Down on the Fish Farm
Firstly dear reader, my apologies. This is a long one. But when it comes to ‘tuna ranching’, there is just so much to say.
A new report from Umami Sustainable Seafood Inc – a US-based seafood company and the largest supplier of sashimi-grade bluefin in the world – says that for the third year running natural spawning of captive bluefin Tuna has been recorded at its research and production facility in Croatia.
The report has been picked up by the press in a kind of lackadaisical, non-critical way. And if the champagne corks aren’t exactly popping, well maybe it’s because, what can we really say about it? Hurrah! Tuna can now get all the same diseases and cause all the same environmental damage as salmon!?
I would not presume to understand all that the business of aquaculture entails. I do, however, understand the environmental damage, to the sea and on land, that is being caused by that industry. Adding yet another big fish to the pond is not going to make things better.
Conservation International has recently endorsed the business of fish farming in its report Blue Frontiers – Managing the Environmental Costs of Aquaculture. And this sounds like an important endorsement, until you look a little closer at Conservation International itself, which earlier this year was accused of corporate ‘greenwashing’ after a senior employee was secretly filmed by undercover reporters discussing ways in which the organisation could help an arms company boost its green credentials (check out the story and the film here).
The revelation didn’t surprise many. Conservation International’s corporate sponsor list reads like a who’s who transnational corporate baddies (see also this 2003 article) and includes the likes of Cargill, Monsanto, McDonald’s, Starbucks, BHP Billiton and Coca Cola (though this is a story for another day…)
Back in the wide blue ocean, it may already be too late for the bluefin – and we have yet to see what the impacts of losing a major predator of the ocean will do to shift the entire ecosystem of the sea. Thus I understand the urgent desire to protect the species. And yes, I know, I know, I know. The assumption, ad nauseum, is that environmentalists like myselfare all a bunch of airy fairy hippies who want to give the world a hug but don’t really understand the intricacy of the science or the awesomeness of the technology behind it all (Mark Lynas, et al take note). Forgive me, but what a load of hairy old bollocks.
The hindsight of countless generations shows that when you mess with Mother Nature you will get burned. It’s not a matter of ‘if’ but ‘when’ and, of course ‘how badly’.
So before anyone gets up to celebrate the miracle of breeding Northern bluefin in captivity let’s consider just for a moment what is known about what has euphemistically become known as ‘tuna ranching’…
It may already be too late for the bluefin – and we have yet to see what the impacts of losing a major predator of the ocean will do to shift the entire ecosystem of the sea. Thus I understand the urgency to want to protect the species.
But let’s begin at the beginning. Why are the bluefin becoming extinct? Is it because of an essential lack of fish farms? The answer is no. Bluefin and other sea creatures are under threat because of an unsustainable global fishing industry where drift nets that would span comfortably from London to Brighton (about 60 miles) scour the sea, clearing it of every living thing. Tuna in particular have been over-fished to feed a luxury market, such as that which exists in the Orient.
It is the market that is destroying the tuna and I am most certainly sceptical of market solutions to save these animals because such solutions will always be driven by the need to preserve the market more than a need to preserve the species.
I cannot think of a single instance in which the ‘market’ has brought about intentional positive change for the environment or for people. The globalised ‘market’ is in fact a major stumbling block on the road to a sustainable society. Business by its very nature takes a small picture, short-term view.
(A businessman I met recently told me that one reason why techno solutions, and therefore market and political solutions, to our environmental problems are always presented in 20 year timeframes is that 20 years is short enough to be attractive to investors, but far enough away that nobody worries to much about the details of whether something will actually work – another story for another day…).
Umami’s news release says that it has made a significant investment growing over 1,000 young tuna into mature brood stock at its aqua farms in both Mexico and Croatia. This is likely the world’s largest brood stock holding, with the eventual goal being to release hundreds of millions of fertilised eggs and fry back into the wild every year.
Sounds phenomenal until you realise that on average a female bluefin tuna can produce 6-10 million eggs in a single spawning season. The number depends on how mature the fish is; a 5 year-old female can produce an average of five million eggs per year, whereas females aged 15-20 years can carry up to 45 million eggs. So allowing these fish to reach full maturity would contribute more to repopulating the ocean.
And even if all these eggs were to hatch, they have only about a 3 per cent chance of making it to become a 6cm-long fry and a 0.1 per cent chance of growing to a saleable size and be sold in markets.
So why release these eggs into the wild? Is it because we want to see the bluefin live freely in the wide wet ocean the way it is meant to, or is it because the fish produce too many eggs to be utilised in captivity anyway, or is it so we have a chance to go on hunting and selling them in ever increasing numbers? Some people believe the ‘why’ doesn’t matter. I disagree. The ‘why’ is everything, especially with market-based solutions, because it explains the true nature of the commitment. The moment the market wobbles the corporation is free to opt out or change its business plan entirely.
Bluefin tuna are among the most highly valued fish on the planet. In a market where a large fish of a high grade can fetch upwards of $100,000 the market value of the fish cannot be considered an incidental issue; it is central to the thinking behind the technology that will be used to breed them in captivity, and the way that the fish are harvested, penned, fed and, in most cases, drugged.
In many ways ‘breeding programmes’, for large pelagic carnivores in particular, are a distraction from the real issues of over-fishing. And they can be a very expensive way of not solving a problem. In addition fish farming is a form of intensive farming as prone to causing environmental devastation and illness for the animals as its land-based equivalent.
Attempts to breed tuna in captivity are decades long and have been largely unsuccessful. Because the market is so lucrative tuna breeding has become a kind of Holy Grail of aquaculture.
Umami’s Croatian enterprise notwithstanding, there are still many problems to overcome when it comes to captive breeding of tuna.
In spite of their great size and apparent aggressiveness, bluefin are an unusually delicate fish, both physically and psychologically. There are currently two ways to raise them in captivity. One can harvest them from the wild and mature them in captivity on tuna ‘ranches’ (a practice that is accelerating the species’ extinction), or you can try to breed them in captivity.
The first option may seem easy but bluefin apparently bruise easily because of their delicate scales, and their gills take in little oxygen compared to other fish, so they have to swim continuously to breathe – even while asleep. Farmed fish breeders often trumpet the fact that captive fish use less energy swimming and therefore this energy can be directed into growth – I hate to imagine what swimming less in captivity might do to a tuna’s metabolism). Transporting them to pens – after they have been scooped up by giant nets – means many die in the process.
Tuna in cages suffer the same problems as salmon. No matter how ‘well controlled’ the stock densities are there is no way such densities can be considered a normal existence for these animals. The fish can become stressed and are likely to become immune compromised and more vulnerable to lice infestations.
Like salmon, bluefin are large carnivorous predators used to having vast oceanic territories to roam in. The cues they receive from this nomadic existence are, in part, what trigger the breeding response. Tuna are also long living creatures that are hardwired to need this vast territory in order to remain healthy. The problems of farming salmon are multiplied greatly in tuna because tuna are that much larger than salmon.
Tuna can take up to 12 years to reach sexual maturity, compared to about three years for say catfish (another common aquaculture fish), and getting them to breed outside their natural habitat is difficult. The early experience of breeders in the US and Japan found that even if the fish could be encouraged to spawn inside a pen and even if the eggs hatched, the fry usually died after a few weeks.
Another major stumbling block of the development of breeding programmes appears to be that life in a floating sea cage or giant tank apparently does not provide the right environmental cues to tell the fish it is time to breed. In the absence of natural cues most breeders use drugs (hormone supplements), though this appears not to be the case with the Umami fish. The drug treatment that mimics the gonadotropin-releasing hormone the fish would normally secrete to trigger the urge to breed, but that does not make it natural. A drug is a drug is a drug.
Recent science shows that breeders can use drug implants to get bluefin to produce eggs in captivity with some success.
However the flaw in this approach is that it assumes that it is some inherent flaw in the fish that it will not breed in captivity. The experience with human hormone treatments such as the Pill and HRT (exogenous oestrogens that are listed by the International Agency for Research into Cancer, IARC, as known carcinogens) shows the devastation that such drugs can cause humans. It is inevitable that they will eventually have consequences for the fish and because our worldview is so unbelievably narrow the ‘solution’– and here I am taking my lead from land-based intensive farming – will probably be to drug the fish with something else – again on the basis that the fish simply is responding in a flawed way to its captive environment.
The delivery of the hormone treatment to the fish is even more aggressive than for salmon, delivered by divers shooting time-release implants into the fish with spear guns.
What is more, in trying to get captive tuna to spawn reliably every year, tuna ranchers may be working very much against the fish’s natural rhythm. We don’t really know whether the assumption that adult tuna spawn every year, is correct. Experiments in captivity challenge this assumption, suggesting that spawning by an individual might occur only once every 2-3 years (see this Oceana report). What is the effect of enforced spawning on the fish’s health and well being?
Not only is the hormonal profile of the captive fish manipulated, so is its diet with high doses of nutrients in a form that the fish would not normally take in the wild. The use of supplements is less to do with the health of the fish and, as a recent study in the Journal of Aquatic Food Product Technology suggests, more to do with the need to maintain the colour of the flesh of the slaughtered fish over its shelf life, thus improving its market value. Nutrient supplements used in this way, to alter the biochemical profile of an animal, are also essentially drugs.
The natural life of these fish can be measured in decades however farmed fish are considered suitable for slaughter for sashimi at 3-4 months. In modern tuna aquaculture once the fish reach this age they are slaughtered. Again it is hard to see how this process of growing them to slaughter them is considered sustainable for the bluefin population as a whole.
Like salmon, tuna are carnivores they require a high-protein diet that can only be met with a mixture of soya (rainforest destructive and usually genetically modified) and other fish (things like pilchards and mackerel, thus hoovering and decimating the populations of smaller fish from the sea. The fish meal industry in Peru and Chile is responsible for some of the worst examples of unsustainable fishing practice and also destroys the lives and livelihoods of local people (see this video report). The fish that are being fed to the captive tuna by the way are good healthful fish that could be fed to humans as a much lower price than luxury tuna.
The feed/conversion ratio for tuna is appears to be very high. Salmon take 3-4 kg of food to produce 1kg of extra weight. Tuna require 25-20kg of extra food to produce an extra kg in weight. Let’s put that in perspective a bluefin tuna in captivity requires eats 20 times more fish than it eventually produces.
Fish in captivity are generally overfed to produce that extra and very valuable kg which fetches a higher price at market. Good for the seller but feeding fish to fish can never be sustainable. It is my view that is aquaculture is to be sustainable as a source of food for humans then we need to concentrate on inland fish such as carp which convert their fish food – which no human would ever want to eat – into weight gain just about at a one-to-one ratio.
The tuna farming industry appears to be growing in spite of the fact that there is little to no study of its environmental impact. It is likely that where major tuna populations are kept in cages, opportunistic species (such as lice) will follow and proliferate nearby and could in theory spread to wild populations. If the fish tuna are overfed there is also more waste from the food and the animals’ excreta which needs to be taken into account in any sustainability profile. Even all this does not take into account greenhouse gas emitted by fish farming, the production of feed meal and the transport of the fish to the customer.
Tuna cages are also often sited in strategic parts of the ocean, for instance where warm currents run. They may interfere or alter in some way the running of those currents and because of their high market value local fisherman may be prohibited from fishing in those otherwise fertile areas, thus impacting local economies. This has already been seen in the tuna farms in the Mediterranean.
In breeding tuna in captivity we are doing something inherently unnatural – shrouding it in the language or methodology of science does not make this any less true; and there are always unintended consequences to such endeavours. (For anyone interested in more it’s worth reading the Greenpeace report Challenging the Aquaculture industry on Sustainability – the concerns raised in it are real and valid).
For all the reasons above, and with the full awareness that somebody somewhere will inevitably call me a hair-shirt-wearing, tree-hugging, fish-kissing, cave-dwelling, luddite for asking this question, I still can’t help but wonder: in terms of resources spent and resilience gained, wouldn’t it be better to see the money being ploughed into captive breeding programmes put into ways of restoring the entire ocean ecosystem?
© Pat Thomas 2011. No reproduction without the author’s permission.
