The science of ROSA

As environmental dynamics alter, the risks and opportunities for aquaculture as well as management strategies and species are almost certain to change. Consequently it is vital to evaluate direct impacts such as increasing temperature, storminess, exposure to wind and waves, frequency of harmful algal bloom (biotoxin) events, and indirect impacts that may follow from changes in carbon and nutrient cycling, community groups, eutrophication and other marine stressors.  It is also important to identify locations and methodologies of culture that minimise detrimental impact at local and regional scales.

Only by modelling the complex set of feedbacks, both positive and negative, through which suspension-feeding shellfish interact with different ecosystem processes and environmental change, can environmental impacts and capacities for culture be realistically assessed.

The UK aquaculture industry has very limited capability for such modelling at present. There is an urgent requirement for practical model tools that account for such interactions, to underpin the sustainable and profitable development of the aquaculture industry, following the European Union Water Framework Directive and the Food and Agriculture Organisation’s guidelines for ecosystem approach.

ROSA will take state-of-the-art ecosystem and fisheries models and combine them to provide a practical tool to support the development and management of UK shellfish aquaculture. This proof of concept project will focus on two key species Mytilus edulis and Crassostrea gigas and lay the foundations for future developments that can be extended to both shellfish and finfish aquaculture. 

A new decision support tool

ROSA plans to develop a novel aquaculture management tool for the UK.  This fully coupled model system will be delivered through a bespoke GIS system, ShellGIS.  Earlier versions of ShellGIS have been applied in the USA by growers and regulators, but not as yet within the UK. 

Multidisciplinary and well established model systems that describe the individual elements required to develop such a management and predictive tool already exist. ROSA will couple them within a portable system that is tailored according to user requirements.

Along with training stakeholders in how to get the most out of the tool, ROSA will develop a road map to guide the future application and development of the model system to satisfy future industry requirements as identified jointly with stakeholders.

Aquaculture and Ocean Acidification

As oceans continue to take up carbon dioxide, ocean chemistry becomes less conducive to shell development, a process known as Ocean Acidification. This leads to a combination of thinner shells and higher energy expenditure by shellfish – both potentially a negative impact on aquaculture. Understanding the chemistry of our coastal waters as it evolves over the coming decades is therefore important. At PML we have developed models that predict this chemical evolution at high resolution in time and in space under climate change scenarios. This information can now be used to evaluate threats to shellfish aquaculture.
At the same time research has also shown that, in some circumstances, the impacts of ocean acidification on shell fish can be limited where food resources are in plentiful supply. In essence individual organisms increase their metabolic rates to compensate for the extra requirements for shell maintenance. The same models developed by PML also predict how marine productivity may change in the future. This will allow us to understand if changes in productivity or food resource will be an additional stress to or potential alleviator of Ocean Acidification impacts.