Science Evidence Data and Digital Portfolio Annual Report 2024 - 2025

Sea Fisheries (SF)

Headlines

• In September, co-hosted and participated in a very successful 2024 UK International Council for the Exploration of the Seas (ICES) Annual Science Conference in Gateshead, with 11 SEDD scientists either on the organising committee, co-chairing theme sessions, presenting and receiving service awards for their contribution to the international marine science community.
• Continued to deliver the statutory fisheries data collection requirements including 18 fisheries survey involving tows at 610 stations, measuring 452,604 fish, sampling 42,627 fish and ageing 29,602 fish from their otoliths (earbones).
• Responded by the deadline to 10 international data calls providing ICES with data for 70 fish stocks.
• Worked with international partners at ICES and with Scottish industry to improve the anglerfish and Rockall haddock stock assessments through a formal benchmarking process to improve the methodology resulting in very significant increased catching opportunities for Scottish fishermen and improved management of the stocks.
• Participated in international exchanges to improve knowledge transfer and external quality assurance (QA). Notably exchanging scientists with The Netherlands on the International Bottom trawl Survey, participating in the Irish and Faroese legs of the international blue whiting survey and engaging in QA and training for otolith reading through ICES exchanges and in person training in Norway and Denmark.
• Provided scientific and technical support in 2024 for the drafting and implementation of the sea fisheries remote electronic monitoring (REM) SSI and the corresponding REM system technical specifications and guidance.

Key Work in 2024 - 25

1. Completing the catch sampling programme (market sampling and observing), fisheries independent surveys using research vessels and charters, associated sample and data processing and data submission to ICES and stakeholders.

Contributes to:

Ensuring we have a fit for purpose evidence base to support fisheries management decisions that complies with international obligations and national legislation.

2. Assessments to generate advice on catching opportunities and fisheries management, including supporting the inshore fisheries management improvement programme, the Future Catching Policy, razor fish trial extension and wrasse.

Contributes to:

Ensuring fisheries management decisions are based on robust scientific advice to ensure stocks are managed sustainably through informed international negotiations and fisheries management decisions.

3. Research on selective fishing gears (a focus on avoiding bycatch in static gears and remote electronic monitoring (REM) research.

Contributes to:

Ensuring future fisheries policy development remains based on current evidence and takes advantage of improvements and efficiencies awarded by new approaches and technology.

Case Study: Electrofishing for Razor Clams Scientific Trial

In 2018, the SG began a trial of electrofishing for razor clams, operating under a scientific derogation. The Science Evidence, Data and Digital portfolio of the MD has been responsible for the biological and ecological aspects of the trial and in 2024 published a substantial report¹ documenting this work alongside a web-based portal providing access to data collected as part of the trial².

Razor clams (Ensis sp.) are marine bivalve molluscs with significant global commercial value which are commonly found around the coast of Europe, inhabiting sediments from fine sand to soft mud in the intertidal and sub-tidal areas. The scientific electrofishery trialwas launched after previous work indicated that electrofishing appears to be a low impact method of harvesting razor clams compared to other potential methods, such as dredging.

The aim of the trial was to provide an evidence base for the sustainable management of a potential commercial razor clam electrofishery, gathering information on both species biology and the fishing method. Features of the study included:

• Provision of self-sampled data by razor clam fishers and processors on length composition of their landings (number of razor clams in 0.5 cm intervals) along with the sample weight and details of the landing (including vessel name, landing date and fishing area). These data enabled MD to carry out stock assessments for a number of the fishery trial areas.
• Further collaborative work with the fishing industry resulted in samples of live razor clams being delivered to the Marine Laboratory (Aberdeen) to allow for scientific sampling and dissection with the purpose of determining spawning period and size. The empty shells were retained and used for age and growth determination carried out as part of a PhD project based at the Scottish Association for Marine Science (SAMS).
• Further development of appropriate survey techniques for razor clams (led by SAMS in collaboration with MD and funded by MFS) utilising towed video as a means of monitoring razor clam density.
• The analysis of Remote Electronic Monitoring data to provide detailed information on spatial fishery footprint, fishery effort and landings per unit effort.

The main scientific outcomes of the trial

• For the Firth of Forth and Clyde trial areas, fishing mortality is estimated to be below maximum sustainable yield levels.
• Growth rates and productivity varies around Scotland.
• A spawning period in the spring has been clearly identified from sampling and this has been integrated into the trial as a seasonal closure.
• Experimental results applying electric fields to non-target species indicate very low and recoverable effects.