1. Chile Report: Salmon Farming
At the beginning of 2019, we took the opportunity to visit salmon farming operations in the Chilean summer.
(Atlantic) Bluefin tuna certainly is one of the most iconic fish in the sea – and for good reason. With a weight of up to 700kg and a length of up to 4.5m, it makes for a truly impressive catch among sports fishers. Its torpedo- shaped body and slightly elevated body temperature, compared to other cold-blooded fish, make it one of the fastest swimmers in the ocean and all but guarantee it a spot at the top of the food chain as an apex predator. Its fatty meat with perfect marbling has turned it into a culinary delicacy and once earned it a spot on the list of endangered species.
Of course, bluefin tuna pricing is also notorious. It regularly makes the news when a particularly prized specimen gets auctioned off for an amount approaching or even breaching the (USD) seven-digit threshold – even though those prices tend to only be achieved for marketing purposes or as a token of good luck, when the first fish in the season gets auctioned off.
From a sustainability perspective, the extreme prices paid for bluefin tuna warrant further investigation because unlike less valuable species, bluefin tuna can still be fished profitably when only a very small number of fish are caught. This would suggest that without protective measures, bluefin tuna stocks will be fished to much more dangerous stock levels. And in fact, with stocks reduced from their all-time high to mere single-digit percentages, bluefin tuna used to be considered “endangered” according to the IUCN Red List of Threatened Species.
In comparison, what people (and in particular the FAO) usually mean by saying a species is “overfished” is that their stocks have fallen below 80% of the level required to achieve the maximum sustainable yield, the long-term equilibrium. While that’s certainly a cause for action, it shouldn’t really be a cause for concern. Bluefin tuna recovered spectacularly in recent years after catch limits were introduced, and so will other species. Fish are much more resilient than we give them credit for. It just takes time. Lots of time.
Inter-governmental organization for Atlantic tuna
Case in point, GBYP, the Grand Bluefin Tuna Year Programme. In 2008, after sustained criticism from NGOs for setting catch limits far in excess of scientifically determined levels and rapidly dropping stock levels, ICCAT, the International Commission for the Conservation of Atlantic Tunas, significantly reduced catch limits for Atlantic bluefin tuna as a short-term measure and set up GBYP as a research program to determine sustainable fishing practices for the long-term.
The research programme, equipped with a budget of almost EUR 20 million, ran from 2011 to 2021 and conducted many scientific tests. Aerial surveys were performed to estimate juvenile biomass and identify trends in aggregations. Fish were tagged and local fishermen instructed to return the expensive and scientifically important hardware to better understand habitat utilization and migration patterns. Old fishing logs were analyzed to backfill historical data, now reaching all the way back to 1512. Biological studies were conducted to identify possible sub-populations and the natal origin of the fish. And finally, complex models were built turning all the accumulated information into a robust advice framework for ICCAT to align its management strategy with. Based on the scientific evidence obtained through GBYP, ICCAT members finally agreed to establish a management procedure for Atlantic bluefin on 21 November 2022.
Signs of recovery
In the meantime, tuna stocks had already recovered significantly. In the fifteen years it took to plan, conduct and implement the research program, the hastily introduced catch limits did wonders for stock levels. Bluefin tuna was reclassified from "endangered" as "near threatened" in 2015. In 2018, the first fisheries entered into MSC assessment and achieved MSC Certification in 2020. And finally, in 2021, IUCN further lowered the extinction status of Atlantic bluefin tuna to "least concern" (see here for the full timeline). Going forward, we are hopeful that the newly introduced management procedure will prove effective and that things will only get better from here on out. Other fisheries management organizations should take note of what has been achieved for both bluefin tuna and the fishermen fishing for the species.
Bluefin tuna farming
And if recovering wild fish populations weren’t enough good news already, let me tell you, farming practices are also advancing on their path to sustainable bluefish tuna – gradually but steadily. Nowadays, profitable bluefin tuna farming is still limited to "ranging", a practice where juvenile fish are caught in the wild and then transferred to fish farms for fattening. But full cycle farming is catching up. After initial breeding experiments in the 1970s, the first successful spawning of juveniles was finally achieved in the 2000s. There were and are many issues that still had to be dealt with after that first milestone. Juveniles were dying by both sinking to the bottom and floating to the top of their water tanks. Likewise, cannibalism was an issue, as was a lack of appetite.
But in 2016, the first full-scale commercial shipping of egg-to-harvest tuna was finally achieved by the Japanese seafood company Maruha Nichiro. At its peak, it sold around 1.000 tonnes of bluefin tuna from closed cycle aquaculture (compared to a total consumption of 40.000 tonnes of bluefin tuna in Japan), albeit not yet at satisfactory margins. For lack of specialized feed, feeding costs are still excessive. The feed conversion ratio stands around 10-15, much higher than, for example, salmon, which only requires 1.2kg of specialized feed to gain 1kg of body weight. Mortality is also still way too high. Nevertheless, proof of concept has been achieved and in particular the Japanese but also Australians and Europeans are determined to make bluefin tuna farming work. Through investments in Maruha Nichro, Kyokuyo, Feed One, and Nippon Suisan Kaisha, Bonafide has been exposed to bluefin tuna farming for quite a while already and we are keen to learn what the future may hold the species.
Read the last blog about our visit to the Amami Islands, Japan, in 2019.
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