Fieldwork was halted in mid March 2020, due to the coronavirus outbreak (but fieldwork for 2019-20 was already almost complete at that point).
Byddai’r cynllun gwaith wedi cael ei gyhoeddi ym mis Mawrth fel rheol, ond cafodd ei ohirio oherwydd bod adnoddau’n cael eu defnyddio i ymateb i’r pandemig.