The National Survey for Wales found that 54% of people thought there had been a decrease in the variety of species in Wales with a further 29% thinking there has been no change.
Canfu Arolwg Cenedlaethol Cymru fod 54% o bobl yn credu bod gostyngiad wedi bod yn amrywiaeth y rhywogaethau yng Nghymru, gyda 29% arall yn meddwl na fu unrhyw newid.