Quality assurance of field identification, using the reference collections

 
The ROG for trawls and dredges recommends that, where possible, the entire sample should be returned to the laboratory for identification and enumeration/counting, however, trawls and dredges can collect large volume samples and, with limited offshore stowage space, fixative and storage buckets, this may not always be possible.  It may be more appropriate to process the sample on deck, for instance using the  SACFOR or DAFOR semi-quantitative enumerations (see the Case Study “Report on applicability of the SACFOR scale for recording relative abundances of colonial organisms in beam trawl samples” (Curtis & Coggan, 2007) (Applying SACFOR report).
 
For quality assurance (QA) purposes, a reference collection should be kept for each set of sample.  The collection should contain at least one example of each taxon/species (except where the identification is unequivocal – e.g. Asterias rubens).  The reference collection can then be processed on return to shore to verify field identification.  Some taxa are not easily separated by rapid assessment in the field (e.g. Macropodia sp., Inachus sp., Ebalia sp., Galathea sp., Nucula sp., Abra sp., pandalids etc.). 
 
If time is not available to adequately identify/separate such taxa to species level, then the entire catch (or sub-sample) of these taxa can be placed in the survey reference collection for later identification (and weighing) onshore (Note: that the term reference collection here applies to a collection of specimens sorted while on survey for later identification in a laboratory.  The term may also be applied to a selection of specimens kept in a laboratory to confirm identifications, as a library and a form of quality control, and also as a national, regional master collection for use in ensuring identifications are consistent at a national and international level).
 
 
 

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