IADC: Scientific Approach to Active Reef Rehabilitation

The International Association of Dredging Companies (IADC) has just released their latest article named ‘ReefGuard: A Scientific Approach to Active Reef Rehabilitation’.

ReefGuard, a mobile coral breeding facility provides a highly controlled environment to aid in integrating the breeding and outplanting of corals.

This article gives a detailed look into how proven small-scale coral breeding techniques can be scaled-up and applied in practice to promote environmental gain around marine infrastructure projects.

Authors: Mark van Koningsveld (Van Oord), Remment Ter Hofstede (Van Oord), Jesper Elzinga (Van Oord), Tijmen Smolders (Van Oord), Miriam Schutter (Van Oord), Ronald Osinga (Wageningen University).

Abstract 

In 2010, Dutch dredging and marine contractor, Van Oord, launched a Coral Rehabilitation Initiative as part of its Sustainability and Marine Ingenuity agenda. The key challenge was to demonstrate that already proven small-scale coral breeding techniques can be scaled-up and applied in practice to promote environmental gain around marine infrastructure projects.

The Initiative’s ultimate goal is to integrate the breeding and out-planting of tens of thousands to hundreds of thousands ‘lab-cultured’ juvenile corals in marine and coastal infrastructure development projects as a nature-based component.

These corals are to be obtained from natural coral spawning events as well as from fragments of opportunity.

A key element of the Initiative has been the development of an innovative mobile laboratory – ReefGuard. This laboratory helps to ensure the availability of a highly controlled environment for the fertilisation, larval settlement and initial outgrowing of sexual recruits (as well as fragments) before outplacement.

After its design in 2012 and construction in 2013, ReefGuard has been applied in four coral breeding experiments.

The first two experiments were executed near Ningaloo Reef in Coral Bay, Australia (2014 and 2015) and the other two in Coral Harbour on New Providence, Commonwealth of the Bahamas (2015 and 2016).

The experiments involved three coral species of the genus Acropora, in-situ as well as ex-situ gamete collection, and employed 10,000, 36,000, 20,000 and 30,000 settlement tiles respectively. The tiles with settled larvae were used in various survival experiments under different laboratory and field conditions.

This was to develop a scientific-base for the design of active reef rehabilitation campaigns.

From these experiments it can be concluded that active reef rehabilitation is indeed a viable option that can be integrated in marine and coastal infrastructure development projects.