Coral bleaching, loss of food leading to ‘unnecessary’ fish fights: Marine ecologists

Marine ecologistsin their research have observed that many species of fishlost food as a result of mass coral bleaching. This particularly affectedthe 38 species of butterflyfish.The colourfully patterned reef fish are amongst the first to be hit by the effects of bleaching primarily because they eat coral, which means their food source is directly under threat.Sally Keith, a marine ecologist at Britain's Lancaster University who spoke to AFP said that the history's worst global bleaching events in 2016 offered a perfect opportunity to study fish behaviour.

After returning to the same spot after a year, researchers were shocked to see the devastation of the reefs and the subsequent dearth of food for thebutterflyfish.

"That changed the playing field of who's eating what," Keith said, putting different species of butterflyfish in increased competition for other types of coral.

Add WION as a Preferred Source

The most common tactic of a butterfly fish to signal to a competitorthat a particular reef is theirs is by pointing its nose down and raising its spinydorsal fins.

The team observed 3,700 encounters between butterflyfish. Before the coral bleaching event, different species of butterflyfish were able to settle disputes using signalling around 28 per cent of the time. But, those numbers plummeted to 10 per centafter the bleaching event, indicating many 'unnecessary fights' according to the new study in the journal, Proceedings of the Royal Society B.

Also watch |WION Climate Tracker: London Zoo begins its annual headcount of animals

"Making poor decisions about who to fight, and where to invest their really valuable energy, could be that little bit that tips them over the edge towards actual starvation," said Keith, the study's lead author.

It is uncertain if the fish would be able to adapt to this new normal brought about by coral bleaching, researchers warned.

(With inputs from agencies)

WATCH WION LIVE HERE: