Dolomite has been found inside ‘reef building’ algae. |
The
century-old mystery of a missing mineral in coral reefs has been solved by a
team from The Australian National University.
The team, led
by Bradley Opdyke of the Research School of Earth Sciences, has uncovered a
hidden stash of the mineral dolomite in coral reefs around the globe, ending a
search that has lasted over 100 years. The discovery was published in Biogeosciences.
“For over a
century scientists have puzzled over the ‘dolomite problem’—the mystery
surrounding the abundance of dolomite in fossil reefs and its apparent absence
from modern reefs,” says Opdyke.
“We have
discovered that dolomite is in fact present in large quantities in modern coral
reefs, but from an unexpected source.”
The team’s
eureka moment came when they found large quantities of dolomite packed inside a ‘reef builder’ species of red algae, Hydrolithon
onkodes.
“There was
dolomite on the reefs all along, but it was hidden within these algae,” says
Opdyke.
“This species
of algae is found in abundance on reefs around the world. The algae work with
coral to ‘cement’ the reef structure to withstand the tremendous hydraulic
pressure of waves.
“This is the
first discovery of dolomite associated with a living organism.”
Student
Marinda Nash and Uli Troitzsch made the surprise discovery while investigating
the effects of climate change on red algae.
“The discovery was completely serendipitous—we were working on an unrelated
question at the time,” says Opdyke. “When we confirmed the finding I said to
Marinda, ‘This is going to be huge’. It opens up a kaleidoscope of future
research topics.”
