The aquaculture industry is on the rise, but this success brings with it challenges and responsibilities. This is what scientists are saying, including Simon Bush, Professor of Environmental Policy at Wageningen University & Research. These and other findings are part of a comprehensive global study published today in the science journal Nature.
In China especially, people are eating and producing more farmed fish than ever before. It is also a growing source of protein in Africa, but who is monitoring the industry to ensure that everything is done sustainably and in a way that is environmentally sound? Simon Bush said: ‘The aquaculture sector has grown enormously but has long suffered from a bad name. It is a sector that’s been underestimated, and that’s still the case. But this article talks about the sector’s growth, and that fact that the sector has long been a substantial part of our food system. The sector is responsible for large quantities of food. It’s time that we started to see the benefits and to take them seriously, but also to monitor things properly, to make the sector sustainable and to keep it that way.’
But Bush also sees many sensitive issues arising from this growth. ‘We need to work on certification, but we also need to look at the role played by governments and by the industry itself. How will these parties work together on better production, but also on things such as more sustainable feed for farmed fish. This could be fishmeal or vegetable oil, soy or even insects. Where does that feed come from? What’s the impact on the environment? But also, how do we deal with fish diseases without using too many medicines and what does aquaculture do to the environment? All this calls for agreements that encourage the sector to become more sustainable,’ said Bush.
Large growth in the aquaculture industry
Freshwater and saltwater aquaculture includes the cultivation of fish and shellfish, as well as seaweed and algae. The sector ranges from large salmon cages in the ocean to freshwater ponds full of tilapia fish on land and mussel beds on the Dutch coast. This industry, which is mainly found in Asia, has undergone immense growth, with production tripling over the past 20 years. Worldwide, the industry has ‘a significant impact on food security, as most farmed fish are affordable,’ said co-author David Little, Professor at the University of Stirling in Scotland.
Twenty years ago, Earth Science professor Rosamond Naylor of Stanford University conducted a major study on the aquaculture industry. Her study created considerable uproar, which put the aquaculture sector in a bad light. The conclusion at the time was that aquaculture caused harm to regular deep-sea fishing. This was because large farmed fish species such as salmon and trout needed large quantities of wild fish as feed, which in turn put pressure on the oceanic ecosystem. Since then, however, there are many more options for alternative fish feed, said fish nutrition specialist Professor Ronald Hardy of the University of Idaho: ‘We have managed to turn carnivorous fish, such as salmon and trout, into virtual vegetarians.’ The situation has improved, so much so that 75% of the freshwater fish that we eat come from breeding ponds. Almost 150 species of freshwater fish, shellfish and marine plants regularly end up on our plates, the products of aquaculture.
The same problems as in agriculture
Thus the past 20 years have seen a dramatic increase in aquaculture. But this growth also gives rise to problems, said Naylor: ‘If we don’t regulate things properly now, we run the risk of having as many extra problems to contend with as in agriculture and arable farming, such as the excessive use of antibiotics and the decline of habitats, putting biodiversity on land and sea at risk.’
And in fact, the researchers show in their study that there needs to be more monitoring of disease control in aquaculture. The overuse of drugs contributes to disease resistance and this is dangerous for the fish and the people who eat them. Climate change is another challenge, said Simon Bush: ‘Drought and lack of rainwater or algae overgrowth affect the water in the fishponds and the health of the fish.’
Sustainable production systems needed
The study also concluded that sustainable production systems are needed now to ensure, for example, that fish waste doesn’t pollute the surrounding waters. Also, robust and better governance is needed to manage the food systems, with equal attention given to nutrition, capacity, fairness and environmental impact both on land and at sea. Issues such as carbon capture and certification have a role to play because ‘if aquaculture is done sustainably, this form of industry can play a major role in global food systems by providing food with a relatively small environmental impact,’ said Dane Klinger, director of aquaculture at Conservation International.