Longline fishing

Fishermen use a very long line in the sea. This line can have thousands of hooks on it. Each hook has food to catch fish. Some lines stay near the top of the water.

Other lines sink to the bottom. This helps catch fish like tuna or cod. Sometimes, other animals get caught by mistake. This can include birds or turtles. People use new tools to help keep them safe.

We can work to protect all sea life.

Longline fishing is a way to catch fish using a very long line. This main line has many hooks attached to it. Each hook hangs from a short branch line called a snood. Some lines hang near the surface to catch tuna. Other lines sink to the sea floor to catch halibut.

A single line can hold thousands of baited hooks. This can lead to bycatch. Bycatch is when animals are caught by mistake. This includes sharks, turtles, and seabirds.

Seabirds often get caught when they try to eat the bait. This is a big problem for albatross birds. To help, fishers use new tools. They might use bright lights or streamers to scare birds away. They also use special hooks to protect sea turtles. Some fishers use a tool called a Hookpod. In New Zealand, a test showed zero birds were caught in six months. Fishing gear can also leave plastic in the ocean. Old lines can shed tiny bits of plastic as they move through the water.

Longline fishing is a way to catch many fish at once. It uses a very long main line in the ocean. Many small branch lines called snoods hang from this main line. Each snood has a hook with bait on the end.

These lines can be set to drift or stay in place with an anchor. Some lines stay near the surface to catch tuna or swordfish. These are called pelagic longlines. Other lines sink to the sea floor to catch halibut or cod. These are called demersal longlines.

This way of fishing works by using many hooks on one line. A single line can hold hundreds or even thousands of hooks. In the Bering Sea, lines can have over 2,500 hand-baited hooks. Some fisheries are much smaller and use only 25 hooks per line. Sometimes fishers use traps instead of hooks to catch crab in deep water. This method is very efficient for catching large amounts of fish. It allows boats to target specific types of fish in different parts of the water.

People have used longlines for a long time. In Hawaii, Japanese immigrants introduced this method in 1917. Back then, people called it flagline fishing. They used flags to mark the floats that held the hooks. Later, boats began using modern tools like monofilament lines and large reels. Because of these new tools, the name changed to longline fishing. This shows how fishing technology has changed over many years.

One big problem with longlining is bycatch. Bycatch is when animals are caught by mistake. This can include sharks, dolphins, sea turtles, and seabirds.

Seabirds like the albatross are at high risk. They try to eat the bait and get hooked. It is estimated that 8,000 albatross are killed this way every year. In Hawaii, the swordfish fishery closed in 2000 because of sea turtle bycatch. It reopened in 2004 after using better circle-hooks and different bait.

Scientists and fishers are finding ways to make longlining safer. They use streamer lines or lasers to scare birds away. Some fishers only set lines at night to avoid birds. A tool called a Hookpod was tested in New Zealand in 2020. In the first six months, it resulted in zero seabird bycatch. We must also watch for plastic pollution from old lines. Old lines can shed many tiny microplastic fragments as they move through the water.

Longline fishing is a commercial angling technique used to catch large numbers of fish. It relies on a very long main line stretching through the ocean. Many short branch lines, called snoods or gangions, are attached to this main line at regular intervals. Each snood holds a baited hook at its end. These hooks are attached using clips or swivels to allow movement. Because a single line can hold hundreds or even thousands of hooks, it is a very efficient way to fish. This method is used globally to target specific species in different parts of the ocean.

Fishermen classify longlines based on where they are placed in the water column. Pelagic longlines are set near the surface to target fish like tuna and swordfish. In contrast, demersal longlines are placed along the sea floor to catch groundfish such as halibut or cod. Some fishers target sablefish, also known as black cod, by setting gear on the sea floor at great depths. While most longlines use hooks, some versions use traps instead to catch crab in deep waters. The lines themselves can be set to drift with the current or held in place by an anchor.

The scale of longline fishing varies greatly depending on the specific fishery. In unstable fisheries, such as those for Patagonian toothfish, fishermen may be limited to only 25 hooks per line. However, commercial longliners in the Bering Sea and North Pacific operate on a much larger scale. In these robust fisheries, a single series of connected lines can be many miles long. These lines often carry over 2,500 hand-baited hooks. This massive amount of gear allows for high volumes of fish to be collected in a single operation.

Longlining has a distinct history in certain regions, such as Hawaii. Japanese immigrants introduced the practice there in 1917. At that time, it was known as flagline fishing because fishers used flags to mark the floats. These floats held the hooks suspended in the water. The name changed to longline fishing once vessels began using modern technology. This included monofilament mainlines, specialized line setters, and large, hydraulically powered reels. These technological shifts transformed the traditional method into the industrial process seen today.

A major concern regarding longline fishing is bycatch. Bycatch refers to the incidental catching and killing of non-target species or immature fish. This includes animals like dolphins, sharks, sea turtles, and various seabirds.

Seabirds are especially vulnerable because they are attracted to the bait or offal. They can become hooked and drown. It is estimated that 8,000 albatross are killed this way every year. This is a serious issue for bird conservation, as 15 of the 22 albatross species recognized by the IUCN Red List are threatened with extinction.

To reduce these deaths, several mitigation techniques have been developed. Some fisheries use weights to ensure lines sink quickly, or deploy streamer lines and lasers to scare birds away. Setting lines at night can also help avoid attracting birds that hunt in low light. In Hawaii, the swordfish fishery was closed in 2000 due to excessive loggerhead and leatherback sea turtle bycatch. It reopened in 2004 after gear was modified. Using large circle-hooks and mackerel-type baits helped eliminate much of the turtle bycatch. In New Zealand, a device called a Hookpod was tested in 2020. In its first six months, it resulted in zero seabird bycatch.

Beyond animal safety, longline fishing also impacts the environment through plastic pollution. According to Greenpeace, modern fishing equipment like longlines makes up a large portion of oceanic macroplastic. Furthermore, fishing lines shed microplastics as they are towed through the water. Research shows that older lines shed significantly more fragments than new ones. New lines might shed 20 microplastic fragments per yard, but 10-year-old lines can shed 760 fragments per yard. Researchers estimate that fishing boats may shed between 326 million and 17 billion microplastic fragments into the ocean every year.

Finally, the industry presents specific safety challenges for the people working on the vessels. In the United States, studies have shown that the risk of non-fatal injuries is significant for longline workers. The rate was found to be 35 injuries per 1,000 full-time equivalent employees. This is about three times higher than the average for all U.S. workers. While this is still lower than the rate for the trawler fleet, which is 43 per 1,000, it highlights the physical demands of the job. Managing these risks involves balancing high-efficiency fishing with the safety of both the crew and the marine ecosystem.