Use constraints: Data can be used freely given that the source is cited (following creative commons license CC-BY). The source should be cited as: “HELCOM HOLAS 3 Dataset (2023).

The commercial landings data has been downloaded from the Scientific, Technical and Economic Committee for Fisheries (STECF) Expert Working Group on Fisheries Dependent Information ( https://stecf.jrc.ec.europa.eu/dd/fdi) in April 2022. The dataset contains data for 2016-2020.

Landing data were aggregated per species and year, for cscode / ICES rectangle. Other species than Cod, Sprat and Herring were excluded from the data. The value for each species and year is the weight of the landing in tonnes (original attribute: ttwghtl).

Baltic International trawl survey (BITS) data

- downloaded from DATRAS database ( https://datras.ices.dk)

- CPUE values per ICES subdivision

- average over 2016-2020, quarter 1 only

- fish <30cm excluded

For ICES rectangles surveyed by BITS, the values shown are the mean CPUE per ICES subdivision based on BITS data, the average for 2016-2020. For ICES rectangles not surveyed by BITS, values are calculated as MAX-value x Weighting factor.

The weighting factor is specific to each ICES rectangle, calculated as the ratio between the commercial landings in that rectangle and the commercial landings in the ICES rectangle with the highest landings in the Baltic Sea (based on averages for 2016-2020). MAX-value = CPUE according to BITS in the ICES rectangle with the highest landings. Landing values per km2 were used in the calculation and the value in the highest complete ICES rectangle was selected, due to the per km2 getting exceptionally high in some really small ICES rectangles.

Attribute information: Ecosystem abundance value from 0 to 1. (Originally: Raster value representing CPUE value / ICES subdivision (within BITS area) or estimated CPUE value / ICES rectangle (outside BITS area), log-transformed and normalised).