Darwin Core can have one of two Core files, taxon or occurrence. The most appropriate for a survey would seem to be occurrence. So I imagine that in the star schema you could also have a related event file detailing the date and location of each survey and a non-core taxon file detailing the taxa that are observed.

However, this does not seem to be possible. The DWC-A validator (http://tools.gbif.org/dwca-validator/), assumes only on core id in the core file so you can't link an occurrence both to a taxon and to an event. This is also true in the Darwin Core Archive Assistant (http://tools.gbif.org/dwca-assistant/). The solution seems to be to put all the information from the taxon core file into the occurrence file, but keep the separate event file linked with the core occurrence id.

Is this correct? It seems rather counter intuitive.

Regards

Quentin