Industrial trawlers once avoided coral reefs and other rocky regions of the ocean floor because their nets would snag and tear. But the introduction of rockhopper trawls in the 1980s changed this. The largest, with heavy rollers over 75cm in diameter, are very powerful, capable of moving boulders weighing 25 tonnes. Now, most of the ocean floor can be trawled down to a depth of 2,000m.
Trawl fisheries are an important component of the capture fisheries sector in Malaysia. It contributes the overall landings in marine capture fisheries (48.19%). As of 2017, Malaysia has 28,172 registered bottom trawl vessels operating in Malaysia’s exclusive economic zones.
The major threat of bottom trawling is habitat destruction; where habitat-forming species such as corals, sponges and fish that dig burrows or build mounds no longer thrive in areas where trawling is practiced. Trawling will reduce the structural complexity of the seafloor.
Another threat of bottom trawling is that it also catches juvenile and low value fish that is not for human consumption. Defined as “trash fish”, these species are killed before maturity and hence have not reproduced to ensure continued stock. A survey conducted by WWF-Malaysia in 2015 estimated that trash fish usually represents 70% to 80% of total catch from trawling in Malaysia. The catch of these juvenile species bear a large cost to marine environment; threatening the sustainability of fish stocks and continued existence of marine biodiversity in the country.
But all hope is not lost, the Malaysia government is putting an effort to reduce bottom trawling through several phases, you can read more about it here: http://www.wwf.org.my/media_and_information/updates__former_newsroom_main_/?uNewsID=18385
Sources: 2017 Statistics from the Department of Fisheries Malaysia (DOFM), Food and Agriculture Organization of the United Nations Report 2013, World Wide Fund for Nature (WWF)
In the game, we show that when an area is trawled, all marine life is lost.