Sponge species distribution and biomass surveys of Caribbean Reefs

Sponge species distribution and biomass was investigated in Caribbean and western Atlantic reefs in 7 countries (Belize, Jamaica, USA (Florida), Bahamas, Puerto Rico, US Virgin Islands and Barbados).The reefs of Belize were intensively surveyed. Surveys were conducted at 5, 10, 15 and 20 m on the seaward facing slopes of Wee Wee Cay, South Water Cay and Glovers Reef. Triplicate 20 m x 2 m transects were surveyed along the depth profile at each depth. All sponges, except boring, thin encrusting and cryptic species were collected, identified to species where possible and weighed. Surveys at Wee Wee Cay at 10 and 15 m were limited to 8 m² because of the large number and volume of sponges. Any additional species that occurred in the remaining 32 m² were recorded. Very large specimens of Xestospongia muta were not collected, but the weights were estimated by calculating the volume from linear measurements and using a weight/volume correction factor calculated from smaller specimens or parts of larger animals which were weighed. Such estimates were made conservatively, erring on the side of underestimation.Similar surveys were carried out in Jamaica (Discovery Bay), USA (Key Largo - French Reef), Bahamas (Exuma Cays - Lee Stocking Island), Puerto Rico (Cayo Enrique, Media Luna), US Virgin Islands (Saint Croix - Buck Island, Tague Bay, Salt River Canyon) and Barbados (West). Triplicate transects were surveyed at depths of 10 m and 20 m at most locations. Transects were variable in size, ranging from 3 m x 2 m to 30 m x 2 m. This research was undertaken to survey sponge species distribution and biomass on Carribean Reefs for comparison with similar data from the central Great Barrier Reef. During these surveys, benthic cover was also surveyed at most locations, using the Line Intercept Transect method.