Over-fishing is depleting the oceans; fishing practices cause untold damage to both wildlife and the sea itself; and industrial-scale fish-farming (acquaculture) is polluting our rivers and streams.

In 2006, the total world fisheries produced 143.6 million tonnes of fish, 92 million tonnes from capture and 51.7 million tones from aquaculture. 110.4 million tonnes (77%) was consumed by humans (47% from aquaculture) with the remainder going to non-food uses such as livestock and fishmeal for fish-farming)19.

According to the Food and Agriculture Organisation (FAO), by the year 2030 an additional 37 million tonnes of fish per year will be needed to maintain current levels of fish consumption, within a world popualtion increased by two billion more people2. The latest World Review of Fisheries and Aquaculture stated that 19% of major commercial marine fish socks monitored by the FAO are overexploited, 8% are depleted and 1% ranked as recovering from depletion19.

The existence of many species is threatened by society’s appetite for fish flesh. A major study in 2006 predicted that all commercial fisheries could die out by 205020. This four-year analysis was the first to examine all existing data on ocean species and ecosystems in order to understand the importance of biodiversity at the global scale. The results revealed that the global trend is a serious concern and projects the collapse (90% depletion) of all species of wild seafood that are currently being fished by the year 2050.

Over-fishing, bycatch, climate change, invasive species and coastal development have resulted in a decline in the number of marine species. The International Union for Conservation of Nature (IUCN) Red List of Threatened Species 2008 showed that approximately 17% of sharks and their relatives, 27% of the world’s coral 845 species of reed-building corals, 25% of marine mammals, 27% of seabirds and six of the seven species of marine turtle are all threatened21.

Ministers for the European Union reached an agreement for 2009 fishing quotas. In the UK, fishermen secured greater quotas of some types of fish with increased catch limits including; 30% more North Sea Cod, 32% more mackerel, 13% more North Sea Plaice and 8% more Monkfish for the West of Scotland, along with a reduction in the prawn quotas18. The number of fish caught is likely to decline further for several decades to come, not because we are eating less fish but because they simply aren’t there to be caught.

300,000 cetaceans are killed every year as ‘by-catch’ of the fishing industries. A report published by the Whale and Dolphin Conservation Society (WDCS), ‘Shrouded by the Sea’, reveals the disturbing truth behind the entanglement of whales, dolphins and porpoises in fishing nets and gear. The investigation highlights the suffering of these animals and provides details of how cetaceans slowly meet their death in fishing nets, many suffering extreme injuries through their underwater struggle to free themselves when trapped22.

Safeguards are often ineffective and illegal fishing is widespread. Blue-fin tuna, for example, is one of the most valuable fish on the planet. There is an increasing demand for its capture. A report by the World Wide Fund for Nature (WWF), also in 2008, found that Italy was amongst those countries responsible for over fishing and violation of the fishery’s management rules, having overshot their allocated quota by 38% in 200723.

The fishing industry is responsible for some of the most environmentally damaging practices affecting our seas and oceans today. Bottom-trawling (trawling for fish on the ocean floor) and dredging (to harvest oysters, clams and scallops) destroy the fragile ecosystem of the sea-bed. Dynamite and poison are used to catch fish in South East Asia, including the use of explosives on coral reefs in the Philippines, where shock waves can kill fish up to 50 metres from the site of blast24.

Aquaculture (fish farming) is also responsible for pollution and endangering wildlife.

Farmed fish have to eat, and the feeding of carnivorous fish intensifies pressure on the oceanic fisheries. For example, it takes 5 tonnes of wild caught fish to feed each tonne of farmed salmon25. Aquaculture can affect existing wild stocks of fish through pollution of waters and release of captured animals. If, for example, species of farmed fish are not already present in surrounding waters then fish-farming can have negative impacts on the already established fish fauna19. Pollution and ecosystem disturbances which arise from aquaculture production units, e.g shrimp farming in some tropical coastal regions, has had a negative impact on both marine and terrestrial environments. Problems are caused by open net cage fish farms and land-based fish farms, which can discharge significant amounts of wastewater containing nutrients, chemicals and pharmaceuticals that impact on the surrounding environment26. For example, reports indicate that Scottish salmon farms alone have breached pollution limits more than 400 times in a 3 year period27.

Whether it’s farmed or caught in the wild, eating fish causes significant damage to wildlife and the oceans. Vegetarians don’t eat fish so going veggie will help preserve precious ecosystems.