Epibionts on Caribbean mangrove roots from Morrocoy National Park and La Restinga Lagoon National Park, Venezuela

Sampling was non-destructive and species present at each root were identified in situ using a photographic identification guide previously prepared using local inventories. To estimate the relative abundance of each species per sample unit, digital underwater photographs were taken from the entire root. Each root was photographed using 10 cm intervals covering the entire length and sides of the root, by means of a vertically fixed measuring tape as reference. These photographs were used to estimate cover of all sesile species present, applying the point intercept technique. All images were scaled and calibrated using the tick marks of a measuring tape to adequately estimate the length of the area photographed. Over each image, a digital gridded quadrat was overlapped with intersections being separated by 1 cm on x- and y- axes. All this digital work, including the quantification of points intercepting a particular organism in the photograph, was done in Coral Point Counter v3.6. With the metric references in each picture given, the area described in an image that partially appears in another was not quantified twice. Data originated from this procedure were loaded into a species × sample matrix, where each cell represented the number of points that a given species had in a specific sample.