Advice on Bottom Trawling in New Zealand's marine environment

To: Hon Poto Williams, Minster of Conservation 
Date: 14 November 2022

The Authority places significant importance on protecting New Zealand’s marine environment and ensuring that its abundant marine life is protected from harmful and damaging fishing practices. It was reassuring to note that the Hauraki Gulf Revitalisation Plan addresses a number of commercial fishing practices that cause significant damage to marine life and ecosystems. Of particular concern to the Authority, however, is the active use of bottom trawling by many commercial fishing companies, and the subsequent destruction it causes to the seafloor.

Bottom trawling is the practice of dragging a heavily weighted net across the seafloor in the aim to catch the largest quantity of fish possible, and is a common method used by commercial fishing companies operating within New Zealand waters. The method is targeted at deep- water species located around sub-marine mountains, which also host significant and diverse marine vegetation. New Zealand is one of only seven countries in the world who also practice bottom trawling within international waters, with the majority of catches being exported to China and the United States.

Destructive effects of bottom trawling

Bottom trawling creates lasting impacts on the biodiversity and healthy of marine environments, the dragging of a weighted net across the sea-floor results in significant amounts of by-catch of non-targeted species. These species often included turtles, juvenile fish and invertebrates that get swept up in trawling nets, and large areas of deep-sea corals can sustain permanent damage affecting their longevity.

It would not be unreasonable to state that the continuing of bottom trawling practices will lead to depleted and permanently damaged marine environments, not to mention the loss of their biodiversity and ecosystems.

Limiting location for bottom trawling

During the consultation period for the Revitalising the Hauraki Gulf: Marine protection proposals, the Authority lodged a submission where it addressed the damages caused by bottom trawling and suggested the need for stronger provisions in the proposals limiting contact by commercial fishing companies with the seafloor, for the purpose of protecting the health of the Hauraki Gulf. The Authority was pleased to have been informed that the plans propose to restrict bottom trawling practices in all Seafloor Protected Areas (SPAs). Additionally it was noted that in the Revitalising the Gulf: Government action on the Sea Change Plan June 2021, the proposals to create “corridors” within the Gulf that allow for bottom trawling to continue, is an effort to limit the destructive damages to the marine biodiversity located on the seafloor. This is a proposal the Authority would be open to discussing and further developing to create the best possible form of protection for the seafloor.

Proposed next steps – advocacy on limiting or banning bottom trawling

The Authority, being a strong advocate for New Zealand’s marine environment and biodiversity, would like to see increased efforts to restrict and reduce the practice of bottom- trawling within New Zealand waters, and for the re-evaluation of this practice within international waters. The Authority understands that through the use of bottom trawling, commercial fishing companies contribute to New Zealand’s economy and export supply, however stronger consideration needs to be given to the importance, health and protection of our marine environment, and the Authority ultimately believes that a complete ban should be put in place in all bottom trawling practices.

The Authority hopes you share our raised concerns and passion for protecting New Zealand’s marine environment and hopes to have further opportunities to discuss this matter with you in the future.