Marine Conservation Biology Institute Marine Conservation Biology Institute
Marine Conservation Biology Institute
Protecting Marine Ecosystems

Destructive Fishing

A radar station
Can you find the shrimp? Up to 90% of the catch of this shrip trawler fishing in the Gulf of Mexico was thrown overboard as bycatch. Image: Elliott Norse

Overfishing - catching more fish than the ocean can produce – has been an ongoing challenge for fisheries managers for decades. Today over ¼ of US fish stocks are overfished, which has led to the collapse of some very important fisheries and fishing communities.

Related to overfishing is the question of how we catch the fish. Certain types of fishing methods destroy or damage the very seafloor habitats where fishes and many other seafloor animals reside. Certain fishing methods are notorious for catching large amounts of bycatch – fish , sea turtles, seabirds and marine mammals - that are unintentionally caught and often incidentally killed in fishing operations.

Among all the fishing methods, bottom trawling, a fishing method that drags a large net across the sea floor, is the most destructive to our oceans. To protect the ocean ecosystems from the impacts of bottom trawling, MCBI has been a world leader in providing solutions to policy makers in the US and abroad.


What is bottom trawling?
Bottom trawling is an industrial fishing method where a large net with heavy weights is dragged across the seafloor, scooping up everything in its path – from the targeted fish to the incidentally caught centuries-old corals. Bottom trawls are used in catching marine life that live on the seafloor, like shrimp, cod, sole and flounder. In the US, bottom trawling occurs on the Pacific, Atlantic and Gulf coasts, capturing more than 800,000,000 pounds of marine life in 2007. Bottom trawls are also commonly used by other fishing nations and on the high seas.


Why is it a problem?
Bottom trawling is unselective and severely damaging to benthic ecosystems. The net indiscriminately catches every life and object it encounters. Thus, many creatures end up mistakenly caught and thrown overboard dead or dying, including endangered fish and even vulnerable deep-sea corals which can live for several hundred years. This collateral damage, called bycatch, can amount to 90% of a trawl’s total catch. In addition, the weight and width of a bottom trawl can destroy large areas of seafloor habitats that give marine species food and shelter. Such habitat destructions can leave the marine ecosystem permanently damaged.


What do we do?
MCBI has successfully pushed trawling impacts to the forefront of the marine conservation debate. We have produced peer-reviewed science that examined the ecological impacts of bottom trawling. We advocate keeping bottom trawls out of vulnerable marine habitats and our National Marine Sanctuaries and switching from high-impact fishing methods, like the bottom trawling, to less destructive fishing methods.


Our Work on Destructive Fishing:

seinerOur Partnership with Holland America Line - Holland America Line and Marine Conservation Biology Institute (MCBI) have partnered to promote sustainable use of the world’s oceans.


seinerHow We Fish Matters - A study on the ecological impacts of Canadian fishing gears ranks bottom trawling as the most destructive major fishing gear in Canada.


shifting gearsShifting Gears - A study of the collateral impacts of fishing methods in US waters ranks bottom trawling as the worst fishing gear in US waters.

fishSustainability of Deep-Sea Fisheries - Determining the (un)sustainability of deep-sea fisheries.

after2008 AAAS Symposium - Dragnet: Bottom Trawling, the World’s Most Severe and Extensive Seafloor Disturbance


coverConservation Biology - Disturbance of the seabed by mobile fishing gear: A comperison with forest clear-cutting.


coralDeep-Sea Corals - Seeking to ban bottom trawling in known deep-sea coral ecosystems.

seascapeHigh Seas Conservation - Reducing the impacts of bottom trawling on the high seas.


redherringsDebunking Claims of Sustainability - High Seas Bottom Trawl Red Herrings. This report rebuts the misinformation spread by some in the fishing industry.







Destructive Fishing Programs:

How We Fish Matters

Shifting Gears

Sustainability of Deep-Sea Fisheries

2008 AAAS Symposium

Conservation Biology

Debunking Claims of Sustainability