Data Limited Stocks

Data Limited Fish Stocks in the Northern North Sea content

Data Limited Fish Stocks in the Northern North Sea

July 2017

Data Limited Fish Stocks report cover


The aim of this project was to collect additional biological and fishery data for a number of data limited fish stocks which are of commercial importance to the local fishing industry, including monk (angler), megrim, plaice, lemon sole, hake and ling. Data limited stocks are those for which there is not sufficient data to enable robust analytical assessment of their stock status.

The project was undertaken through monthly observer trips onboard Shetland-based whitefish trawlers.


Data was analysed and forwarded to ICES Working Groups and fishermen’s organisations and representatives as appropriate, and a final project report was produced (below).

The data collected during the project are available from Dr Chevonne Angus.

Start Date and Duration

The data collection phase of the project ran from July 2013 to June 2015.


NAFC Marine Centre; Scottish Government; Shetland Fishermen's Association.

Further Information

Further information about the project and a copy of the data collected are available from Dr Chevonne Angus.

Download the Project Report

Data Limited Fish Stocks in the Northern North Sea (pdf)

Report Summary

In 2013, NAFC Marine Centre began a two year project with the aim of undertaking regular observer trips on board demersal fishing vessels working out of Shetland to collect fishery and biological data on six commercially important data-limited species: anglerfish (Lophius spp.), ling (Molva molva), lemon sole (Microstomus kitt), plaice (Pleuronectes platessa), hake (Merluccius merluccius) and megrim (Lepidorhombus whiffiagonis). As well as recording spatially resolved catch and discard data, key biological characteristics of each of the six species including growth rates, length at maturity and spawning pattern were described. Dedicated fishing activity was also undertaken to tag and release anglerfish and flatfish species for later recapture in the commercial fishery.

Results of the study indicate that quota restrictions are still resulting in significant discarding of key commercial species. Anecdotal evidence suggests that hake and ling discarding is primarily driven by restrictive quotas while discarding for plaice is largely driven by market influences. Discarding of the remaining species was relatively low.

The work undertaken in this study has provided a valuable dataset for a number of commercially important species in the northern North Sea that can assist in their long term monitoring, assessment and, ultimately, management. As is the nature with continuous datasets, their value deceases when data collection stops and trends are no longer monitored. This ultimately has the potential effect of reducing the value of existing data. The current project has therefore highlighted the need for a more consistent, long term data collection regime to ensure that this monitoring can continue.