Katryna Kerr

Document Type

Internship Report

Publication Date

Fall 2015


Coral reefs have become exposed to an increasing number of stressors. Temperature extremes, increased ocean acidification and human impacts such as ship groundings have become almost common. These stressors have had a significant impact on coral abundance and caused increasing coral reef decline. Since 2005, Acropora corals located in U.S. waters have received improved monitoring attention due to the listing of Acropora cervicornis and Acropora palmata as “threatened” under the U.S. Endangered Species Act. These corals are vital to the framework structure of reefs and instrumental to shoreline protection. In 2014, the National Oceanic and Atmospheric Administration, to help assess the current status of Acropora corals and devise actions to foster species recovery, drafted a recovery plan. One such action is to compare current Acropora coral populations and distribution to that of past surveys to evaluate historical trends in the Florida Keys. Reefs of the Florida Reef Tract have been exposed to two high-temperature anomalies in 2005 and 2014, one cold-water anomaly in 2010, as well as increased human impacts. In this study, twelve reefs located in the Florida Keys National Marine Sanctuary were chosen as study sites based on available historical Acropora data. Each reef was surveyed to document the present abundance and condition of Acropora colonies. These survey data were incorporated and then converted into maps using ArcGIS software. These maps provide insight into the current and historical state of the reefs with respect to Acropora abundance as well as an increased understanding of how reefs and coral populations respond to multiple stressors. The results of this analysis showed that the reefs have experienced either positive or negative change over the years with respect to Acropora abundance and spatial distribution on the reef itself. A second aspect of this project was to assess the impact of active Acropora restoration efforts on Acropora abundance. Active propagation and restoration of Acropora have become extremely popular to help recover reefs to a pre-degraded state. At eight reefs were restoration was undertaken, we shown that the transplantation efforts overall had a positive effect with regards to Acroporid abundance at the reef scale. The results of this study support the work of programs such as the Coral Restoration Foundation, which supplement natural occurring coral populations with healthy transplanted corals. These techniques improve the genetic diversity of the reef as well as its overall health. Active restoration, such as population enhancement, has almost become vital to help reefs recover from disturbances


Department: MBF

MPS track: TME

Location: National Oceanic and Atmospheric Administration Southeast Fisheries Science Center

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