Coral reef ecosystems deliver numerous benefits for people and biodiversity, nevertheless, these ecosystems are endangered and have been affected by numerous threats. Since 1970s Caribbean has lost around 80% of its coral reefs coverage that could bring also a loss on ecological functions and ecosystem services provision. Some ecological functions of coral reefs are related to its biological and tridimensional complexity. This research proposal is focused on generating knowledge about the relationship between coral reefs complexity and its capacity of providing ecosystem services, so we can advise from biological scientific basin about the ecological, biological and socio-economic importance of coral reefs for biodiversity and human wellbeing. This will be achieved through establishing the complexity of different reefs areas with contrasting conditions, in order to evaluate particular interactions with ecosystem services such as biodiversity habitat, coastal protection and providing adequate conditions for other ecosystems development. Complexity will be determined by registering bio-ecological attributes of coral reefs benthic communities and its tridimensional bio-topography. Reef barriers composition profiles will be also evaluated and compared with some general profiles determined in the past at study area around 20 and 40 years ago. Biodiversity habitat service will be evaluated by visual censuses of reefs fishes and benthic macrofauna, correlations with reef complexity will be explored. Coastal protection will be evaluated trough quantifying wave energy attenuation by coral reefs barriers trough field measurements, possible relationships with reefs complexity will be evaluated. The importance of reefs for providing adequate conditions to facilitate the development of other ecosystems such as seagrass meadows will be estimated by spatial distribution analysis using Geographic Information Systems tools, and results from wave energy attenuation measurements. Finally, based on the bio-ecological results obtained by this research an economic valuation will be performed using a battery of methods and biological inputs, valuation results will be used to communicate the importance of coral reefs ecosystems and its complexity for biodiversity, human well being, and sustainable development at Caribbean oceanic islands.