Restorative Methods to Preserve and Protect Our Coral Reefs

 by Alice Collins

What restorative methods can be implemented to protect and preserve coral reefs? Coral reefs have been described as one of the most sensitive ecosystems to human activity, both in regards to climate change and pollution. Consequently, their restoration and protection is of utmost importance, not just to their biodiversity but also to us. Climate change affects coral reefs due to the increasing acidity of oceans which is resulting from an increased influx of CO2 into surface waters. This increased acidity affects coral reefs because they are extremely sensitive to environmental changes. Coral responds to this change by expelling algae, ending their symbiotic relationship and causing them to bleach. This is significant because an estimated 25% of marine life relies on coral reefs at some point in their lifetime, so a loss of coral will have enormous knock-on effects on marine ecosystems . Additionally, coral reefs provide a natural barrier to large waves and storm surges (which are becoming increasingly frequent and intense) protecting coastal communities and ecosystems from flooding events. Coral reefs benefit an estimated 500 million people globally, due to their rich fish stocks and tourism opportunities, meaning they are of enormous economic importance. This significance is exaggerated due to the fact that the majority of people relying on coral reefs are living in low-income developing countries where access to economic opportunity is restricted. 

Creating an artificial reef (Wiki Commons)

As scientists have recognised the significance of coral reefs, a large amount of research has gone into how they can be protected and restored. There are three main restorative methods: structural, biological and physical. Structural restoration focuses on increasing the extent of reef structure and habitats available for coral and other reef organisms or grown on. One such method is the construction of artificial reefs which are structures made from . This method can also be implemented to extend reef boundaries, aiming to increase biodiversity and fisheries. 

Biological restoration focuses on increasing the number of living corals on existing reefs,with a goal of regrowing populations of coral in areas where it has declined. Some examples of methods include collecting and rehabilitating broken coral fragments and culturing coral larvae in coral nurseries.

Physical restoration involves addressing the conditions in which coral reefs are living in and looking at ways in which these can be improved. One method is growing corals on mid-water nurseries where there is less stress from sedimentation, pollution and predation. Another method implemented is Biorock Technology which involves technology such as mineral accretion devices. These alter the water chemistry around the structures using low voltage electricity. They work by both lowering the pH of the water and also causing carbonate salts such as CaCO3 and MgCO3 to precipitate out of the water, allowing corals to focus their energy into growth and reproduction instead of on skeletal structure. Experience has shown that one type of restoration on its own is usually ineffective, whereas a combination of methods is much more likely to have a positive and longer lasting effect.