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Fishing has long been a crucial source of food and livelihood for communities around the world, but it can also have significant environmental impacts. One method of fishing that has garnered attention in recent years is the use of gill nets. But what is a gill net for fishing, and how does it work? In this article, we’ll take a closer look at gill nets and their impact on aquatic life.

A gill net is a type of fishing net that is designed to trap fish by their gills as they swim through the mesh. The net is typically set vertically in the water and can range in size from a few feet to several hundred feet long. The mesh size of the net is designed to allow smaller fish to escape while catching larger fish by their gills. Gill nets have been used for centuries in commercial fishing, but their use has become increasingly controversial due to concerns about bycatch and their impact on the environment.

In the following sections, we’ll explore how gill nets work, the pros and cons of using them, and their impact on aquatic life. We’ll also look at regulations surrounding their use and alternatives to gill nets.

what is a gill net for fishing

How Gill Nets Work:

Gill nets are typically made from nylon or other synthetic materials and consist of a series of vertical panels of netting, suspended by floats at the top and weighted at the bottom. The mesh size of the netting determines what size fish can swim through, with larger fish getting trapped by their gills.

When set, the gill net is placed in a position where fish are known to swim, such as along a migratory path or near the bottom of a river or ocean. As fish swim through the net, they become caught in the mesh by their gills. The mesh is designed to be virtually invisible underwater, so fish swim into the net without realizing they are being trapped.

Once the net has been set for a period of time, the fishermen retrieve it, pulling the fish up along with the net. The fish are then sorted and either kept for sale or released back into the water. In some cases, fish that are not the intended catch, also known as bycatch, may also be caught in the net and thrown back or sold.

what is a gill net for fishing

There are two types of gill nets: drift nets and set nets. Drift nets are set out in the water and allowed to drift with the current, catching fish as they swim through the mesh. Drift nets can be up to several miles long and can trap a wide variety of marine life, including whales, dolphins, and sea turtles. Set nets, on the other hand, are anchored to the sea floor or riverbed and are typically used in shallow waters or near shorelines. They are less likely to catch non-target species and are therefore considered to be more environmentally friendly.

While gill nets can be an effective way to catch fish, they also have significant drawbacks.

Pros and Cons of Using Gill Nets in Fishing:

Like any fishing method, using gill nets has both advantages and disadvantages. Let’s take a closer look at some of the pros and cons:

  • High Yield: Gill nets can be very effective at catching large numbers of fish, making them an attractive option for commercial fishermen.
  • Low Cost: Gill nets are relatively inexpensive to manufacture and easy to use, which makes them an accessible option for small-scale fishermen.
  • Selectivity: Gill nets can be designed to target specific fish species and sizes, making them a more selective fishing method than others.
  • Efficiency: Gill nets can be set and left in the water for a period of time, allowing fishermen to catch fish without actively monitoring the net.
  • Bycatch: One of the main drawbacks of gill nets is that they can catch non-target species, such as dolphins, turtles, and seabirds. This bycatch can cause significant harm to the environment and threaten endangered species.
  • Habitat Damage: Gill nets can damage the habitats where they are set, including coral reefs, seagrass beds, and rocky shores.
  • Lack of Control: Gill nets can be difficult to control in high seas or strong currents, and they can drift away and continue catching fish long after the fishermen have left.
  • Abandoned Nets: When fishermen lose or abandon gill nets in the water, they can continue to trap and kill fish and other marine life for years, known as ghost fishing.

Overall, while gill nets can be an effective way to catch fish, they also pose significant risks to the environment and non-target species. The next section will explore the impact of gill nets on aquatic life.

Impact of Gill Nets on Aquatic Life:

The use of gill nets in fishing has been controversial due to its negative impact on aquatic life, particularly non-target species. Gill nets can catch unintended marine animals, such as dolphins, sharks, turtles, and seabirds. Once caught, these animals often suffocate or drown, resulting in a significant loss of biodiversity.

According to the International Union for Conservation of Nature (IUCN), the use of gill nets is responsible for a large portion of global marine mammal deaths, particularly in regions where large numbers of dolphins and porpoises are found. For example, in the Black Sea, gill nets are the primary cause of death for the critically endangered harbor porpoise population.

Gill nets can also have a significant impact on fish populations. Overfishing, combined with the use of gill nets, has led to a decline in several fish species, including cod, tuna, and salmon. The use of gill nets has also contributed to the decline of other marine animals, such as sea turtles, which are often caught accidentally.

In addition to the impact on specific species, gill nets can also have an overall negative effect on the ecosystem. The damage to the habitats where the nets are set, such as coral reefs and seagrass beds, can have long-lasting effects on the ecosystem as a whole.

The impact of gill nets on aquatic life is a complex issue that requires a balance between the needs of fishermen and the protection of marine life. Next, we will explore some of the regulations and policies in place to address this issue.

Regulations and Policies on Gill Net Use:

Due to the negative impact of gill nets on aquatic life, many countries have implemented regulations and policies to manage their use. These regulations vary by region, but they generally aim to minimize the impact of gill nets on non-target species and protect marine ecosystems.

For example, in the European Union, regulations restrict the use of gill nets in certain areas, such as marine protected areas and areas with high dolphin and porpoise populations. The use of larger mesh sizes and acoustic deterrents is also required to reduce bycatch of marine mammals and birds.

In the United States, the use of gill nets is regulated by state and federal agencies. In some states, the use of gill nets is banned altogether, while in others, regulations require the use of escape panels to reduce bycatch of non-target species.

Internationally, the United Nations Food and Agriculture Organization (FAO) has developed guidelines for the use of gill nets. These guidelines recommend the use of larger mesh sizes and the avoidance of areas with high bycatch rates of non-target species. The FAO also encourages the use of alternative fishing methods, such as traps and hook-and-line fishing, as a more sustainable alternative to gill nets.

While these regulations and policies have been implemented to reduce the negative impact of gill nets on aquatic life, enforcement remains a challenge in many regions. In some cases, illegal and unregulated fishing practices continue to threaten the sustainability of marine ecosystems.

Alternatives to Gill Nets:

As the negative impact of gill nets on aquatic life becomes more apparent, there has been an increased focus on alternative fishing methods that are more sustainable and environmentally friendly. Here are some alternatives to gill nets:

  • Hook-and-Line Fishing: This method involves using a fishing line with a hook to catch fish one at a time. This method is more selective and allows fishermen to target specific species without catching non-target species.
Hook & Line Fishing
  • Trap Fishing: Traps are a passive fishing method that allow fish to enter but not exit, making them a more sustainable alternative to gill nets. Traps can be made from various materials, such as wire or bamboo, and can be used to catch a variety of fish species.
  • Purse Seine Nets: Purse seine nets are large, circular nets that are set around a school of fish and then drawn closed like a purse. This method is more selective than gill nets, as fishermen can release non-target species before closing the net.
  • Trawling: Trawling involves dragging a net through the water to catch fish. While trawling can be more efficient than gill nets, it can also have negative impacts on the seafloor and non-target species.

Overall, the move towards more sustainable and selective fishing methods is crucial to the long-term health of marine ecosystems. By reducing bycatch and minimizing the negative impact on non-target species, alternative fishing methods can help to maintain healthy fish populations and protect the biodiversity of our oceans.


In conclusion, gill nets are a fishing tool that has been used for centuries to catch fish in large quantities. However, their use has been increasingly controversial due to their negative impact on non-target species and the environment. Gill nets have been shown to cause significant harm to marine ecosystems, including the death of thousands of marine mammals and birds each year.

While regulations and policies have been put in place to manage the use of gill nets and protect marine life, enforcement remains a challenge in many regions. It is important to recognize the negative impacts of gill nets and seek alternative, more sustainable fishing methods that minimize bycatch and protect marine ecosystems. As consumers, we can also make a difference by choosing sustainably caught seafood and supporting fishing practices that prioritize the health of our oceans. By working together, we can protect marine life and ensure the long-term sustainability of our oceans for future generations.