RTI: Spatio-temporally explicit fisheries management



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 and Objective

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.

Target Group

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.

Data and Methods

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.

Our Research Questions

  • Is it possible to minimize unwanted bycatches (e.g. flatfish) in the western Baltic Sea demersal trawl fishery with the RTI incentive-based approach?
  • Is RTI able to solve the potential choke-species problem of e.g. Baltic plaice or cod in this mixed fishery?
  • How could an adaptive spatio-temporally resolved management of the two western Baltic cod sub-stocks be carried out by RTI?
  • Is the RTI approach realistically applicable in the Baltic Sea? Are adaptations necessary?
  • What are the views from the fishing sector, environmental organisations and policies? Consultations with stakeholder provide valuable, practically relevant insights. Only consultation with the fishing sector would lead to their buy-in and thereby compliance.

Links and Downloads



Involved external Thünen-Partners


3.2015 - 9.2018

More Information

Projekt type:
Project status: ongoing


hits: 5

  1. Kraak SBM, Reid DG, Bal G, Barkai A, Codling EA, Kelly CJ, Rogan E (2015) RTI ("Real-Time-Incentives") outperforms traditional management in a simulated mixed fishery and cases incorporating protection of vulnerable species and areas. Fisheries Res 172:209-224, DOI:10.1016/j.fishres.2015.07.014
  2. Kraak SBM, Reid DG, Codling EA (2014) Exploring the RTI (real-time incentive) tariff-based approach to single-species fisheries management. Fisheries Res 155:90-102, DOI:10.1016/j.fishres.2014.02.014
  3. Kraak SBM, Reid DG, Codling EA (2013) Explorations of tactical fisher behaviour under the RTI (Real-Time Incentive) tariff-based fisheries management system using simple simulations. Copenhagen: ICES, 22 p
  4. Kraak SBM, Reid DG, Barkai A, Meredith G, Felaar F (2013) Olrac-RTI: a new and operational apprach to holistic management of fisheries for multiple commericial species and ecosystem objectives : Part 1. Copenhagen: ICES, 21 p
  5. Kraak SBM, Reid DG, Gerritsen HD, Kelly CJ, Fitzpatrick M, Codling EA, Rogan E (2012) 21st century fisheries management: a spatio-temporally explicit tariff-based approach combining multiple drivers and incentivising responsible fishing. ICES J Mar Sci 69(4):590-601, DOI:10.1093/icesjms/fss033