marine

Marine heatwaves continue decimating corals in the Pilbara with climate change

Marine heatwaves are having a marked impact on coral reef systems off the Pilbara coast. A CSIRO and University of Western Australia study in progress found bleaching and decimation of ancient porite corals - many up to 400 years old - in a recent visit to Barrow Island. The oceans around Australia were unusually warm in 2013. Globally the deep oceans are also continuing to warm.

“We suspect this bleaching event was due to marine heatwaves that occurred in the region over the past few summers, and to see it up close was sobering,” said Dr Russ Babcock, CSIRO lead scientist, “But to offset this loss, some reefs only a short distance north showed much less damage and will continue to contribute to a healthy ecosystem."

Greens propose boost to funding for Antarctic and Southern Ocean marine research

Hobart as an important scientific hub and gateway for Antarctic and southern ocean marine research, not only for Australia but for other national scientific expeditions. That is the vision of a new policy initiative launched by the Greens today to boost the research and logistics capacity of Australian Antarctic, climate and marine scientists based in Hobart.

WA marine heatwave - Elevated sea surface temps & marine biodiversity

Dec 29, 2012: High sea surface temperatures (SST) of up to five degrees above normal are currently being experienced off the north-western Australian coast in a marine heatwave event. Like the extreme marine heatwave event in 2011 this will change marine ecosystems causing coral bleaching and fish mortality and impact on fisheries management and biodiversity.

A similar event occurred over several weeks during the 2010/2011 summer which impacted seafood stocks and marine ecosystems and was associated with an extremely strong La Niña event and a record strength Leeuwin Current down the Western Australian coast.

Geography: 

Coral reefs being pushed to extinction by global warming

Increasing sea surface temperatures are imperilling coral reef ecosystems say Australian marine and climate scientists. A new scientific paper reveals that atmospheric warming of 2 degrees celsius is too much for nearly all the world's coral reef ecosystems, including the Great Barrier Reef. The scientists argue that to preserve greater than 10 per cent of coral reefs worldwide would require limiting global warming to below 1.5 °C. This equates to the goal of reducing carbon in the atmosphere to 350ppm, rather than a 2 degree rise or 450ppm that the UN Framwework Convention on Climate Change has adopted as the safe limit at several meetings.

Atmospheric concentration of CO2 currently stands at 392.41ppm. With current pledged reduction in emissions we are heading for 4.4 °C of warming by the end of the century according to the Climate Scoreboard.

Related: The True Cost of Australia's Coal Boom | Greenpeace report: Boom Goes the Reef: Australia's coal export boom and the industrialisation of the Great Barrier Reef (PDF) | The Conversation: - Climate change guardrail too hot for coral reefs?

International Day for Biological Diversity - Seagrass meadows are key carbon sinks for combatting climate change

UNESCO's International Day for Biological Diversity on May 22 focussed strongly on conserving our marine diversity. One of the important marine ecosystems are the seagrass meadows around the coasts of the world. A new global scientific research study just released has shown that seagrass meadows store significantly more carbon than any land based forest. They are very important as carbon sinks. But they are also suffering a major decline due to pollution from agricultural and mining development and chemical runoff, coastal development changing water turbidity upsetting photosynthesis in seagrass, and increasing sea surface temperatures affecting seagrass growth due to global warming.

The new global study of seagrass meadow ecosystems has found that coastal seagrass beds store much more carbon than can be stored in even the most carbon dense forests, such as the temperate native forests of Victoria. Seagrass meadows can store up to 83,000 metric tons of carbon per square kilometre, mostly in the soils below them. In comparison, a typical land forest stores around 30,000 metric tons per square kilometre mostly as wood. It is the first global study to analyze the carbon storage capacity in seagrasses.

More Information: Seagrass Watch | Global Seagrass Monitoring Network

Species biodiversity under threat from the velocity of climate change

Scientists have been able to calculate the velocity of climate change on land and ocean environments using temperature records to determine isotherms and their change in a fifty year period from 1960 to 2009. So how fast are climate envelopes moving? The general median answer is 27.3 km/decade on land, and 21.7 km/decade in the ocean. This equates to a speed needed to outrun climate change on land (2.7 kilometers per year) and in the oceans (2.2 kilometers per year). This rate of movement of thermal climate envelopes poses problems for species facing a high speed migration, or a difficult and abrupt adaptation or extinction.

Related: Indybay - Climate change and habitat loss threaten biodiversity, extinction rate underestimated | Science Network WA - Rare frog population sent to the South-West

Promotion: 

Oceans at high risk of unprecedented Marine extinction scientists warn

A report issued last week from the International Programme on the State of the Ocean (IPSO) has strongly warned of the damage to the health of the world's oceans and marine life from several factors including the impacts of climate change. The report warned that if the current business as usual trajectory of damage continues "that the world's ocean is at high risk of entering a phase of extinction of marine species unprecedented in human history."

Only 5% of Philippine coral reefs remain

Read this and weep: A marine scientist from the University of the Philippines has revealed that only 5 percent —equivalent to just around 1,000 square kilometers—of the country’s total reef area remain in good condition in the face of the wanton destruction of our coral reefs by poachers.

The estimated reef area of the Philippines ranges from 19,000 to 27,000 square kilometers, depending on the territorial boundaries and depth ranges. This makes the Philippines’s reef areas one of the biggest in Southeast Asia, more so if those in the disputed Kalayaan Islands were included.

Marine extinction looms with ocean acidification increasing

Scientiists from Bristol University say that ocean acidification is ocurring at a faster pace than anytime in the last 65 million years, raising the possibility of a mass marine extinction event similar to what ocurred about 55 million years ago.

Related: Dr Jeremy Mathis on CO2 acidification threatens northern oceans - (KFSK Public radio audio) | European Project on Ocean Acidification Blog | The Ocean in a High CO2 World | Sigourney Weaver highlights Ocean Acidification in video documentary

Promotion: 

Scientist: Extinction threatens coral reefs unless CO2 limited to 350ppm

COPENHAGEN. Dec 9, 2009. Extinction of Coral reefs and 10-20% of marine species is likely if greehouse gases aren't brought down to 350ppm, warned Professor Ove Hoegh-Guldberg from the University of Queensland. He gave a presentation (audio 14mins 19s) at the US Pavilion at the COP15 climate negotiations in Copenhagen about the threat of climate change to the world's coral reefs. Over 500 million people living in approximately 90 nations are dependant in some way on coral reefs.