Ocean acidification could make squid develop abnormally

Corals aren’t the only sea creatures that might suffer from the consequences of ocean acidification. According to a PLOS ONE study, squid raised in acidified waters take longer to hatch and develop abnormally.

Scientists are particularly worried about the effects of acidification on larvae, since “young animals may not be as resilient to physiological stress as juveniles or adults,” the research team writes. For example, other studies have shown that acidified waters can cause organ damage in some fish larvae and lower their survival rate.

The study authors placed some Atlantic longfin squid eggs in normal seawater and others in seawater with extra carbon dioxide, which makes the water more acidic. In one experimental trial, nearly two-thirds of the squid in normal water had hatched by the 14th day, but less than 1 percent of the squid in acidified water had hatched. The researchers saw a similar pattern in a second trial.

Studying the animals’ anatomy revealed more differences. Mineral structures called statoliths, which help the squid sense movement, were smaller in the squid from acidified water. The statoliths also had more pores and were oddly-shaped.

If squid take longer to hatch, predators could be more likely to snap up the eggs, the team says. And without normal statoliths, the animals might have trouble orienting themselves and swimming. — Roberta Kwok | 4 June 2013

Source: Kaplan, M.B. et al. 2013. Adverse effects of ocean acidification on early development of squid (Doryteuthis pealeii). PLOS ONE doi: 10.1371/journal.pone.0063714.

Image © Tom Kleindinst, Woods Hole Oceanographic Institution