Showing posts with label marine. Show all posts
Showing posts with label marine. Show all posts

Friday, August 22, 2014

Coral reef ecosystems acidifying 3 times faster than open ocean

New research shows that the rate of ocean acidification in coral reef ecosystems is more than three times faster than in the open ocean, much more than previously thought. This has big implications for reef ecosystems around the globe suffering under multiple stressers of increased sea surface temperatures, nutrient and other pollution and commercial fishing pressures.

Biogeochemist researchers from Southern Cross University Led by recent graduate Dr Tyler Cyronak detailed this new insight in a study published in Geophysical Research Letters titled Enhanced coral reef acidification driven by regional biogeochemical feedbacks.

Ocean acidification is well documented in open waters. Cold waters like in the southern ocean can more readily absorb carbon dioxide, so ocean acidification was thought to be proceeding more rapidly in marine ecosystems in cooler waters (see my 2007 article: Scientists say Ocean Acidity Increasing at Faster Rate)

This new research highlights that coral reef waters are also rapidly acidifying. This research examined studies done in coral reefs since the 1960s and found that the rate of acidification in coral reef ecosystems was more than three times faster than in the open ocean.

Friday, February 21, 2014

Marine heatwaves continue decimating corals in the Pilbara

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."

A marine heatwave extreme bleaching event ocurred in 2011 that was widely spread along the Western Australian coast. Preliminary results from the study show that further damage was done in the 2012-2013 summer with elevated water temperatures.

Tuesday, February 11, 2014

ExClimate: Experiment shows coral reefs in peril in a high CO2 world

Professor Ove Hoegh-Guldberg takes us through and explains a controlled experiment his Institute is conducting in coral reef ecosystem reaction to various temperature and carbon dioxide environments.

Hoegh-Guldberg is Director of the Global Change Institute at the University of Queensland and an important authority on tropical marine biology, coral reef ecosystems and climate change.

He argues that Coral Reef ecosystems have already changed significantly from pre-industrial times, and will change even further as human carbon emissions increase in the atmosphere with many species likely to be pushed to extinction due to heat stress and ocean acidification from anthropogenic climate change.

Tuesday, January 21, 2014

Ocean Heat Content to 2000m continues warming

Ocean heat content has continued rising in the last 12 months to December 2013. This is observed in the top 700 meters of depth, as well as down to 2000 meters depth.

What pause in global warming? The Oceans take up about 93 per cent of the solar energy hitting the earth. The graphs show clearly there has been no let up in global warming, with oceans continuing to warm.

While atmospheric temperatures appear to have slowed over the last 15 years - a warming hiatus - but substantial warming is still occurring to the global system including adding heat to the world's oceans, melting Arctic sea ice, and the Greenland and Antarctic ice sheets.

Sunday, January 5, 2014

Sea surface temperatures unusually warm around Australia in 2013

Sea surface temperatures around Australia in 2013 were unusually warm reported the Australian Bureau of Meteorology in it's annual climate statement. Record ocean temperatures were recorded for January and February, with November the second-highest on record. This continues a long term trend for increasing sea surface temperatures around Australia and globally.


Sunday, May 19, 2013

Heading for cooler waters - Climate Change Impact of warming oceans on global fish stocks

For the first time scientists have demonstrated the impact of climate change on ocean warming and sea surface temperatures affecting global fisheries stocks. Previous studies were limited to individual fisheries. The changes have been occurring clearly since the 1970s, the scientists say. The implications of this research raises the need for timely changes in fisheries management practices and adaptation plans for communities dependant on fishing, particularly climate vulnerable developing countries in the tropics.

"Given global fisheries contribute hugely to the world's economy and food security, this is a significant finding," said co-author Dr Reg Watson from the University of Tasmania's specialist Institute for Marine and Antarctic Studies."We are no longer talking about future hypotheticals - we are talking about impacts on a global scale that we can already demonstrate."

Previous research by Dr Watson published last year demonstrated that marine fishes are now smaller in size. "Last year we showed that one of the consequences of climate change and excessive fishing is that globally marine fishes are smaller," said Dr Watson.

The paper - Signature of ocean warming in global fisheries catch - was published in Nature on 15 May 2013. The study was lead by Assistant Professor William Cheung, University of British Columbia, with collaboration from Professor Daniel Pauly and Dr Reg Watson.

I wrote about a related issue on the Velocity of climate change imperiling ocean diversity, particularly with regard to Australia, in January 2012.

Friday, March 15, 2013

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.

Tasmania presently hosts the Antarctic Climate and Ecosystems Co-operative Research centre (ACE CRC) , the Australian Antarctic Division, along with CSIRO's Division of Marine and Atmospheric Research. But funding for the ACE CRC will come to an end in the next year. The University of Tasmania, CSIRO and ACE CRC are currently working on a proposal for a new Antarctic research organisation.

Antarctica and the Southern Ocean influence the regional and global climate and in this period of climate change understanding the mechanisms and changes taking place will provide valuable information for climate adaptation. Temperatures are increasing at 3 times the global average on West Antarctica, ice streams are accelerating ice mass loss with the collapse of the West Antarctic Ice Sheet a real possibility in the decades and centuries ahead. The Southern ocean is warming and freshening at a much faster rate than the global ocean. The food web in the southern ocean is changing with Penguin numbers suffering with krill decline due to Global Warming

Sunday, December 30, 2012

Elevated sea surface temps threatening marine biodiversity in Western Australia

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.

Friday, December 28, 2012

China's coral reef ecosystems suffer devastating 80 per cent decline

In the last 30 years the coral reef ecosystems off the coast of mainland China and Hainan Island have suffered an 80 per cent decline largely due to unrestrained economic development driving coastal development, pollution and overfishing.

The study, published in the journal Conservation Biology - The Wicked Problem of China's Disappearing Coral Reefs - was conducted jointly by scientists from the Australian Research Council Centre of Excellence for Coral Reef Studies and James Cook University, and from the South China Sea Institute of Oceanology, Chinese Academy of Sciences.

"A wicked problem is one that is very hard to solve without having a whole lot of other foreseen and unforeseen consequences to people, industries and to the environment itself," said lead author Professor Terry Hughes.

Tuesday, October 2, 2012

Guest Post: Calls for climate action as Great Barrier Reef suffers major coral loss

By Charis Palmer, The Conversation

The Great Barrier Reef has lost half its coral cover in the last 27 years, and it could halve again by 2022 say researchers from the Australian Institute of Marine Science.
A study published today in the Proceedings of the National Academy of Sciences, found storm damage drove 48% of the loss, the crown of thorns starfish 42%, and bleaching 10%.

Monday, March 12, 2012

Ocean acidification increasing at unprecedented rate not seen in last 300 million years

In a new study marine scientists warn that the rate of ocean acidification presently occurring is unprecedented in the last 300 million years. This is due to dissolving carbon dioxide from the atmosphere, much of which human activity has contributed over the last 200 years through the use of fossil fuels. The extent of the acidification and rate of acidification enhances the prospect for a mass marine extinction event this century.

Related: Dec 2011 - Ocean acidification warning to Durban climate negotiators to act on reducing CO2 emissions | June 2011 - Oceans at high risk of unprecedented Marine extinction scientists warn | April 2010 - Paleo-perspectives on ocean acidification - marine ecosystems under threat | Feb 2010 - Marine Extinction looms with Ocean Acidification increasing

Sunday, February 5, 2012

Sea Cucumber poo moderates impact of ocean acidification on coral reefs

Ocean acidification is a major threat to coral reefs and other marine zooplankton and creatures using calcium carbonate shells. Marine and Climate scientists working at the University of Sydney's research station, One Tree Island, on the Great Barrier Reef have discovered that sea cucumber poo increases the alkalinity of the reef water providing a buffer to the increasing acidity caused by ocean acidification.

It is a vital marine process that provides some buffer to corals with the impacts of ocean acidification. "We have found that sea cucumbers play a vital role in reducing the harmful impact of ocean acidification on coral growth," said Professor Maria Byrne, the director of One Tree Island Research Station.

Wednesday, January 18, 2012

Wandering Albatross Riding the winds of climate change

We are stacking the climate dice against the survival of many species on planet earth. A few species may be able to ride the changes, at least temporarily. And so it is with the largest of birds, the wandering albatross, with some populations of this species able to take advantage, so far, of the changing winds of climate change. But for how long?

Global warming has caused the westerly winds in the Southern Ocean to increase in intensity and move poleward. The wandering albatross, with a three metre wing span, spends much of it's life soaring above the ocean searching for food, with the changes in the winds increasing it's foraging ability, breeding capacity and reducing it's conflict with commercial long line fishing operations.

Wednesday, January 4, 2012

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.

Here is how scientists measured the velocity of climate change ocurring:

We used global surface temperatures over 50 years (1960-2009) to calculate the distribution of the velocity and seasonal shifts of isotherm migration over land and ocean on a 1°-by-1° grid. The velocity of climate change (in km/year) was calculated as the ratio of the long-term temperature trend (in °C/year) to the two-dimensional spatial gradient in temperature (in °C/km, calculated over a 3°-by-3° grid), oriented along the spatial gradient. We introduced the seasonal climate shift (in days/decade) as the ratio of the long-term temperature trend (°C/year) to the seasonal rate of change in temperature (°C/day). We present seasonal shifts for spring and fall globally using April and October temperatures.

Friday, December 2, 2011

Ocean acidification warning to climate negotiators to act on reducing CO2 emissions

Climate negotiators in Durban were urged to consider ocean acidification and changes taking place in the southern ocean due to increasing greenhouse gas emissions and climate change. The International Union for the Conservation of Nature (IUCN) and ocean researchers released important briefings on ocean acidification and changes taking place in the southern ocean on November 29, 2011.

At the United Nations Framework Convention on Climate Change (UNFCCC) Durban climate talks the IUCN and Ocean Acidification Reference User Group urged that Ocean acidification should no longer remain on the periphery of the international debates on climate change and the environment and should be addressed by the UN Framework Convention on Climate Change and other global environmental conventions. At the same time ocean researchers in Australia also released a position analysis paper that the southern ocean was undergoing major changes in becoming warmer, even at great depths; more acidic; and freshening with a drop in salinity levels.

Related: Oceans at high risk of unprecedented Marine extinction scientists warn | IUCN - The acid truth about our oceans: experts urge action to limit ocean acidification | ACE CRC - Research shows that Southern Ocean is warming and freshening

Monday, November 14, 2011

Sea Surface Temperatures around Australia remain elevated, La Niña builds slowly

The Sea Surface temperature Anomaly around Australia in November 2011 remains elevated. A slow cooling in the tropical mid Pacific indicates that La Niña is also slowly building. A persistently warm Indian Ocean is also a main driver for forecast wetter conditions in Australia this summer.

Monday, June 27, 2011

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 and 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."

Dr. Alex Rogers, Scientific Director of IPSO and Professor of Conservation Biology at the Department of Zoology, University of Oxford, gives the overview of the main problems affecting the ocean — and some suggested solutions.

Related: International Programme on the State of the Ocean (IPSO) | The Ocean in a high CO2 world | Frontline - World's oceans in crisis: What can be done?

Saturday, June 11, 2011

Arctic Deep sea oil: Cairn Energy oil spill response plan missing

Activists from Greenpeace have been harassing the drilling program of Cairn Energy in the Arctic off the Greenland coast citing the lack of a publicly available oil spill response plan for drilling in the sensitive Arctic environment. Cairn Energy, an Edinburgh registered company, is presently involved in exploratory deep sea oil drilling in the Arctic in the Davis Strait (Iceberg Alley).

Wednesday, April 13, 2011

Queensland climate becoming more extreme according to coral reef record

The Queensland climate is becoming more extreme with more frequent rain and drought events since the nineteenth century according to research on coral reef cores published in the scientific journal, Paleoceanography by Dr Janice Lough from the Australian Institute of Marine Science in April 2011.

Penguin numbers suffering with krill decline due to Global Warming

A new study of declining penguin populations shows a strong correlation between penguin numbers and krill availability. Krill availability is affected by reduced sea ice conditions due to global warming and climate change.

"For penguins and other species, krill is the linchpin in the food web. Regardless of their environmental preferences, we see a connection between climate change and penguin populations through the loss of habitat for their main food source," said Dr. Wayne Trivelpiece, lead author and seabird researcher of the National Oceanic and Atmospheric Administration's Antarctic Ecosystem Research Division. "As warming continues, the loss of krill will have a profound effect throughout the Antarctic ecosystem."

Related: On the brink: Penguins face an uncertain climate future (Oct 2010)