Abstract

In a scenario of global climate change and increasing anthropogenic disturbances on seagrass ecosystems, establishing baseline references of seagrass cover, distribution and dynamics are needed for a better understanding and management of these ecosystems. Long-term changes in seagrass distribution in Caja de Muertos Island Nature Reserve, Puerto Rico were assessed using remote sensing techniques. A WorldView-2 image from 2014, historical aerial photographs from 1950 to 2010 and field data were used to analyze spatial trends within four zones of the Reserve. Remote sensing data were ana-lyzed using object-based image analysis. Overall seagrass extent increased by 64%, contrasting with the worldwide declin-ing trend in seagrass habitats. This increase was mainly driven by an increase in the patchy seagrass cover category, which was also the most persistent cover for the 64-year period. The temporal and spatial differences observed were mainly asso-ciated with natural factors. The seagrass persistence map that was created can be used by managers to determine the severi-ty of a natural or anthropogenic impact within the studied zones, and to decide if management actions are needed. These data represent a baseline by which future seagrass changes can be analyzed as well as valuable information for the conser-vation of seagrass beds in the Reserve.

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