Just because you don’t have to know the origin of your food doesn’t mean you shouldn’t. Veronica Rotman provides a guide on what decisions we can make at the supermarket to avoid harming the oceans. 

Fifty years ago, we understood the ocean to be an infinite bowl of sashimi and snapper. The lack of knowledge and understanding of the ocean fed into the concept that it is so vast, abundant and resilient – the garden of Eden.

We now know this isn’t the case. Not all fish are sustainable due to fishing practices that take too many fish, catch non-target species, and destroy habitats.

Although we are a coastal country, many Kiwis feel estranged from the ocean and how we can help it. It is hard to feel particularly connected to the ocean when selecting perfect fillets from sterile seafood cabinets at the supermarket. But your decision while you are there can harm and hinder the ocean. So what to buy?

You can make better informed choices by looking at the Fish Finder section of the OpenSeas website which provides information on the sustainability of wild species fished in New Zealand waters. You can also get information on a much wider range of fish species, from New Zealand and Antarctic waters, through the Ministry of Primary Industries’ stock status table (the current table is dated December 2019). 

New Zealand aquaculture species (species that are farmed) are among the best options including farmed greenshell mussels, paua, salmon and kingfish (please see below for more information). Wild-caught species such as cockles are pretty good as well as albacore and skipjack tuna, kahawai, mullet, trevally, pilchards, pot caught blue cod and kingfish.

Fish to avoid include bluefin and yellowfin tuna, tarakihi, orange roughy, bottom trawl hoki, jack mackerel, striped marlin, barracouta, silver warehou, any shark species and arrow squid. Other than the specific species you buy, there are other things you can do to reduce your impact on our oceans.

New Zealand-caught

Buying from commercial fishers in Aotearoa means the supply chain is traceable, you are supporting local businesses and reducing emissions associated with imported fish. Such traceability cannot be ensured in imported fish and there are other issues with overseas boats including trawling, concerns around slave labour and the use of chemicals.

Sustainable fishing methods

Hook and line, and pot caught are best as bycatch can be quickly released. Longline fishing involves dispersal of a central line with thousands of small hooks and can be good when effective seabird bycatch mitigation strategies such as tori lines or sunken hooks are employed. Midwater trawling is okay. However, bottom trawling or dredging causes significant damage to seafloor habitats, releases as much carbon as air travel and tends to result in unwanted bycatch. This method is used for many common species in New Zealand – some gurnard, tarakihi, hoki and snapper are caught by bottom trawling, so always check when buying. Set nets hang in the ocean at different depths and purse seines are vertical net curtain which surrounds large schools of fish; both of these methods pose a substantial risk of bycatch to marine mammals and sharks. Retailers and restaurants should be able to provide information on the fishing method used to gather kaimoana. It should be a legal requirement for the fishing method to be included on packets and cans of seafood products and inside selection cabinets with fish.

Aquaculture – bad or good?

In New Zealand aquaculture is done relatively well. We do not use antibiotics or steroids, salmon sea lice are not rampant, and most farms are in sensible places. It is not without its problems however, and there are some significant environmental impacts due to nutrient influx from fish feed and faeces, and the use of wild fish in feed. The feed conversion rate of salmon is favourable to pork, lamb and beef which requires larger amounts of feed to produce 1kg of meat. However, avoid overseas products as some salmon farms cannot be held in such stead with wide use of drugs, overcrowding, and the spread of disease into wild populations. Aquaculture of greenshell mussels and oysters is very sustainable in New Zealand. Shellfish literally munch to purify the ocean – therefore improving water quality – so choosing farmed options assists ecosystem services, stabilises sediment, removes nitrogen from the environment and helps add oxygen to sediments and bottom waters.

Don’t be frosty about frozen fish

Flash freezing at the peak of freshness preserves premium flavour, nutritional quality and prevents fish from being wasted. Seasonal variations in fish mean it is difficult to deliver a fresh supply across all seasons, and much can go to waste as fresh fish degrades overtime. But look at the packet to ensure fish is from New Zealand.

Enquire and eat easy

You have a right to know where your fish comes from and retailers and restaurants have an important responsibility in providing that information. This should include knowing the species, region where captured, and fishing method used. If this is not readily known, one could appropriately query the sustainability of fish and the ethos of the restaurant. Similarly, supermarkets and other retailers should be able to provide this information.

Buy directly from your local commercial fisher

An increasing number of fishers are opting to provide catch directly to consumers. This is brilliant as it maintains traceability throughout the supply chain and removes the middleman – meaning more money to fishers, and less fish caught and sold to make ends meet. However, some are not able to. In New Zealand, 76 percent of the fishing quota is owned by 10 big businesses. Profit margins often reduce for fishers who lease quota from these corporations, and it’s more difficult for them to invest in new innovation and more environmentally sustainable fishing methods. This is a problem.

Catch to order

This explains itself and means nothing to waste. One of the best examples of this in Aotearoa is Gravity Fishing. Nate Smith receives requests from restaurants each week and fishes seasonally and selectively to fulfil those orders, using more sustainable hook and line techniques rather than bottom trawling. He also sells fish whole instead of filleted, encouraging the use of all parts of the fish.


Inarguably, the best way to ensure the sustainability of your dinner is to source it yourself. Foraging allows us to be wonderfully selective, self-sufficient and more invested in the outcome of our catch – creating beautiful dishes and honouring the kai. But only take what you need, the recreational daily quota for snapper is 10 fish per person. That is an enormous quantity of fish for a boat full of five. We are becoming so sophisticated with fish-finding technology, faster boats that increase accessibility and more people than ever are out fishing. Spearfishing is likely the most selective method, creating a connection with the fish underwater before appreciating it on the table.

It is such a privilege to enjoy the kaimoana of Aotearoa, please respect our oceans by choosing carefully and sparingly, fishing respectfully and appreciating every bite. Just because you don’t have to know the origin of your food doesn’t mean you shouldn’t. Finally, if you are in the fortunate position not to rely solely on the ocean for subsistence, consider reducing your commercial seafood consumption in favour of other options such as plant proteins.

Veronica Rotman is studying for an MSc in Marine Science at the University of Auckland.

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