First field trial for Seeding Units in Australia
Aric and I were both excited to visit and work with our colleagues at the Australian Institute of Marine Science (AIMS), a premier research hub in coral reef science globally. These colleagues are also leading Australia’s ambitious Reef Restoration and Adaptation Program (RRAP) aiming to develop effective means for coral restoration across the entire Great Barrier Reef over the coming decade. Our current collaboration focusses on testing the performance of SECORE’s new Coral Seeding Unit prototypes at the AIMS National Sea Simulator and on the Great Barrier Reef. Our AIMS colleagues, Dr. Carly Randall, Dr. Line Bay, and their team worked to settle Acropora tenuis larvae on the SECORE substrates following their coral spawning last November and have since been culturing them in tanks at the National Sea Simulator. Our trip was timed to participate in the exciting step of outplanting the substrates with their 3-month old baby corals to a site on the Great Barrier Reef.
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Photos: top) Margaret Miller and AIMS scientist Carly Randal talk about the baby corals, which are growing on the settlement substrates kept in tanks in the National Sea Simulator. Bottom) On the following days the scientists strung the substrates on lines and transported them hanging in PVC racks to prevent tangling. The trip to the harbor was made in a truck, the way out to the research vessel Cape Ferguson in a zodiac. (all images: Aric Bickel)
During the first few days, we worked with Dr. Randall’s team to prepare the substrates for outplanting. One of the quirks of Australian coral reef field work is that there are very strict regulations regarding placement of materials on the sea floor. The permit for our outplanting required that the substrates all be connected by a line or string (to enable their easy removal, if required). Thus, the preparation steps involved somewhat tedious stringing of individual substrates on lines (sets of 20 per line), temporarily tied off to a PVC rack in between each unit to prevent tangling. These PVC racks were designed precisely to fit the flow-through tanks on the ship for transit to the reef, and then served as the means for divers to carry them to the reef for deployment. The seeding units can be individually identified by their position on one of the twelve strings to quantify the survivorship of settlers on future surveys.
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Photos: top) Out on the reef, the scientists carefully carried the racks to the reef sites, which had been selected before; bottom – left). Each string of substrates was secured to the reef framework using a hammer and pins; middle) The seeding units were placed in small crevices or holes in the reef structure; right) Now we keep our fingers crossed that the Acropora tenius youngsters will develop into such impressive corals as the colonies growing in close vicinity to the test sites. (all images: Australian Institute of Marine Science / Andrea Severati)
Despite AIMS’ many advantages as a venue for coral research, the GBR field sites are far offshore and this field work requires an ocean-going vessel. Our cruise was aboard the R/V Cape Ferguson which ably supported our field trip. After a busy morning loading frames and substrate strings onto the ship, and a fairly rough 5 hours crossing to Backnumbers reef, we spent the afternoon snorkeling to find site(s) appropriate for outplanting the substrates. Backnumbers is a beautiful reef with scattered bommies (small patch reefs in column form), about 2 meter depth on the top flats, and sloping walls down to 10 meters depth. Many of the reef surfaces had coral cover approaching 100%, which presented another challenge with regard to our permit conditions since the substrates were not to be placed in contact with any living coral. We decided the reef flats were too shallow and settled on 3 sites along ‘shoulders’ of the bommies, ranging from 4 to 6.5 meters depth. It was exciting to see the substrates planted among the Great Barrier Reef corals! We hope the new outplants grow up to join their mates on Backnumbers Reef!
Many thanks to Carly, Line, Christine, Grant, Andrea, Nicole, Annika, Gina, and the crew of the R/V Cape Fergueson for hosting and working with us on such a great trip!
Margaret Miller
