The CSNIreOT4 begins in 1992 and ends in 2016, Moriarty et al (2017) detail the survey’s history.
The Celtic Sea Northern Irish Quarter 4 Otter Trawl Groundfish Survey Monitoring and Assessment Data resource contains both biological and sampling information. There are two sampling areas a “Full” data set, this includes rectangles that have a poor temporal sampling record. The “SSA” or “Standard Survey Area” sampling area only contains rectangles that have consistent temporal sampling and meet the criteria set out in Moriarty et al, (2017).
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.

Acknowledgements
Mathieu Lundy, AfBI
Vaishav Soni, ICES Data Centre
International Council for Exploration of the Sea (ICES)