Spatially explicit estimates of length and biomass of Clupea harengus (Norwegian spring spawning herring) from acoustic and trawl surveys in the North-East Atlantic in May 2006 ...

• Main Author: Huse, Geir
• Format: Dataset
• Language: English
• Published: PANGAEA 2014
• Subjects: Event label; LATITUDE; LONGITUDE; DATE/TIME; Code; Area; Clupea harengus abundance as Nautical Area Scattering Coefficient; Clupea harengus, biomass; after MacLennan et al. 2002; Calculated from nautical area scattering coefficient; Basin Scale Analysis, Synthesis and Integration EURO-BASIN; North East Atlantic
• Online Access: https://dx.doi.org/10.1594/pangaea.827192; https://doi.pangaea.de/10.1594/PANGAEA.827192

Acoustic estimates of herring and blue whiting abundance were obtained during the surveys using the Simrad ER60 scientific echosounder. The allocation of NASC-values to herring, blue whiting and other acoustic targets were based on the composition of the trawl catches and the appearance of echo recordings. To estimate the abundance, the allocated NASC -values were averaged for ICES-squares (0.5° latitude by 1° longitude). For each statistical square, the unit area density of fish (rA) in number per square nautical mile (N*nm-2) was calculated using standard equations (Foote et al., 1987; Toresen et al., 1998). To estimate the total abundance of fish, the unit area abundance for each statistical square was multiplied by the number of square nautical miles in each statistical square and then summed for all the statistical squares within defined subareas and over the total area. Biomass estimation was calculated by multiplying abundance in numbers by the average weight of the fish in each statistical square ... : The research leading to these results received (partial/full) funding from the European Commission FP7 EURO-BASIN (European Basin-Scale Anal ysis, Synthesis, and Integration; Grant Agreement 264 933). ...