Archive for June, 2013

Ocean Acidification International Coordination Centre

Within less than a decade, ocean acidification has gone from a science without a label involving few scientists to a research topic studied by many hundreds that is considered the #1 research front in Ecology and Environmental Sciences (King and Pendlebury, 2013)1. As research activities on ocean acidification continue to develop, there is a growing need for international collaboration and coordination.

In recent years, EPOCA2, the first multi-national project on ocean acidification, partly filled this need. This 4-year European project ended in 2012. Recognizing the need to continue and develop international activities, the SOLAS-IMBER joint Working Group on Ocean Acidification (SIOA) and the Ocean Acidification International Reference Users Group (OA-iRUG) called for an international effort to coordinate, promote and facilitate science and related activities.

Responding to this call and to the increasing concern about ocean acidification from many of its Member States and international organizations, the International Atomic Energy Agency (IAEA) stepped in and announced a new project, the “Ocean Acidification International Coordination Centre (OA-ICC)”, at the UN Conference on Sustainable Development (Rio+20) in June 2012.

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Effects of ocean acidification on phytoplankton in upwelling areas influenced by river discharges

Barbara Jacob is currently a post-doctoral associate at the Aquatic Ecosystem Functioning Lab (LAFE) under the sponsorship of Dr. Cristian A. Vargas at the Environmental Science Center EULA Chile (Universidad de Concepción), Chile. Her research is focused on understanding the effects of ocean acidification on natural phytoplankton communities as well as on key algal species (flagellates vs. diatom species).

About 48% of carbon dioxide released to the atmosphere in the last 200 years has been caused by man (Raven et al., 2005). The oceans have absorbed nearly half of the fossil-fuel carbon dioxide (CO2) emitted into the atmosphere since pre-industrial times. This capacity causes the reduction in seawater pH and carbonate saturation, a process known as “ocean acidification”. Studies of the effect of ocean acidification on phytoplankton suggest that increasing the concentration of CO2 may stimulate phytoplankton growth rate or efficiency of resource utilization and hence alter the species composition of phytoplankton communities. Recent studies have shown effects of ocean acidification increases the dissolved inorganic carbon consumption of a natural plankton community with rising CO2 (Riebesell et al., 2007). Stoichiometric changes in the C:N ratio of the primary production to high pCO2 levels may affect the availability of labile carbon that could be used by heterotrophic microbial community, in terms of their utilization of the mineral nutrients, which in turn, can limit the primary production due to the reduction of mineral nutrients.

Continue reading ‘Effects of ocean acidification on phytoplankton in upwelling areas influenced by river discharges’

Marine phytoplankton can adapt to ocean acidification

Kai Lohbeck is a PhD student in the BIOACID project at GEOMAR (Kiel, Germany). His interdisciplinary work combines biological oceanography and evolutionary biology to investigate the potential for evolutionary adaptation to ocean acidification in marine phytoplankton.

The uptake of fossil fuel-derived carbon dioxide by the surface ocean alters seawater carbonate chemistry and results in a drop in ocean pH (Caldeira and Wickett 2003). These changes, dubbed ocean acidification, have a severe impact on many marine organisms, especially those that build their cell walls, shells, scales or skeletons from calcium carbonate (Orr et al., 2005).

Coccolithophores, a group of planktonic microalgae that are among the most productive calcifying organisms in the sea (Westbroek et al., 1989), were found to be sensitive to ocean acidification with most studies showing a decline in growth and calcification rate at increased CO2 levels (Riebesell and Tortell 2011).

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Effects of ocean acidification on iron availability to marine phytoplankton

Dalin Shi is currently a professor at the State Key Laboratory of Marine Environmental Science, Xiamen University, China. His research focuses on the biogeochemical cycling of trace metals in the ocean and their roles in the global carbon and nitrogen cycles.

About one-third of the anthropogenic carbon dioxide (CO2) released into the atmosphere dissolves in the ocean, increasing the partial pressure of CO2 (pCO2) and lowering the pH in surface water. These changes in seawater chemistry, commonly referred to as ocean acidification, will likely have significant effects on marine phytoplankton, which are responsible for about half of the contemporary global primary production (Field et al., 1998) and form the basis of all marine food webs.

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Ocean acidification report presented at United Nations

A report co-ordinated by Dr Sebastian Hennige and Professor Murray Roberts from the University’s Centre for Marine Biodiversity & Biotechnology (Life Sciences) was presented at the United Nations in New York on 18 June 2013.

Life in a changing ocean

‘Life in a Changing Ocean’ is an updated synthesis of the impacts of ocean acidification on marine biodiversity written by world authorities on the subject from Australia, China/Hong Kong, France, Germany, India, Japan, Monaco, Norway, Sweden, UK and USA.

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Article sur l’acidification de l’océan dans la rubrique Science de Tai Kona (in French)

Le bimestriel Tai Kona, Notre magazine de la Mer, n°3 juin/juillet 2013 présente dans la rubrique Science un article sur le sujet de l’acidification de l’océan co-rédigé par Gilles Boeuf, Président du Muséum National d’Histoire Naturelle et Lionel Loubersac, ancien délégué de l’Ifemer en Nouvelle-Calédonie.

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Floating tubes test sea-life sensitivity

Ocean labs probe effects of ocean acidification on ecosystems.

Researchers suspend 20-metre-tall sacs in a Swedish fjord to enclose entire ecosystems for study.

Global warming is not the only worrying consequence of rising carbon emissions. As levels of carbon dioxide increase in the atmosphere, more of the gas dissolves into the oceans, making the water more acidic. Marine scientists fear that the conditions will disrupt ecosystems by, for example, inhibiting some organisms’ ability to build shells. Yet the effects are unclear: in small-scale laboratory tests, certain species have proved surprisingly resilient, and some even flourish.

Marine biologist Ulf Riebesell says that these results tell only part of the story: scientists need to scale up and examine whole ecosystems. Lab studies of isolated species ignore variables such as competition, predation and disease, he says. Even minor effects of acidification on the fitness of individual species — especially small photo­synthetic organisms such as phytoplankton — can upset food chains, eventually harming larger species. “If you only focus on the lab results, you are being misled,” he says.

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Ocean acidification is chemistry, not conjecture

As a scientist working on the impact of climate change on marine ecosystems, one of my duties is to communicate my work. My main goal is to convince students, citizens, economists and politicians that we need to take urgent action to reduce our carbon dioxide emissions. This is not an easy task and I often face very difficult questions. Are we really warming the planet? Is there really a link to our carbon dioxide emissions?

I am not a climate scientist and I do not have the expertise to judge the quality of the science behind global warming. But while I’m not a chemist either, I can understand that if carbon dioxide (CO2) is dissolved in water (H2O), it turns into carbonic acid (H2CO3). This is such a simple relationship that there is no place for controversy.

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Manche mögen’s sauer (audio; in German)

Wie gut Organismen mit der Ozeanversauerung zurechtkommen

Lange ging man davon aus, dass besonders kalkhaltige Organismen Schwierigkeiten mit der Ozeanversauerung haben würden. Forscher wollen jetzt weitere Ursachen gefunden haben. Sie untersuchen auch Auswirkungen der Versauerung auf das Gleichgewicht des Ökosystems.

Sam Dupont plant den Krieg der Sterne. In seinem Labor am Sven Lovén Zentrum in Kristineberg bereitet der Forscher seine Akteure darauf vor: Er setzt einen Handteller großen, lila gefärbten Seestern in ein Aquarium. Im Nachbarbecken sitzt ein Sonnen-Seestern. Er ist mindestens viermal so groß und ernährt sich mit Vorliebe von kleineren Seesternen. Ein paar Wochen lang können sich die beiden Widersacher in ihren Aquarien an einen neuen pH-Wert gewöhnen. Dupont hat sie in saureres Meerwasser gesetzt, um sie anschließend aufeinander loszulassen. Er vermutet, dass sich der saurere pH-Wert auf das Fluchtverhalten des kleinen Seesterns auswirkt.

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Haven försuras snabbt (in Swedish)

Hot mot växter och djur. Världshaven försuras rekordsnabbt och ingen vet hur det påverkar ekosystemen. Nu efterlyser forskare nya, bättre experiment.

Jordens hav blir allt surare. Det är en effekt av att vattnet tar upp mycket av den koldioxid som finns i luften. I takt med att koldioxidutsläppen ökar blir också försurningen större. De senaste 150 åren har surhetsgraden ökat med 30 procent och forskare tror att försurningen kommer att gå allt snabbare de kommande hundra åren. Men kunskapen om hur framtidens hav kommer att se ut är mycket bristfällig.

– Ingen vet det idag. Jag vet däremot med hundra procents säkerhet att det kommer att bli förändringar. Vissa arter kommer att dö ut redan inom några decennier om vi inte minskar koldioxidutsläppen, säger marinbiologen Sam Dupont vid Göteborgs universitet.

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Ocean acidification in the IPCC AR5 WG II

OUP book