Destructive fishing practices are fishing practices which easily result in irreversible damage to habitats and the sustainability of the fishery ecosystems. Such damages can be caused by direct physical destruction of the underwater landform and vegetation, overfishing (especially of keystone species), indiscriminate killing/maiming of aquatic life, disruption of vital reproductive cycles, and lingering water pollution.
Many fishing techniques can be destructive if used inappropriately, but some practices (such as blasting, electrocution and poisoning) are particularly likely to result in irreversible damage to the ecosystem. These practices are mostly, though not always, illegal (see also illegal, unreported, and unregulated fishing), and even where they are illegal, regulations are often inadequately enforced.