Killing Nemo: Clownfish on Coastal Reefs Live Shorter Lives

It’s our fault, apparently.

An Orange-Fin Anemonefish (Amphiprion Chrysopterus) in Fiji. November 17, 2006.Dave Fleetham/Design Pics/ZUMA

This story was originally published by The Guardian and is reproduced here as part of the Climate Desk collaboration.

Young clownfish on coastal reefs are dying faster as a result of exposure to artificial light at night, according to new research.

An international team of scientists studying reefs on Moorea, a tiny island of French Polynesia, have found that orange-fin anemonefish—a species of clownfish—exposed for long periods to human-generated artificial light were 36 percent less likely to survive than clownfish living in reefs farther from the coast.

The clownfish that did survive grew 44 percent slower than their counterparts who lived under natural nocturnal lighting conditions.

Stephen Swearer, a professor of marine biology at the University of Melbourne and one of the study’s authors, said Moorea was home to many luxury hotels with bungalows over the water—many of which are intentionally lit at night.

“Rooms have these little windows, like a portal in the floor, so you can turn the light on and look at the fish swimming around underneath,” he said.

For more than 18 months, the researchers monitored young clownfish living in anemones close to shore, where they were perpetually exposed to light pollution, and fish who lived in anemones away from areas inhabited by humans.

Swearer said it was unclear why light-exposed fish had a reduced growth rate and were more likely to die. One possible explanation for the increased death rate was the light attracting predators. Another was that long-term exposure resulted in adverse physiological effects on the clownfish.

“Basically, these fish are just really tired, not being able to lower their activity levels at night,” said Swearer. “They may then behave in ways that mean they have less energy to avoid predation.”

Swearer said more research was needed on the effects of light pollution on other marine animals. More than 20 percent of the world’s oceans were exposed to “ecologically relevant levels of artificial light,” he said.

The harmful effects of artificial light on turtle hatchlings is already well established, as sea turtles rely on the light of the moon and stars for navigation. Hatchling strandings and deaths have previously been attributed to light pollution in north Queensland.

Swearer said artificial light near coastal reefs needed to be better regulated. “There are ways in which you can light so that you’re not resulting in conditions that lead to public safety concerns [for humans], but that also can mitigate the risk that they might pose to wildlife,” he said.

“We can make sure populations of species that we care about have refuge from that stressor.”

More Mother Jones reporting on Climate Desk

WE'LL BE BLUNT

It is astonishingly hard keeping a newsroom afloat these days, and we need to raise $253,000 in online donations quickly, by October 7.

The short of it: Last year, we had to cut $1 million from our budget so we could have any chance of breaking even by the time our fiscal year ended in June. And despite a huge rally from so many of you leading up to the deadline, we still came up a bit short on the whole. We can’t let that happen again. We have no wiggle room to begin with, and now we have a hole to dig out of.

Readers also told us to just give it to you straight when we need to ask for your support, and seeing how matter-of-factly explaining our inner workings, our challenges and finances, can bring more of you in has been a real silver lining. So our online membership lead, Brian, lays it all out for you in his personal, insider account (that literally puts his skin in the game!) of how urgent things are right now.

The upshot: Being able to rally $253,000 in donations over these next few weeks is vitally important simply because it is the number that keeps us right on track, helping make sure we don't end up with a bigger gap than can be filled again, helping us avoid any significant (and knowable) cash-flow crunches for now. We used to be more nonchalant about coming up short this time of year, thinking we can make it by the time June rolls around. Not anymore.

Because the in-depth journalism on underreported beats and unique perspectives on the daily news you turn to Mother Jones for is only possible because readers fund us. Corporations and powerful people with deep pockets will never sustain the type of journalism we exist to do. The only investors who won’t let independent, investigative journalism down are the people who actually care about its future—you.

And we need readers to show up for us big time—again.

Getting just 10 percent of the people who care enough about our work to be reading this blurb to part with a few bucks would be utterly transformative for us, and that's very much what we need to keep charging hard in this financially uncertain, high-stakes year.

If you can right now, please support the journalism you get from Mother Jones with a donation at whatever amount works for you. And please do it now, before you move on to whatever you're about to do next and think maybe you'll get to it later, because every gift matters and we really need to see a strong response if we're going to raise the $253,000 we need in less than three weeks.

payment methods

WE'LL BE BLUNT

It is astonishingly hard keeping a newsroom afloat these days, and we need to raise $253,000 in online donations quickly, by October 7.

The short of it: Last year, we had to cut $1 million from our budget so we could have any chance of breaking even by the time our fiscal year ended in June. And despite a huge rally from so many of you leading up to the deadline, we still came up a bit short on the whole. We can’t let that happen again. We have no wiggle room to begin with, and now we have a hole to dig out of.

Readers also told us to just give it to you straight when we need to ask for your support, and seeing how matter-of-factly explaining our inner workings, our challenges and finances, can bring more of you in has been a real silver lining. So our online membership lead, Brian, lays it all out for you in his personal, insider account (that literally puts his skin in the game!) of how urgent things are right now.

The upshot: Being able to rally $253,000 in donations over these next few weeks is vitally important simply because it is the number that keeps us right on track, helping make sure we don't end up with a bigger gap than can be filled again, helping us avoid any significant (and knowable) cash-flow crunches for now. We used to be more nonchalant about coming up short this time of year, thinking we can make it by the time June rolls around. Not anymore.

Because the in-depth journalism on underreported beats and unique perspectives on the daily news you turn to Mother Jones for is only possible because readers fund us. Corporations and powerful people with deep pockets will never sustain the type of journalism we exist to do. The only investors who won’t let independent, investigative journalism down are the people who actually care about its future—you.

And we need readers to show up for us big time—again.

Getting just 10 percent of the people who care enough about our work to be reading this blurb to part with a few bucks would be utterly transformative for us, and that's very much what we need to keep charging hard in this financially uncertain, high-stakes year.

If you can right now, please support the journalism you get from Mother Jones with a donation at whatever amount works for you. And please do it now, before you move on to whatever you're about to do next and think maybe you'll get to it later, because every gift matters and we really need to see a strong response if we're going to raise the $253,000 we need in less than three weeks.

payment methods

We Recommend

Latest

Sign up for our free newsletter

Subscribe to the Mother Jones Daily to have our top stories delivered directly to your inbox.

Get our award-winning magazine

Save big on a full year of investigations, ideas, and insights.

Subscribe

Support our journalism

Help Mother Jones' reporters dig deep with a tax-deductible donation.

Donate