Global Warming impair the olfactory system of a marine fish

Researchers say global warming threatens fish survival by affecting fish's olfactory abilities.

Fish do not have exoskeletons, but they have sensory cells in the nasal cavity and can detect odors. Fish use olfactory sights to find food, to find safe habitats, to avoid predators, or to identify fish with each other.

According to researchers at the Exeter University in England, global warming is causing the world's oceans to become darker, resulting in olfactory loss of fish.

Generally, carbon dioxide is in the form of gas, but it can also be absorbed in water. As you go down the ocean, carbon dioxide levels rise and the acidity of the waters becomes worse. According to the researchers, the carbon dioxide level of the ocean has increased by 43% since the Industrial Revolution.

In an experiment to investigate the effects of carbon dioxide on fish, the researchers used sea bass. It is considered as one of the most important fishes because of its large population of fishes and economically. The researchers split the sea bass into two groups and then released the A group into the same water as the current carbon dioxide concentration and the B group released it into the same water as the ocean carbon dioxide concentration at the end of the century (late 1990s) about 20 years ago.

As a result of observing the movement of the perch, the group A in the higher acid water was less active than the group B, and the response was slower even when the smell of the food appeared. In addition, the group showed a higher level of anxiety than the group.

The researchers analyzed that acidified water affects the olfactory receptors and odor molecules in the anterior part of the fish nose, resulting in a dull olfaction of the fish.

Previous studies have shown that carbon dioxide levels can interfere with brain activity in fish, and this is the first time that studies have been done to identify the relationship between carbon dioxide concentration and fish nose.

Professor Rod Wilson of the University of Exeter, who led the study, "proved that carbon dioxide directly affects the olfactory sense of fish. This is because carbon dioxide prevents the information processing of the brain itself as well as the central nervous system. "As the carbon dioxide increases in the future, we can not know how quickly fish can overcome these problems."

A detailed study was published in the current issue of the journal Nature Climate Change.