A similar horse mussel reef located nearby was already protected by the former North Western and North Wales Sea Fisheries Committee (NWNWSFC) Byelaw 21.
Mae rîff cregyn dilyw arall gerllaw eisoes yn cael ei diogelu gan Is-ddeddf 21 y cyn Bwyllgor Pysgodfeydd Môr Gogledd-orllewin Lloegr a Gogledd Cymru (NWNWSFC).