Pacific Marine Heatwave

Science Center Objects

The USGS conducts research on marine wildlife, habitats, and ecosystem processes to provide science to inform our partners as they make decisions relative to species status, resource use, and human activities. These studies examine impacts of severe heatwaves on marine ecosystems of the North Pacific. 

Return to Ecosystems

Seabirds, and their forage fish prey, serve as practical indicators of change in the marine environment— natural or human induced— and can be readily monitored at sea. For all these reasons, marine bird research is a vital part of the Department of Interior mission in Alaska. Through the projects listed below, we use a multidisciplinary approach that incorporates study of marine habitats and food webs to better understand why seabird populations and their prey fluctuate over time and what can be expected in the future. 

Seabirds and Forage Fish Ecology 

Tufted Puffin carrying fish

Tufted Puffin carrying fish to bring back to its young in its burrow.
(Credit: Sarah Schoen, USGS. Public domain.)

Alaska's coastal and offshore waters provide foraging habitat for an estimated 100 million birds comprising more than 90 different species; from loons and seaducks that nest inland, to petrels and puffins that breed on islands off shore. All these birds depend on the sea to provide a wide variety of food types— from clams, crabs and urchins nearshore— to krill, forage fish, and squid offshore. The availability of nesting habitat and suitable prey are important natural factors that regulate the distribution and abundance of marine birds. But seabird populations are also affected by human activities that have direct impacts (pollution, bycatch in fishing gear) and indirect effects (global warming alters food availability) on birds.

Cook Inlet Seabird and Forage Fish Study

A massive die-off of Common Murres was documented in the Gulf of Alaska (GOA) during the fall and winter of 2015-2016 in association with a record-breaking marine heat wave in the GOA.

Condition of Forage Fish in Prince William Sound During the Marine Heatwave

Changes in the body condition of a key forage fish species, Pacific sand lance (Ammodytes personatus), are examined to understand how energy transfer to predators may have been disrupted during the recent marine heatwave in the North Pacific (late 2013 to mid 2016).

Top to bottom: Pacific capelin, Pacific herring, Pacific sand lance, and juvenile walleye pollock

Key forage fish in Alaska (from top to bottom): Pacific capelin, Pacific herring, Pacific sand lance, and juvenile walleye pollock. Cook Inlet, Alaska.
​​​​​​​(Credit: Mayumi Arimitsu, U.S. Geological Survey. Public domain.)

Detecting Long-term Changes in Forage Fish Populations in Prince William Sound, Alaska 

Forage fish are small pelagic schooling fish that play a key role in transferring energy between plankton and top marine predators. Many seabirds, marine mammals, and commercial fish species depend on forage fish to grow and survive.

Seabird Die-offs in Alaska

Beginning in 2015, large numbers of dead seabirds have been appearing on beaches in most marine areas of Alaska. Although seabird die-offs are known to occur sporadically (e.g. 1970, 1989, 1993, 1997/1998, and 2004) in Alaska, these recent die-offs have been distinguished from past events by their increased frequency, duration, geographic extent, and number of different species involved.

Harmful Algal Bloom Toxins in Alaska seabirds

Elevated ocean temperatures are linked to the development of harmful algal blooms (HABs). Toxins from these blooms may pose health threats to marine organisms, including seabirds. Since 2015, the USGS has worked with a variety of stakeholders to develop testing methods and research projects to better understand the geographic extent, timing and impacts of algal toxins in Alaska marine ecosystems, including possible links to recent seabird die-offs.

Collaborative Work with Partners and News Stories

USGS and FWS Collaborate on 2019 Short-tailed Shearwater die-off event in Bristol Bay, Alaska

Harmful Algal Bloom Toxins in Alaska Seabirds - 2018

Marine heatwave likely caused mass starvation of seabirds off US west coast

‘The blob,’ food supply squeeze to blame for largest seabird die-off