You are here

Disease Outbreak Investigation on the Reefs of Kauaʻi

Principal Investigator: Greta Aeby

Kauaʻi’s economy depends on tourism and recreational use of its ocean habitats. A recent outbreak of the coral disease, Montipora Banded Tissue Loss (MBTL), on the reefs of Kauaʻi is of ecological and economic concern. Research is needed to understand the extent of the disease on Kauaʻi’s reefs, the cause of the disease and what potential environmental stressors may be contributing to its spread. It is only after we have an understanding of disease ecology can management strategies be developed to support the conservation and sustainability of these coastal resources. Fourteen sites around Kauaʻi will be surveyed seasonally for two years to determine the prevalence and frequency of MBTL occurrence. MBTL occurrence is hypothesized to be driven by poor water quality due to current land management practices. Direct measurement of environmental data at our survey sites (coral and macroalgal cover, sediment load, seawater temperature, dissolved organic matter, and sewage indicator bacteria) combined with GIS-based environmental co-variables (human populations, rainfall, distance to shore, distance to stream mouths, amount of stream discharge, distance to sewage outfalls) will be used to develop statistical models to examine the relationship between disease prevalence and environmental stress. Mapping of the disease in relation to land usage, hydrology, and human populations will also aid in predicting hotspots for future MBTL outbreaks. Disease virulence (harm to host) and spread will be assessed by tagging colonies in the field and following disease progression through time. The pathogens causing the disease (etiology) will be investigated using two complementary approaches. First, the microbial consortium associated with MBTL will be determined, and second, infection trials will be performed to recreate disease in our lab at UH Mānoa. Community involvement is key to conservation of our coral reefs. We include a strong educational component to inform and engage Kauaʻi Community College students and local communities. Educated “citizen scientists” will be critical in influencing key decisions in regards to the health of their local coral reefs. The results from this study will allow informed decisions by policymakers and stakeholders on land management practices, in a time in which expansion of resorts as well as continued human population growth could greatly impact the sustainability of Kauaʻi's reef ecosystems.