Hi can anyone offer advice on how to keep oyster catchers safe when nesting?

its going to be a hard one as they tend to nest in fairly open places though they do seem to pick some sensible places- there was a pair nested on the roof of one of the stands at Kelso racecourse so the chicks were fairly safe from ground predators until they fledged, though still vulnerable to airborne. We have another pair local that always nest in a sheepfold.