Soft coral gametes have copper resistance

The eggs and sperm of a soft coral species from the Great Barrier Reef have some resistance to copper.

According to a new study by Reichelt-Brushett and Michalek-Wagner of Southern Cross University, Australia, which is due to be published in the next issue of the journal of Aquatic Toxicology, the gametes of Lobophytum compactum show surprising levels of copper resistance.

The pair studied the effect of copper on fertilisation during the mass coral spawning of 2004 on the Great Barrier Reef with corals exposed to 132ug/l averaging 65% fertilisation, compared with 90% in those which were not exposed to any copper.

However, higher copper doses did have a more dramatic effect on the number of coral gametes fertilised.

Reichelt-Brushett and Michalek-Wagner explain: \"Copper doses were increased in experiment two and the EC50 value for copper effects on fertilisation success was 261ug/l.

\"In this follow-up experiment, fertilisation success was significantly lower than in the controls after exposure to copper concentrations of 117ug/l and above.

The report says that the EC50 level recorded is much higher than that previously seen or published for the gametes of hard corals, oysters, fish or urchins.

For more details see the paper: Reichelt-Brushett, AJ and K Michalek-Wagner (2005) - Effects of copper on the fertilisation success of the soft coral Lobophytum compactum. Aquatic Toxicology. 2005. Jul. 2.