Does farming fish reduce pressure on stocks in our ocean? Pat Baskett suggests that in attempting to fix a mess of our own creation, we may be creating yet another
Factory farming was the 20th century’s answer to providing animal protein for the world’s billions. Its unsustainability and the environmental disasters that continue to ensue are well documented. Eliminating this way of producing food, particularly by dairy farms, is one of the key recommendations in The Climate Change Commission’s draft report. The salmon you serve, however, has no such caveats on how it can be produced.
One might ask when does a farm become a factory? In the case of fish, can we expect the ocean to be more forgiving than the land has been from animal farming? Do fish farms produce protein less unsustainably than, say, beef farms? Some people might also ask what are we doing to these creatures that spawn in fresh water, spend their lives in the sea and navigate back to their inland origins to reproduce.
New Zealand King Salmon (NZKS), our largest salmon-farming company, posted an after-tax profit last year of $18 million, mostly from the Marlborough Sounds. The Ministry for Primary Industries has a strategy to increase the overall industry profit to $1 billion by 2025 and then to $3 billion 10 years later. This is in line with international growth in demand. About half of all seafood the world eats is said to come from aquaculture.
The common notion has been that farming fish reduces the pressure on wild stocks - that having depleted the oceans we can preserve some minimum for our dinner tables. As a principle it is demonstrably false - not only because in attempting to fix a mess of our own creation we may be creating yet another.
All creatures in captivity need feeding and the problem of what we feed our huge dairy herds is mirrored in fish farms. Feed pellets consist of fishmeal, fish oil, plant proteins and by-products from local poultry and meat industries. Aquaculture has been heavily criticised because fishmeal can come from so-called trash or forage fish, often scooped up along the coasts of north-west Africa and north-west South America where pelagic species are essential to the diet of poorer coastal people. But these species are also an essential part of the wider marine ecology and serve as food for bigger fish, and for seabirds (including penguins) and marine mammals.
NZKS says the fishmeal and oil in the pellets it uses includes anchovies from Peru in an operation that claims sustainability. NZKS also makes the interesting comment that the proportion of fishmeal in their pellets has declined, from 51 percent in 2004 to 33 percent in 2019. “Novel sources of nutrient and proteins are under development,” they say. The industry would be economically unsustainable if a full marine diet was provided.
The consumer might well ask what they, too, are eating along with their salmon filet. This terrestrial part of the food has a profound impact on the flesh and on the omega-3 content. There are two types of omega fatty acids - omega-6 which is found in the oils of seeds and grains, like sunflower and corn oil and omega-3 in seafood and in some plants such as flaxseed and walnuts. Many of the fish raised on farms are high in omega-6 fatty acids due to the significant component of the terrestrial diet.
Their wild counterparts, on the other hand, have a higher content of the beneficial omega-3 fatty acids. In one study, the omega-3 to omega-6 ratio was about 10 in wild salmon and three to four in farmed salmon. In the northern hemisphere they use the omega 6 content to distinguish the farmed from the wild stock to protect the consumer from getting confused.
My question concerns sustainability and the long-term viability of using more energy to feed yet another animal species in order to feed us. NZKS uses a nice acronym, the FCR, the Food Conversion Ratio which shows they use 1.8 tonnes of feed to produce one tonne of salmon - 1:1.8. This is better than your beef steak which they claim has an FCR of 6:10. Whether its salmon or beef, we need a way to eat them that is carbon neutral, doesn’t damage ecosystems or exploit the resources of poorer nations.
NZKS has had salmon in cages in the Marlborough Sounds for 30 years. Aquaculture, including mussel farms, is said to affect about 3000 hectares and provide substantial employment for local people. Salmon farming has a higher environmental impact than mussels because the latter take their nutrition from the sea and don’t need extra feed. Eleven areas are designated for salmon farms in Queen Charlotte Sound and Pelorus Sound. These sites are in locations where the tidal flow is considered either high or low.
This consideration is important for the dispersal of the feed residue (nitrates, phosphates) and salmon faeces which impacts the benthic environment, along with the accumulation of copper from the paint which is used as an anti-fouling, as on boats. Studies done by the Ministry for Primary Industries are mostly sanguine about these effects. A 2013 MPI “Literature Review of Ecological Effects of Aquaculture” describes the main ones as organic enrichment and smothering, biofouling drop-off and debris and seabed shading by structures. It also claims that “the development of management strategies to reduce (this) risk has largely been successful”.
Thus the industry flourished economically, with resource consents granted by the Environmental Protection Authority. Only in 2019 did Fisheries New Zealand publish “Best management practice guidelines for salmon farms in the Marlborough Sounds”, their purpose being to provide a “…central set of Water Quality Standards (WQS), and requirements for monitoring and managing potential water column nutrient enrichment….”
This project involved participation of all stakeholders including NZKS, MPI, NIWA, Cawthron, Council and community representative Rob Schuckard.
It’s estimated that 85 percent of drop-off beneath cages is dissolved, with the remainder being particulate.
Assurances in the guidelines that the immediate impact “decays rapidly with distance, primarily with mixing with more distant waters” but also with uptake by marine creatures are tempered by caution about these effects causing changes more widely than immediately below the cages. Water quality in the Marlborough Sounds is also affected, they warn, by terrestrial runoff and it’s the total accumulation that is significant.
Eric Jorgensen describes himself as “born and bred” in the Sounds. He’s been on various advisory groups to MPI including the group providing advice on the relocation of the low flow sites. He is also a member of the stakeholder panel for the Sustainable Seas National Science Challenge whose aim is that “the New Zealand marine environment is understood, cared for and used wisely for the benefit of all, now and in the future”.
Both community representatives, Schuckard and Jorgensen, have dedicated much time working “for the common good” but express frustration. Jorgensen describes the “deposition footprint” of low flow salmon farms in the Sounds as “bordering on catastrophic”. He also cites a lack of foresight and inadequate strategic planning with regard to the development of open ocean aquaculture.
Schuckard describes NZKS’s practices as giving environmental readings that are non-compliant. Farms are managed with too many fish. Running them less “hot”, he says, is the only solution. He worries about effects on one of our most endangered seabirds, the endemic king shag, which number 800 and whose only habitat is the Sounds. This iconic species is an apex predator and it reflects in many ways the overall wellbeing of the Sounds. A management plan has been set up initiated by and partially funded by NZKS, the Department of Conservation, Marlborough Council and the Marine Farming Association. Nevertheless, says Schuckard, “The implications of slow creep from marine farming, including salmon farming, on the quality of king shags’ feeding area is only indirectly and marginally being studied.”
Both men refer to the effects of warmer water temperatures, increased fish mortality and declining productivity. Both men are concerned about the need to find new, high-flow locations for six of NZKS’s farms.
Schuckard is critical of the political process around the consideration of relocation sites. “Council did not support the community members’ strong condemnation of MPI’s unfair relocation process, which disallowed Environmental Legal Aid to the community and cross-examination of experts was not possible.”
Meanwhile, as the wrangle continues over where to put these six existing farms, NZKS and MPI have another plan up their sleeves which they see as key to achieving those economic targets. An open ocean farm in the sea 6km off Cape Lambert will avoid the competing uses and values that complicate expansion closer inshore, they say, and provide better dispersal of waste. Inherent in NZKS’s application is access to an asset – the ocean – which, Schuckard points out, is part of the commons. “All New Zealanders own that resource. If ocean farming is more of the same, we need to be concerned.”
Jorgensen is - in the true sense of the word, he stresses - ambivalent. He considers that open ocean farming, appropriately located in high energy sites will significantly decrease adverse environmental effects compared to existing locations. It will also likely result in higher productivity and continue to provide jobs. But, he says, strategic direction and regulatory frameworks are crucial.
“Really,” he says, “we should be aiming to evolve to closed farming systems where waste is captured and re-purposed.”
The Cape Lambert site is classed by the Marlborough District Council as an outstanding natural landscape with habitat for dolphins, seabirds, migrating whales. Putting fish farms on the land is another possibility, as done in Canada, Norway, China.
No, says NZKS, too expensive. The hearings on its application to farm off Cape Lambert were postponed in April. The delay, NZKS chief executive Grant Rosewarne was reported as saying, will cause more salmon to die in the warmer waters closer inshore.
