Rising water temperatures in the Arctic could lead to widespread jellyfish invasions, causing destruction to ecosystems

As climate change warms the Arctic Ocean and melts sea ice, many species of jellyfish and other zooplankton could spread toward the North Pole, destroying ecosystems. The “jellying” of the Arctic may already have begun.

“There are ecological impacts that we can hardly predict,” he says Charlotte Havermans At the Alfred Wegener Institute in Germany. “For some of these species, we don’t know anything about their ecology.”

Havermans and colleagues combined several datasets on the distribution of the eight best-recorded jellyfish species and their gelatinous relatives across the Arctic. They examined a representative range of species, all the way down to tiny hydroids. agranta digitalThe poisonous lion’s mane jellyfish (only 1 to 2 centimeters long)Chianea capillata), and can extend tentacles over 30 meters in length.

We then model how each species’ habitat will change later this century in response to rising ocean temperatures, melting ice, and other ocean changes under moderate to high emissions scenarios. did. Their model accounted for vertical variation across the water column, which is especially important for jellyfish that live only at certain depths.

Most species are likely to expand their ranges and move toward the North Pole, primarily due to decreased sea ice. The lion’s mane jellyfish, which can compete directly with fish due to its size, showed the largest predicted expansion, nearly tripling its range.All other species except deep sea saw significant expansion. Sumithea Arcticaa slight reduction was observed.

There are already some signs that jellyfish are starting to expand north, sometimes with undesirable effects. Havamans pointed to the fjords in Norway’s Svalbard archipelago, where jellyfish have outnumbered cod and disrupted fisheries. “Sometimes it gets really occupied and there’s almost no fish left there,” she says.

There have been other reports of a sharp increase in jellyfish numbers in recent years, sparking debate about a broader ‘jellification’ of the world’s oceans, but there is a lack of data to identify clear trends. is difficult, says Habermans.

Christopher Lynam The UK Center for Environment, Fisheries and Aquaculture Science says the impact of such expansion will also depend on how other organisms respond. The additional competition could be harmful to some species, he says. For other predators, such as spiny sharks and deep-sea scavengers, these newly arrived fish can serve as a gelatinous food source.