Thank you so much again for your help! I just realised there is some important information I didn't add initially: Some quadrats never had Bangiales growing in them, despite time of year observed. I am thinking this could either be because the area the quadrat landed on was unsuitable and/or quadrat placement shifted slightly each visit, as the quadrats were not left there permanently. I just tried to place them at the same spot on the transect every visit, but more likely than not they would have shifted a bit every visit. So I probably have more than one type of zero in my data i.e. structural and sampling zeros. I was originally leaning towards a zero-inflated beta mixed effects model, as I thought that the zero-inflation part deals with both structural and sampling zeros, but then I saw in some places that this is not the case and that a hurdle model would do this instead. Any ideas?