Shark babies remain strong despite acidification
AN Australian study published this week has found that certain baby sharks are able to cope with the level of ocean acidification predicted for the end of this century.
Dr Jodie Rummer from the ARC Centre of Excellence for Coral Reef Studies (Coral CoE) at James Cook University (JCU) and her co-authors studied epaulette shark embryos as they were developing.
“Overall, there were no differences between growth and survival in sharks reared under current day conditions versus those reared under ocean acidification conditions predicted for the year 2100,” Dr Rummer said.
However, she also conveys caution. Shark gills play an important role in helping correct pH disturbances – the team thinks that the risk of death under ocean acidification conditions may be highest before the embryo’s gills are fully developed.
Those that got past this stage though, were able to carry on with business as usual.
Epaulette shark eggs normally incubate for 3–4 months before they hatch.
Over the course of the study, the researchers raised epaulette shark eggs from 10 days after they were laid until 30 days after they hatched.
During this time, the sharks were raised in one of two groups: today’s current ocean conditions or conditions meant to simulate ocean acidification predicted for the year 2100.
The researchers counted gill and tail movements of the developing embryos. They measured how much yolk the embryo was consuming and how much the embryo was growing.
And, upon hatching, they further monitored survival and growth.
Carbon dioxide emissions into the atmosphere have been increasing dramatically since the industrial revolution.
The oceans are absorbing approximately 30 per cent of this carbon dioxide, causing ocean acidification.