Cod abundance
Short description
Baltic International Trawl Survey (BITS) data (2011-2016) from ICES DATRAS database was used as a base to create a map of cod relative abundance (quarter 1 data, CPUE values per ICES subdivision). Cod = 30cm was included. For ICES rectangles surveyed by BITS, values shown are the mean CPUE per ICES subdivision based on BITS data, average for 2011-2016. 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 highest landings (based on averages for 2011-2016). MAX-value = CPUE according to BITS in the ICES rectangle with highest landings. ICES rectangles outside the BITS survey area with no reported cod landings were given the value 0. Values were first log transformed and then normalized.
Point of contact
HELCOM Secretariat
data@helcom.fi
Spatial extent
['7.530495', '34.131647', '52.277123', '66.475422']
Type
dataset
Metadata information
Identifier
Keywords
Species distribution ; GEMET - INSPIRE themes, version 1.0 ;

fish ; marine ecology ; GEMET ;

MADS ; HOLAS2 ; ecosystem component ;

Resource provider(s)
HELCOM Secretariat
data@helcom.fi

Lineage
Data source: Baltic International trawl survey (BITS) data - downloaded from DATRAS database (https://datras.ices.dk) - average over 2011-2016, quarter 1 only - fish <30cm excluded Landings data from EU Joint research Centre (https://datacollection.jrc.ec.europa.eu/dd/effort/maps) from years 2011-2016 (= fisheries data). Data reported as tonnes / ICES statistical rectangle Data quality: The fisheries independent BITS surveys are designed for estimating demersal fish abundance in the Baltic Sea. However, the data in SD 21 (Kattegat) is not standardized with the rest of the area, thus it may not be comparable. Further, the areas outside BITS survey area are based on an estimate derived using landings data. 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). Spatial resolution: Original data in ICES rectangles, here 1 km x 1 km grid.