Effects of hypoxia on fish physiology

Abstract

Oxygen is essential to sustain life for all fish and invertebrates. Hypoxia is an ever-increasing threat to aquatic systems. Dissolved oxygen (DO) in water bodies is essential for fish survival and plays a crucial role in fish growth, development, and physiological processes. Although fluctuations in its levels may be a natural phenomenon, hypoxia caused by eutrophication and organic pollution is now considered one of the most pressing and critical water pollution problems in the world, especially in densely populated regions. It stresses fish, causing them to exhibit fluency, inhibiting their growth and development, and causing tissue damage. Oxidative stress reduced immune function and altered metabolism have also been observed. Severe hypoxia can cause massive fish mortality, resulting in significant economic losses to the aquaculture industry. In response to hypoxia, fish exhibit a range of behavioral and physiological changes that represent self-protection mechanisms developed through long evolution. Knowledge of the aetiological factors, pathogenetic mechanisms, and risk factors allows the development of effective methods for the prevention and treatment of this pathological condition Therefore, the effects of low dissolved oxygen on fish are a major concern and are being actively studied. This article includes a review of information related to hypoxia and how it affects various characteristics of aquatic organisms.