Researchers from the University of Melbourne have discovered that a species of crayfin, which is an important food source for some marine species, has a genetic vulnerability that makes it particularly vulnerable to climate change.
The findings are published in the journal Environmental Research Letters.
Crayfins are the world’s largest craybones, which measure about six metres in length.
Their shells are made up of about 60 per cent calcium carbonate, which they absorb from the ocean and use as a source of calcium.
When the shells become stressed, this carbonate begins to precipitate, forming an acidic solution that breaks down into calcium carbonates.
The calcium carbonats are also highly resistant to the effects of ocean acidification, so they can survive for millions of years underwater.
But as the ocean warms, this calcium carbonat supply drops off as the planet warms.
This causes the crustacean population to drop as the climate warms and the carbonates begin to crystallise.
The researchers used data from the Australian Museum’s Crustacean Record to study how this process would happen.
Crustal cells are extremely dense structures that hold calcium ions in.
They also contain a number of other minerals, such as calcium phosphate and magnesium.
They form a shell-like structure, and are known to contain a lot of water, both as a result of their water-holding capacity and the high pressure they can withstand.
The team studied how the shell formed over the past 2.6 million years.
It found that the calcium carbonators inside the shell, which are called “nearly all-encompassing cells”, were about half as dense as they are today.
This means the calcium phosphate ions inside the shells could be up to 10 times more effective in trapping water than they are now.
In addition, the researchers found that as the shell gets older, it becomes more likely that the carbonate ions will break down.
This is because the shell’s internal structure begins to change, leading to more calcium carbonation within the shell and a further reduction in the concentration of calcium phosphate.
“In a warmer climate, it’s quite likely that we would see the shell get older and become more acidic, and we would then see an increase in the calcium content in the shell,” said Dr Daniel Dyer, from the School of Biological Sciences.
“The most likely scenario is that we’d see a loss of all-embracing cells in the future.”
“The shells of these species tend to be quite compact in size and this makes them difficult to collect and study,” Dr Dyer said.
“There’s also a large amount of calcium carbonated in the shells of the most common crustaceans and the majority of crays.”
The team’s findings suggest that this change in shell structure may be part of the reason for the rise in acidification that has already been documented.
The research is one of the first to look at how the carbonation and calcium carbonations are changing in the marine environment over the last 10 million years, as the world has warmed.
“We’ve known for some time that the environment of the ocean is changing and this work is helping us to understand what this change is doing to marine organisms,” Dr Glyn Hughes, an expert on ocean acidity at the University, said.
Dr Dyers and Dr Hughes also discovered that the shells are more likely to dissolve when they are exposed to water that has been carbonated by the ocean.
This results in more calcium-carbonate particles that the marine creatures need to live.
“If you’re in a warm climate, you have a lot more calcium in your environment and this increases the likelihood that the shell will dissolve,” Dr Hughes said.
The scientists are also working on how the calcite-rich shells of crickets might affect the calcification of crustaceae and other marine organisms.