Irish Sea Cod Tagging Project

The Marine Institute, in partnership with AFBI in Northern Ireland and CEFAS in the UK, have been conducting a cod tagging project in the Irish Sea between 2016 and 2018. The project has been funded by the European Commission with the three research agencies working alongside the fishing industry and recreational fishermen to gain a better understanding of the factors that have an influence on cod (Gadus morhua) in the Irish Sea.

BackgroundFloy tags with unique tag number and contact details

Historically, landings of cod from the Irish Sea were an important source of revenue to the fishing industry in Ireland and the UK. Landings peaked in the late 1980s (14,168 tonnes) and have steadily declined since. Following advice from the International Council for the Exploration of the Sea (ICES), since 2000 the European Commission has introduced a series of closed area, season and gear measures to aid the recovery of the Irish Sea cod stock.

Measures introduced have included selective gears to avoid catching cod, seasonal area closures to protect spawning aggregations and fishing effort management. With this long term management plan in place and low fishing effort – cod is mainly caught as by-catch in the Nephrops fishery – a slow improvement in the spawning stock biomass (SSB) has been seen since 2009 - 2010. Despite this improvement, the stock is still vulnerable and there is a need to better understand the factors that have an effect on the size and status of the stock.

Project Objectives
Tagging Gun and Tags. Photo Macdara O'Cuaig.
  • Tag several thousand cod (Gadus Morhua) between 2016 and 2018 throughout the Irish Sea with floy tags.
  • Publicise the project to maximise the recovery of tagged cod – from commercial and recreational fishing.
  • Use information from tag recoveries to gain a better understanding of cod mortality, abundance, distribution and movement patterns.
  • Conduct a collaborative research project with interest groups, including other research agencies and stakeholders.
  • Make the data available to the public using online GIS mapping.
  • Compare results of previous cod tagging studies with project outcomes to assess changes.
  • Use findings of the work to make recommendations on the assessment of the stock and its future management.
Reporting a tagged cod

If a tagged cod is captured, a reward of €25 for red tags, €75 for pink/blue/yellow tags is offered for the following information;

  • Date of capture
  • Location of capture (Latitude and Longitude)Tagged Cod
  • Total length
  • Tag number and colour
  • Number of boxes/baskets and size detail (Small/Med/Large) of other untagged cod caught in the catch

Please store the cod UNGUTTED on ice/frozen and we will organise collection.

Information we can collect

When we receive an ungutted, tagged cod we collect as much information from the fish as possible, including;

  • Length
  • Weight
  • Sex
  • Maturity stage
  • Stomach contents
  • Otoliths - used to estimate the age of the fish

To report a tag and claim a reward or for more information on the cod tagging programme please contact Jonathan White on;
Phone: +353 91 387 200


Below is a map of the release sites of tagged cod in the Irish Sea and neighbouring areas.

Map of release sites of tagged cod

Below is a map of the recapture sites of tagged cod from the Irish Sea, Celtic Sea and North Channel 

Map of the recaptures sites of cod tagged

 Agri-Food and Biosciences InstituteCefasMarine Institute EASME