Real-case exploration of the RTI tariff-based fisheries-management approach for the mixed groundfish trawl fishery in the western Baltic Sea
Fishers love their freedom. And yet, their activities must be sustainable. In that respect, policy has targets for the commercially exploited fish stocks as well as for the marine ecosystem. We explore for the first time with real fisheries data the usefulness of a novel fisheries-management approach based on 21st-century technology, that aims at delivering both: flexibility for fishers and sustainability.
Background: Traditional fisheries management is not very responsive to small scale spatio-temporally varying distributions of fish stocks. Often it is single-species management assigning yearly catch quotas to relatively large management units. But with the development of new technologies new possibilities arise for spatio-temporally explicit fisheries management. With the introduction of the so called “vessel monitoring system” (VMS), an automatic satellite-based surveillance system obligatory for vessels larger than 12m length, and in connection with electronic logbook data, the spatial and temporal distribution of fishing effort and catches can be reconstructed and analysed species-, gear-, or métier specific. This allows to adapt fisheries management virtually “in real-time”. For example it could account for spawning aggregations or the overlap of sensitive and commercially exploited species. Such an approach (named “RTI” (Real-Time-Incentives)) is already under conceptual development since 2011 (Kraak et al. 2012). Now the applicability of the approach is tested with real data for the first time. The RTI approach is explored in the case of the groundfish trawl fishery in the western Baltic Sea. This is a mixed fishery targeting cod with various flatfish as (sometimes valuable) bycatch. The aim of the project is to develop a solution for minimizing unwanted bycatch and achieving successful ecosystem-based fisheries management.
Policy makers, fishery, science
The RTI approach integrates fisheries as well as environmental objectives within one single tariff unit, the so called “Real-Time Incentives”. With these all fisheries effects on the marine ecosystem can be managed with only one “currency”. As a result an incentive emerges for the fishermen to reduce their impact on the ecosystem, since this will immediately fall back onto them as “costs” which they have to pay.
According to the RTI concept, the management area is divided into several grid cells at high spatial resolution. Each cell is associated with a certain “cost” (RTI tariff) assigned to fishing in that cell. Thereby it is possible to integrate multiple political objectives from the fishing as well as the environmental sector. Accounting for natural migrations of fish stocks, these tariffs can be updated regularly at any chosen time scale, e.g. weekly. The required information is based on real-time data from commercial fisheries or scientific surveys. The information from the commercial fisheries would be processed by merging VMS (vessel monitoring system) and logbook data (Gerritsen and Lordan 2011). The RTI tariffs are displayed in colour coded heat maps, enabling each fisher to chose when and where to fish, until his annual RTI quota is exhausted. The total amount of annually available RTIs depends on internationally agreed targets for fishing mortality for each stock respectively, according to scientific advice. The tariffs can be organised métier- or gear-specific, providing benefits to fisheries with lower negative impacts (e.g. owing to higher selectivity). Traditional total allowable catch quotas would be completely replaced by the RTI system.
3.2015 - 9.2018
Project status: ongoing