Greater North Sea International Otter Trawl Quarter 1 Groundfish Survey Monitoring and Assessment Data Products - 2017-2019 Update
The Greater North Sea International Quarter 1 Otter Trawl Groundfish Survey Monitoring and Assessment Data update resource contains both biological and sampling information for 2017-2019. This is linked to the earlier release for this region and quarter (Moriarty and Greenstreet 2017).
The “Full” data set includes rectangles that have a poor temporal sampling record. The updated resource provided is for the “SSA” or “Standard Survey Area” sampling area, and consists of two parts, “sampling information” and “biological information” (explained below). The SSA only contains rectangles that have consistent temporal sampling and meet the criteria set out in Moriarty et al, (2017). The SSA has been kept consistent with the previous release for continuity.
The “sampling information” contains all the technical information required to describe each individual haul.
The “biological information” contains all of the biological information required to describe the species length and weight distributions in each haul. Biological information is further classified by “baseline” data. This data contains a mix of species, genus, and family classifications, with a tag to say if it required further assessment and “null” length values, with a tag to say a length frequency distribution needs to be assigned. The “k-NN” or “k” number of nearest neighbours data has reconciled all of the taxonomic data to the highest resolution possible, and assigned an appropriate length distribution to the sample in question. Product type:
• This product is the Standard Survey Area - Standard Monitoring Programme this is the recommended product for all analyses.
• This product is the knn/resolved product which is recommended for all analyses.
Jens Rasmussen, Marine Scotland Science
Chris Lynam, CEFAS