CEFAS26-75 ITT for provision of pelagic trawler vessel for the IESNS survey

The Supplier will provide s pelagic trawler, suitably equipped to participate in an acoustic-trawl survey. The survey is part of the international IESNS (International Ecosystem Survey in the Nordic Sea), a collaboration between Icelandic, Faroe, Norwegian, EU and UK research institutes which has been conducted since 1997.

The survey is carried out to investigate distribution and migrations of the Norwegian Spring-spawning herring, blue whiting and other pelagic fish, and to produce a biomass index for herring and a recruitment index for blue whiting. The survey will cover the southern end of the distributional range of the spring-spawning herring population. Furthermore, data on the hydrographic conditions and plankton distribution will be obtained to investigate the possible effects of the ecosystem on the distribution and abundance of target fish species.

Aims and Objectives

The main objectives of the survey will be to:

• carry out a predetermined survey cruise track collecting fisheries acoustic data

• collect biological samples by directed trawling on insonified fish echotraces to determine species composition, size, age structure and maturity stage of target pelagic species.

• collect physical oceanography data from vertical profiles (CTD).

• collect plankton samples using ring-nets

Cefas will provide a minimum of 6 scientists to oversee the survey operations, working with the vessel to deliver the scientific objectives of the survey.

Scope of Requirements

Survey activity

An acoustic-trawl survey to map and quantify herring and blue whiting. This will be performed by continuously (24h) running acoustic transects and carrying out ad hoc midwater trawling within the survey area.

Additional objectives will include collection of plankton and hydrographical data in the study area.

Survey area and time of operation

The UK survey component will take place between Latitudes 62° and 69° North and Longitudes 13° West and 6° East (see full specification in bidder pack for total survey area and example of UK component in green).

The survey will be a total of approximately 13 days and will be conducted within the period 20/04/2027 – 31/05/2027. The vessel must be available for 13 consecutive days (this excludes time to calibrate the echosounders in a suitable port as well as transit from berth port to requested mobilisation port) within this period and ideally commencing at the start of this period.

Embarkation and disembarkation is required to take place in a Scottish mainland port e.g. Fraserburgh, Peterhead.