Mermaids are mythical creatures we heard about in fairy tales. However, we did not hear that they may like to rest with a glass of wine. Although it is a joke, mermaid’s wineglass is real.
It is a delicate, single-celled alga, called Acetabularia acetabulum, living on shallow seafloors, where sunlight can still filter down for photosynthesis. Now scientists at the University of Washington’s Friday Harbor Laboratories conducted a research, which shows that more acidic ocean can weaken the protective shell of the mermaid’s wineglass.
Acetabularia acetabulum, like many marine creatures, has a supportive skeleton made of calcium carbonate. It protects this alga from predators and supports the round reproductive structure on top. However, increasing acidity in the ocean lowers levels of calcium carbonate available to living organisms. Although no studies before showed that this somehow damages mermaid’s wineglass, scientists noticed they grow differently in different parts of the ocean, like near the seeps. Therefore, they set out to figure out what is affecting their growth.
Difference of this alga depended on the place they are growing in. Those who were far from the seeps appeared whiter, which, according to scientists, indicated about their well-developed skeletons. Mermaid’s wineglass growing closer to the vents was more brown and green.
These underwater seeps are created by volcanic activity. Because of gas (including dissolved carbon dioxide) and minerals released into the water column, water here is becoming more acidic. Scientists analysed algae growing closer to the seeps and found they were thinner and droopier. Scientists wondered if results were affected by preservatives used, which meant they had to go to Italy to work with live algae.
During this research, scientists collected samples of the algae from near and far the seeps near an island off the northern coast of Sicily. They also measured the carbon dioxide levels of the water at each site. These sites are relatively shallow, which made it really easy to take samples and work on the seabed. Scientists found that carbon dioxide levels were five times higher at sites closest to the seeps – the more carbon dioxide, the more acidified water in the spot is. They figured that high levels of carbon dioxide affected skeletons of mermaid’s wineglass.
Results showed that mermaid’s wineglass skeletons near these seeps contained 32% less calcium carbonate, which made them 40% less stiff and droopier than their counterparts from low carbon dioxide waters. Furthermore, even small increase in carbon dioxide caused losses in stiffness of skeletons of these algae.
Scientists think that this may have several negative effects. Firstly, mermaid’s wineglass is less protected from ocean currents and animals gracing onto it. Secondly, weak posture means it is harder to disperse offspring. However, scientists also think that thinner skeletons may transmit more sunlight to make food.
This research betters the understanding about function of the calcium carbonate skeletons. It will also help predict how climate change could affect creatures like the mermaid’s wineglass. Laura Newcomb, one of the authors of the study, said: “Calcium carbonate skeletons are quite widespread in marine life, found in algae and plankton and even in larger creatures like snails and corals. And in a more acidified ocean, some creatures are able to cope and do just fine. Some, like the mermaid’s wineglass here, suffer but still persist. Others will really struggle.”
Because of human activity this may be bigger problem that we may think. Because we are pumping more carbon dioxide into the atmosphere, oceans absorb more of these gasses than they have for millennia. This means that acid levels in oceans are very likely to increase. Some algae, like the mermaid’s wineglass, may be bent, but some may be broken too. Actions have to be taken to reduce greenhouse gas emissions as soon as possible, because all life forms in all ecosystems are negatively affected by them.
Source: Washington University