Zooplankton community associated with mesophotic coral reefs in the Colombian Caribbean Sea

Abstract

The morphological, phenological and ecological characteristics of shallow coral reefs have been widely studied, but only recently have mesophotic corals begun to be studied. Very little is known about these ecosystems and their associated communities, such as the zooplankton community, which constitutes a food source for reefs and for the organisms that inhabit them. In the present study, changes in zooplankton composition were characterised during two hydroclimatic periods in a mesophotic environment of the submarine mountain Bajo Frijol, in Corales de Profundidad National Natural Park, Colombia. Zooplankton was collected using a portable pumping device, which contained three collectors of differing mesh sizes; this allowed the capture of zooplankton ranging in size from 45 to 300 μm. Temperature, conductivity, oxygen and pH were obtained and complemented with MODIS AQUA satellite information. In this ecosystem, the zooplankton organisms with the greatest richness and abundance were small-sized copepods, radiolarians and tintinnids. The oceanography of the area results in greater zooplankton abundance, richness, and diversity in June when the coastal current allows greater chlorophyll-a concentrations in the area and smaller organisms are favoured by greater retention within the corals of the mesophotic system. The biodiversity reported for Bajo Frijol is the first detailed approach to the community of mesophotic coral reefs in the Colombian Caribbean Sea, contributing to new records to the Global Biodiversity Information Facility.