However, there are significant and ongoing challenges that would require substantial time, money, and resources to address, with no guarantee of obtaining sufficiently robust data.
Fodd bynnag, mae heriau arwyddocaol a pharhaus y byddai angen cryn dipyn o amser, arian ac adnoddau i fynd i'r afael â nhw, ac nid oes unrhyw sicrwydd y byddai data digon cadarn ar gael yn y diwedd.