The aquaculture industry has become a major player in the global seafood market. To some researchers, this seems like the promising advancement of an industry that can take pressure off of wild stocks while still supplying global demand. But it’s not clear that aquaculture seafood is getting into the same mouths as the wild-caught fish it is replacing.
While looking at how the decline in marine fish will impact global nutrition, a team of researchers, including Edward Allison, a professor of marine and environmental affairs at the University of Washington, also looked at aquaculture in nutritionally vulnerable nations. These were countries with a large percentage of their population that both heavily rely on seafood, in particular on fish, for micronutrients, like iron-zinc and vitamin A.
Given the susceptibility of these populations to malnutrition, Allison’s team wanted to know whether the benefits of aquaculture were getting to the people who needed it the most. For the most part, the team concluded, they did not.
They concluded that aquaculture was displacing coastal wild catch fisheries in many places, yet the most nutritionally vulnerable people were neither receiving aquaculture-grown fish nor were they benefiting from the industry’s profits, with which they might buy food to supplement their diet. The team published their findings in the journals Nature and after further analysis published a related article in Frontiers in Marine Science.
That conclusion provoked ire from the industry, and from other researchers. In response, a team led by Ben Belton, an assistant professor of international development at Michigan State University, published an article in the journal, Global Food Security, arguing that Allison’s team had misrepresented the state of aquaculture in many developing nations.
Now, Allison and Belton are working together closely on a paper that Allison says he thinks will address some of the contentions and look at the future of aquaculture. The two teams are actually mostly on the same page, said Allison, even if their conclusions differed.
“There has been a sort of to-and-fro, an exchange of views and attempts to support our arguments with data and they’ve come back and supported theirs with data,” said Allison. “So, I think it’s actually a quite constructive scientific argument, and it’s one that I think is a healthy debate.”
Oceans Deeply spoke with Allison about the role of aquaculture in addressing nutrition needs around the world, how the industry has changed and about the ongoing scientific debate.
Oceans Deeply: How would you characterize the criticism to your papers?
Edward Allison: First of all, that they felt that we had not given due attention to the small and medium enterprise sector that was farming fish quite intensively in freshwater ponds, largely, and was supplying low-cost fish to domestic markets in countries like China and Thailand and more recently Bangladesh. And second, (they felt) that we hadn’t accounted for the fact that these fish were (sold) at a low price, and therefore accessible to the poor.
Oceans Deeply: What was your response to that?
Allison: You know, we largely agreed with them. But where we disagree with them is in what contribution that is making to the people who are nutritionally vulnerable, because where the fish is being farmed at the moment and is consumed domestically, is largely in the East and Southeast Asian nations.
One of the big exceptions is Bangladesh, and that is where Ben Belton and his colleagues have been working. There, farmed fish is now playing an important role in reaching nutritionally vulnerable, poorer people. But, when you look at our analysis of where nutritionally vulnerable, poorer people with high quantities of fish in their diets are, most of them are in West and Central Africa, and in other countries in Asia – in the Mekong Delta countries – Cambodia and so on. In those places, aquaculture is not yet a significant supplier of fish.
So, I would contend that we’re right about the places that we’ve identified and the global picture, and they’re right about the places they’ve talked about.
Oceans Deeply: Why do you think that your paper attracted the kind of strong response that it did?
Allison: I think that people who work with aquaculture feel that they’re unfairly attacked by people concerned about environmental issues and also, to some degree, social issues.
Although people are concerned about the sustainability of fisheries and the environmental impact of some fishing techniques, they see it as less transformative of the environment, and also reliant on maintaining a healthy environment, than aquaculture, which changes the landscape that it is conducted in. It has had a number of environmental issues that, in the past, have caused people concern, from overuse of antibiotics to the escape of non-native fish. Eutrophication and deoxygenation under fish cages due to overfeeding, fish waste. There has been a litany of environmental impacts associated with some aquaculture operations, but aquaculture is a new industry, and the industry has learned and, to a very large degree, cleaned up its act.
There are now certification schemes that reward good environmental performance and increasingly also good social performance. One of the social impacts of aquaculture is that, when practiced in the sea, for example, it changes what was a common pool, or open-access resource, into a private resource that only the owners of the fish farm can access. So, there were equity and employment implications in the transition from wild fish to farmed fish.
So, that is the range of arguments, and I think that people working in aquaculture have felt that the sector is unfairly tarnished by its past reputation and that it has learned the lessons and is supplying a nutrition good to the world, and yet it’s being blocked rather than facilitated in doing that. And they feel that a lot of the criticism comes from environmentalists and academics in the wealthy countries.
Oceans Deeply: You say that the industry has learned from its past. Can you be more specific?
Allison: Aquaculture is now farming a wide range of species that supplies consumers at all levels, and it’s reducing its environmental footprint in various ways, including its dependence on wild-caught feed.
There’s this notion that, instead of allowing fish to stay in the sea to feed in the marine food chain, seafood was instead being ground up and fed to farmed salmon, and that this was a waste of resources and meant that aquaculture – far from alleviating the pressure on fisheries – was adding to it. But we’ve seen evolution in the aquaculture feed sector, such that the quantity of fish meal and fish oil required to produce farmed fish is steeply declining, as other plant-based foods substitute for them.
The emerging area of concern with this is, do people get the same nutritional benefits from farmed fish that they do from wild fish, and in fact, that is the other part of the controversy that is yet unresolved. Ben Belton himself has been the author of a paper in Bangladesh that shows that when people switch from wild-caught fish to farmed fish, the nutrition content of their diet decreases.
There are various reasons for that. If you’re eating a small sardine-like or anchovy-like fish, you’re getting all the vitamins and minerals that are contained in the bones, the eyes, the head, the viscera – all these parts are eaten and they tend to be the ones with the richest nutrients. Ironically, those are the parts we throw away, those of us who eat only bigger fish in filet form. Most of the farmed fish are these larger ones that you normally eat in filet form, or certainly gutted without the head.
If you do eat them whole, depending on what they’ve been fed, they’re not necessarily as nutrient rich. Typically, they have lower omega-3 content. Carps and tilapia are not known for high omega-3 content, for example.
Now, one of the advantages, I think, of aquaculture, is that you can, through the way that you rear them and what you feed them, actually manipulate the nutrient content of the fish and supply consumers with fish that meets their nutrition requirements. That’s an exciting possibility for aquaculture. There is the possibility to develop product lines that are nutrient enriched, just as we have nutrient-enriched rice and sweet potatoes, for example. You could have nutrient-enriched fish.
Oceans Deeply: Is there anything else that you would like to say?
Allison: Just that, I think that we’re moving toward convergence on ideas for how both capture fisheries and aquaculture need to be supported if we’re to maintain a healthy food system, and to support people’s quest for improved health. Micronutrient deficiencies, the so-called hidden hunger, are a major global problem, and I think that fish is a huge part of solving that problem. If we can produce fish, whether it is wild or farmed, in environmentally benign ways, they can play a major part in our nutrition system.
I see a future where we have a diverse range of fish and seafood products that are both farmed and fished, and this argument over which one is better, I think will recede as we embrace both.