DiadSea

Building transnational marine management and conservation strategies for diadromous fish in the Atlantic Area.

Twaite shad on a net.

What is DiadSea?

DiadSea is an EU-funded INTERREG Atlantic Area project. Inland Fisheries Ireland(IFI) is an Irish beneficiary partner in the project, alongside the Marine Institute (MI). 

This exciting new project aims to build transnational marine management and conservation strategies for diadromous fish in the Atlantic Area. 

What is the DiadSea project investigating?

The DiadSea project will investigate the marine habitats of diadromous fish, complementing the work undertaken by IFI for the DiadES project, which focused on freshwater habitats. 

The serious knowledge gaps that exist regarding diadromous fish at sea will be addressed through various work packages that IFI will be both contributing to, and leading.

What are diadromous fish species?

Diadromous fish species divide their lifecycle between two different habitats (freshwater and marine waters). 

This presents significant threats to these species, including overfishing, habitat degradation, ocean warming, and shifts in ocean currents, among others. Because these fish are split between two different habitats throughout their lives, there are numerous management, conservation, and societal challenges associated with protecting and conserving them.

Survey: Which diadromous fish have you caught as bycatch?

Coastal anglers can use this survey to report which diadromous fish species they have caught as bycatch

Project Objectives

Within DiadSea, the distribution of diadromous species at sea will be mapped to identify important marine areas for these fish. The latest ocean and climate models will be used to predict the future of these fish stocks. A large-scale Diadromous Fish Observatory will be created comprised of stakeholders involved in diadromous fish management and conservation. A variety of informative networking activities will be held for stakeholders with the aim of emphasising the importance of diadromous species.

Diagram of connectivity between management measures for diadromous fish.

Diagram on connectivity between management measures from the DiadSea policy brief. 

Target Species for DiadSea

  • Atlantic salmon
  • Sea trout
  • European eel
  • Flounder
  • Allis shad
  • Twaite shad
  • Smelt
  • Sea lamprey
  • River lamprey
  • Thin-lipped mullet
  • Golden-grey mullet
Chelon ramada data from the DiadES Web Atlas.

Chelon ramada data from the DiadES Web Atlas.

Work Package 1 (WP1)

Inland Fisheries Ireland will lead Work Package 1 (WP1) for the DiadSea project. This work package focuses on biological data collection. The work is broken down into four main activities:

  • Activity 1.1: Compilation of historical fisheries-dependent and independent data relating to diadromous fish in their marine phase. This will result in the creation of a database for historical biological diadromous fish data at sea.
  • Activity 1.2: Assessment of data gaps and definition of required solutions. We will develop a briefing note on diadromous fish identification at sea and produce a report relating to the existent data gaps and the identified solutions.
  • Activity 1.3: Filling the identified data gaps relating to diadromous fish in their marine and estuarine phase. This will involve the use of exciting and modern sampling methods such as environmental DNA (eDNA) sampling; microchemistry and genetic analysis of both shad and sea trout; and survey work with anglers and port observers. The Web Atlas created during the DiadES project will also be refreshed with up-to-date datasets.
  • Activity 1.4: Networking activities and stakeholder engagement led by the University of Évora. Thematic digital poster infographics will be produced.
DiadSea work package 1 activities

Project Partners

We aim to work together with many stakeholders, port observers and commercial fishers to gather as much information as possible relating to these fish while in the marine environment.

This is an EU-funded INTERREG Atlantic Area project with a number of European beneficiary partners and associated partners.

Beneficary partners:

  • UÉvora – University of Évora (lead project partner, Portugal)
  • FCUL – Faculty of Sciences of the University of Lisbon (Portugal)
  • IPMA – Portuguese Institute for the Sea and Atmosphere (Portugal)
  • MI – Marine Institute (Ireland)
  • USC – University of Santiago de Compostela (Spain)
  • INRAE – National Research Institute for Agriculture, Food and the Environment (France)
  • MNHN – National Museum of Natural History (France)
  • Logrami – Loire Migratory Fish Association (France)
  • IFI – Inland Fisheries Ireland (Ireland)

Associated partners in Ireland:

  • The Rivers Trust
  • Irish Federation of Sea Anglers – Angling Council of Ireland
  • Sea Fisheries Protection Authority
Interreg Atlantic Area logo

Downloads & Links

DiadES River of Life poster

DiadES Policy Brief: A Transnational and Non-Sectoral Approach to Diadromous Fish Species Management
(551.84 KB)

DiadSea fish ID booklet cover.

DiadSea Fish ID booklet

This booklet has been designed as an aid for migratory fish species identification, specifically diadromous fish. The species mentioned in this booklet have historically been poorly recorded at sea and often discarded or ignored as bycatch. These fish species are hugely important ecologically, culturally and economically, as well as useful indicators of climatic change. Accurate identification of the presence of diadromous fish in the marine environment is essential to fill the knowledge gaps about their distribution at sea. If you catch any of the fish species listed in this booklet, we would greatly appreciate it if you could contact us with the following details:

  1. Fish species (a corresponding photo if possible)
  2. Exact or approximate capture location
  3. Date of capture
  4. Fish measurements where possible

You can email us the details at Diad@fisheriesireland.ie.


DiadSea horizontal logo