Warmer ocean temperatures caused by global warming could cause sharks and other fish to become more aggressive, according to a new Australian study.
Research conducted by the University of New South Wales found that a slight lift in water temperatures -- just two or three degrees -- can cause some fish to become up to 30 times more aggressive than they normally would be.
The studies were conducted on young damsel fish, but head researcher Dr Peter Biro told ninemsn it is possible that sharks could also undergo a similar transformation in warm water.
| Or maybe not; it's all speculation ... |
"I would imagine that it might also affect sharks ... we think it is linked to the metabolism of the fishes -- it increases their need to feed," Dr Biro said.
| I imagine that it causes sharks to eat scientists. Careful Doc next time in the water ... |
The research involved putting the damsel fish in varying temperatures of water and placing other fish behind glass to see how they reacted.
Dr Biro said it was "obvious" the warmer water had an effect.
"Some fish would literally charge at the glass," he said. "I'm quite confident that if the glass was not there they would have torn the other fish to shreds."
| So he's re-created Siamese beta fish behavior ... |
He predicted the increased aggression caused by climate change would cause some fish populations to dwindle, but it would eventually correct itself.
"They would experience declines in the short term ... but long term i would expect them to adapt," he said.
The test also exposed previously unknown behavioural traits that exist among the damsel fish species. While some fish showed extreme aggressive reaction to the warm water, others did not react at all.
The majority of the fish tested appeared to be at least twice as aggressive in the warm water.
So there might possibly be some evolutionary pressure in some species, depending on whether the increased aggressiveness is evolutionarily advantageous or disadvantageous, which is not known. Also not known is whether the oceans will warm in the near future, but they might... possibly. And while this might matter in the short term, even medium term the changes will cancel out.
That was certainly profound. I hope Dr. Biro does not plan to think so deeply on many other subjects over the course of his career -- he might do himself an injury. |
|