Local Coral Gets Shady
New research is being undertaken in Gladstone Harbour to determine how much sunlight local corals need to thrive, by covering them with shades. It is hoped that the outcome of the research will assist in the management of future dredging projects where coral habitats are at risk. Although corals are animals they live closely with algae which are plants and therefore need sunlight to survive. Turbid water caused by flooding or activities such as dredging may reduce the sunlight reaching the coral and therefore could inhibit coral growth.
Lead researcher Dr Ralph Alquezar from Vision Environment (VE) said there was very little known about how much light local species of coral required. “By placing shades over the coral for several weeks and measuring the negative effects of reduced light on the coral, such as bleaching and degradation, we can determine how much light they need to survive and grow.”
By then ensuring this amount of light was available to the coral during a dredging project, the approach could assist in managing the project and protecting the coral from potential degradation. A similar novel approach was implemented to protect seagrass during Western Basin Dredging Project in Gladstone, which resulted in minimal impact from dredging to important seagrass habitats.
“In order to minimize the impact to coral during the experiment, only small shards of transplanted coral are covered by the shades” Dr Alquezar said. The shades are placed over the coral by divers who also undertake the regular undersea coral health checks. “At the same time we measure the light under the shades and compare this to unshaded coral”
The research is a self-funded initiative of VE. Phase 1 of the shading experiments were conducted over several months in the Gladstone area. VE researchers are now planning phase 2 of the studies.