Flexing your mussels: futureproofing shellfish aquaculture in the face of global climate change

Wild capture fisheries and the farming of fish and shellfish species (aquaculture) are vital for global food security, nutrition, and the livelihood of hundreds of millions of people worldwide. However, the oceans are changing at a rate unprecedented for 300 million years. These changes pose a significant challenge to marine organisms, impacting marine ecosystems and the goods and services that these crucial habitats provide.

Sustainably increasing seafood production is key in order to meet the increasing demand of a population projected to exceed 9 billion by 2050, and whose food demand is likely to increase by 70% during this same period. However, our capacity to do so is currently limited by the overexploitation of wild fish stocks, as well as the environmental impact of fishmeal being used to grow many aquaculture species. Current projections suggest we face a 28 million tonne deficit in demand-supply of seafood within the next decade unless aquaculture growth can be doubled over this same period. Climate change poses a major challenge to this expansion with industrial innovation and scientific expertise being key for addressing one of society's greatest challenges. Promoting the production of species with less environmental impact (i.e. filter-feeding species such as mussels and oysters) arguably offers the main route for sustainable expansion of this sector globally. However, mussels and oysters are also traditionally considered to be amongst the most vulnerable with respect to climate change. Urgent research is therefore required to develop climate change resilient shellfish species to enable future production.
This project will study the impact of elevated temperature and reduced salinity on different species of marine mussels from across their global range. Mussel aquaculture is worth £1.5bn globally, and is the primary aquaculture sector in Europe by weight. Consisting of three closely related species, which readily cross-breed (hybridise), marine mussels also offer a unique opportunity to investigate the impact of hybridisation on climate change tolerance. This is a key existing knowledge gap that when addressed will enable the improved management of farmed mussel populations worldwide, as well as a better understanding of the impact of environment on population structure and evolution in wild stocks.

During my fellowship, I will employ novel genetic technology to develop an industry relevant tool (SNP array) to assist in the production of climate resilient mussels. Subsequently, I will utilise a multidisciplinary experimental approach combining these genetic techniques with traditional measures of mussel performance and physiology, measuring these responses in multiple populations from across the global geographic range. This pioneering approach will enable me to address the overarching question "does hybridisation confer an advantage to multi-stressor exposures in a commercially important bivalve species?" This question is of fundamental scientific importance. Answering it will provide an unprecedented mechanistic understanding of the adaptation and evolution of physiological tolerance in response to abiotic stress in mussels. It also has significant implications for the sustainable development of mussel aquaculture in the 21st century. By providing a unique, industry-relevant, resource that will significantly advance understanding of ecological physiology and evolutionary biology, as well as enable the identification of genes that confer tolerance (e.g. through genome wide association studies) and selective breeding of mussels, this study will revolutionise the future of bivalve aquaculture.