Methods and policy pathways to optimize production of mixed stocks of biological resources

Global environmental issues related to food security, biodiversity, and use of antibiotic, pesticide and
fertilizers suggest use of smart mixtures of crops/stocks in agriculture, forestry, and farming: so called polycultures. A barrier to this is, however, the complexity of polycultures compared to monocultures.
This complexity lies not only in physically tending and harvesting mixed cultures, but also in identifying and maintaining the optimal mix. Indeed, ecological theory (Rossberg 2013, ISBN 9-780470973- 55-4) predicts that sensitivity of the composition of such mixtures to external pressures, e.g. fertilization, climate, pests, increases steadily with the number of species, both in the wild and in managed systems. Hence there is a need for methods (1) to set attainable management objectives for polycultures in light of inherent tradeoffs, (2) to identify corresponding optimal mixtures, (3) to understand the predictability of outcomes and of the management intensity required to attain optima in view of inherent uncertainties. A third, political, aspect of complexity arises when stakeholders with different roles participate in management and use. One then needs to (4) understand agreeability of objectives, e.g. in terms of inherent incentives to collaborate.
These are generic problem areas, located within the remit of BBSRC Strategic Priority 1 (agriculture and food security) addressing the highlighted research need to "increase the efficiency and sustainability of crop and animal production", while "minimising negative environmental impacts" and "preserving biodiversity and other ecosystem services". Interdependencies between these problem areas advises to study them for a specific system, so not to miss important practical constraints. A good model system is the intensely managed mixed fishery of the North Sea. It is well described by ecological models, and the benefits of managing it as a polyculture (rather than as a set of independent "wild" stocks) are acknowledged amongst stakeholders.
Aim of this project is to develop a prototype management plan addressing the four problem areas enumerated above.
Workplan:
Year 1: Address (1) and (2) above. Using the existing North Sea Ecosim model developed by Cefas, find optimal polycultures corresponding to the objectivities proposed, e.g., by Farcas & Rossberg (2016, doi:10.1093/icesjms/fsw113). These include the current approach, which disregards biological interactions; maximization of total biomass yield; and game-theoretical approaches.
Year 2: Address (3). Quantify the impact of model uncertainty on management outcomes and the resulting need for adaptation of plans to achieve objectives.

Year 3: Address (4). Interact with the stakeholder community (fishers, scientists, policy makers, NGOs) and document attitudes and responses to the evaluated policy options. Based on this, propose a long-term management plan to stakeholders.
This interdisciplinary research pulls together thinking from complex systems theory, control theory, economic theory, biology, and political science. It will test hypotheses previously developed by Farcas and Rossberg (2016). Scientific publications will address audiences beyond those interested in fisheries because, as explained, the underlying principles are of much wider relevance.
For the non-academic partner Cefas, policy advice on fisheries management is core business and, in view of Brexit, demand for UK competency in fisheries management has increased.