Risk Factors in the Natural Habitat of Fish: A Review

Fish can be found in abundance in most bodies of water. Despite the fact that no species has yet been detected in the deepest 25% of the ocean, they are present in almost every aquatic environment, from the abyssal and even hadal depths of the deepest oceans (where they can be found as cusk-eels and snailfish) to the high mountain streams. Habitat destruction is the leading cause of biodiversity loss. The rise in nutrient loading, particularly nitrogen, is one of the main factors contributing to habitat degradation. Trawling diminishes the environment’s complexity by removing sedimentary features and biogenic structures like sponges, bryozoans, and shell aggregates. The construction of dams on tidal rivers has harmed estuarine habitat: estuary community structure, water chemistry, food webs, and loss of freshwater and estuary habitats. Since 1950, the catch of fishes associated with coral reefs has declined by 60% per unit of effort. Ever growing human populations and acidity have significantly impacted fish diversity. The literature reviewed unequivocally demonstrated how anthropogenic effects have altered ichthyofauna and reduced biodiversity in aquatic environments around the globe. Identifying current and potential habitat hazards and the conservation and improvement actions required to eliminate or minimise those concerns is crucial in determining important fish habitats.