Smaller clownfish sound alarm on sea fire

Helen Briggs

BBC Environmental Correspondent•@hbriggs

Clownfish is one of the most well-known reef fishes, known for its orange and white stripes

A study found that similar to the movie found that Nemo's famous fish are shrinking to cope with ocean heat waves.

The study documented clownfish living on coral reefs, which dropped dramatically when ocean temperatures emanate in 2023.

The discovery is a big surprise and can help explain the rapid decline in size of other fish in the world's oceans, scientists say.

There is growing evidence that animals are changing to combat climate change, including birds, lizards and insects.

This study was conducted in Kimbe Bay, a key area of marine biodiversity

Getty image is a turtle with its forelimbs stretching out to swim, on a coral bed at the bottom of the sea, as light filters through blue water — This study was conducted in Kimbe Bay, a key area of marine biodiversity

"Nemos can contract, and they do this to survive these thermal stress events," said Dr. Theresa Rueger, senior lecturer in tropical marine science at Newcastle University.

Researchers study clownfish living in reefs near the Bay of Jinbe, Papua New Guinea, a hot spot for marine biodiversity

The wild clownfish is almost the same as those depicted in the movie Discovery Nemo, in which a timid clownfish lives on the giant barrier reef in search of his son.

Scientific research took place in the summer of 2023, when the temperature of the ocean increased, causing a large number of corals to turn white.

Scientists have taken multiple measurements of the response of a single clownfish.

They found that the fish not only lost weight, but also had to be a few millimeters shorter. In heat waves, this is not a one-off – 75% of the fish shrinks at once.

Clown fish swimming on the Great Barrier Reef in Australia

Getty image of a pair of orange and white striped clown fish swimming together on bright white coral reefs — Clown fish swimming on the Great Barrier Reef in Australia

"Not only do they eat and lose weight, they can also actively change their body shape and make themselves a smaller person, require less food and use oxygen more efficiently," Dr. Rueger explained.

As seen in other animals, such as marine iguanas, fish may be absorbing fat and bones, although this needs to be confirmed by laboratory studies.

Dr. Rueger joked that some movie rewriting might be needed, and so did Nemo's new chapter.

"This movie tells a very good story, but the next chapter of the story is surely, how does Nemo deal with the ongoing environmental change?" she told BBC News.

Mushroom soft coral on the reefs of Papua New Guinea in the Pacific

Getty image poses multicolored coral in green, red and pink crowd in blue seabed — Mushroom soft coral on the reefs of Papua New Guinea in the Pacific

Global warming is a huge challenge for warm-water animals, who must maintain a constant body temperature to prevent their bodies from overheating.

Animals respond in various ways: transfer to cooler areas or higher ground, changing the timing of critical life events, such as reproduction and migration or switching their body shape.

The study was published in the journal Science Advances.

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