According to the Worldwide Fund for Nature, 70 percent of the world's fisheries are fully exploited or over-exploited. Overfishing is the single biggest threat to marine ecosystems. A large part of the overfishing problem relates to by-catch, or unwanted marine animals that are discarded during fishing. Trawl and driftnet fishing result in large by-catch rates, severely degrading ecosystems in the process. To protect marine life, the international community must implement global sustainable fishing regulations and enforcement mechanisms. Regulations must focus on maintaining individual species populations and minimizing by-catch.
In coastal areas, pollution causes bioaccumulation of toxins and reproductive problems in fish and other sea creatures. Agricultural runoff results in large quantities of water-born phosphates, which stimulate algae growth, often resulting toxicity and depletion of oxygen levels in coastal waters. Algae blooms result in large seasonal dead zones in coastal areas near major rivers. To protect marine ecosystems, stricter pollution standards must be put in place and enforced, especially regarding the discharge of toxins directly into waterways. Limits should also be enforced regarding levels of nitrogen and phosphorous used in agricultural.
Habitat destruction is particularly damaging to marine life when it occurs in coral reefs, which are are among the most biologically diverse ecosystems on the planet. Coral reefs throughout the world are endangered, threatened by pollution, overfishing, destructive fishing practices using explosives and toxins and global warming. To save coral reefs, sustainable fishing practices must be implemented, including a global ban on fishing using dynamite and poisons like cyanide.
There are numerous ways that individuals can help protect ocean ecosystems. Conservation organization always need financial donations and volunteers to help educate the public, lobby the government, or clean beaches and coral reefs. Since government policy directly impacts regulations and environmental practices, some of the most effective conservation activities involve writing elected representatives and otherwise advocating for better environmental policies. Individuals can also avoid eating threatened fish species, and using products that cause water pollution.