Fish farming in the UK is not without its critics, most of which centre around whether it is sustainable or not.
Most of the UK aquaculture industry is based on near-shore cage farming of salmon, or trout production along water courses in British rivers.
These two species are predators and so need a diet rich in protein. In aquaculture this is typically supplied in the form of fishmeal, a large proportion of which is small fish, such as anchovies and sardines. This practice has been heavily criticised, as it puts pressure on existing fish stocks, reduces prey items for endangered species as well as removing an otherwise cheap food source from poor people in developing countries. Anglers also blame sea lice, (which are often present in large numbers on farmed salmon) for the decline of wild salmon and trout stocks which spawn in UK rivers. The theory is that as juveniles swim back to sea from UK rivers they pick up the sea lice as they swim past caged salmon and eventually die due to high parasitic loads.
Attending Aquaculture UK 2016, the biggest exhibition and conference of its type in the British Isles, allowed me an insight into whether this industry had a sustainable mindset in its future outlook. Whilst the bulk of this event appears to be targeted at industry, as a PhD student I was pleasantly surprised to come away from it having been able to listen to some excellent seminars and participate in stimulating conversations. There wasn’t much discussion of the challenges posed by climate change and the word sustainability was mentioned only in passing. These are key issues that will need to be addressed by the aquaculture industry should it wish to remain ahead of other food production industries and something I am investigating in my doctoral studies.
Indeed, the commercial interests of this industry appear to lie squarely on the shoulders of only two species, trout and salmon. Whilst there is no denying the appeal of this high-end product, the high levels of fishmeal in their diet does raise the question of whether alternative species would be more sustainable. Undoubtedly there are technological challenges to the development of other species, but this is an industry accustomed to challenges. One approach to this problem is the extraction of protein from whisky waste products (pot ale), for use as a fishmeal substitute. This process is in the early phases of mass scale production but will help mitigate some of the harmful effects of continued fishmeal use.
Production has also increased due to the honing of breeding stock for maximum growth and survivability. This has been possible with the use of genomic selection, where key traits are identified in the genes of particular families of fish. These high-quality salmon and trout are then sold to fish farmers, who have fish that are more resistant to sea lice and other diseases.
The development of lumpfish (a fish species that eat sea lice) is the sort of innovation this industry needs to face some of its biggest challenges. The problem of sea lice is being tackled from multiple angles but there is considerable scepticism within the industry that this problem has any significant impact on wild salmon and trout populations. A review of the pertinent data by Dr Martin Jaffa calls into question this effect and surmises that change in how we record salmon and trout catch data, as well as poor data interpretation have led to the belief that the UK aquaculture industry is responsible for the apparent decline in these fish stocks. These knowledge gaps represent opportunities for more research in the field to identify where the real issues lie.
The UK aquaculture industry is certainly making use of cutting edge knowledge to continue to develop but needs to foster outside the box thinking to truly master the future challenges it will face. The proposed development of a centre for excellence by the Scottish Aquaculture and innovation Centre (formed in 2014) shows there is recognition for the need to a body that pulls together the various stakeholders into a cohesive force. Will this be sufficient to reverse the diminishing share that the UK Industry holds in the global market? Only time will tell.