations that collect information about the marine ecosystem. By working together and sharing our knowledge, we can understand changes we see within a larger context of interconnections. Then we can better identify strategies that allow us to mitigate or adapt to these changes.

When a massive seabird die-off coincided with an extreme marine heatwave, we knew the ocean ecosystem had dramatically changed. We found every level of the food web was altered.

Last updated: July 22, 2020