Volcanic eruptions serve to sustain reefs
Could the pumice, a light and porous volcanic rock that surges into the ocean once a volcano erupts in Tonga or elsewhere in the south-west Pacific save the Great Barrier Reef?
Sydney: Could the pumice, a light and porous volcanic rock that surges into the ocean once a volcano erupts in Tonga or elsewhere in the south-west Pacific save the Great Barrier Reef?
The first ever research in this regard, conducted by Queensland University of Technology geologist Scott Bryan, indicates that yes, this is not only possible, but could explain how the Great Barrier Reef was formed in the first place.
Bryan and his colleagues studied the westward flow or rafting of pumice after volcanic eruptions in Tonga in 2001 and 2006, the journal Public Library of Science ONE reports.
Pumice forms when frothy molten rock cools rapidly and forms a lightweight bubble-rich rock that can float in water, according to a Queensland Technology statement.
Bryan said his study found plants and tiny animals including corals latched on to pumice as it was swept by ocean currents towards north eastern Australia.
"The pumice raft created after the 2006 Home Reef volcano erupted in Tonga initially formed at least a 440 square kilometre floating mass. The mass slowly broke up into streaks and millions to billions of marine organisms such as cyanobacteria, barnacles, molluscs, corals, anemones, and crabs began hitching a ride" said Byran.
"The pumice we observed travelled more than 5,000 kilometres in eight months and for the first time we were able to document the more than 80 species of plant and animal life that made the journey with it. Some biological cargo latched on in the waters around Tonga and Fiji while others came aboard elsewhere along the raft`s 900-plus-day journey," added Bryan.
Bryan said when these tiny corals, coralline algae, anemones and other reef dwellers arrived in north-eastern waters they became part of the Great Barrier Reef.
"This is good news because we know the reef is being replenished as a result of volcanic activity in the south-west Pacific and volcanic activity is frequent with eruptions in the area occurring every five to 10 years," he said.
"On the downside, marine pests, for example some species of sponge or mussel, can also be carried along on the pumice," he said.