Tokyo Study Reveals Global Warming's Effect on Fish
Reduced Plankton Volume Affects Fish Nutrition
Impact of Rising Temperature: Decrease in Fish Weight: A new study has revealed that due to global warming, there is a decline in the weight of fish.
In research conducted at the University of Tokyo, it was discovered that as temperatures rise, the volume of floating plankton (fish food) in the sea decreases, resulting in fish not getting the desired nutrition.
In the study, researchers analyzed the overall biomass and individual weights of 13 species of fish and examined data from four families of fish from 1978 to 2018.
The study also examined ocean temperature changes between 1982 and 2014 to see the effects of temperature changes on the sea surface and any impacts on the lower surface.
According to the results of the study published in the journal Fish and Fisheries, a decrease in fish weight was observed in two decades, one in the 1980s and the other in the 2010s.
Initially, the decrease in weight was attributed to an increase in the population of Japanese sardines, which led to increased competition for food among other species.
However, further analysis revealed that due to seasonal changes, competition for food increased as warmer seas resulted in fewer nutrients being brought up to the surface easily, unlike colder, nutrient-rich waters.
Professor Shishi-Ichi Ito of the university explained that higher temperatures cause the upper layer of the sea to form an additional layer, and studies from the past have shown that instead of larger plankton, smaller plankton, and less nutritious jellyfish-like gelatinous species have taken over.