Climate conditions play a significant role in the reproductive success of mature female Antarctic krill and are a factor in fluctuations of the population that occur every five to seven years.

Environmental factors, including large-scale climate patterns that affect availability of food, influence the females’ overall health during the spawning season. While those climate patterns are natural, they are trending warmer and more intense due to climate change, which is likely to have a negative impact on the krill population, said Kirsten Steinke, a doctoral student working with biological oceanographer Kim Bernard at Oregon State.

«This ecologically important species serves as the base of the food web in the Antarctic peninsula, supporting everything from whales to penguins to seabirds,» said Steinke, the study’s lead author. «Understanding the connection between the environment and population health is critical for predicting future demographic patterns and responses to climate change in the krill population.»

The findings were published recently in the journal Marine Ecology Progress Series. Co-authors are Bernard, an associate professor in OSU’s College of Earth, Ocean, and Atmospheric Sciences; and Robin M. Ross and Landgon B. Quetin of the University of California, Santa Barbara.

Antarctic krill, also known as Euphausia superba, is a type of zooplankton that can live five to seven years and grow to a length of a little more than two inches.

The western Antarctic Peninsula is home to a significant portion of Antarctic krill biomass. It is also where the bulk of the krill fishery occurs; it is the largest fishery in the Southern Ocean, with an estimated 313,000 tons harvested in 2018. Krill are used as feed for fish farms and as a source of supplements such as omega-3 oil.

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Materials provided by Oregon State University. Original written by Michelle Klampe. Note: Content may be edited for style and length.