What is Dirty Fishing?
Dirty Fishing, also known as bycatch, describes commercial fishing activities that result in the catch of huge amounts of fish and other ocean life, which are then thrown back, dead or dying. According to a United Nations report, worldwide commercial fishing operations result in the waste of some 16 billion pounds of fish. In addition, hundreds of thousands of marine mammals, sea turtles, and sea birds are killed every year through dirty fishing.
Such waste and destruction occurs because many marine species share the same waters. Industrial fishing gear and methods indiscriminately capture untargeted wildlife, in addition to the desired catch. Enormous trawl nets scoop up everything above a certain size, and both immature fish and adults grab the bait on the thousands of hooks set in longline fishing. When fishing boats use destructive bottom-trawling gear, which drag gargantuan nets across the ocean floor, deep sea corals and sponges are often pulled up and destroyed in the hunt for a lucrative take.
While virtually all fishing gear captures some unwanted catch, some of the gear types that do the greatest damage to ocean wildlife include trawls, longlines, and gillnets.
Trawls: Ocean Bulldozers
Trawls are large, cone-shaped nets that are towed along the bottom of the ocean, sweeping up just about anything in their path. Through their actions, they clearcut the sea floor, which destroys ecosystems that may have taken centuries to form (i.e. coral and rocky reefs, seagrass beds, etc.) and eliminates hiding places that many marine species depend on for protection. It is estimated that trawlers annually scrape close to 6 million square miles of ocean floor. Globally, shrimp trawlers catch and throw back between five and 10 pounds of dead marine life for every pound of shrimp landed. In all, shrimp fishing accounts for 35 percent of the world's unwanted catch. Annually, in the U.S. South Atlantic and Gulf of Mexico, shrimping operations reportedly discard as much as 2.5 billion pounds of fish while drowning thousands of endangered and threatened sea turtles. Each year as the shrimp fishery season opens off the coast of Texas, hundreds of sea turtles killed by shrimp trawl nets wash up on south Texas beaches.
Longlines: 40 Miles of Hooks
Longlines are fishing lines up to 40 miles
long, with each containing hundreds of deadly hooks. Longlines hook and kill numerous fish species such as the severely depleted white marlin, and hundreds of thousands of endangered and threatened turtles, marine mammals, and sea birds each year. Researchers estimate that 200,000 loggerhead and 50,000 leatherback turtles were caught worldwide by pelagic longline fishing gear in 2000. According to the National Marine Fisheries Service (NMFS), 75 percent of the loggerhead turtles and 40 percent of the leatherback turtles taken by U.S. longliners in the Atlantic are caught by just a few boats on the Grand Banks in the North Atlantic. Dirty fishing by longliners also accounts for 70 percent of U.S. blue marlin deaths and 94 percent of U.S. white marlin deaths.
Gillnets: Walls of Death
Gillnets are mesh panels of net made from plastic, and are so efficient that in the process
they also capture many other kinds of fish and ocean wildlife, which are usually discarded. Globally, gillnets catch and kill more than 30 different species of marine mammals, including bottlenose dolphins and harbor porpoises. In the United States, gillnets entangle and kill hundreds of endangered and threatened sea turtles every year. These fisheries deploy hundreds of yards of net and leave them in the water for long periods of time, from several hours to several days. Sea turtles entangled underwater can drown in just minutes of forced submergence.
