A new report dismisses claims from NGOs that bottom-trawling methods should be banned
A new study has shown that the risks from bottom-trawling remains “unquantified”, but it does believe that there are benefits both environmentally and economically if fishing is carried out in a sustainable manner.
The paper does not condemn all forms of bottom-trawling unlike claims made by on-governmental organisations such as Seas-at-Risk who were part of the group calling for the EU to ban “destructive” bottom-trawling.
The study called “Trawl impacts on the relative status of biotic communities of seabed sedimentary habitats in 24 regions worldwide” was carried out by thirteen researchers across the globe from the UK, the USA, Australia, Argentina, the Netherlands, Italy and Finland.
The result of the report contradicts claims by non-governmental organisations (NGOs) and the Netflix documentary Seaspiracy which have claimed that bottom-trawling and beam-trawling are destroying the sea floor in great swathes across the globe.
The report published by the National Academy of Sciences says that even though there is not enough detailed evidence provided about trawling effort and location as it is not publicly available, results have shown that the majority of trawled sea areas are in good health where bottom-trawling is managed sustainably.
The research was aimed at sedimentary habits as this is the type of habitat that comprises the majority of the seabed where the most bottom trawling occurs. The study looked at 24 large regions worldwide where trawling footprints have been previously mapped. It found that across all regions, 66% of the seabed was not trawled, 1.5% was depleted but recommended regional analyses to refine parameters for local specificity.
The paper says that results of the research are “sufficiently robust to highlight regions needing more effective management to reduce exploitation and improve stock sustainability and seabed environmental status—while also showing seabed status was high in regions where catches of trawled fish stocks meet accepted benchmarks for sustainable exploitation, demonstrating that environmental benefits accrue from effective fisheries management.
When it came to trawl depletion rates of benthic communities in mud, sand, and gravel habitats, otter trawls caused the lowest depletion followed by beam trawls and towed dredges. Depletion rates were lower in sand than in gravel and mud, but recovery rates for benthic species took longer in gravel due to the greater proportions of longer-lived species found in more stable gravel habitats.
The study says that balancing fishery production and ecosystem sustainability remains a globally challenging issue. Recognition of the wider environmental consequences of fishing, including seabed impacts of trawling, has contributed to the development of an “ecosystem approach to fisheries” which are being adopted widely into international and national policy commitments, fishery management plans, and sustainable-seafood certifications.
To read the full study click here.