Archive for January, 2014

Researchers plea for long-term ocean acidification research

turtle

(photo credit: thinkstock.com)

More research is necessary for an accurate determination of how marine species will cope long-term with ocean acidification, according to a new research review in the journal Trends in Ecology and Evolution.

“We can’t measure evolutionary responses in all organisms, so we need to choose carefully to get the most bang for our buck,” said review author Jennifer Sunday, a post-doctoral researcher at The University of British Columbia in Canada. “Species of ecological and economic importance, or species that will allow us to make useful generalizations, should be studied so we can project changes in our ocean ecosystems.”
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Cantwell: key fishery bill should tackle the threat of ocean acidification

During Commerce hearing, Cantwell says new cooperative research to protect salmon populations should be considered in Magnuson-Stevens Reauthorization

Cantwell also secures support for her bill that gives fishermen flexibility to grow businesses by refinancing federal loans

WASHINGTON, D.C. – During a Senate Commerce Committee hearing today, U.S. Senator Maria Cantwell (D-WA) warned of ocean acidification’s impact on salmon fisheries and the jobs they support. To combat the problem, she called for new cooperative research between fishermen and scientists to be considered as part of a Magnuson-Stevens Act Reauthorization.
Continue reading ‘Cantwell: key fishery bill should tackle the threat of ocean acidification’

Session on ocean acidification at the SCAR 2014 Open Science Conference, Auckland, 25-28 August, 2014

In response to perturbations of the global carbon cycle, driven mainly by fossil fuel emissions, the Southern Ocean is exhibiting rapid, yet regionally distinct, ocean acidification. In the coming decades, modifications to carbonate speciation and reductions in seawater pH and saturation state will influence Southern Ocean functioning from the physiological to the climate scale. The Southern Ocean is a dominant climate regulator and a potentially enormous marine resource and so improved knowledge is required on the resilience of the system to ocean acidification. Presentations are invited on new Southern Ocean understanding (from observational, experimental and modeling approaches) on the scale of past, present and future ocean acidification; responses of marine organisms and ecosystem structure, functioning and biodiversity; perturbations to biogeochemical cycling and feedbacks to the climate system; and the societal and policy challenges of ocean acidification.

Please note that the deadline for submitting abstracts to the SCAR 2014 Open Science Conference is the 14th of February .

To submit your abstract please go to: http://www.scar2014.com/call-for-abstracts/
Continue reading ‘Session on ocean acidification at the SCAR 2014 Open Science Conference, Auckland, 25-28 August, 2014’

Fishy behavior: ocean acidification alters the way fish behave

fish behavior

(photo: Green Africa Directory)

Shellfish and their calcium carbonate shells have taken the spotlight during the ocean acidification discussion. We know that other animals in the ocean will be affected, but we’ve only just begin looking beyond shells and skeletons. Biologists have started to look at the behavior of fish in lower pH conditions – with surprising results.

If you put a fish in acidifying water, you’re likely to see quite a drastic change in behavior. That is not really a surprise. What is surprising is how different fish are behaving under the lower pH levels predicted for the year 2050. Two studies looking at fish behavior in response to ocean acidification has us a bit confused and definitely curious about the implications. The studies – one on rockfish and the other on clownfish – have yielded contradictory and puzzling results. Clownfish, a famous crowd favorite, are showing a unusual lack of fear for predators. Rockfish, a yummy but lesser-known group of creatures, have demonstrated a heightened state of anxiety. These results have us all scrambling to understand what the future might hold for the world’s fisheries.
Continue reading ‘Fishy behavior: ocean acidification alters the way fish behave’

Ocean acidification promises a grim future for shellfish unless we take action

The phrase “climate change” has passed through the lips of every scientist and policy maker in the nation. It is a looming cloud on the horizon that has already seeped tendrils into our everyday lives. This phenomenon born of fossil-burning machines has a lesser-known cousin that is just as evil – ocean acidification.

Climate change does not cause ocean acidification (OA ). Rather they are both the consequence of industrial human activity on earth. For decades OA has been silently infiltrating our oceans, carrying a promise of death and calamity along with it. Scientists are only just now discovering the implications. OA could have profound and devastating effects on entire ecosystems and our seafood supply in the years to come, however, with proper education and positive action, people have the ability to halt OA’s awful process and reclaim our oceans.
Continue reading ‘Ocean acidification promises a grim future for shellfish unless we take action’

Ocean acidification leaving fish in the dark: study

fish eyesIncreasing carbon dioxide in the world’s oceans could hamper fishes’ eyesight, slowing their reaction times and leaving them vulnerable to predators or unable to hunt, new research has shown.

Experts say it adds to the existing evidence that ocean acidification will be bad for marine ecosystems and possibly fisheries.

Ocean acidification is one of the effects of increasing atmospheric carbon dioxide by burning fossil fuels, which is also increasing global temperatures.
Continue reading ‘Ocean acidification leaving fish in the dark: study’

Ocean acidification will interfere with fish eyes

F1_mediumThe idyllic coral sands and crystal seas that lap the Great Barrier Reef are probably most people’s definition of a tropical paradise: but all is not well in paradise. As global CO2 levels rise, the pH at the surface of the oceans is gradually falling. Göran Nilsson from the University of Oslo, Norway, explains that dissolved CO2 levels are predicted to rocket by the end of the century, increasing by approximately 500 μatm from today’s level of about 400 μatm. The resulting 0.4 drop in the water’s pH will dramatically affect the reef’s inhabitants by altering their ion balance and disrupting one of the brain’s key neurotransmitters: GABA. ‘GABA performs a function in virtually all neural circuits in the brain’, says Nilsson, who explains that alterations to the system can dramatically disrupt behaviour, making predators attractive and increasing the boldness of usually shy creatures. Nilsson adds that juvenile damselfish also fail to respond correctly to glimpses of a predator after exposure to elevated CO2 and says, ‘This suggests that the function of the visual system is affected by high CO2’. Curious to find out how increasing ocean acidification might affect the vision of residents of the Barrier Reef, Nilsson, Wen-Sung Chung, Justin Marshall, Sue-Ann Watson and Philip Munday decided to find out how increased CO2 alters the visual responses of damselfish retinas by focusing on the speed of the retina’s response to flickering light (p. 323).

Continue reading ‘Ocean acidification will interfere with fish eyes’

Ocean acidification slows retinal function in a damselfish through interference with GABAA receptors

Vision is one of the most efficient senses used by animals to catch prey and avoid predators. Therefore, any deficiency in the visual system could have important consequences for individual performance. We examined the effect of CO2 levels projected to occur by the end of this century on retinal responses in a damselfish, by determining the threshold of its flicker electroretinogram (fERG). The maximal flicker frequency of the retina was reduced by continuous exposure to elevated CO2, potentially impairing the capacity of fish to react to fast events. This effect was rapidly counteracted by treatment with a GABA antagonist (gabazine), indicating that GABAA receptor function is disrupted by elevated CO2. In addition to demonstrating the effects of elevated CO2 on fast flicker fusion of marine fishes, our results show that the fish retina could be a model system to study the effects of high CO2 on neural processing.
Continue reading ‘Ocean acidification slows retinal function in a damselfish through interference with GABAA receptors’

7th New Zealand Ocean Acidification Annual Workshop – “the acid test”, 11-12 February 2014, Wellington

On the 11th and 12th February 2014 the 7th New Zealand Ocean Acidification Annual Workshop will be held in Wellington. The meeting will be attended by scientists, policy makers and stakeholders. Papers will be presented on recent work in this southwest Pacific region ranging from: the influence of carbonate saturation states on deep sea corals, to microbial activity in high CO2 vent waters and sea ice, to the influence of ocean acidification on shellfish aquaculture, larval and juvenile invertebrates, and possible consequences for tropical coral reefs.

Three international keynote speakers, Libby Jewett (NOAA), Phil Munday (James Cook University, Australia) and Andreas Andersson (Scripps, USA) will provide a more global context for the work that is going on in this region.  Discussion will focus around the future monitoring of ocean acidification in this region. The meeting is being organised by the National Institute of Water and Atmospheric (NIWA) Research, hosted by Victoria University, Wellington, with support from the University of Otago, New Zealand Ministry of Primary Industries and the Ministry of Business, Innovation and Employment.

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Natural variability and anthropogenic change in equatorial Pacific surface ocean pCO2 and pH

The equatorial Pacific is a dynamic region that plays an important role in the global carbon cycle. This region is the largest oceanic source of carbon dioxide (CO2) to the atmosphere, which varies interannually dependent on the El Niño-Southern Oscillation (ENSO) and other climatic and oceanic drivers. We present high-resolution observations of surface ocean CO2 partial pressure (pCO2) at four fixed locations in the Niño 3.4 area with datasets encompassing 10 ENSO warm and cold events from 1997 to 2011. The mooring observations confirm that ENSO controls much of the interannual variability in surface seawater pCO2 with values ranging from 315 to 578 µatm. The mooring time series also capture the temporal variability necessary to make the first estimates of long-term pH trends in the equatorial Pacific, which suggest the combination of ocean acidification and decadal variability create conditions for high rates of pH change since the beginning of the mooring record. Anthropogenic CO2 increases play a dominant role in significant observed seawater pCO2 trends of +2.3 to +3.3 µatm yr-1 and pH trends of -0.0018 to -0.0026 yr-1 across the full time series in this region. However, increased upwelling driven by increased trade winds, a shallower thermocline, and increased frequency of La Niña events also contribute an average of 40% of the observed trends since 1998. These trends are higher than previous estimates based on underway observations and suggest that the equatorial Pacific is contributing a greater amount of CO2 to the atmospheric CO2 inventory over the last decade.
Continue reading ‘Natural variability and anthropogenic change in equatorial Pacific surface ocean pCO2 and pH’


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