Archive for the 'Media coverage' Category

Noses baffled by ocean acidification

Smell is like noise, the more scents we breathe in one sniff, the more difficult it is to distinguish them to the point of olfactory saturation. Experimental work with clownfish reveals that the increase in dissolved carbon dioxide in seawater, mimicking ocean acidification, alters olfactory physiology, with potential cascading effects on the demography of species.

Places such as a restaurant, a hospital or a library have a characteristic bouquet, and we can guess the emotional state of other people by their scents. Smell is critical between predators and prey of many species because both have evolved to detect each other without the aid of vision. At sea, the smell of predators dissolves in water during detection, attack, capture, and ingestion of prey, and many fishes use this information to assess the risk of ending up crunched by enemy teeth (1, 2). But predator-prey interactionscan be modified by changes in the chemical composition of seawater and are therefore highly sensitive to ongoing ocean acidification (see global measuring network here).

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Potential sources of variability in mesocosm experiments on the response of phytoplankton to ocean acidification (update)

Mesocosm experiments on phytoplankton dynamics under high CO2 concentrations mimic the response of marine primary producers to future ocean acidification. However, potential acidification effects can be hindered by the high standard deviation typically found in the replicates of the same CO2 treatment level. In experiments with multiple unresolved factors and a sub-optimal number of replicates, post-processing statistical inference tools might fail to detect an effect that is present. We propose that in such cases, data-based model analyses might be suitable tools to unearth potential responses to the treatment and identify the uncertainties that could produce the observed variability. As test cases, we used data from two independent mesocosm experiments. Both experiments showed high standard deviations and, according to statistical inference tools, biomass appeared insensitive to changing CO2 conditions. Conversely, our simulations showed earlier and more intense phytoplankton blooms in modeled replicates at high CO2 concentrations and suggested that uncertainties in average cell size, phytoplankton biomass losses, and initial nutrient concentration potentially outweigh acidification effects by triggering strong variability during the bloom phase. We also estimated the thresholds below which uncertainties do not escalate to high variability. This information might help in designing future mesocosm experiments and interpreting controversial results on the effect of acidification or other pressures on ecosystem functions.

Continue reading ‘Potential sources of variability in mesocosm experiments on the response of phytoplankton to ocean acidification (update)’

Strengthening resilience to ocean acidification in Tokelau

Tokelau is one of four Pacific islands embarking on work to strengthen the island atolls resilience to the impacts of ocean acidification, a new and emerging challenge for our region.
For Tokelau, this is now underway with a special inception workshop held in Samoa, to plan implementation of the different activities.

With the Tokelau General Fono recently endorsing the Tokelau Climate Change Strategy – ‘Living with Change’ the protection of the ocean is featured as a high priority.

Being part of the New Zealand Pacific Partnership on Ocean Acidification (NZPPOA) regional project to build resilience to ocean acidification is especially important for Tokelau and her community.

“It goes without saying how invaluable the ocean and ocean life is to the Tokelauans and to all other Pacific islanders. ‘Our Ocean is us, our cultural identity’. Our lives are intertwined with the ocean life in all and every aspect– economy, culture, language,” said the Ulu o Tokelau Faipule Siopili Perez.

“For decades, knowledge and skills passed down from our ancestors has been the key to our harmony with the changing nature. I believe resilience and innovation, an amalgamation of traditional knowledge and modern technology and both rooted in science, can only bring out the best of results for the nature and the people.”

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How do higher CO2 levels impact marine life?

As the concentration of carbon dioxide (CO2) in the atmosphere continues to climb, a group of researchers at Lamont-Doherty Earth Observatory are investigating how this change will impact the Earth system, with a focus on oceans and marine life.

Atmospheric CO2 exchanges with carbon dissolved in the surface ocean, depending on the relative concentrations of each. This gas exchange is similar to the process that allows ‘bubblers’ in fish tanks exchange gases for fish to thrive. As CO2 enters the surface ocean, the acidity of surface seawater generally increases, a process commonly referred to as ocean acidification.

With support from World Surf League PURE, Lamont paleoceanographer Bärbel Hönisch and postdoctoral researcher Kelsey Dyez are studying the respective effects of ocean warming and acidification on plankton collected from a global suite of sediment cores. The time period of this study covers the last ice age (characterized by colder and more alkaline seawater) and into the current warm period (warmer and more acidic seawater).

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Pacific leaders tackle ocean acidification

If the land is well and the sea is well, the people will thrive. This adage is relevant now more than ever as climate change is encroaching on our shores.

Leaders from around the Pacific have joined in to tackle the issue of climate change specifically focusing on ocean acidification. Last week, was the opening of the New Zealand Pacific Partnership on Ocean Acidification (P.P.O.A) project and the Tokelau Project Inception Workshop at Taumeasina Island Resort.

The New Zealand Pacific Partnership on Ocean Acidification (P.P.O.A) project is a collaborative effort between the Secretariat  of the Pacific Regional Environment Programme (SPREP), the university of the South Pacific, and the Pacific Community which aims to build resilience to ocean acidification in Pacific Island communities and ecosystems, with financial support form the NZ Ministry of Foreign Affairs and Trade and the Government of Monaco.

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Cuba inaugurates ocean acidification observatory

Photo credit: Julio Martínez Molina

Dazhu Yang, deputy director general of the International Atomic Energy Agency’s (IAEA) Department of Technical Cooperation, inaugurated the Caribbean Regional Ocean Acidification Observatory in Cienfuegos.

Cienfuegos.– On March 22, Dazhu Yang, deputy director general of the International Atomic Energy Agency’s (IAEA) Department of Technical Cooperation, inaugurated the Caribbean Regional Ocean Acidification Observatory in Cienfuegos as part of the IAEA’s RLA/7/020 project.

In his opening remarks, Yang described the inauguration of the Observatory as “an important event,” recalling that the IAEA “is a member of the United Nations family, founded in 1957, an organization which works with member states – such as Cuba – to promote the peaceful use of atomic energy and its utilization for development and in the field of environmental protection: one of the most important in regards to cooperation.

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WITNESS: Investigating ocean acidification (Part 2)

In the second part of his WITNESS blog investigating the dangers of increasing ocean acidification, CONOR PURCELL learns that increase rates are already 10 times higher than at any time in the last 55 million years which, naturally, does not bode well for all ocean ecosystems

The continental shelf rolls out for some hundreds of kilometres west of Ireland’s Galway coast, before the Rockall Trough. Here the seafloor falls sharply off the shelf down to abyssal depths of over 3000 metres. Continentals shelves like this are host to a range of marine ecosystems, including cold water corals; a much less discussed variety compared to their warm water cousins.

According to Dr Tríona McGrath, a marine scientist at the National University of Ireland Galway, and funded by Ireland’s Marine Institute : “The Rockall Trough hosts an array of cold water coral ecosystems, interacting with a range of water masses along the Irish continental margin, Rockall Bank and Porcupine Bank. These deep water reef structures support a rich biodiversity and are particularly vulnerable in a more acidic ocean.”

Continue reading ‘WITNESS: Investigating ocean acidification (Part 2)’

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Ocean acidification in the IPCC AR5 WG II

OUP book