In recent years, large-scale mass deaths of fish have been occurring frequently in many parts of the world. This is because global warming caused by climate change is depleting the oxygen in the water. As water temperatures rise, warmer water is lighter than colder water, so the water in the upper layers, which takes in oxygen from the air, cannot reach the deeper layers where the water temperature is cooler.
In addition, the rise in water temperature stimulates the metabolism of underwater organisms, which consumes more oxygen. However, the lack of oxygen in the water causes asphyxiation and death.
Lack of oxygen in the water inhibits the behavior and growth of living creatures, and ultimately kills a large number of them. If this is repeated, the ecosystem of living creatures in the water may be destroyed. And we who live on land cannot remain unaffected. The mass deaths of aquatic organisms will have a devastating effect on the livelihoods of people living along the coasts, and fishery resources will also be severely depleted. The disposal of the large number of carcasses also requires a great deal of labor and public expense. Furthermore, there is concern that nitrous oxide, a greenhouse gas, will be emitted from the depleted water, causing further global warming.
In order to break this vicious cycle, global warming must be halted at all costs. While large-scale efforts by national governments and corporations are essential to curb global warming, even a conscious effort on the part of individuals can have a positive effect. We can do this by conserving energy such as electricity and gas, reducing the use of petroleum-based products such as plastics, eating less meat and more plant-based foods, choosing environmentally friendly and sustainable products and services, and so on. We must not forget that it is the actions of each and every one of us that will create the future of our planet.
