Summary PROJECT INACTIVE

During 2016-17, two CSUMB students analyzed data they had collected in the summer of 2015 while participating in a 10-day oceanographic research cruise to survey the deepest known coral reef in U.S. waters, a place called Pulley Ridge, which is located west of Florida in the Gulf of Mexico. The project was collaboration between a team of deep-sea technical divers, a team using an autonomous undersea vehicle (AUV), and our team of two CSUMB students and one faculty member who used a small ROV designed and built by CSUMB students to record video of marine life at a depth of about 70 meters (200 feet). This year, those students helped analyze the data from those ROV videos and co-authored a paper, currently in review, on the abundance and impact of invasive lion fish populations in this deep, remote reef located over 100 km from shore.

Student Involvement

Two undergraduates designed and built the ROV used for this research project. Two other undergraduates participated in the 10-day research cruise, where they were in charge of piloting and maintaining the ROV and collecting the data. One more undergraduate assisted in analyzing the data. One of these students who went on the cruise later presented this work at the International Coral Reef Symposium in Honolulu.

Broader Significance

Pulley Ridge is an example of a Mesophotic Coral Ecosystem, or MCE. These amazing ecosystems were previously thought impossible – they occur in water too deep, and therefore too dark (or so we once thought) to support the growth of corals that need light for the photosynthetic algae cells living in their tissues. However, advances in mixed-gas diving equipment, remotely operated vehicles, and other technologies for studying these depths have revealed that MCEs are actually common, though the corals living there do grow much more slowly than those living closer to the surface. A new and exciting area of coral reef research (of which this project is a part) is testing the hypothesis that MCEs may provide a hidden “refuge” for fish and coral species that are being decimated on many shallower, coastal coral reefs by overfishing, coastal pollution, invasive species, and rising sea surface temperatures. MCEs, it is believed, are largely isolated from these nearshore, near-surface impacts and may provide a source of fish larvae and coral larvae to repopulate surface reefs if/when conditions there improve. To address this hypothesis, we first need to know if the species present on MCEs are the same as the ones inhabiting shallower coral reefs.