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Intersessional Subgroups

What is the role of the ISSGs?

Regional cooperation is meant to improve the efficiency of data collection through sharing of expertise, data, best practices, knowledge and collaborative tasks. The RCGs bring together several Member States to coordinate planning and implementation of data collection .Their workplan across the year, from one round of the annual technical meetings to the next, is supported with the setup of the Intersessional Subgroups.

In these subgroups the experts concentrate on specific Thematic Focus Areas, and sometimes they are pan-regional. During the relevant RCG’s technical meetings, the different ISSGs present progress and hurdles encountered across the period and propose the update of their Terms of Reference with the tasks and targets for the new intersessional period for approval. The work performed by ISSG is essential for RCG technical meeting preparation and meeting discussions

Some of the RCGs refer to the ISSGs as Working Groups, their general purpose is the same, although there may be slight differences on their procedures to adapt to the dynamics of the RCGs to which they are more directly related.

Access to ICES Sharepoint for RCG Intersessional Subgroups (ISSGs)

Intersessional subgroups (ISSGs)

RCG Overviews

The intersessional subgroup on RDB catch, effort and sampling overviews was established to streamline and facilitate the work on the fisheries and sampling data of the MS and prepare data overviews in advance of the RCG meetings. Before the subgroup was set up, the different RCG conducted data analysis and overviews separately with minimal exchange, resulting in redundancies and efficiency loss. Furthermore, a substantial part of the work was being carried out during the RCG meetings themselves and so not readily available to inform RCG preparation and meeting discussions.

The tasks and output from the subgroup fall into 2 main types of work

i) To develop tools for internal RCG work and

ii) Preparatory work for decision making, including input for regional work plans.

At present, three different documents are being developed utilizing RDB data:

  1. Catch and Effort Annual Overview
  2. Catch and Effort Multiannual Overview
  3. Sampling Overvies


Chairs: Ana Claudia Fernandez, Lucía Zarauz 



The intersessional subgroup on Electronic Monitoring Technologies was established in 2021 to ensure that initiatives made on developing new electronic technologies and the use of these technologies to improve fisheries data collection in EU Member States as well as initiatives made in third countries are disseminated. 

Furthermore, to convey that cooperation is made possible and that all ideas are taking into account when developing the best possible new electronic technologies and its implementation.   

The tasks and output from the subgroup are as a first step: 

Initiate the development of an intinery of the use of the following data collection technologies:  

  • Electronic monitoring (EM)  
  • Machine learning development, e.g., for automatic species identification and catch weight estimations in real-time 
  • Electronic measuring boards 
  • eDNA for species identification 
  • etc.


Second step would be initiation of cooperation when ever possible for cost efficiency in fisheries data collection by the use of electronic technologies. 

Chairs: Gildas Glemarec 

Involved RCG: RCG NANSEA, RCG Baltic, RCG LDF 


 Umbrella group 

The aim of the ISSG Optimized and Operational Regional Sampling Plans, also referred to as the “Umbrella Group”, is to develop guidance for the development of optimized and operational regional sampling plans (RSPs) and collate ‘theoretical gaps’ and new developments in optimization tools relevant for the development of RSPs. The “Umbrella Group” supports the development of RPSs by different case studies, by interacting with the case studies and providing guidance in terms of work flow, highlighting needs identified by them or evident from their work, promoting links between them and drawing knowledge from lessons learned from their work. Moreover, in terms of methodologies and tools used by the case studies for the development of RSPs keeps an updated overview of existing optimization tools and of their application in the RSPs case studies. 

Chairs: Kirsten Birch Håkansson, Harriet van Overzee, Rita Vasconcelos 

Involved RCG: Panregional 

Towards a regional sampling plan for the freezer trawler fleet exploiting pelagic fisheries in the Northeast Atlantic 

The EU freezer trawler fleet targeting small pelagic species (mackerel, herring, horse mackerel, blue whiting, sprat and argentine) in the North Atlantic and North Sea was identified by the RCG as a potential candidate for the development of a regionally coordinated sampling plan. The fleet comprising mainly Dutch, German, UK and French flagged vessels is sampled currently by the Netherlands and Germany. The primary aim of this subgroup is to propose a statistically robust regional sampling plan for the European pelagic freezer trawler fleet to be considered for inclusion in a regional workplan. 

ChairsAndrew Campbell (Marine Institute, Ireland) and Jens Ulleweit (Thünen Institute of Sea Fisheries, Germany) 


Towards a regional sampling plan – Case Study of the trawl fishery in Iberian Waters

Trawl fisheries in Iberian waters (27.8.c and 27.9.a) are operated mainly by Portuguese and Spanish vessels which land mostly in national ports. These fisheries are multi-specific and important in terms of landed weight and value.

In recent years there has been an interest in developing and implementing a regional sampling plan for these fisheries aiming at optimizing the sampling effort and quality of biological data on these fisheries.

Work towards this end has been developed in previous projects FishPi (2016-2018) and FishPi2 (2018-2019), specifically building theoretical scenarios of regional sampling plan, respectively for single species and multi-species. This work has been further developed in the RCG NANSEA, namely in one of its ISSGs (Inter Sessional Sub Group), and in Project Fishn’Co.

Such work has consisted in using existing data on fisheries landing and effort to theoretically design possible alternative scenarios of distribution of on-shore sampling effort among Portuguese and Spanish fishing ports of 8c and 9a. The best scenarios were selected based on bias and precision of the estimates produced by the scenarios (in simulations); and also based on feasibility and suitability of the scenarios (i.e. if effort in each port could be implemented as proposed in the scenarios, if relevant ports with landings of relevant metiers/fleets/species are included, and if foreign landings could be sampled).

Work is being developed in the short-medium term towards the definition of a pilot study to be implemented in practice, followed by an evaluation of the estimates obained. 

Chairs: Rita Vasconcelos 

Involved RCG: NANSEA  


The intersessional subgroup case studies for Protected, Endangered and Threatened Species (PETS) monitoring was established with the aim of improving coordination in the collection of PETS data at regional level.

The main tasks that have been carried out during the last years have been to identify the high-risk fisheries and their sampling coverage at regional level, to identify the most appropriate sampling methodologies for each fishery, to improve and standardize sampling protocols, etc.

In addition, potential case studies for regionally coordinated sampling programmes have also been identified. Much of this work is being done in collaboration with the main ICES working groups involved in these issues (e.g., WGBYC, WGCATCH). 

Chair Estanis Mugerza 

Involved RCG RCG NANSEA, RCG Baltic 


The intersessional subgroup evaluation on the data collected for the Small-Scale Fisheries (SSF), was established with the aim of improving coordination in the collection of SSF data, in order to improve the knowledge of these fisheries. Based on the needs of the main end-users, the data to be collected are identified and the best way to do this in a regionally coordinated manner is analysed.

This work is carried out in collaboration with the main ICES working groups focused on issues related to commercial fisheries sampling methodologies (e.g., WGCATCH). 

ChairEstanis Mugerza 

Involved RCGRCG NANSEA, RCG Baltic 



WGRDBESGOV is a governance group which oversees the current Regional Database (RDB) and the new Regional Database & Estimation System (RDBES) that is under development.  

​​​​​​​​​WGRDBESGOV consists of members from the EU Regional Coordination Groups (RCGs) that upload data to the RDB/RDBES​, and from ICES member countries. The group explores data governance questions including data policy, gives guidance on technical developments, and monitors the use of the RDB/RDBES.  

The RDB/RDBES stores detailed commercial fisheries sampling data and aggregated effort and landings data. The aims of the RDBES are:  

  1. to ensure that data can be made available for the coordination of regional fisheries data sampling plans, including for the RCGs,  
  2. to provide a regional estimation system such that statistical estimates of quantities of interest can be produced from sample data,  
  3. to serve and facilitate the production of fisheries management advice and status reports, and  
  4. to increase the awareness of fisheries data collected by the users of the RDBES and the overall usage of these data 

Chairs: Els Torreele, Lucía Zarauz 


ISSG Diadromous 

The intersessional subgroup for diadromous species is a specialised, pan regional subgroup focusing on coordination of data collection and advice for regional workplans on diadromous species (primarily eel, salmon, sea trout) in line with DCF regulation. Tasks may include listing end-user needs (variables required, frequency, intensity), coordination of possible needs for regional agreements and suggesting time frames for implementations. Data needs of end-users may include both, commercial and recreational fisheries in marine and inland waters of which the latter always needs to be discussed in close coordination with ISSG recreational fisheries. 

Currently the focus of the ISSG Diadromous still is to improve assessment-driven data collection under DCF and to strengthen the interaction between end-users and the ISSG Diadromous / data collection itself. This is intended to be done by encouraging end-users for direct input on data needs for improvement of assessment and comparability in used methodologies as well as by considering regional differences and difficulties in data collection. The goal is to let end-users and ICES EGs further specify the data needs meant for stock assessment and policy advice and thus directly influence data collection. Inputs from end-users is of importance, since ISSG Diadromous has a wide scope including multiple species with different life cycles and stocks, of which the ISSG cannot determine and specify data needs on its own.  

Main tasks of the group are 

  • Strengthening of communication with end-users (to get and provide direct input on issued connected to data availability for assessment) 
  • Promotion of data workshops (to collect best data for assessment) 
  • Promotion of transition from national to regional work plans in the suitable parts of data collection for diadromous species under DCF 


Chairs: Marko Freese and Tapani Pakarinen 



ISSG Surveys 

This ISSG mainly deals with the cost-sharing of research surveys-at-sea under the DCF EU-MAP. In addition, the group monitors implications such as COVID-19 on surveys from a DCF perspective and react when appropriate and requested. We link to the regionalisation process within and act as focal point for RCG contact. We review proposed substantial changes to the design, set-up or other aspects of surveys having an impact on MS’s Work Plans, effort and/or budget allocation, or obligations. We contribute to Regional Work Plans with regard to surveys and finally also discuss new challenges in fishery-independent data collection due to usage and protection of marine areas. 

ChairsSieto Verver (The Netherlands) and Christoph Stransky (Germany) 

Involved RCGsRCG NANSEA, RCG Baltic 

End-user and RCG  

The aim of this ISSG is to review and the streamline dialogue between data providers (RCGs) and end users (ICES, Commission) in order to identify effective processes to meet end-user needs and allow the RCG to prioritize its activity relating to future data collections, storage and transmission functions. Annual information meetings between ICES, Commission and RCG chairs are held to ensure good cooperation and to be able to follow the progress over time. 

The tasks of this ISSG include: 

  • Continue with the designed questioannire on the impact of various factors on data collection from commercial fisheries and research surveys 
  • Communication channel between ICES and RCG chairs 
  • Communnication channel between Commission and RCG chairs 
  • Communication channel between end-user and RCG chairs  


Involved RCGsRCG NANSEA, RCG Baltic