Table 24.1 - Overview of significant impacts on the environment arising from fishing

Environmental media
Fishing activity Resources Water Nature and Wildlife
Marine fishing overexploitation -> depletion of certain fish stocks, reductions in genetic diversity, impacts on natural ecological dynamics processing plants and factory ships -> water pollution beam and otter trawls and dredges -> impacts on benthic organisms
flushing of holds -> water pollution (including oil) gill, drift nets and longlines -> impacts on vertebrates
anti-fouling preparations, such as tributyl tin from hulls of boats (now banned in EU countries) -> water pollution discarded fishing gear at sea -> impacts on birds and marine mammals
damage to oil/gas pipelines from trawling -> risk of rupture and threat to ecology
discards of unwanted fish and offal -> water pollution and odour
Freshwater fishing overexploitation -> depletion of certain fish stocks, reductions in genetic diversity, impacts on natural ecological dynamics (removal of top predators from freshwater bodies)   lead from recreational fishing -> toxic effects on waterfowl
discarded commercial fishing gear and anglers' tackle -> threat to waterfowl and aquatic mammals
Aquaculture   discharge of surplus food and animal wastes from fish farms -> eutrophication escape of farmed fish, exotic and transgenic fish -> impacts on gene pool of wild populations, increasing competition for same ecological niches
use of anti-fouling paint on aquaculture facilities -> water pollution increased demand for fishmeal (used for food in aquaculture)
physical barriers established for making fish farms -> potential to hinder movement of migratory fish species