Ocean acidification due to rising carbon dioxide levels in the atmosphere may be putting the reproductive capabilities of some marine species at risk, reports a new study published in Current Biology by Swedish and Australian scientists.
The study looked at the impact of lower pH levels on Heliocidaris erythrogramma sea urchins. The researchers lowered the pH from 8.1, the present value of sea water, to 7.7, the forecast pH value of sea water in 2100 assuming CO2 emissions continue at their current rate. The found a 25 percent drop in the fertilization success of the species due to a decline in the mobility of its sperm.
“A 25 percent drop in fertility is the equivalent of a 25 percent drop in the reproductive population. It remains to be seen whether other species exhibit the same effect, but, translated to commercially and ecologically important species such as lobsters, crabs, mussels and fish, acidification would have far reaching consequences,” said Jon Havenhand, a researcher from the Department of Marine Ecology working at the Sven Loven Centre for Marine Sciences in Tjarno.
Marine scientists have warned that ocean acidification poses other threats to marine life, including reducing the capacity of many organisms to form calcium carbonate shells. Plankton, pteropods, mollusks, and corals are particularly at risk.
mongabay.com, 30 July 2008. Article.