Crabeater seals in Antartica will have to swim farther distances to find food sources as warming oceans reduce the amount of krill in the waters
- Scientists at UC Santa Cruz studied the movements of crabeater seals
- They combined seal data with climate change models and krill population data
- They used the joint model to predict how seals and other Antarctic predators will be affected as climate change and fishing continues to reduce krill population
Life for crabeater seals in the Antarctic could get even more difficult in the coming years, as climate change and commercial fishing make their main food source more scarce.
A new study from the Institute of Marine Sciences at UC Santa Cruz modeled the seasonal movements and feeding patterns of crabeater seals and krill, their primary food source.
The data was collected from electronic tags placed on crabeater seals on the Antarctic peninsula dating as far back as 2001, and combined with environmental models showing the effects of climate change on the region, and ocean circulation models.
New research from UC Santa Cruz predicts warming temperatures in the Antarctic peninsula will push krill further south toward the pole to escape the growing number of predators in the region, making life especially hard for crabeater seals
The team found that, as the waters around the Antarctic peninsula continue to warm, krill will likely be driven further south, to colder waters to escape the growing population of predators coming to the region to hunt for them.
‘We’re using the feeding behavior of this one predator as an indicator of the habitat for their prey and how that could change,’ UC Santa Cruz’s Luis Huckstadt told Eurekalert.
Past research has shown that krill in Antarctica have already move 270 miles southward over the last 90 years.
‘The shift in krill habitat away from coastal waters in the north has big implications for species like penguins and fur seals, which can’t make long foraging trips because they have to come back to land to feed their offspring,’ Huckstadt said. ‘It will be challenging for a lot of species.’
‘Things are changing so fast in Antarctica, the changes we’re seeing in our model might be coming sooner than we expected.’
Despite their name, crabeater seals subsist on a diet of mostly krill, meaning their fate is especially bound up with that of the minuscule crustacean
The growing presence of commercial krill fishing boats has also placed environmental pressure on crabeater seals, as they compete for a dwindling supply of food with a growing number of human and non-human predators.
‘We don’t really have a good grasp on how fishing pressure will change in the future, and that’s one reason so many marine protected areas have been proposed for the western Antarctic Peninsula,’ Huckstadt said.
Recent estimates suggest commercial krill fishing removes at least 300,000 tons of krill from the Antarctic each year.
‘The peninsula is critical habitat for krill, which is the most abundant and important prey species in this region,’ Huckstadt said.
‘Everything depends on krill, so any changes will cascade through the ecosystem.’