Photographie sous-marine et analyse des peuplements benthiques essais en rade de Brest

Treatement of faunistical data collected by sub'marine photography is applied on an infralittoral area of "rade de Brest". Automatic cartography of the most important epibenthic species gives, in a first approach, some precisions on spatial pattern of these organisms : size and density of agregats, connecting or excluding relationships, influences of the bottom characteristics. Statistical analysis of individual distribution of each species by both parametric and non parametric tests completes this cartographic examination and point out different levels of heterogencity at different spatial scale. In a third step a synthesis regrouping all the distributions is given by the two first axis of an inertia analysis. This technique may introduce an attempt to recognize the relative contribution of the sedimentological and behavioural factors to the observed pattern. [NOT CONTROLLED OCR]