The shell of the mussels is formed at a very early stage of their development, when they are very sensitive to the pH of seawater. (Photo: Stock file)
More light on the effect of acidification on mussels
Friday, January 12, 2018, 22:30 (GMT + 9)
Research on one-day-old mussel larvae explores the effect of climate change on the development of the shell, which could be used in the fields of aquaculture and biotechnology.
The study, funded by the European Union (EU), analyzes the way in which acidification influences the unexplored mechanisms of calcification, growth, malformation and the dissolution of mussel shells. They are highly sensitive to low pH levels in the ocean caused by increasing uptake of carbon dioxide from the atmosphere dissolved in seawater.
The discoveries of CACHE (Calcium in a CHanging Environment) help to explain how bivalve larvae such as mussels generate shells under moderate acidification conditions, and offer a direct relationship between oceanic carbonate chemistry and the rate of calcification of the larvae.
Mussels begin to form their shells when they are one day old. In a report published in Nature Communications, the researchers explain how they used fluorescent dyes to record the deposition of calcium carbonate in larvae from one to two days of life. They discovered that calcium is not formed intracellularly, as was previously thought, but is extracted from seawater and transported by specific proteins before the calcium carbonate is formed.
Then they studied the conditions that occur just below the shell. This study shows that the larvae were able to increase the pH and carbonate concentration under their shell, and increase the rate of calcification. In conditions of greater acidity the calcification capacity of the larvae was reduced. In higher concentrations of CO2, a greater dissolution of the shells was observed and a higher mortality was observed.
Bivalves produce several fundamental ecosystem services, such as biofilters and bioindicators of the concentration of pollutants in a body of water. They are especially vulnerable to ocean acidification, but until now little was known about how they regulate calcium to produce a shell, how this process can be modified by changing environmental conditions and what the consequences at the population level are. The absence of this type of information restricts the ability to predict biodiversity and the future of aquaculture. The research carried out by CACHE points out that the larvae are more sensitive to acidification due to their limited capacity for ionic regulation.
Molluscs absorb a soluble form of calcium in seawater and convert it into an insoluble compound without using large amounts of energy in the process, so unravel how they do it could have applications in the field of biotechnology.
CACHE´s main objective is to increase the knowledge we have about the production of calcium in the marine environment and train young scientists to solve complex biological problems through multidisciplinary methods.
Knowing how molluscs of economic relevance produce their shells and regulate that production under different environmental conditions will provide information on the response of species in a changing climate and ways to generate resistant populations for use in aquaculture.