Archive for April, 2019

Save the date: 5th International Symposium on the Ocean in a High-CO2 World (Lima, Peru, 7-10 September 2020)

The SOLAS-IMBER Working Group on Ocean Acidification (SIOA) is pleased to announce that the 5th International Symposium on the Ocean in a High-CO2 World will be held in Lima, Peru during 7-10 September 2020. The lead organizers are Drs. Wilmer Carbajal (Pedro Ruiz Gallo National University, Peru) and Michelle Graco (Institute of the Sea of Peru, IMARPE) and colleagues, based on their successful bid that was submitted to the SIOA.

Continue reading ‘Save the date: 5th International Symposium on the Ocean in a High-CO2 World (Lima, Peru, 7-10 September 2020)’

Ocean acidification ‘could have consequences for millions’

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The control site for the Japan research shows high biodiversity comprising tropical scleractinian corals and temperate macroalgae. (Credit: Ben Harvey)

Ocean acidification could have serious consequences for the millions of people globally whose lives depend on coastal protection, fisheries and aquaculture, a new publication suggests.

Writing in Emerging Topics in Life Sciences, scientists say that only significant cuts in fossil fuel emissions will prevent the changes already evident in areas with projected future carbon dioxide levels becoming more widespread.

They also call for a binding international agreement that builds on the United Nations Sustainable Development Goals to minimise and address the impacts of ocean acidification.

Continue reading ‘Ocean acidification ‘could have consequences for millions’’

Ocean acidification impacts on coastal ecosystem services due to habitat degradation

The oceanic uptake of anthropogenic carbon dioxide emissions is changing seawater chemistry in a process known as ocean acidification. The chemistry of this rapid change in surface waters is well understood and readily detectable in oceanic observations, yet there is uncertainty about the effects of ocean acidification on society since it is difficult to scale-up from laboratory and mesocosm tests. Here, we provide a synthesis of the likely effects of ocean acidification on ecosystem properties, functions and services based on observations along natural gradients in pCO2. Studies at CO2 seeps worldwide show that biogenic habitats are particularly sensitive to ocean acidification and that their degradation results in less coastal protection and less habitat provisioning for fisheries. The risks to marine goods and services amplify with increasing acidification causing shifts to macroalgal dominance, habitat degradation and a loss of biodiversity at seep sites in the tropics, the sub-tropics and on temperate coasts. Based on this empirical evidence, we expect ocean acidification to have serious consequences for the millions of people who are dependent on coastal protection, fisheries and aquaculture. If humanity is able to make cuts in fossil fuel emissions, this will reduce costs to society and avoid the changes in coastal ecosystems seen in areas with projected pCO2 levels. A binding international agreement for the oceans should build on the United Nations Sustainable Development Goal to ‘minimise and address the impacts of ocean acidification’.

Continue reading ‘Ocean acidification impacts on coastal ecosystem services due to habitat degradation’

During abrupt warming, lobsters in acidic water have reduced heart function, fewer infection-fighting cells

During abrupt warming, lobsters in acidic water have reduced heart function, fewer infection-fighting cellsOcean acidification and warming may be an unhealthy combination for lobsters, say University of Maine scientists.

The heart rates of lobsters (Homarus americanus) who lived 60 days in water with predicted end-century ocean pH levels became erratic significantly sooner during an abrupt warming event than those of lobsters in ocean water with current pH levels.

The findings could be “likened to putting people on a treadmill and finding that people exposed to ocean acidification fell off the treadmill from exhaustion much sooner than those not exposed,” says Heather Hamlin, a reproductive endocrinologist and associate professor in the School of Marine Sciences.

Continue reading ‘During abrupt warming, lobsters in acidic water have reduced heart function, fewer infection-fighting cells’

Responses to ocean acidification and diurnal temperature variation in a commercially farmed seaweed, Pyropia haitanensis (Rhodophyta)

To investigate carbon and nitrogen metabolism in Pyropia haitanensis in response to the combined conditions of ocean acidification and diurnal temperature variation, maricultured thalli were tested in acidified culture under different temperature treatments. The results showed a combined effect of ocean acidification and diurnal temperature difference on the C and N metabolism and growth of P. haitanensis. In acidifed culture, algal growth, maximum photosynthetic rate, nitrate reductase (NR) activity, amino acid (AA) content and AA score (AAS) were more significantly enhanced in seaweed under diurnal temperature variation than in seaweed at constant temperature. In acidified seawater, soluble carbohydrates in P. haitanensis increased due to greater dissolved inorganic carbon (DIC), whereas soluble proteins decreased. Under the diurnal temperature treatment, higher temperature during the light period enhanced accumulation of algal photosynthates, whereas lower temperature in the dark period reduced energy consumption, resulting in enhanced algal growth, AA content and AAS. We concluded that suitable diurnal temperature difference would be conducive to C fixation and N assimilation under ocean acidification. However, excessively high temperatures would depress algal photosynthesis and increase energy consumption, thereby exerting a negative effect on algal growth.

Continue reading ‘Responses to ocean acidification and diurnal temperature variation in a commercially farmed seaweed, Pyropia haitanensis (Rhodophyta)’

Transport of carbon dioxide and heavy metals from hydrothermal vents to shallow water by hydrate-coated gas bubbles

Deep-sea hydrothermal plumes are of major importance in the biogeochemical ocean cycles and in this study we focus on plumes emitted from the Jan Mayen vent fields in the Norwegian-Greenland Sea. These vent fields are of interest because of the high CO2 concentrations and also due to the different styles of venting occurring here. Venting at these sites occurs between 550 and 700 m depth and is characterized by the release of hydrate coated bubbles as well as focused flow venting. This study aims to enhance our current understanding of the impact of CO2 rich hydrate coated bubbles on the water column as well as the interaction between hydrothermally derived gases and metals in the water column. Three water column surveys were conducted in this area in between 2012 and 2014, in which the non-buoyant plume (NBP) produced by focused flow venting from both the Troll Wall and the Perle & Bruse vent sites was identified by primordial helium (3He), methane (CH4), carbon dioxide (CO2) and dissolved manganese (Mn) enrichments close to 500 m water depth. Our results show that venting of hydrate coated CO2 rich bubbles increases bubble rise height, which results in shallow acidification locally above the vent sites. A polymetallic anomaly in the mid-depth water column above the NBP is also hypothesized to be a result of the hydrate coated bubbles. We argue that nanoparticles get sequestered to the hydrate lattice and travel with the bubbles until the lattice becomes unstable due to gas expansion upon depressurization during ascent. This process could fuel the primary production in the pelagic water column.

Continue reading ‘Transport of carbon dioxide and heavy metals from hydrothermal vents to shallow water by hydrate-coated gas bubbles’

New web-based simulation and decision support tool for experimental design: the Multiple Environmental Driver Design Lab for Experiments (MEDDLE)

A new guide to running best practice experiments in ocean research was developed by the Scientific Committee on Oceanic Research (SCOR) Working Group 149. The Multiple Environmental Driver Design Lab for Experiments (MEDDLE) provides learning material and user-friendly experimental design tools to help scientists create accurate and statistically meaningful single and multi driver experiments. The MEDDLE simulator is a computer model that mimics some typical responses of marine organisms to multiple drivers. It allows users to run several virtual laboratory experiments by setting the combined levels of the drivers, choosing the number of replicates, and considering natural variability. The aim of this new tool is to provide guidance in supporting best practices for oceanic research.

Continue reading ‘New web-based simulation and decision support tool for experimental design: the Multiple Environmental Driver Design Lab for Experiments (MEDDLE)’

Experimenting with multistressors

Understanding climate change impacts on species and ecosystems is complex, as individual systems will be exposed to different effects. Ocean acidification is one example stressor (or driver), but it is unlikely to occur in isolation; climate change will result in multiple stressors to organisms, such as warming, nutrient changes and stratification of the water column. All of these will affect and interact with each other in different ways. To date, most research has considered a single stressor. To understand what the future ocean may look like, there is a need to consider many possible permutations of stressors, and their synergies and antagonistic effects.

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Dungeness crabs in changing waters: research on ocean acidification (video)

Research suggests that Dungeness crabs are sensitive to the increasing acidity of our oceans. This research will help answer the question of how ocean acidification affects Dungeness crab and will inform strategies to sustain this robust fishery.

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Expert assessment of risks posed by climate change and anthropogenic activities to ecosystem services in the deep North Atlantic

Sustainable development of the ocean is a central policy objective in Europe through the Blue Growth Strategy and globally through parties to the Convention on Biological Diversity. Achieving sustainable exploitation of deep sea resources is challenged due to the huge uncertainty around the many risks posed by human activities on these remote ecosystems and the goods and services they provide. We used a Delphi approach, an iterative expert-based survey process, to assess risks to ecosystem services in the North Atlantic Ocean from climate change (water temperature and ocean acidification), the blue economy (fishing, pollution, oil and gas activities, deep seabed mining, maritime and coastal tourism and blue biotechnology), and their cumulative effects. Ecosystem services from the deep sea, identified through the Millennium Ecosystem Assessment framework, were presented in an expert survey to assess the impacts of human drivers on these services. The results from this initial survey were analyzed and then presented in a second survey. The final results, based on 55 expert responses, indicated that pollution and temperature change each pose a high risk to more than 28% of deep-sea ecosystem services, whilst ocean acidification, and fisheries both pose a high risk to more than 19% of the deep-sea ecosystem services. Services considered to be most at risk of being impacted by anthropogenic activities were biodiversity and habitat as supporting services, biodiversity as a cultural service, and fish and shellfish as provisioning services. Tourism and blue biotechnology were not seen to cause serious risk to any of the ecosystem services. The negative impacts from temperature change, ocean acidification, fishing, pollution, and oil and gas activities were deemed to be largely more probable than their positive impacts. These results expand our knowledge of how a broad set of deep-sea ecosystem services are impacted by human activities. Furthermore, the study provides input in relation to future priorities regarding research in the Atlantic deep sea.

Continue reading ‘Expert assessment of risks posed by climate change and anthropogenic activities to ecosystem services in the deep North Atlantic’


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