Source: MIL-OSI Submissions
Source: Fish and Game NZ
North Canterbury Fish and Game Council is closing their two salmon hatchery operations in the Upper Rakaia River in order to protect the wild sea-run salmon fishery.
The decision to end sea-run salmon hatchery operations is based on reviews of scientific studies and expert assessments commissioned by Fish & Game which demonstrate that hatchery releases in North Canterbury have likely negatively impacted the regions wild sea-run salmon fishery.
The decision recognises that protecting wild locally adapted salmon and trout populations, and the habitats they depend on, is essential to ensuring the long-term resilience and sustainably of the New Zealand angling resources and opportunities.
It is now understood that large scale releases of hatchery reared salmon smolt have likely been a major contributing factor in the current weakening of North Canterbury’s wild sea run salmon fishery.
The council came to this decision after having undertaken a review of historical hatchery practices in the region, the economic strain and budget overruns cause by these hatchery operations, along with an internal assessment of hatchery practices and external scientific advice on the adverse impacts hatchery releases can have on wild salmon populations.
This end of sea-run salmon smolt releases by the North Canterbury Fish & Game Council is part of their renewed determination to focus on managing and restoring the regions wild sea-run salmon populations. This decision was based on the best available scientific knowledge and ecological guidelines for how to manage and restore wild salmon populations.
Research by retired NIWA scientist Martin Unwin showed that wild salmon populations in New Zealand have evolved local adaptions, which create a “home court advantage” that results in both genetic and behavioural differences which are inherited by their offspring.
As a consequence, releasing hatchery reared salmon can be detrimental to the wild locally adapted salmon population.
The Fish & Game hatchery sites at Montrose and Whiskey Creek have now been closed and made safe.
North Canterbury Fish & Game Council will retain and aim to further develop one sports fish hatchery operation at the Issacs facility in Christchurch.
Current hatchery stocks have been released where they won’t negatively impact the wild fishery – Lake Coleridge for salmon, and in some smaller high-country lakes for brown and rainbow trout.
Once improved the Issacs hatchery facility will allow North Canterbury Fish & Game Council to rear and releases trout or salmon to landlocked urban ‘stepping stone’ fisheries, and potentially also to augment harvest opportunities in some lake trout fisheries.
To achieve this the Council are actively seeking to form partnerships and attract sponsors. An approach that is already being successfully applied in other Fish & Game regions like Otago and Nelson/Marlborough.
Once modified the Issacs hatchery operation will also ensure North Canterbury Fish & Game are able to also raise trout or salmon for releases associated with monitoring and research purposes.
Anglers can help by limiting their harvest of wild (non-fin clipped) salmon to four fish per season, and also assist Fish & Game in our Rakaia research project by providing information and otolith samples from any salmon harvested.
The otolith (earbone) of salmon enables fishery managers to see the life history of the fish and will help Fish & Game identify parts of the river system that may require extra habitat rehabilitation and protection work.