Ocean acidification process. (Photo Credit: NOAA)
More acidic oceans could cause problems to squid
Thursday, June 06, 2013, 05:00 (GMT + 9)
Ocean acidification could have a drastic impact on the squid worldwide, warns a group of researchers from Woods Hole Oceanographic Institution (WHOI).
According to a new study, soon to be published in the journal Plos One, due to the ecological and commercial importance of these cephalopods, this fact could have enormous impact on the marine environment and coastal economies.
"Squid are at the center of the ocean ecosystem—nearly all animals are eating or eaten by squid," explains Aran Mooney, WHOI biologist and co-author of the study.
"So if anything happens to these guys, it has repercussions down the food chain and up the food chain," adds the expert.
Research suggests that ocean acidification and its consequences are the new pattern.
During the past 150 years, the world's oceans have been acidifying gradually, mainly due to increased concentrations of carbon dioxide (CO2) in the atmosphere.
Seawater absorbs some of the CO2 and turns it into carbonic acid and other chemical products that lower the pH of the water and makes it more acidic.
If carbon dioxide levels continue to rise, it is expected that the acidity of the oceans will rise too much, and this may affect the species that inhabit the ocean.
Mooney and Max Kaplan, lead author of the study, gathered male and female specimens of Atlantic longfin squid (Loligo pealeii) from the waters of Vineyard Sound, on the US east coast of the Atlantic in the summer of 2011, and placed them into a storage tank in WHOI Environmental Systems Laboratory.
After that squid mated and the female specimens laid their egg capsules (each can contain 200 to 300 fertilized eggs), the researchers divided the capsules between two smaller tanks installed in Vineyard Sound.
These two smaller tanks represented two environments: the ocean today, and more acidic oceans of the future.
One of them was continuously exposed to air pumped from the outside, to simulate the actual interaction of the ocean with the atmosphere, while the other received air that was enriched with higher levels of CO2, which made ell seawater almost three times more acidic.
The scientists then observed how the eggs hatched and how the squid began to develop in each of the two tanks.
Hatching time, body length, and other growth parameters were measured.
"Amazingly, we found effects or changes in all those parameters. Animals raised in high CO2 took longer to develop," stressed Mooney.
The research team, composed also by Daniel McCorkle and Anne Cohen, plans to conduct additional studies to better understand the way the squid can meet the changing ocean conditions.
The scientists also hope to observe and measure the differences in behavior in the squid that is farmed in more acidic seawater in order to better understand how the lives of cephalopods can change as the ocean around them changes.
By Analia Murias