Bottom Trawling – Destroying Ocean Biodiversity

by | Apr 12, 2022 | Environment, Trending

Home » Environment » Bottom Trawling – Destroying Ocean Biodiversity

In 2021, Netflix released a documentary on the fishing industry called “Seaspiracy.” The film was immediately met with explosive reviews and was the centre of debates between scientists, organizations, and companies. Even as the film was surrounded by controversy, it certainly made the public much more aware of the dark side of the fishing industry. A couple of main points highlighted in the documentary were bottom sea trawling and bycatch, two fishing practices that are destroying ocean biodiversity.

It has been estimated that trawling yields a global catch of 30 million tonnes per year, which is an amount higher than any other fishing method. While bottom trawling seems to be profitable, it is one of the most harmful practices.

This is a practice that has been going on for several decades. But it is only in recent years that we have realized the unprecedented damage caused by bottom trawling.

Bottom Trawling

So, what exactly is bottom trawling?

In bottom trawling, a heavy fishing net is dragged along the seafloor using a trawler. These nets are as large as a football field and essentially pick up every living thing in their path, including sediment from the sea bed.

As bottom trawling drags the nets directly across the sea bed, it picks up every type of living organism, even those that are of no use. Thus, due to their large capacities, these nets destroy almost everything in their path and end up killing animals such as dolphins, seahorses, coral, and many other marine species.

Impacts of Bottom Sea Trawling

Bottom trawling has devastating impacts on aquatic biodiversity. As it captures every living organism in a particular area, many of the animals that are caught are discarded as they are of no use. For example, more than 80% of the shrimp caught via trawling are discarded in Panama.

Additionally, many of these unwanted catches are juveniles of a species. This directly threatens the survival of a particular species because if the species are unable to breed and continue their offspring, they will eventually become extinct.

Furthermore, trawling has been found to destroy deep-sea coral ecosystems. Coral reefs are crucial components of the aquatic ecosystem. They support more species than any other marine environment and provide income to millions of people. They also protect coastal areas against the forces of waves, storms, and floods.

Bottom trawling also causes social conflicts. For example, it often leads to disputes with local, small-scale fishers whose livelihoods depend on fishing. For example, commercial trawling operations conducted by foreign fleets in Guinea drag through the equipment of local fishers, which causes considerable losses to them. Also, because of the large capacity of trawling nets, local fishers can capture only a small percentage of fish which is not economically profitable for them.

As more and more people become conscious of their food choices, there is an increased awareness of the harm caused by practices such as bottom trawling. As a result, there is an acceleration in the movements that call to ban such practices. This enables governments to take action and provide some solutions.


There are many initiatives undertaken at national and international levels to regulate the practice of bottom sea trawling. Countries such as Hong Kong, Indonesia, Palau, and Belize have entirely banned the practice, whereas Australia, Brazil, Canada, Malaysia, and China have established strict no-trawl zones. In New Zealand, more than a third of its waters have been closed, i.e. it is prohibited to conduct bottom trawling or to dredge in those waters.

In India, at a local level, for instance, the Palk Bay Scheme was launched in 2017. The scheme is focused on the state of Tamil Nadu and aims to provide 2000 fishing vessels to fishers so that they can catch fish sustainably and stop bottom trawling.

At an individual level, we as consumers can make some conscious decisions to do our part in perpetuating the practice of bottom trawling. Some of the things that we can do include:

  1. Avoid seafood that is largely caught through bottom trawling, such as shrimp.
  2. Support local fishers and look for labels that tell you the exact source of the seafood.
  3. Spread awareness about the harm caused by such practices and encourage your local communities to help in stopping these practices actively.
  4. Work with or support organizations and NGOs that do on-ground work to stop the practice. Some of these organizations are Seas at Risk, Oceana, and the Marine Conservation Institute.

Thus, we have seen how bottom trawling is exceptionally harmful to the beautiful biodiversity of our planet. We can hope that if all involved parties work together, we can find a way to a more sustainable future. Everyone involved in the industry benefits from their profession while ensuring that our marine resources are well protected and taken care of.




  • Dr. Emily Greenfield

    Dr. Emily Greenfield is a highly accomplished environmentalist with over 30 years of experience in writing, reviewing, and publishing content on various environmental topics. Hailing from the United States, she has dedicated her career to raising awareness about environmental issues and promoting sustainable practices.

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