by Lisa Carr
The world’s corals have been declining at a worrying rate. Up to 80 per cent of all coral in the Caribbean has disappeared in the last four decades and other ocean areas are showing equally alarming statistics.
The decline can be attributed to human destruction, rising sea temperatures, steady acidification from carbon emissions, disease and pollution and the outlook for our coral is looking bleak. Existing management and restoration projects can be hard to enforce. At the end of January, an anchor from a private yacht owned by the co-founder of Microsoft, Paul Allen ploughed into a sensitive protected reef in the Cayman Islands and it destroyed a majority of the coral in the delicate ecosystem. Other footage has emerged online of cruise ship anchors tearing through protected regions of seabed destroying coral and therefore the habitats of many species.
However, hope lies in research recently conducted in a lab. A species of coral was successfully reintroduced into a wild population after being cultivated ex situ. SECORE scientists from a non-profit conservation group in conjunction with researchers from the University of Amsterdam and the CARMABI Marine Research Station in Curaçao have successfully produced coral embryos using fertilisation techniques in the lab environment. This could resurrect troubled species away from unsettled reefs to then be reintroduced in the wild. Introduction of new species members into a wild environment can provide genetic diversity to a population, mitigating the likelihood of an entire population being wiped out by one disease and more hardy coral can adapt to the changing ocean environment.
The species targeted in this research was elkhorn coral (Acropora palmata); a keystone reef species with ecological importance that helps defend against storm damage and provides a habitat for a plethora of marine life. This species in particular is critically endangered due to a disease outbreak in the 1970s, therefore researchers hoped to develop a technique that could help the species recover and didn’t limit its genetic diversity like pre-existing ‘coral gardening’ techniques. By collecting the gametes released by elkhorn coral colonies, sexual reproduction could be conducted in the controlled lab environment and new diverse populations could be planted back on the reef and monitored. Seven out of nine colonies survived and continued to grow on the reef, an encouraging sign and the colonies have continued to release gametes indicating sexual maturity.
This research provides an inkling of hope for the future of our reefs, but the troublesome story continues. This technique needs to be refined and will continue to be tested on a larger scale, but for the species to survive and other species to flourish, reefs need to be more protected. For now, the bigger picture is still looking bleak but with great research like this ongoing, perhaps it’s not all doom and gloom.