Once per year, eight evenings after the August full moon, reef building corals in the Caribbean undergo a highly coordinated mass spawning event. Corals spawn at the same time every year, and each species has a unique time window it which it but none of the other species on the reef spawn. This timing is quite amazing, and for some species is predicable to within 5 minutes from year to year. How do corals know it is time to spawn? Our working hypothesis is that corals respond to lunar and solar light (but how?) and release both gametes and a chemical signal that tells other nearby individuals to also release. We are investigating behavioral, chemical, molecular and cellular components of this synchronized spawning event. Field work is performed in the Gulf of Mexico (Flower Garden Banks), in the Dutch Antilles(Bonaire/Curacao) and on the Great Barrier Reef (Australia). In the Gulf our favorite species are the blushing star coral S. intersepta and the great star coral Montastraea cavernosa while over in Australia it is Acropora millepora.
Work in our lab has demonstrated that light receptors regulate the time at which corals spawn and that this is a direct response to light perception- biological clocks are not involved. We are currently exploring the role of entrained circadian / circalunar rhythms in selecting the date of spawning. Lab techniques include microarrays, proteomics, gene cloning, cell biology, and bioinformatics. Field techniques involve manipulating coral culture conditions using lunar and solar light and various pharmacological compounds to alter signal transduction pathways. A variety of field techniques are utilized including SCUBA (hot mixes, tri), rebreathers, ROVs and submarines. All field workers have advanced dive training.
We also have projects exploring coral ecology and the interaction between newly recruited corals (babies!), algae, and hervirorous vertebrates and invertebrates. This project utilizes a unique research platform that we built at a depth of 80' in the Flower Garden Banks National Marine Sancuary. The platform allows us to set up long term coral recruitment experiments under controlled conditions.
OLDACH, Matthew |
MSc |