Biologists from the University of Chicago have discovered that mussels raised in an acidic experimental environment grew smaller shells than those produced at normal levels, survival rate being the same for both ways of growing mussels.
Researchers have collected specimens of Mytilus galloprovincialis from France in 2016 and 2017 for this study. The Mediterranean mussel is one of the few species that provide a valuable food source all over the world.
For this study, researchers have bred dozens of combinations from 16 males and 12 females to guarantee a genetically diverse population of larvae having 192 different combinations total. They divided the larvae into two groups, one developing in water with the ambient pH level of 8.1 while the other in seawater wit the pH level of 7.4.
Over six weeks, researchers have taken samples every few days to analyze the genetic makeup of the surviving larvae and measure the shell size. Mussels from the lower pH water conditions grew at a slower rate compared to the ones growing in ambient pH conditions.
How The Living Organisms Adapt To Climate Change and Global Warming
Although two weeks the small pH populations caught up, but not entirely as the most vulnerable of them died out before this point, survivors continuing growing at a regular rate. After day six, they separated the fastest shell growers from the slowest in each pH environment.
Mussles’s shell size indicates how strong it is. But that doesn’t mean that if a muscle grows fast in the ocean that it will also survive in a low pH scenario.
“There seems to be a unique kind of genetic makeup of the individuals that end up growing best in the low pH environment, relative to the ambient conditions,” said Mark Bitter, a UChicago graduate student who led the study.
This study looks promising in the context of rapid climate change. It’s good that there are already species that adapt to extreme conditions. However, “Just because you can run a marathon doesn’t mean you can turn around and swim right after that. It’s a multi-stressor scenario,” said Bitter.