eChapter Name: Heavy Metal Toxicity and Its Disruptive Effects on Fish Reproduction
9789358871449
eBook Name: REVOLUTIONIZING AQUACULTURE AND FISHERIES: INNOVATIONS AND TECHNOLOGIES FOR A SUSTAINABLE BLUE ECONOMY
Introduction
The aquatic ecosystem is full with harmful contaminants like heavy metals. Due to farming, mining, geochemical composition, and anthropogenic wastes, their concentration has dramatically increased. Heavy metals contaminate aquatic ecosystems through multiple pathways, such as industrial effluents, agricultural runoff, and atmospheric deposition. Once released heavy metals into water bodies, these metals undergo bioaccumulation, wherein they accumulate in aquatic organism’s tissue, including fish, gradually over time over time. Toxicity of heavy metals due to their long persistence in the environment and non-biodegradable nature. Additionally, heavy metals undergo biomagnification, leading to increasing concentrations as they ascend the food chain, posing greater risks to higher trophic level organisms, including fish. Fish serve as crucial bioindicators for evaluating the potential risks of pollution (Lakra & Nagpure, 2009). Exposure to pollutants, particularly heavy metals like cadmium (Cd), iron (Fe), lead (Pb), and copper (Cu), can lead to both acute and chronic toxicity, disrupting various physiological functions, including reproduction. A ealthy reproductive system in fish signifies their ability to maintain population sustainability. Fish are widely consumed due to their desirable taste and affordability, making them a vital and cost- effective source of animal protein.
Fish are more susceptible to heavy metal pollution than other aquatic species, despite being one of the most widely distributed species. Some heavy metals like cadmium, mercury, arsenic, and lead have no biological significance, while some like iron, copper, and zinc are vital to the metabolism of fish. Heavy metals concentration in the water bodies has increased significantly as a result of farming, mining, geochemical composition, anthropogenic wastes, and other factors. Heavy metals are among the most hazardous and widely distributed contaminants, naturally occurring as trace elements in the hydrosphere (Sankhla & Kumar, 2019). Fish, however, breed in environments that are naturally contaminated with heavy metals. Fish reproduction is essential to the natural ecosystem and is required for the development of aquaculture. Several studies show that heavy metals interfere with fish reproduction by preventing the induction of vitellogenin, postponing oogenesis, increasing the secretion of luteinizing hormone, and lowering the parameters of the gonadal somatic index and ovulation.