Abstract Summary
In recent years, a series of natural and anthropogenic disturbances have caused damage to the only coral reef barrier in the Gulf of California, located at Cabo Pulmo National Park. Therefore, the administration of the protected area considered the implementation of management actions intended to reverse the degradation of the system, one of them, restoration of the reef using naturally generated coral fragments. The objectives of the presentation are to describe the implementation of this project at Cabo Pulmo, and to determine the effectiveness of the in-situ restoration, analyzing changes in coral growth and survival resulting from the application of two methodologies and two depths. For the project, 200 coral fragments of the genus Pocillopora were recovered and placed at 8 and 14 m deep, using two methodologies: plastic straps and epoxy resin; Subsequently, the colonies were monitored between November 2017 and May 2018 to estimate their growth and mortality. The survival percentage was 84%, although colonies at -14 m presented only 2% mortality, significantly lower than that of the shallow site (21%). In contrast, no difference in fragment mortality between methods was found; thus, the restoration efforts carried out in the park might be more successful if conducted in deeper areas of the reef regardless of the technique used. A secondary analysis of the data was done to generate a model to predict future effectiveness of a restoration effort, based on survival rate and growth rate of the fragments. The model shows that by year 5, coral cover reached its maximum, and afterwards the recovered surface start declining, returning to the initial value after 10 years. Considering that natural recruitment is extremely low, our results call for a detailed plan to introduce new fragments to the reef after year 4 of the initial restoration to support the recovery.
