How is bycatch problems affecting marine life?


Ecologically, bycatch can change the availability of prey, which affects marine ecosystems and the productivity of fisheries. Bycatch can negatively affect species such as dolphins, sea turtles, protected fish, and whales by harming animals, contributing to population declines, and impeding population recovery.Bycatch causes serious physical harm and often death in marine life. Often, when fish or other aquatic animals are brought up to the surface by fishing gear, the rapid change in water pressure causes their internal organs to rupture, which can be lethal.

Why is bycatch a problem?

Bycatch occurs because modern fishing gear is very efficient, often covers an extensive area, and can be highly unselective—it catches not only the target species but many other marine animals as well. Poor fisheries management in certain countries further contributes to the problem.

What are bycatch threats?

Fishermen sometimes catch and discard animals they do not want, cannot sell, or are not allowed to keep, creating what we know as bycatch. Bycatch can be fish, but also includes marine mammals, sea turtles, and seabirds that become hooked or entangled in fishing gear.

How is bycatch affecting sharks?

Longlines catch a large amount of bycatch because the baited hooks provide an easy meal for any indiscriminant predator, including sharks. They are often set in the water for extended periods of time, and by the time they are removed from the water, the hooked sharks are often dead.

See also  How much does a good fishing setup cost?

How is overfishing and by catch problem affecting marine life?

It can change the size of fish remaining, as well as how they reproduce and the speed at which they mature. When too many fish are taken out of the ocean it creates an imbalance that can erode the food web and lead to a loss of other important marine life, including vulnerable species like sea turtles and corals.

Why is bycatch a problem?

Bycatch occurs because modern fishing gear is very efficient, often covers an extensive area, and can be highly unselective—it catches not only the target species but many other marine animals as well. Poor fisheries management in certain countries further contributes to the problem.

What is the result of bycatch?

Bycatch can negatively affect species such as dolphins, sea turtles, protected fish, and whales by harming animals, contributing to population declines, and impeding population recovery. Other impacts of fisheries on marine mammals may include removal of their preferred prey and sometimes habitat damage.

When did bycatch become a problem?

Bycatch issues originated with the “mortality of dolphins in tuna nets in the 1960s”.

How many fish are affected by bycatch?

Another study found that between 17 and 22 percent of the wild fish caught in the U.S. is bycatch. According to other estimates, the global bycatch percentage accounts for 40 percent of the world’s total catch, amounting to 63 billion pounds per year.

What animal is most affected by bycatch?

Many animals are impacted, with the species most drastically hurt being sharks, seabirds, turtles, and dolphins.

How many animals are killed by bycatch?

When humans overfish, our oceans suffer. In a single year, U.S. fisheries unintentionally catch almost 2,000 federally protected marine mammals, almost 12,000 sea turtles and more than 7,600 seabirds. Worldwide more than 650,000 marine mammals die as fishery “bycatch” annually.

How many sharks are killed by bycatch?

Approximately 50 million more sharks die annually as bycatch in unregulated fisheries, often through the use of destructive and indiscriminate fishing methods such as longlines, gillnets, and trawls.

How many dolphins are killed as bycatch?

About Operation Dolphin Bycatch Scientific evidence shows between 6,000 and 10,000 dolphins are dying each year due to non-selective fishing methods used to target sea bass.

How many sharks are affected by bycatch?

According to the FAO, there are few fisheries that don’t catch sharks as bycatch, and some fisheries actually catch more sharks than their targeted species. Estimates suggest tens of millions of sharks are caught as bycatch each year.

See also  What is a good fishing gear ratio?

What are the negative impacts of overfishing?

Overfishing is devastating for coastal and ocean ecosystems as well as the communities that rely on fishing as a source of income. Other problems associated with overfishing are: The eradication of marine and coastal life, many coastal birds, seals, other fish species and ocean mammals rely on fish for survival.

What happens if we stop fishing?

Seafood is a major source of protein across Southeast Asia and islands in the Indian and Pacific Oceans. So while in Europe or the US we could eat more meat or soy products to make up for lost protein, a fishing ban could lead to food scarcity in communities with little land-based farming.

Why is overfishing bad for coral reefs?

Overfishing can alter food-web structure and cause cascading effects, such as reducing the numbers of grazing fish that keep corals clean of algal overgrowth. Blast fishing (i.e., using explosives to kill fish) can cause physical damage to corals as well.

How is overfishing done?

Overfishing is catching too many fish at once, so the breeding population becomes too depleted to recover. Overfishing often goes hand in hand with wasteful types of commercial fishing that haul in massive amounts of unwanted fish or other animals, which are then discarded.

How long do baby sharks grow inside their mother?

Their gestation periods vary from five months to three years, though most sharks gestate for about 12 months.

Why is bycatch a problem?

Bycatch occurs because modern fishing gear is very efficient, often covers an extensive area, and can be highly unselective—it catches not only the target species but many other marine animals as well. Poor fisheries management in certain countries further contributes to the problem.

How many sea turtles are killed by bycatch?

Bycatch Victims It is estimated that 300,000 small whales and dolphins, 50 million sharks and rays and 250,000 turtles die annually as bycatch.

Which animals are caught in bycatch?

Bycatch can be fish, for example undersized animals, egg-laden females, or non-target species. It also includes other animals such as dolphins, turtles and seabirds that can get hooked or entangled in fishing gear.

How common is bycatch?

While bycatch data is often outdated and inaccurate, researchers estimate that 17-22 percent of U.S. catch is discarded every year, according to the best available data. Bycatch in the U.S. could amount to 2 billion pounds every year, equivalent to the entire annual catch of many other fishing nations around the world.

What percentage of marine life caught is bycatch?

BYCATCH, OR THE CATCH OF NON-TARGET FISH AND OCEAN WILDLIFE, IS ONE OF THE LARGEST THREATS TO MAINTAINING HEALTHY FISH POPULATIONS AND MARINE ECOSYSTEMS AROUND THE WORLD. According to some estimates, global bycatch may amount to 40 percent of the world’s catch, totaling 63 billion pounds per year.

See also  Which fish breed most?

Which fishing industry has the largest bycatch?

The shrimp industry results in a particularly high amount of bycatch — according to Seafood Watch, for every pound of shrimp caught, up to six pounds of bycatch is caught.

How much of the world’s catch is bycatch?

In total, 38 million tonnes of sea creatures are unintentionally caught. That is 40% of fish catch worldwide. A large amount of this is either thrown back into the sea as ‘rubbish’, dead, dying or seriously injured, or disposed of on land.

How does bycatch affect marine mammals?

Marine mammals populations are among those most affected by bycatch. In fact, research suggests that bycatch is far more deadly to marine mammals than any other human activity. 1 Since marine mammals need to breathe air at the surface, they are particularly susceptible to drowning in fishing nets.

What is bycatch and why does it matter?

Bycatch can be fish, but also includes other animals such as dolphins, whales, sea turtles, and seabirds that become hooked or entangled in fishing gear. For NOAA Fisheries, bycatch refers to“discarded catch of marine species and unobserved mortality due to a direct encounter with fishing vessels and gear.”

What are the causes of bycatch in fishing?

Causes. Longlines, trawling and the use of gillnets are the fishing methods that most commonly result in bycatch. Longlining is a commercial fishing method commonly targeting swordfish, tuna and halibut, where hundreds or thousands of baited hooks hang at intervals along a single fishing line.

How can fishing gear be improved to reduce Bycatch mortalities?

INSPIRING INNOVATION Bycatch mortalities can often be reduced by modifying fishing gear so that fewer non-target species are caught or so that non-target species can escape. In many cases, these modifications are simple and inexpensive. WWF created the International Smart Gear Competitionto promote the development of such innovative technology.

Leigh Williams
Latest posts by Leigh Williams (see all)