Heat wave forces clown fish for shrinking - survival strategy discovered!

Heat wave forces clown fish for shrinking - survival strategy discovered!

The effects of climate change on the marine wildlife are not only an abstract concept, but are concrete in the changes in behavior and physiology of living beings. A current study published in the specialist magazine "Science Advances" impressively illuminates how clown fish react to extreme water temperatures. A research team from the University of Newcastle analyzed 67 wild clownfish pairs in Kimbe Bay, Papua New Guinea. During a five -month heat wave from February to August 2023, in which the water temperatures rose by an average of four degrees above the normal value, 100 of the 134 -examined fish shrank.

Around 44% of these fish shrank by a few millimeters, while 30% shrank several times. Only about 25% remained unchanged. It was striking that there was no difference in the shrinking between rank or gender, but a couple effect was observed: shrinking one partner had an impact on the other. These coordinated adjustments seem to reduce friction in the hierarchical relationship of the fish, which improves their chances of survival during the heat phase. In fact, the shrinking fish had up to 78% higher survival probability, while 11 fish died during this very stressful conditions.

fish size and climate change

Research shows that with increasing water temperatures, the oxygen requirement for fish also increases, while less dissolved oxygen is present in the water. This means that shrinking is an energetic strategy in order to be able to survive in overheat water. However, these adaptation mechanisms are not only limited to clown fish; Similar shrinkage processes have also taken place in other types, such as sea lizards. There is suspicion that these developments in fish size can also be observed in seases influenced by climate change.

The problem could continue to be tightened by fishing. A WWF report shows that the oceans play a central role in global climate by producing oxygen and absorbing carbon dioxide. Climate change increasingly challenges for marine ecosystems, which has negative effects on fishing. Rising water temperatures and a higher carbon dioxide content lead to warmer and acidic water, which disturbs the behavior and food intake of fishing. Forecasts show that 99% of the coral reefs could die by the end of the century, which would be devastating for many marine life.

consequences for fishing and nutritional security

For fishing, smaller and less compensated stocks mean an immediate threat. Scientists estimate that every additional degree Celsius warming could lead to a decline in global fishing potential by over 3 million tons. In particular, developing countries in which over two thirds of the population are dependent on sea fishing. By 2050, a reduction in fishing quantities is expected by 50%, which could have dramatic effects on the protein -rich diet of these regions.

In order to meet these challenges, sustainable fishing management strategies and innovative aquaculture approaches are of crucial importance. Scientists emphasize that an increase in fish biomass would be possible by up to 60% by improving the fish stocks, provided that global warming is checked. The WWF therefore recommends considering fish as a delicacy and paying attention to sustainable procurement practices in order to reduce ecological footprint and protect the marine biodiversity.