How to choose the right tinned fish

Few convenience foods can match canned fish when it comes to nutritional value and price, so it’s no wonder the supermarket shelves are packed with tuna, salmon and sardines. But, as we fill ourselves with omega-3-laden protein and delight in sticking to the budget, can we also feel virtuous about our impact on the environment?

The answer is an irksome ‘it depends’. It depends on what type of fish you’re eating, and it depends on where and how it was caught.

These days a lot of brands include that information on their cans. Yet decoding all of that when you’re in the supermarket is still a serious drag – so we decided to make eco shopping easy by investigating the world of canned fish and explaining what all the terminology means. Read on for an easy green guide to seafood in a can. Or – ahem – just skip to the end for our list of recommended brands…

Where does canned fish come from?

There are a number of types of tuna (our favourite canned fish, according to Countdown) but it is mostly skipjack that end their days in cans. Different brands source skipjack from different places so your plate could be piled with swimmers from Indonesian waters, catch from the western central Pacific or fish from the south west Atlantic. As well as skipjack, albacore tuna from New Zealand waters, yellowfin from the Pacific and longtail tuna from Thailand can also be bought tinned.

Sardines are a slippery fish in more ways than one. A range of different small, oily species are canned and sold as sardines. Most on New Zealand shelves are Atlantic herring from Canada or North America or brisling from Norway, Poland or Scotland.

Canned salmon is more straight-forward. Most is red (sockeye) or pink (humpback) wild Alaskan salmon which heralds from the north, predominantly the US and Canada.

How are tuna caught?

Forget the postcard image of a fisherman at sunset perched on a jetty with his rod and line, catching fish one at a time: huge nets are used to catch 60 per cent of tuna. Long nets called purse seines are arranged around a school of fish then the bottom is pursed together to trap them. Although purse seines are not in themselves particularly controversial, the fish aggregation devices (FADs) that are often used in conjunction with them are. FADs are floating objects that are placed in the water to attract sea life. Unfortunately while the FADs attract the target tuna, they can also attract vulnerable and undersized fish and sea animals, including sharks, turtles and rays. This ‘by-catch’ ends up in the purse seines. FADs are a major concern to environmentalists and fishery managers.

Long-lines are also under fire. Boats lay lines up to 150km long with thousands of baited hooks. Greenpeace says the method, often used to catch albacore, yellowfin and bigeye tuna, contributes to overfishing and can see endangered and vulnerable species hooked. The long-line boats can spend extended periods at sea, handing their catch over to fish carrier vessels. Greenpeace says this can mean there are no impartial observers, increasing the risk of illegal, unreported and unregulated fishing and shark finning.

Trolling, often used to catch albacore tuna, is more sustainable. A fishing boat tows a line or lines, close to the surface or in midwater. It rarely results in by-catch and if it does, the animal or fish can be quickly freed. 

The postcard image of fishing does still have a toe-hold in commercial tuna fishing. Pole and line fishing involves one fisherman using a hook and line to catch one fish at a time. It is almost impossible to endanger fish stocks or to end up with by-catch using this traditional method. It also provides more jobs to small coastal communities. The method, however, does have some impact on the environment: pole and line fisheries use an average of 25,000 tonnes of baitfish each year to attract tuna.

How are salmon and sardines caught?

Salmon are a helpful fish. They school together to spawn in rivers and are not surrounded by many other species because of the temperate to cold water they prefer. The upshot? They are easy to target and by-catch is less of an issue than it is with many other fish. Used carefully, purse seines and trolls can catch salmon cleanly. Gill nets are also used. This is where nets hang straight down in the water like a curtain and when the salmon swim into them they become entangled. They can have some by-catch issues.

Sardines are caught by purse seines but also mid-water trawlers and weirs. While the word ‘trawler’ can evoke images of a minced seabed, mid-water trawlers are not the culprits. Unlike deep-sea trawlers, their nets make no contact with the seabed and can be a clean method of catching sardines. Weirs consist of poles or reeds driven into the seabed in a semi-circle, hung with netting. They are placed in tidal areas so the water flow directs the fish into the weir where they are trapped.

What is the best canned fish to buy?

When shopping for canned tuna, Greenpeace oceans campaigner Karli Thomas advises buying pole-and line-caught skipjack, as skipjack stocks are much healthier than many other types of tuna. Next best is FAD-free purse seine skipjack. If you’re buying albacore tuna, she says, make sure it is troll caught and from the Pacific (the species is in trouble in some other areas). She recommends avoiding yellowfin, which is being overfished, and longtail, as the species’ numbers are unknown.

Peter Trott of the World Wildlife Fund says purse seine or troll-caught is the best bet when it comes to buying canned salmon. The Australian policy manager of seafood markets says most Alaskan salmon fisheries have good reputations but that it is wise to choose cans that carry the Marine Stewardship Council (MSC) label.

Sardines can also go in the trolley. “You don’t need to feel guilty because of the biological nature of those species,” says Trott. “They’re generally highly fecund – they have lots and lots of babies and they’re short-lived. They can withstand a high level of fishing pressure and environmental impact.” However, he says, you must still be choosy. “You can’t just fish them willy nilly – you need control.” Most of the sardines on New Zealand shelves are from areas that are likely to be well managed, says Trott, but again he recommends choosing an MSC-certified brand. These are in short supply right now so if you can’t find the logo, buy purse seine caught sardines.

Unfortunately, some seafood brands have ignored the push for better labelling and don’t provide shoppers with any useful information on the packaging. So if a can doesn’t tell you what species of fish it contains, where it was caught or how it was caught take action, says Katherine Short, an expert at sustainable seafood advisory company Terra Moana. “Take it to the information counter at the supermarket and say, ‘There’s not enough information on the tin.’ If enough people do that there will be change.”

What about the eco-labels?

The Marine Stewardship Council (MSC) is a global organisation certifying fisheries that meet its sustainability, environmental impact and responsible management criteria. Its label – a blue oval with white tick – appears on fish products that measure up. Sustainability experts say it offers the best guarantee that you’re buying the right product. “Of all the eco labels MSC comes out tops,” says Short.

On the other hand, the phrase ‘dolphin friendly’ is plastered across many seafood cans. Thomas says it’s important to remember that this logo doesn’t mean that the product doesn’t have other by-catch, sustainability or environmental issues, so read the label carefully and take this claim with a pinch of salt.

Green Ideas recommends

These canned fish products are all good sustainable choices.

Salmon (all MSC-certified)

Select wild caught pink salmon
Available at Countdown

Select wild caught red salmon
Available at Countdown

John West wild Alaskan pink salmon
Widely available at supermarkets

Natural Sea wild premium Alaskan pink salmon, salted or unsalted
Available at health food stores including Naturally Organic, Commonsense Organics, IE Produce, Puti Puti Ra and Cornucopia Natural Foods

John West wild Alaskan salmon, skinless and boneless
Widely available at supermarkets

Sardines (all MSC-certified)

Fish 4 Ever sustainably-fished Scottish brisling sardines
Available at selected New World supermarkets and health food stores including Commonsense Organics, Huckleberry Farms, IE Produce and Naturally Organic

Connetable Les Filets de Sardines, smoked or lemon and basil flavour 
Available at selected health food stores including Huckleberry Farms, Naturally Organic and Commonsense Organics

Tuna (all caught by pole and line)

John West pole and line skipjack tuna, in spring water or olive oil blend
Available at a wide range of supermarkets|
MSC-certified

Fish 4 Ever skipjack chunks in brine 
Available at selected New World supermarkets and health food stores including Commonsense Organics, Huckleberry Farms, IE Produce and Naturally Organic

Select sandwich tuna
Available at Countdown

Sealord albacore tuna
Available at a wide range of supermarkets
MSC-certified

Pams tuna chunks in oil or spring water 
Available at New World supermarkets

Select tuna chunks in brine, olive oil or spring water
Available at Countdown

Select flaked tuna in a range of flavours
Available at Countdown