The Sea Change Tai Timu Tai Pari report (Hauraki Gulf Marine Spatial Plan) launched last month makes a strong case for ending bottom trawling, purse seining, and dredging in the Gulf as fishing methods which damage the seabed. The report notes that there was “overwhelming support” for this in public surveys and consultation during the four and a half year collaborative process. Will Government Ministers listen?
If fish stocks and the marine life of the Tikapa Moana/Hauraki Gulf Marine Park are to recover from past and ongoing damage by industrial fishing, it’s vital that these fishing methods are phased out. This would allow living habitats on the seafloor such as horse mussel and green lipped mussel beds, sponge gardens, kelp forests and scallop beds to regenerate or be restored. These living seabed habitats support other species and provide important nursery areas for juvenile fish.
Scallop dredging, and dragging large trawl nets over the seafloor, destroy these living habitats, just as bullldozers pushing over rimu and beech trees would destroy the homes trees provide for birds, vines, insects and other species.
For too long fisheries management has ignored the importance seafloor habitats have in sustaining fish stocks and marine wildlife. It’s focused just on the fish, rather than where and how they live.
When the Ministry of Primary Industries assesses individual fish stocks to set the Total Allowable Catch and Total Allowable Commercial Catch, it doesn’t consider the health of the habitat on which that species depends, or how damage to the seabed is likely to affect how many fish can be caught. Until relatively recently it has also failed to consider the impacts of different types of fishing gear.
From the 1920s to the 1960s commercial dredging for green lipped mussels completely destroyed more than 500 square kilometres of mussel beds in the Firth of Thames and inner Gulf. As filter feeders, mussels helped keep water clean. As a result of their destruction water quality in the Firth is worse than it was 60 years ago.
Scientists estimate that the Hauraki Gulf supports less than half the biomass it did nearly a century ago, in 1925, with the extent of the decline varying between different species. Industrial fishing has contributed to this decline by destroying habitat.
The Hauraki Gulf could be so much healthier and have many more fish, sea birds, seaweeds, dolphins, and other marine life if we ended bulk fishing methods like trawling and purse seining which damage and disturb the seafloor and the vital habitats there.
Having abundant kai moana in local areas is a key part of cultural wellbeing. Ending fishing methods which damage the seabed so that fisheries can recover would enable mana whenua to exercise their traditional rights, pass on Mātauranga Māori, and fulfil their kaitiaki responsibilities. It would also benefit recreational fishers.
The Hauraki Gulf Marine Spatial Plan includes a timeline to phase out fishing methods which damage the sea bed. Bottom trawling and Danish seining would end in the Inner Gulf and the east coast of Coromandel Peninsula by 2018 and over the entire Tikapa Moana/Hauraki Gulf Marine Park out to Great Barrier Island by 2025. (see Map 4.1, p 78).
Auckland Council, land developers and users must also better control sediment loss from the land as this smothers habitats such as seagrass, and clogs filter feeders such as mussels. Sub-tidal sea grass meadows would have supported large numbers of juvenile fish but now they are functionally extinct in the Hauraki Gulf. They can recover if we take action now.
We can help the Hauraki. Government Ministers need to take the first step and outlaw fishing methods that damage the seabed.
As the Sea Change Tai Timu Tai Pari report says, Ātea moana, tauranga ika, toka mātaitai. Managing fisheries and marine habitats together, to increase abundance and biodiversity, in order to provide multiple benefits.