Shining a light on clownfish survival

Exposure to artificial light in coral reefs is stifling clownish survival. So clownfish survival and it’s ability to reproduce. All depending on less artificial light. Because it’s impacting the species. A species made famous by the movie Finding Nemo.

Jessica Bassano

Researchers from Flinders University in South Australia researched fish and artificial light at night (ALAN). When increased ALAN occurred it masked natural cues of the ocean. This therefore destroyed All proper prompts for clownfish eggs hatching.

Worst of all, this problem further exacerbated by increasing urbanization in coastal areas. Areas where artificial light spills out into reefs close to shore.

The Saving Nemo foundation was established by Flinders University and the University of Queensland. Founding in 2005 breeding clownfish and raising awareness of their declining numbers in the wild.

The clownfish survival of a small distinctive orange and white fish. It became popular aquarium additions.  Additions following the global success of the 2003 Disney animated film. Therefore despite the movie’s conservation message, there are consequences. In conclusion, the sudden increase in demand severely impacting the population. Finally and now wild clownfish survival came into question.

In the latest project, Saving Nemo research director Dr Emily Fobert monitored 10 pairs of breeding clownfish.  Clownfish of varying sizes.

All of the clownfish studied were part of the same species. This species is called amphirprion ocellaris. They are the most common of clownfish species. Also known as the false clownfish.

There are 30 species of clownfish. All or most of which live in anemones. Anemones are in the shallow waters of the Indian Ocean. As well as the Red Sea and the western Pacific.

So half the fish Dr Fobert observed in the study were exposed to low levels of overhead LED light at night. The LEDs imitated commercially available and widely used lights near coral reefs. The other half were exposed normal daylight and darkness.

Clownfish are attuned to lunar cycles. They often lay their eggs around the full moon. They’ll lay between 100 and 1500 eggs in a single clutch. Therefore, the number of eggs depend on the clownfish’s age, health, diet and species. After about eight days, and within a few hours of sunset, the little Nemo’s hatch.

Most importantly, NONE of the eggs exposed to LED lights hatched.

The research team turning off artificial nightlights. As they continued monitoring for 60 days. Most noteworthy, these trials occurring without artificial light. Suddenly hatch rates returned to 80 per cent.

Dr Fobert said the results indicated increasing amounts of ALAN. So it had the potential to significantly reduce reproductive fitness of reef fish.  Reef fish that settled in habitats near the shore.

She is now examining other species of reef fish. Again reef fish that share similar reproductive behavior to see if they are affected by ALAN.

The results from the new study by Flinders University and the University of Melbourne. They are published today in Biology Letters.

Dr Fobert said there was no clear solution to tackling ALAN. Especially near coral reefs. Then researchers were looking at a number of ways to reduce the impact of light. Light on marine biology.

So in conclusion, that might not be entirely necessary. Even especially if the resorts want to attract the fish so they can live there.

Dr Fobert said other options to reduce the impact of light included motion censored streetlights.

In conclusion, this is Republished With Permission. Finally as This is a Creative Commons story from The Lead South Australia. They are a news service providing stories about innovation in South Australia.