If a good example of sustainable fishing is needed, it can be found – believe it or not – in a burger.
McDonald's well-known Filet-o-Fish is made with hoki, one of New Zealand's pre-eminent fish catches and exports worth $230 million; it is also a prime example of sustainability.
"The Filet-o-Fish is one of our most popular menu items and our goal is always to source as many of our ingredients as we can locally, through a sustainable supply chain," says McDonald's spokesman Simon Kenny.
Fisheries New Zealand (part of the Ministry for Primary Industries) declined an interview for this story* but supplied its official, updated documentation on hoki status so it could be included – and the story of how hoki is fished illustrates their sustainability efforts that affect that supply chain.
They are fast-growing fish that reach up to 1.3m in length, live in deep water, have a life span of up to 25 years, usually caught in the colder waters of the deep south of New Zealand, according to that Fisheries New Zealand's documentation. Because hoki grow and reproduce quickly, scientists estimate the numbers of hoki with up to three surveys a year – obtaining information used to decide the size of the hoki quota the fishing industry can take.
The NIWA vessel Tangaroa is engaged on one such survey right now and the information they supply is used to set the quota.
Fisheries New Zealand say they have altered catch limits in response to changes in the numbers of fish to manage the fishery, citing examples from between 2001 and 2007.
During that time, hoki catch limits were cut from 250,000 tonnes to 90,000 tonnes because there was a significant reduction in the number of young fish reaching adulthood.
Further scientific research showed that, as of 2009, hoki stocks had fully rebuilt to target levels and could sustainably support increased catches – so catch limits between 2009 and 2015 increased from 90,000 tonnes to 150,000 tonnes. However, last year, after information indicating the hoki population may be declining, the catch limit was reduced to 115,000 tonnes to ensure the stock remains sustainable.
"Sustainably managed fisheries maintain healthy fish stocks and minimise the impact of fishing on ecosystems – and that forms part of McDonald's global goal that 100 per cent of wild-caught fish is from verified sustainable sources," says Kenny. "Hoki is one of the few approved species for McDonald's Filet-o-Fish because of its mild taste, flaky flesh, and other qualities."
It isn't just McDonald's using hoki – NIWA says chances are hoki is in the fish fingers you buy in the supermarket; New Zealand Fisheries say hoki exports contributed more than $230 million to the New Zealand economy.
The method scientists use to measure hoki stocks will resonate with recreational fishermen. In an article on its website entitled Science of the high seas, NIWA confirms the ability to react to observed changes in fish populations, and raise or lower the catch accordingly, is the key to a sustainable fishery.
The NIWA ships use an acoustic transducer attached to the hull which NIWA Fisheries' Principal Scientist Richard O'Driscoll describes as a "fancy version of a fish finder".
Pulses of sound are emitted towards the seafloor. When these acoustic pulses reach something in the water, they're reflected back to the researchers' computer screens on board. Different fish send back different patterns and the amplitude of the returning soundwave is proportional to the density of fish. The results are analysed and can be used to estimate species' abundance.
A trawl net is also used to catch a small representative sample. Once the fish are on board, their weight, gender and size are recorded and the fish's ear bone – or otolith – is removed. Fish add another layer to their otolith every year – like tree rings, these tiny layers can be counted to determine age.
In addition to catch limits, the main fisheries are closed for a week during the spawning season to support successful spawning; four large areas of hoki fishing (which provide important nursery grounds for young fish) are also closed, helping to ensure more young fish reach adulthood and breed.
Hoki's sustainability has also been underscored by an independent certifying body, the internationally recognised Marine Stewardship Council (MSC). Hoki was the first fishery in New Zealand – and one of the first in the world – to achieve MSC certification (in 2001). It lasts for five years; the fishery was re-certified in 2007, in 2012 and 2018.
As to the future, a recent KPMG report, Climate-related risk scenarios for the 2050s, suggests that, by 2050, hoki may migrate further south because of anticipated higher water temperatures – raising the prospect that it may become uncommercial to fish.
Kenny says the information being garnered by NIWA and Fisheries New Zealand will continue to inform the sustainability of the hoki fishery and McDonald's ability to use it in their burgers.
"It's really important that we work with our suppliers and assess information from independent experts to identify ways to restore depleted fish stocks, improve fishery management and conserve marine environments. Sourcing our food responsibly is critical for us to continue to use high-quality raw materials long into the future."
*Fisheries New Zealand and NIWA have no relationship with McDonald's, commercial or otherwise.
To find out more: mcdonalds.co.nz/whats-in-it