Clownfish could disappear due to climate change.

In order for the clownfish to reproduce it needs the anemones to be healthy and these in turn need the corals, which are in serious danger.

Clownfish could disappear due to climate change.
Clownfish could disappear due to climate change.

The colourful clownfish is in danger again and this time the reason has nothing to do with Pixar's animated film. 

If Finding Nemo unleashed the madness of having one or more specimens of clownfish in the aquarium at home and brought with it a significant decline in its population, now climate change and more specifically the survival of the corals are putting the cute little fish in check. 

The explanation was given by a team from France's National Center for Scientific Research (CNRS), which observed for more than 10 years the clown fish living on Kimbe Island in eastern Papua New Guinea. The study has been published in Ecology Letters.

What the researchers wanted to know is what impact genetics and the environment had on the breeding success of these animals. What they discovered was that the fish's habitat, including the anemone in which it lives and its geographical location, are the elements that contribute the most to the success or lack of success in reproduction. 

The genetic aspect played a role, but in a minor or insignificant way. This finding implies that the species will be susceptible to short-term, small-scale changes in habitat structure. In addition, the clownfish may have a limited ability to adapt to these changes.

Clownfish establish symbiotic relationships with anemones: they use them to protect themselves from predators, as they are poisonous to other fish and they feed on the faecal matter they expel, as well as being protected by them from butterfly fish, which love to eat anemone tentacles.

The problem comes when the anemones, home of the clownfish, are in danger, which is happening because they depend on the corals, threatened by the warming of the seas, pollution and human hands.

According to Benoit Pujol, a CNRS researcher, the ability of a species to adapt is guaranteed by its reproductive success. Clownfish don't reproduce as easily because they need a stable and gentle environment.

In each anemone live a female, a sexually active male and other males that are not sexually active. When the female dies, the sexually active male becomes female and the larger of the non-sexually active males becomes sexually active. If the anemones remain healthy, the clownfish will be able to reproduce, otherwise it could become extinct.

The death of the corals will be the beginning of the end

Gabriel Grimsditch is a member of the Marine Ecosystems Division of the United Nations Environment Programme and says that rising sea temperatures as a result of global warming and human activities are wiping out corals.

"Corals are very sensitive to temperature changes in the water, in the sea, and live in symbiosis with microscopic algae that live inside them and give them energy. When the temperature rises too high, this symbiosis that gives life and energy to the coral breaks. And when it breaks it is like a fever in humans, the coral is very stressed, is very weak and loses its color and whitens. 

In this situation the coral can die very easily and we see that there are many corals that when bleached survive a few days, a few weeks, maybe a few months, but in many cases lose their lives," explains Grimsditch.