Gill nets are a type of fishing net that have been in use for centuries. They are designed to catch fish by entangling them in the netting, which is made up of a series of small mesh panels.
Gill nets are commonly used in commercial fishing operations around the world, where they are often employed to catch large numbers of fish quickly and efficiently.
While efficient, these nets have also been the subject of controversy. Read on below to learn more about these nets.
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Understanding Gill Nets
A gill net is a type of fishing net that is designed to catch fish by entangling them in the gills. It is made up of a series of vertical panels of netting that are suspended in the water column by floats at the top and weights at the bottom. Fish that swim into the net become entangled in the mesh and are unable to escape.
The mesh size of a gill net is an important factor in determining its effectiveness. The mesh size determines the size of the fish that can be caught and the amount of bycatch that is caught. The mesh size is usually chosen based on the target species and the size of the fish that are being caught.
Gill nets are typically made from monofilament, which is a single strand of material that is used to create the netting. Monofilament is strong and durable, which makes it ideal for use in fishing nets.
Weights are used to keep the bottom of the net in place and prevent fish from swimming underneath it. The weight of the net is usually determined by the depth of the water and the strength of the current.
Gills are the respiratory organs of fish, and they are located on either side of the fish’s head.
When a fish swims into a gill net, its gills become entangled in the mesh, which prevents it from breathing. This can lead to the death of the fish if it is not quickly released from the net.
Types of Gill Nets
Below, we’ll discuss the different types of gill nets in use around the world and what they’re purposes are.
Drift gillnets are designed to float in the water column and are commonly used in commercial fishing.
They are usually made of nylon or other synthetic materials and can be up to several hundred meters long.
Fish swim into the net and become entangled in the mesh. Drift gillnets are typically used to catch pelagic species such as tuna, salmon, and herring.
Set gillnets are anchored to the seabed and are commonly used in shallow waters. They are typically shorter than drift gillnets and are designed to trap fish as they swim along the seabed.
Set gillnets are often used to catch demersal species such as cod, haddock, and flatfish.
Encircling gillnets are designed to surround a school of fish and are commonly used in commercial fishing.
They are typically used to catch pelagic species such as tuna, mackerel, and sardines. Encircling gillnets can be several kilometers long and can be set at different depths to target specific species.
Gill nets can be highly effective at catching fish, but they can also have a negative impact on the environment.
They can trap and kill non-target species, such as dolphins, seals, and sea turtles. In addition, lost or abandoned gill nets, known as “ghost nets,” can continue to trap and kill marine life for years after they have been lost.
Materials Used in Gill Nets
Gill nets are made from a variety of materials, each with its own advantages and disadvantages. The most common materials used in gill nets are nylon, multifilament, and paracord.
Nylon is a popular choice because it is strong, durable, and resistant to abrasion. Multifilament is also a good choice because it is lightweight and has a high breaking strength.
Paracord is a newer material that is gaining popularity because it is strong, durable, and lightweight.
In addition to the netting material, gill nets also require weights to keep them in place and floats to keep them buoyant. Lead weights are commonly used because they are heavy and sink quickly, but they are also toxic and can harm the environment.
Cork is a more environmentally friendly option that is becoming increasingly popular. It is lightweight and floats, making it ideal for use as floats in gill nets.
The thickness of the netting material used in gill nets is also important. Thicker netting is more durable and can withstand more wear and tear, but it is also more visible to fish and can reduce the effectiveness of the net.
Thinner netting is less visible but is also less durable and may need to be replaced more frequently.
Gill Net Fishing Techniques
Gill net fishing is a method of fishing that uses nets that are hung vertically in the water. The nets are made of monofilament or multifilament nylon, and they have a mesh size that is designed to catch specific species of fish.
Gill nets can be set at various depths and can be used in both freshwater and saltwater environments.
Gill net fishing involves suspending a net vertically in the water column, with the top of the net held up by floats and the bottom of the net held down by weights.
Fish swim into the net and become entangled in the mesh. The net is then retrieved, and the fish are removed.
Gill nets are not attached to a fishing line, but they are suspended vertically in the water column.
The net is held in place by floats at the top and weights at the bottom.
Gill nets are hung vertically in the water column, with the top of the net held up by floats and the bottom of the net held down by weights.
Gill nets can be designed to catch specific species of fish. The mesh size of the net is chosen to allow the desired species to swim into the net and become entangled, while preventing other species from being caught.
Gill net fishing is a passive fishing method, as the net is suspended in the water and does not require active effort to attract fish.
Gill nets are different from seines, which are nets that are dragged through the water to catch fish.
Seines are typically used in shallow water and can be used to catch a variety of species. Gill nets are used in deeper water and are designed to catch specific species of fish.
Species Targeted by Gill Nets
Gill nets are fishing nets that are designed to entangle fish by their gills. These nets are commonly used by commercial and recreational fishermen to catch a variety of fish species.
Gill nets are effective at catching fish because they are nearly invisible in the water and can be set at different depths to target different species.
Gill nets are commonly used in the open sea to catch a variety of fish species. Some of the most commonly targeted sea species include tuna, cod, salmon, herring, shad, sharks, swordfish, and sturgeon.
These fish species are often caught using gill nets because they swim in schools and can be easily caught in large numbers.
Gill nets are also commonly used in rivers to catch a variety of fish species. Some of the most commonly targeted river species include Alaska, haddock, pollock, flounder, hake, barracuda, mullet, rockfish, and seabass.
These fish species are often caught using gill nets because they are migratory and can be easily caught as they swim upstream.
It is important to note that gill nets can also catch unintended species, known as bycatch. Bycatch can include fish that are not targeted by the fishermen, as well as other marine animals such as dolphins, sea turtles, and seabirds.
Fishermen can reduce the amount of bycatch by using different types of fishing gear or modifying their fishing techniques.
Gill Nets and Bycatch
Gill nets are a type of fishing net that are commonly used to catch fish. They are made of nylon or other synthetic materials and are designed to entangle fish by their gills.
Gill nets are widely used in commercial fishing and are often set up in long lines that can stretch for miles.
However, gill nets are also known to capture and entangle marine mammals and other non-target species, a phenomenon known as bycatch. Bycatch is a significant problem in many fisheries, as it can result in the unintentional capture and mortality of non-target species.
Marine mammals, such as dolphins, cetaceans (including humpback whales, fin whales, and right whales), harbor porpoise, common dolphin, and right whale dolphins, are particularly vulnerable to gill net bycatch. Gray seals are also known to be incidentally captured in gill nets.
The mortality rate of bycaught marine mammals varies depending on the species and the circumstances of the entanglement.
In some cases, animals are able to free themselves from the net, while in others, they may become severely entangled and die as a result.
Efforts are being made to reduce the bycatch of marine mammals and other non-target species in gill net fisheries. One approach is to use acoustic reflectors to deter marine mammals from approaching the nets.
Another approach is to illuminate the nets with ultraviolet light, which can make them more visible to marine mammals and other non-target species.
Despite these efforts, gill net bycatch remains a significant problem in many fisheries, and ongoing research is needed to develop more effective solutions to reduce the incidental capture of non-target species.
Environmental Impact of Gill Nets
Gill nets have a significant impact on the environment, particularly on the habitat and marine life. The nets are designed to trap fish by their gills as they try to swim through the mesh.
However, the nets also catch other marine animals, including dolphins, turtles, and sharks, which are often killed or injured in the process.
The use of gill nets in the northwest and southwest regions has been a major concern for environmentalists. The nets cause significant damage to the habitat, including coral reefs, seagrass beds, and other important marine ecosystems.
The nets can also cause physical damage to the seabed, which can lead to long-term ecological damage.
Gillnet fisheries have been known to cause overfishing, which can lead to a decline in the population of certain fish species. This can have a ripple effect on the entire ecosystem, as other marine animals depend on these fish for food.
Overfishing can also lead to a decrease in biodiversity, which can have long-term consequences for the environment.
There have been efforts to reduce the impact of gill nets on the environment. For example, some countries have implemented regulations that require fishermen to use larger mesh sizes, which reduce the number of non-target species caught in the nets.
Other countries have implemented seasonal closures to protect certain species during their breeding seasons.
Regulations and Modifications
Gillnets are regulated in many countries to reduce bycatch and protect non-target species. The United Nations has made recommendations for the use of gillnets in commercial fishing, including the use of pingers to deter marine mammals and the use of vertical panels to reduce bycatch.
In addition to regulations, there are also gear modifications that can be made to gillnets to reduce bycatch.
One common modification is the use of larger mesh sizes, which allows smaller fish to escape. Another modification is the use of anchors to keep the net on the sea floor and reduce the risk of entanglement.
Experimental modifications have also been tested, such as the use of visual and acoustic alarms to alert marine mammals to the presence of the net.
These modifications have shown promise in reducing bycatch, but further research is needed to determine their effectiveness in commercial fishing fleets.
Frequently Asked Questions
How does a gill net work?
A gill net is a type of fishing net that is hung vertically in the water column to entangle fish by their gills.
It is made of a series of panels of netting that are tied together, forming a wall of netting.
The netting is usually made of monofilament or multifilament nylon, and the size of the mesh can vary depending on the target species.
What is the purpose of a gill net?
The purpose of a gill net is to catch fish in a specific area. It is commonly used in commercial fishing to catch large quantities of fish, such as salmon, herring, and cod.
Gill nets can also be used in recreational fishing to catch smaller species, such as trout and perch.
What types of fish are caught with gill nets?
Gill nets are used to catch a variety of fish species, depending on the size of the mesh and the location of the netting.
In marine environments, gill nets are often used to catch larger species, such as salmon, tuna, and cod.
In freshwater environments, gill nets are used to catch smaller species, such as trout, perch, and walleye.
Are gill nets harmful to the environment?
Gill nets have been criticized for their potential to harm non-target species, such as marine mammals, sea turtles, and birds.
When these animals become entangled in the netting, they can drown or suffer serious injuries.
Gill nets can also have negative impacts on the environment by causing habitat destruction and altering the food chain.
What are the regulations around gill netting?
The regulations around gill netting vary depending on the location and the target species. In some areas, gill netting is heavily regulated or banned altogether due to concerns about overfishing and bycatch.
In other areas, gill netting is allowed with certain restrictions, such as mesh size and the number of nets that can be used.
What are the alternatives to gill netting?
There are several alternatives to gill netting that are considered more environmentally friendly, such as hook and line fishing, trap fishing, and seine netting.
These methods are generally more selective and have lower bycatch rates than gill netting. However, they may not be as effective at catching large quantities of fish.