Thanks a lot for the information.

I suppose when the record is composed of multiple  specimens  (whose number is recorded in ObservedIndividualCount) the individual attributes of each specimen (age, sex, maturity, etc) cannot be stored.

 

Tomas Bar



On Fri, Nov 28, 2008 at 4:14 PM, Tim Robertson <trobertson@gbif.org> wrote:
Hi T. Bar

You might consider the OBIS extensions for Darwin Core since you are concerned with marine stuff.

http://iobis.org/obis/obis.xsd

SampleSize:  the size of the sample from which the collection/observation was drawn.  It can be a volume (e.g. for a phytoplankton sample), a linear distance (e.g. for a visual transect or net haul), a surface area (e.g. for a benthic core), etc.  This field must also include the units, e.g. 200 mfor a transect, or 0.25 m^2 for a benthic grab (use ^ to denote a superscript).  Note that when multiple collections/observations are reported from the same physical sample, a code identifying the sample can be placed in the Field_Number field to allow all collections/observations from a single sample to be connected.  

IndividualCount is a count of specimens (e.g. not a count of species).  If you want to indicate multiple species, then you would have a record for each along with the identification and the count  of individuals of that species.

So in the OBIS schema you have:
ObservedIndividualCount: The number of individuals (abundance) found in a collection/record event.

Cheers,
Tim


On 28 Nov 2008, at 17:05, bar tomas wrote:

Sorry if this question is misplaced in this discussion list, but I haven't been able to find a mailing list on the conceptual aspects of Darwin Core.

 

I am interested to know if there are any recommendations on how to represent abundance in Darwin Core. I have seen some datasets using IndividualCount and SampleSize. For instance, for a fishing survey, would you use IndividualCount for the number of species in a catch, and SampleSize for the distance towed?

 

Thank you very much
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