Ngāi Tahu Seafood Resources has applied to build a large-scale salmon farming operation in Foveaux Strait, about 2km off the coast of Stewart Island.
The Hananui Aquaculture Project, which is being processed under fast-track legislation, is predicted to contribute about $500 million in annual gross revenue, representing a 150% to 200% increase over current national salmon farming export revenues.
The application has reached the stage where the applicant is replying to comments from stakeholders. More than 15 stakeholders made comments, the majority of them supportive of the proposal.
The Department of Conservation raised issues around the altering of sea lion and seal behaviour around the fish farm.
Department of Conservation senior technical adviser Jody Weir said the fish farm could ultimately lead to the animals becoming more desensitised to humans, making them more bold and potentially aggressive in their efforts to access this newfound food source.
Marine mammal ecologist Deanna Clement, in giving evidence for the applicant, said pinniped attraction to finfish farms was well documented globally and most of the improvements in marine farm layouts, design and materials that have evolved over the past 20 years or more were focused on restricting pinniped access to the farms and stock, while preventing any subsequent entanglements.
Pinnipeds were a diverse, highly adapted clade of semiaquatic marine mammals, including seals and sea lions, she said.
Open ocean guidelines had been developed by Fisheries NZ, which addressed the best practices and technologies available to minimise and mitigate the interactions between finfish open ocean aquaculture and marine mammals in New Zealand waters. These guidelines were co-developed with Doc and species experts, industry representatives and various stakeholders, she said.
Reviews of fish farms living with sea lions showed it became clear predator nets were the cause of most marine mammal entanglements and subsequent deaths.
Over the past decade, the understanding of risks had greatly increased and the current advances in netting technology were continuing to rapidly change in response, Dr Clement said.
‘‘Hence, mandating the exact netting material required as part of the consent now could prohibit the farms from using the best performing netting technology and materials in the future, given that the proposed installation of pen infrastructure installation is anticipated to occur five years following consent.’’
The nets would have a mesh size which minimised a predator’s ability to penetrate the net with their head, flippers or tail.
Dr Clement said marine mammals, and especially pinnipeds, were curious and clever by nature.
There was no way to completely stop them from being attracted to and investigating any novel human-made object that is placed in the marine environment such as a jetty, fishing line, boat, marina or marine farm, if they so choose.
The project’s marine mammal management plan was set up so the attraction of pinnipeds to the farm was minimised while net materials and pen design mitigations were intended to prevent access and subsequent entanglements.
Department of Conservation scientist Chloe Corne suggested audio recording and visual recording to set the base line data prior to construction to record the number of whales in the fish farm area.
But Dr Clement said to try to record the change in how animals use the farm areas would be near impossible to determine statistically given that it is expected one or maybe two whales visit the farm areas each year based on current data.
The panel indicated it was now set to have a conditions hearing on June 22. The scheduling of the hearing gave no indication the project would be approved, panel chairman Bal Matheson KC said.
A final decision was not due until August 10.
