In the sea, the deeper you go, the less light there is. This is because light rays are absorbed and scattered by particles suspended in the water. Beyond 50 metres in depth, and up to some 200 metres in depth, where some light still prevails, is called the circalittoral zone.

A close look at this zone would reveal either a hard seafloor or a soft seabed. Where there is a hard seafloor, species attach themselves to the seabed. We can mention tubeworms, sponges and corals, with varying characteristics depending, for instance, on wave action. In the soft seabed you would be more likely to find burrowing animals, like the heart urchins, or animals which live on the sediment, like brittle stars and sea cucumbers, or which are partly embedded in the sediment, like sea pens and soft corals.

One of the more important marine communities found in this zone are the maerl beds: coralline red algae. Maerl coralline algae, known in Maltese as Korallina tar-Ramel Ħaj, are particularly large and productive towards the north-east of the island.

Even in the clearest water, belowthe depth of 200 metres the light intensity is so low that it no longer supports significant algal growth. Should you require more information, please contact nature.requests@mepa.org.mt.

The United Nations declared 2010 to be the International Year of Biodiversity. Malta together with many other countries around the globe is carrying out a number of initiatives to celebrate life on earth and the value of biodiversity for our lives. We are all invited to take action in 2010 to safeguard the variety of life on earth: biodiversity.