Scotland's 10 Year Farmed Fish Health: strategic framework

Background to the Framework

The Scottish Government committed within the 2017/18 Programme for Government to develop a strategic farmed fish health framework for Scotland, recognising that such an initiative was an essential component part for the consideration of the work of the Aquaculture Industry Leadership Group ( AILG) and the industry 2030 strategy. This framework will ensure that fish health remains the focus of sustainable production and growth in Scotland.

The Scottish aquaculture sector has looked to demonstrate its commitment to protecting the health and welfare of farmed fish. Healthy farmed fish have better survival rates and require fewer interventions by farmers, and so it is in the interests of farmers and other stakeholders that farmed fish are reared in good health. It is recognised that some have concerns about the environmental sustainability of aquaculture and its impact on wild salmon in particular, and there remains improvements to be made which could have wider environmental benefits, including the potential for reduced farmed – wild fish interactions. The challenges for aquaculture going forward are multi-faceted. That is why the Scottish Government and industry take a long-term strategic approach to ensuring that fish health and survival improve, and that Scotland can lead in fish health status.

Global marine ecosystems will be affected by climate change (warming of the seas) and ocean acidification and the aquaculture industry will need to be able to adapt as necessary. Changes include increased plankton community variability and fluctuations in environmental conditions. In particular, fish farmers have experienced increased sea temperatures in successive years, and this can be linked to increased fish mortality. The characteristics of natural jellyfish and phytoplankton blooms are such that they lead to high mortalities in farmed fish.

Climate change is set to continue. The combination of ocean acidification with sea temperature rise and deoxygenation is of particular concern. In the absence of the production of new medicinal products, medicine efficacy declines. When this is coupled with environmental variability, the pressures on salmon and trout health and welfare will only increase without appropriate intervention. Salmon and trout farmers must constantly adapt to the changes if the industry's success is to continue and expand. Changes will present both threats and opportunities to aquaculture. By working in partnership to plan and prepare for change now, the aquaculture sector will be better placed to face any consequences that the combination of ocean acidification, sea temperature rise and deoxygenation will bring.

Just as humans face fresh strains of seasonal flu each year so too do the disease challenges facing animals naturally evolve and change over time. The finfish industry, in common with other food animal production systems, recognises the need for continual adaptation, and the Scottish Government will continue to support the sector's resilience.

Like its global competitors farming in other parts of the world the Scottish fish farming industry has had to tackle the emergence of amoebic gill disease, which was first associated with farmed salmon mortality in Scotland in 2006 with wide scale re-emergence in 2011. Since then, researchers have developed a complex understanding of gill health, including evidence of the coincidence of amoebic gill disease, proliferative gill disease and several interacting gill pathogens, complicating the overall management of fish health.

Sea lice, gill disease and treatment losses are common features of salmon aquaculture internationally and international collaboration and data sharing will be vital to increasing our understanding of their characteristics, interactions and management. There is a constant need for greater understanding of pathogens and parasites and how these are adapting with respect to the Scottish environment and farm production methods.