An Introdution to Coral Reefs

This blog is all about how the environment in which coral reefs exist is being altered, and how this in turn affects the coral reefs, and then how in turn this will impact the world as a whole.

Coral reefs. Beautiful natural structures. They are found all over the world, mainly in tropical and sub-tropical oceans. Millions of tourists flock to sunnier climes year on year to glimpse coral reefs, and the marine life that lives in and around these reefs. But what actually is coral?

Well, it is commonly mistaken as rock, when in fact it is actually an animal. It is easy to see why they are mistaken as rock, as they lay down a calcium carbonate substrate to attach themselves to the sea floor. They are marine invertebrates of the phylum Cnidaria. They are made up of tiny polyps, and lots of these little polyps will make up a reef. Each polyp is a single cylindrical cavity, with a tenticled mouth. Also, they are sessile, which means they do not possess a means of self-locomotion.

Corals are very delicate. They are extremely sensitive to changes in temperature and the acidity of oceans. The way in which they feed is through various types of microscopic algae, known as Symbiodinium. These live inside the coral and help with feeding, through photosynthesis. This is why corals can be found in shallow waters, as they need the sun’s rays to survive.

Reefs can be found throughout the Western Atlantic and Indo-Pacific oceans, as shown on Figure 1 (from NASA). However, in recent years, coral reefs have been exposed to a manner of different problems, and now they are in danger of being lost forever.

 

 

 

 

 

So what are the threats to coral reefs, and how have these threats come about? It has to be said, the majority of the problems facing coral reefs is as a result of anthropogenic activities. These include overfishing, rising temperatures due to extreme levels of co2 as a result of fossil fuel combustion, mining, pollution (which limits the ability of the coral to photosynthesise) and many others. Some of these factors have resulted in oceans becoming more acidic, higher in pollutants, warmer, all of which is having a pronounced effect on the coral reefs. I will go into more detail on these different factors in future posts. I will then put up some posts on how the coral reefs can be protected, and how we can all help to ensure their longevity.