More than ten seagrass blades per photo were observed in hundreds of
the 5300 photographs examined (Roper and Brundage, 1972). There is no information on the average area covered per photo, but in Figute y9 about 20 apparent blades occur within an area of about 40 mi, After a hurricane, 48 blades per photograph were recorded on the Blake Plateau at 516 m depth(Menzies et al., 1967); the area covered tr photo is not stated.