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.
