Seaweed Poison - Good or Bad?

Chemistry sure causes a lot of really weird things to happen to the ocean (besides acidification and temperature change...). A study is suggesting that seaweed might be stunting coral reef growth from the chemicals they release into the water around them.

The study in Sydney has researchers proving that some seaweeds or algae have the ability to produce toxic chemical signals that "deter coral larvae from settling on reefs devastated by bleaching, storms, or other impacts". I guess that can work in favor for the corals though. They can find better homes this way because they could move to a place where bleaching hasn't destroyed everything.

Does the seaweed/algae thing sound a little familiar? A previous post from this blog might jog your memory.

Seaweed can produce other signals too, like ones that encourage coral growth. So seaweed has a good side and a bad side. A good side because some help corals grow (calcareous red algae) and a bad side because they compete with corals for the ocean floor space and are competition for the same resources. According to past observations, algae nearly always beat the corals in the race to resettle the devastated area. However, factors like the number of organisms that eat the algae also need to be considered - like turtles.

[Quotes]

"On the Great Barrier Reef we have been relatively lucky, but elsewhere we have seen a number of instances where seaweeds simply took over the reef, completely preventing the corals from coming back," said McCook (Laurence McCook of ARC Centre of Excellence for Coral Reef Studies (CoECRS) and the Great Barrier Reef Marine Park Authority).

"The greatest threat seems to be when we get thick mats of algae combined with sediment runoff, which smother the reef and stop corals gaining a foothold - a serious problem for our coastal reefs", he added.

posted by Sage @ 9/01/2008 06:13:00 PM Comments: 0