Microlitter colour and transparency (BODCNVS-969)

[gwemon]

Below are extracts from the email trail that led to the decision to create a new vocab for micro-litter transparency and to deprecate the term "transparent" as a colour class in H04 to be replaced by "colourless".
--- Request received from 8 April 2021 ---
Thanks to ISPRA we had the opportunity to have a look at the standard used in UNEP_MAP for the reporting of the micro-litter and we have seen that they report color and transparency as two different fields.
We reviewed the old email exchanges with you about this subject and at the moment of creating the terms for microlitter, the term opaque was not created because it was not related to any meaningful color.
We would like to evaluate with you the possibility of creating a new P01 to define the transparency of microlitter items with a new vocabulary H with 2 terms (transparent and opaque).
--- Response sent 8 apr 2021
I think it would be more consistent to have Colourless as an entry in H04 and then a transparency vocab which would have the terms Transparent and Opaque. We could deprecate Transparent and replace by Colourless for better traceability of changes.
--- Additional information 9 April 2021
We have been checking existing protocols and examples that we have on hand and the situation is the following:
-TGML: categorizes only color but inside has the terms transparent and opaque.
-UNEP-MAP and DeFishGear categorizes color and transparency (opaque or transparent without intermediate degrees).
-Baseman/CEFAS/ICES reports/protocols and some examples that we have, categorize only the color and transparent is one of them.
In our opinion, if we go ahead with the term colourless instead of transparent and then, the new P01 to describe the transparency, all cases might be reasonably covered.

[gwemon]

To summarise, what was needed was:
1- Deprecate "transparent" and add "colourless" to H04;
2- Add a "replace by" relationship between the two;
3- Create a new collection H06 for "EMODnet micro-litter transparency classes"
4- Populate with 2 terms: "opaque" and "transparent"
5- Create 2 new P01 codes for Transparency class of micro-litter particles in sediment and in water body which would be constrained by H06 concepts.

[gwemon]

New H06 collection created and populated with 2 terms as discussed: http://vocab.nerc.ac.uk/collection/H06/current/