Hard Corals

This blog post will be focused on hard corals, and how these are very significant to the coastal system. Hard corals can just be healthy corals that's are naturally hard, but there is also an order of coral known as Scleractinia, which has a nickname called 'stony coral'. These occur in all the worlds oceans, and as suggested by their name, they are harder and more sturdy than other orders of coral. But why is this hard coral so important?

An example of a Scleractinia Coral.

The answer is that they provide a natural barrier against waves, which helps to protect global urban populations, coastal communities and the beach itself against erosion and water damage (such as flooding). The corals reduce the amplitude of the incoming waves by absorbing energy. The waves then have less erosionary power to cause damage. They act as a dampener against the waves. This ability of coral reefs to act as protection against waves will become even more important due to climate change. It is thought that the frequency and severity of storm events such as hurricanes are likely to increase. This will mean that more and more protection against storms will be required.

Governments spend billions on flood defence schemes the world over. Defra spent £2.56 billion between 2007 and 2011, and this figure is set to rise.

DEFRA Spending From 2006-2015

From the figure, we can see just how much DEFRA has been spending on flood defense. Spending reached a peak in 2010-2011, where it totaled almost £700 million. This is an astronomical figure, and without corals as a form of natural defence, who knows how much it could have been, or how much it will be in the future.

 We can see that so called 'hard engineering' is incredibly expensive, and perhaps other soft engineering techniques should be considered. The question is are soft engineering methods effective enough?

The protective nature of coral reefs assumes that they are healthy. They are no longer as effective at absorbing wave energy. This can be caused by acidification or even bleaching due to high temperatures. This means they are more likely to suffer damage from the waves as their structural integrity has been compromised. This can then result in more coastal erosion as they are then not as well equipped to protect the coastline.

Here we've had a brief look at how hard corals protect the coast. It may well be wise for governments to invest in promoting coral reef growth, as this will help coral populations to soar, as well as being less expensive than large man made structures such as sea walls, groynes and dykes.

Sources

1. Coral.org/blog/hard.corals.natures.seawalls/

2. https://www.google.co.uk/amp/s/www.carbonbrief.org/factcheck-how-much-is-the-government-really-spending-on-flood-defences/amp