Climate Change Is Having A Rather Unusual Effect On Venomous Sea Creatures


Lionfish are moving to Georgia. Vladimir Wrangel/Shutterstock

Climate change is having a rather unusual side effect, according to a paper published in the journal Wilderness and Environment Medicine last month – and we're not sure you're going to like it. Rising ocean temperatures are disrupting the habitats of marine life, encouraging venomous creatures like lionfish, crown-of-thorns starfish, and species of jellyfish to expand their habitats. 

The paper was a retrospective analysis of various studies and medical literature concerning climate change, toxicology, and projections specific to venomous marine animals, including jellyfish, sea snakes, frogs, fish, and starfish. Collectively, the studies predicted an increase in population numbers (particularly those of jellyfish and crown-of-thorns starfish) and an extension in range (specifically that of sea snakes and lionfish). 


The bad news – these changes combined with human population growth and coastal development may increase unfriendly confrontations with the venomous beasties.

But not all species will be affected in the same way. “The big pattern is that there isn’t necessarily a pattern,” co-author and PhD student Isabelle Neylan at the University of California, Davis (previously of the University of North Carolina in Chapel Hill), told National Geographic. Most animals, she added, won't necessarily increase in number. Instead, their ranges will be pushed northwards or southwards as water in their current habitats closer to the equator gets too hot. And not all will be able to adapt to the changes.

Toxic frogs, for example, are seeing populations plummet as a result of climate change. This, the researchers say, is because of their sensitivity to temperature change or any other small tweak to their environment. 

"If temperatures continue to rise to record levels over the next decades, it is predicted that the populations of these once plentiful and critically important animals [toxic frogs] to the aquatic ecosystem will decline and their geographic distributions will shrink," the study authors explain.


Sea snakes are set to be another victim. Worldwide, numbers of many of the planet's most poisonous land and aquatic serpents are on the decline. Saying that, there are a few exceptions to the rule and biologists have noted increased numbers in states like California and Hawaii.

So, who will be the winners? Jellyfish, for one. The results of the analysis suggest they are likely to increase in range and number thanks to warmer temperatures and higher acidity levels. The non-native lionfish, too, could see its range extend from Florida to the Carolinas and Georgia. Meanwhile, crown-of-thorns starfish, which are terrorizing the Great Barrier Reef, are inching southwards from the Indo-Pacific waters to the shores of northern Australia.

“These species have human interest because they’re poisonous but they reflect the broader patterns that we’re seeing – range shifts, abundance changes, either declines or increases – and that is upsetting the balance of what we would normally see in the ecosystem," explained Neyland. 

[H/T: National Geographic]