- A quantitative method for monitoring and analysing intertidal communities is presented. 60 quadrats from an intertidal field experiment on the effects of predation by Stramonita haemastoma (L.) were used as an example to describe the method. Camcorder recordings were quick, included audio descriptions and identifications, and gave results that could be reviewed in the field. Individual video frames of quadrats were selected, digitized, and analysed using digital image processing. A color montage of the processed quadrat files demonstrate how digital image segmentation can be used to obtain direct area estimates of cover and help visualize results. Although faster, less direct point estimates undersample, resulting in significantly higher total cover values ( = 0.05). Images can be compactly stored on optical disk and monitoring programs using this technique could serve as data archives similar to those now used for satellite images. 1992.