Under the revised Common Fisheries Policy, a landing obligation (discard ban) will be introduced for all EU demersal fisheries from 2016. By 2019, a landing obligation is due to be in place for all quota species, i.e., all species subject to Total Allowable Catches (TACs).
Against this background, the aim of this FIS-funded project was to build a vessel-level discarding model for Scottish demersal whitefish and prawn (Nephrops) trawlers in order to investigate discarding behaviour under different assumptions about the costs and benefits of complying with the landing obligation. Depending on average daily catch rates and prices, the model predicts landings, discards and profits for fishing trips of varying lengths under
different assumptions about the enforcement of a discard ban and penalties for illegal landings.
The study is designed to complement, rather than duplicate, other sectoral-level modelling and impact assessments of the landing obligation by focusing specifically on the behaviour of individual fishing vessels under a landing obligation for different species.
The model is informed by economic theory and is underpinned by a survey of demersal and prawn trawler skippers based in North East Scotland. Skippers were interviewed about their discarding behaviour and their perceptions about the likely impact of the landing obligation on their fishery. The model predicts levels of discards of different species in response to a variety of factors including market prices, quota prices and the size of the vessel’s hold, in addition to the expected penalty costs of discarding at sea or landing fish without quota.
The model can be used to illustrate the difficulty of imposing a discard ban in a multispecies fishery when there are quota supply constraints for “choke” species as well as limits on the amount of storage space available in a vessel’s hold or fish room. It clearly demonstrates how discarding needs to be perceived as a costly activity if a landing obligation is to be effectively enforced in practice.
The model is intended to be useful for fisheries policy makers and managers seeking to understand the incentive structure of a landing obligation at the individual vessel level, as well as fishing industry representatives wanting to examine the possible implications of the landing obligation for various types of fishing vessel under different policy scenarios.