• Question: What factors do you think could affect the formation of a coral reef on a recently subnerged shipwreck?

    Asked by squirej30 to Sean on 23 Jun 2011.
    • Photo: Sean Clement

      Sean Clement answered on 23 Jun 2011:

      Hey Squire.

      Brilliant question. First of all, depth is the critical factor. If the shipwreck hits the seabed at any depth over 40m, then it’ll be difficult as coral reefs are rarely found past that depth due to there being lower light levels than at the surface.

      The shipwreck would also have to land somewhere that is connected to other coral reefs via ocean currents. These currents would be needed to bring coral larvae to the ship in order for them to settle and start growing. What would need to arrive first though would be a certain type of algae known as CCA (short for Crustose Coralline Algae) This stuff kind of looks like pink paint but is REALLY important because Coral larvae have a much better chance of survival if they settle on a surface covered in CCA than any other…

      So, once you’ve got the location and the transport sorted, what do you need next? Well, a lot of time! Corals take a long time to grow with the fastest growing only doing so by a mere 7cm per year and the slowest barely even pushing 1cm per year. Corals are also at their most vulnerable when they are juveniles or ‘recruits’ On artificial reefs such as shipwrecks, there tend to be a lot of recruits! Basically, the wreck would need to be left undisturbed for while, preferably out of reach of any troublesome storms or hurricanes…