Fishing - multispecies management approaches: evaluation

Executive summary

The North Sea is a mixed fishery where different species are caught together in a mixed assemblage. Even though different species are caught together, stocks are managed on a single-stock basis. This is done primarily through the setting of Total Allowable Catches (TAC) and each fisher or fleet will utilise their quota for each stock at different rates. The introduction of landing obligations has prohibited the practice of discarding, including the discarding of over-quota catches. This has led to fishing activity of fishers and fleets being "choked" by the stock for which the quota is exhausted first.

In response, this project was initiated to evaluate the ability of multispecies management approaches to address this challenge to inform policy discussions in consultations with a variety of stakeholders. In this report four such approaches are evaluated through model simulations. These include the Shetland Fishermen’s Association (SFA) ‘Others’ pool scheme, two interspecies flexibility schemes and a Quota Points System scheme. The simulations were conducted in a multi-stock, fleet-based model to evaluate their performance against a set of performance indicators. The model included assessment results for multiple demersal fish stocks and Nephrops Functional Units from the North Sea as well as fleet-based effort and catch data as inputs.

The results show that all the multispecies management approaches modelled went some way to alleviate choking effects while three of the approaches also kept stocks at healthy biomass levels. One approach led to several stocks falling below the minimum biomass levels required for reproduction to remain unimpaired. An evaluation of the economic sustainability of the fleets indicated that these approaches benefited some fleets more than others.

Based on these results, some of the management approaches may be of interest to policymakers and stakeholders for further exploration and evaluation. These explorations should include investigating changes in fleet profitability, testing alternative model assumptions and considering additional limits on quota transfers and/or safeguards on biomass levels.