A consortium consisting of Van Oord, Australian research institute CSIRO, and Delft University of Technology are testing a new method for large-scale coral rehabilitation at the Great Barrier Reef in Australia.
Climate change and coral bleaching have resulted in the reef losing more than half of its coral cover since 1985. The consortium hopes to identify the best method for overcoming a crucial bottleneck in the upscaling of reef rehabilitation.
Rehabilitation Method
The consortium partners’ rehabilitation method involves harvesting coral eggs and later transplanting the coral larvae in places where coral is meant to grow. This is a proven concept that is already being applied on a small scale and in tanks.
Adapted Pump Systems
In this new test phase, the researchers will analyse on site whether the method can be scaled up. Van Oord’s dredging vessels are collecting vast numbers of coral eggs using specially adapted pump systems.
It is important that the fragile eggs are still alive when they reach the storage tank. To make their journey as smooth and safe as possible, TU Delft’s and Van Oord’s researchers have spent the past few months optimising the pumping systems. For example, the pump needs to cause no eddies during suction and has to stay floating on the surface of the water. Also, the type of pump turned out to play an important part in the design.
Testing on Location
Over the coming weeks, testing on location will show how the pumping systems really perform in currents and waves. The researchers will be testing two types of pumps and two types of storage tanks in Australia. During the Dutch lab tests, alternatives were used to mimic the structure of coral eggs as closely as possible, such as fish spawn, peas, blueberries and little balls of gel.
Coral Rehabilitation
If the pumps and tanks prove to be an effective way of collecting coral eggs on a large scale so they can later be released to settle on the reef, this will be an important step towards the rehabilitation of coral reefs.
Professor Mark van Koningsveld, from TU Delft and Innovation Manager at Van Oord, explains: 'With a single ship, we could collect and transport some two billion eggs. That sounds like a lot, but on healthy parts of the Great Barrier Reef, that is only a negligible amount of the available total. However, if we can get them to develop into larvae and subsequently release them in spots where the reef is damaged, that would solve one of the main bottlenecks for the rehabilitation of such reefs.'
ReefGuard & Coral Engine
Australian research institute CSIRO has a long track record in coral research. Van Oord has also made its mark in coral research by providing access to existing techniques at scales necessary to develop hydraulic infrastructure, for example its development of the ReefGuard and the Coral Engine. Delft University of Technology is the third research partner and is contributing its knowledge of pump systems and hydrodynamic processes.
