Investigating Variation in Coral Reef Morphology with Photomosaics and Analysis of Percent Cover

Coral reefs serve as an important component of tropical marine ecosystems’ functionality and composition. However, coral cover in the Caribbean reefs continues to decline due to climate changes. Corals are adapted to thrive in a limited range of environmental conditions, where small changes in the oceans structure, such as temperature, light intensity, and physical disturbances, can lead to wide- scale loss of organisms. In the present study, I investigated five categories of coral reef morphology--massive, brain, flowering, plating, and branching--to assess how variations in depth change coral coverage and abundance. A section of the coral reef was surveyed off the coast of Bonaire, Netherland Antilles, in the Southern Caribbean. The study collected large-scale imagery, called photomosaics, were used to create a robust, archived dataset with detailed representation of the benthic organisms. The study site contained two 50m2 subplots, one shallow and one deep, to represent two separate conditions based on environmental variables such as light intensity and nutrient availability. Each subplot was traced in Photoshop based on each morphological type. The GPS coordinates of each subplot boundary allowed for the images to be placed into a geographic information system to calculate precise percent coverage data from each type of morphology. Plating, flowering, and massive corals had a higher percent area cover in deeper depths compared to shallower depths. Brain and branching corals had a higher percent area cover in shallower depths. With variations in morphology and rising sea levels, certain species of coral may dwindle in numbers, leading to declines of biodiversity and coverage.