ASSESSMENT OF A BARNACLE BIOERODER AND ITS IMPACT ON A DOMINANT REEF-BUILDING CORAL FROM A HIGH CORAL COVER REEF
Although multiple studies use density as a proxy for the impact of macrobioeroders on a coral reef, few assess the only genus of thoracican barnacles known to burrow, Lithotrya. This study aims to 1) develop a procedure for quantifying Lithotrya dorsalis density in colonies of Orbicella franksi from photos of coral reef benthos, 2) describe the bioeroder's distribution within populations of this coral, and 3) determine its impact on host colony growth. We used a NOAA dataset spanning 2006-2015 collected from ~40 long-term coral reef photostations at the Flower Garden Banks (Gulf of Mexico). Log-transformed mean barnacle densities in 2014 were similar in the East and West Banks but significantly decreased with increasing colony area and depth, contradicting previous reports that density exhibited no relationship or increased with depth. Based on published modeling efforts, the 2014 size structure of O. franksi indicates this coral population experiences minimal disturbance. Ongoing time-series analysis is investigating how bioeroder colonization affects colony growth and population demographics from 2006-2015 photos. In past decades FGBNMS has experienced consistently high coral cover (~50%) and minimal nutrient pollution, in stark contrast to many Caribbean reefs. The methods described in this study can be extended across a spectrum of reef disturbance regimes to better understand how bioeroders impact their hosts.
Maher, R. L., Rice University, USA, firstname.lastname@example.org
Johnston, M. A., NOAA Office of National Marine Sanctuaries, Flower Garden Banks National Marine Sanctuary, USA, email@example.com
Correa, A. M., Rice University, USA, firstname.lastname@example.org
Time: 18:15 - 19:45
Location: Poster/Exhibit Hall
Presentation is given by student: Yes