Archive for September, 2018

Abstract submission open: ASLO Aquatic Sciences Meeting 2019 acidification session

The ASLO 2019 Aquatic Sciences Meeting will include a session on Acidification (session #CS05).

Deadline for Abstract Submissions: 22 October 2018

Meeting information: ASLO 2019 Aquatic Sciences Meeting: Planet Water Challenges and Successes, 23 February – 2 March 2019, San Juan, Puerto Rico

Meeting description: A wealth of topics will be discussed at the meeting, many stemming from key areas of importance to the area itself at this crucial time – the role of science at the center of all economic, societal and environmental recovery and development efforts, studies on renewable energy, environmental sustainability, clean water, and rebuilding and maintaining terrestrial ecosystems. 

Science and innovative problem-solving are keys to creating a better and more resilient world, and this speaks truth to the residents of Puerto Rico. While ASLO’s meeting in San Juan will benefit Puerto Rico for the short-term, the outcomes of the ASLO 2019 Aquatic Sciences Meeting can impact the island for the long-term.  This presents an excellent opportunity for ASLO to showcase how they are doing their part to train scientists in communication to the public and to teach effective research skills to future generations. As with all ASLO meetings, organized activities will be available that will allow participants to use culturally-relevant projects and strategies to make science more engaging. 

The scientific program will take place Sunday, 24 February, through Friday, 1 March.  The full meeting dates are set Saturday, 23 February, to Saturday, 2 March, to allow meeting participants to take part in educational activities, volunteer opportunities, and culturally relevant events that will focus on environmental and ecosystem restoration as well as the resilience of the land.

Submitting abstracts: Please send your submissions to session co-chairs Chris Langdon ( and George Waldbusser ( in addition to submitting them at the meeting website.

Continue reading ‘Abstract submission open: ASLO Aquatic Sciences Meeting 2019 acidification session’

Origin and dynamics of dissolved organic matter in a mariculture area suffering from summertime hypoxia and acidification

Based on six cruises from March to September in 2016, we investigated monthly distributions of dissolved organic matter (DOM) and ancillary water chemistry parameters in a mariculture area in the Northern Yellow Sea, where summertime hypoxia and seawater acidification were observed. The most severe oxygen depletion (hypoxia covered approximately one-third of the aquaculture area) and the largest pH decrease (8.07 ± 0.05 in surface layer vs. 7.66 ± 0.07 in bottom layer) were revealed in August. Concentration of dissolved organic carbon (DOC) and the absorption properties of chromophoric DOM (CDOM) were used to characterize DOM. Results showed that DOM mainly originated from marine in situ processes. In March, a DOM pool with the lowest DOC concentration of 211 ± 23 μmol L−1 and nearly uniform optical characteristics were presented in the well-mixed water column. In August, however, DOC increased to 361 ± 29 μmol L−1 in the surface layer and 342 ± 25 μmol L−1 in the bottom layer. Two non-linear relationships between the absorption coefficient at 355 nm [aCDOM(355)] and the absorption spectral slope over 275–295 nm (S275−295) were revealed. According to modeling results, the non-linear relationships were mostly caused by the conservative mixing of a refractory CDOM pool with a freshly produced CDOM pool. Apparent oxygen utilization in August was positively related to DOC, but not to aCDOM(355) and S275−295, presumably due to multiple sources of CDOM in bottom waters. Both aCDOM(355) and S275−295 respond largely to decreasing pH; however, they would be less affected by ocean acidification since this process leads to a limited pH decline.

Continue reading ‘Origin and dynamics of dissolved organic matter in a mariculture area suffering from summertime hypoxia and acidification’

Meet Darren Pilcher

Darren Pilcher is a research scientist with NOAA’s Pacific Marine Environmental Lab who is currently working on modeling OA in the Bering Sea.

Q: How did you get into the field of OA?

In graduate school, I studied the processes that determine the exchange of carbon between the water and the atmosphere.  The oceans provide a critical service by taking up a portion of the carbon that we emit into the atmosphere, but unfortunately this process also results in ocean acidification.  I was interested in understanding how this process will effect ocean ecosystems, particularly in high-latitude waters such as Alaska, where OA and climate change are occurring more rapidly.

Q: What kind of background to you need for the modeling work you do?

I was a chemistry major as an undergraduate, so you don’t necessarily need a computer science degree, however you do need a strong background in mathematics and physical science since this is the language that our computational models are written and operated in.

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Clams and climate change — new Alaska study examines the connections


Shellfish biologist Jacqueline Ramsay monitors ocean chemistry using a Burke-O-Lator at Alutiiq Pride Shellfish Hatchery. (Photo by Paula Dobbyn)

July fourth in Seward is known for its fireworks, festivities and the grueling Mt. Marathon race that draws elite athletes from around the world. But for a University of Alaska Fairbanks (UAF) graduate student, the holiday took on a whole different meaning this year.

“It was the first time I was able to successfully spawn razor clams in the lab,” said Marina Washburn, who is working on her master’s degree at UAF’s College of Fisheries and Ocean Sciences (CFOS). Her research is based out of Seward.
As locals and visitors watched a parade snake through downtown, Washburn stared into a bucket, her eyes wide as she observed new life forming at the bottom.

“We weren’t sure it was possible to spawn razor clams. My first attempt failed. When they finally hatched, I felt I could celebrate,” she said.

Washburn needed clam larvae to study how ocean acidification affects the shellfish. Razor clams have virtually disappeared on the eastern shores of Cook Inlet. Clam populations in Southcentral Alaska overall have declined since the late 1990s, according to University of Alaska researchers. It’s negatively affected people who clam for subsistence, recreation and commercial purposes.

Continue reading ‘Clams and climate change — new Alaska study examines the connections’

Preparation and optimization of optical pH sensor based on sol-gel

Making use of the sol-gel technique, an optical pH sensor was prepared, which was made from an organic carrier with four indictors including congo red, bromophenol blue, cresol red, and chlorophenol red, cross-linked by tetraethyl orthosilicate (TEOS) and cellulose acetate. The actual detection range of the optical pH sensor is 2.5–11.0. The optimal ratio of ethyl orthosilicate, absolute ethanol, deionized water, and hydrochloric acid in glue precursor of the sensor-sensitive membrane was explored. The orthogonal experiment was designed to optimize the dosage of cellulose acetate, N,N-dimethylformamide (DMF), indicator, hydrochloric acid, and precursor glue in preparing the sensor-sensitive membrane. The linearity, measurement accuracy, repeatability, stability, and response time of the prepared pH sensor were tested. The measurement results were analyzed using a support vector machine and linear regression. The experimental results show that the optical pH sensor has a measurement accuracy of up to 0.2 pH and better stability and repeatability than the traditional pH glass electrode.

Continue reading ‘Preparation and optimization of optical pH sensor based on sol-gel’

Arctic expedition finishes mission

Two unmanned ice stations have been set up to extend China’s ability to observe the northern seas, scientists from the Chinese icebreaker Xuelong said as they wrapped up their most recent expedition.

The domestically developed systems will monitor the interaction of gases, ice and the ocean in the Arctic region. The project will contribute to studies of the Arctic ecosystem and marine environment, scientists said at a media briefing on Wednesday after the return of Xuelong (Snow Dragon).

Measuring ocean acidification and the spread of microplastics were the other major objectives of the expedition of 23,150 kilometers, following on studies from last year.

Ocean acidification is internationally acknowledged as worsening in the Arctic, mainly as a result of rising carbon dioxide emissions. Also, microplastics may trigger environmental disasters, such as the bleaching of coral reefs and negative effects on marine biodiversity, researchers said.

“After carbon from emissions are absorbed, the seawater will be acidified and changes will happen to the local ecological community,” said Chen, adding that more than 3,000 bottles of water – samples from the surface to the sea floor – were collected for lab tests.

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Independent and interactive effects of reduced seawater pH and oil contamination on subsurface sediment bacterial communities

Ocean acidification may exacerbate the environmental impact of oil hydrocarbon pollution by disrupting the core composition of the superficial (0–1 cm) benthic bacterial communities. However, at the subsurface sediments (approximately 5 cm below sea floor), the local biochemical characteristics and the superjacent sediment barrier may buffer these environmental changes. In this study, we used a microcosm experimental approach to access the independent and interactive effects of reduced seawater pH and oil contamination on the composition of subsurface benthic bacterial communities, at two time points, by 16S rRNA gene-based high-throughput sequencing. An in-depth taxa-specific variance analysis revealed that the independent effects of reduced seawater pH and oil contamination were significant predictors of changes in the relative abundance of some specific bacterial groups (e.g., Firmicutes, Rhizobiales, and Desulfobulbaceae). However, our results indicated that the overall microbial community structure was not affected by independent and interactive effects of reduced pH and oil contamination. This study provides evidence that bacterial communities inhabiting subsurface sediment may be less susceptible to the effects of oil contamination in a scenario of reduced seawater pH.

Continue reading ‘Independent and interactive effects of reduced seawater pH and oil contamination on subsurface sediment bacterial communities’

Webinar: managing global acidification on a regional scale: how the US Mid-Atlantic and Northeast coastal acidification networks (MACAN and NECAN) are working to understand impacts through partnerships

Time: Oct 2, 2018 1:00 PM in Eastern Time (US and Canada)

Description: The chemistry of the ocean is changing. Carbon dioxide released through emissions and deforestation is absorbed and dissolved into the ocean. The regional Coastal Acidification Networks of the US Northeast and Mid-Atlantic (NECAN and MACAN) are consortiums of scientists, marine industry, and resource managers with a central goal of sharing information to better understand the impacts of acidification to appropriately manage and adapt to these conditions. Coordinators for NECAN and MACAN will discuss how these regional efforts work towards identifying and pursuing opportunities to understand coastal and ocean acidification in the Mid-Atlantic and Northeast, building upon the skills and interests of individual members and providing a forum to share best practices in monitoring, sampling collection, and researching effects to collectively meet the challenges of our changing coastal and ocean waters.

Continue reading ‘Webinar: managing global acidification on a regional scale: how the US Mid-Atlantic and Northeast coastal acidification networks (MACAN and NECAN) are working to understand impacts through partnerships’

$11.75M awarded for ocean acidification, coral ecosystems, HABs, and hypoxia research in 2018

NOAA’s National Centers for Coastal Ocean Science (NCCOS) are pleased to announce a total of $4.37 million in funding for 16 new research awards in Fiscal Year 2018, with an additional $7.38 million for 30 continuing awards. The newly funded projects span the ecology and oceanography of harmful algal blooms (announced earlier this month), coastal hypoxia research, ocean acidification thresholds in coastal ecosystems, and coral ecosystem connectivity in the western Gulf of Mexico, and involve over 74 scientists at 39 institutions. All awards went through a rigorous competitive peer review process. Regions of research projects include the Great Lakes, New England, the Gulf of Mexico, coastal California, the Pacific Northwest, Chesapeake Bay, Alaska, and Florida.

NCCOS is funding the latest scientific research to support environmental managers coping with increasing and recurring toxic algae and hypoxia, potential loss of coral reef habitat, and the threats of ocean acidification. Improved understanding of these timely coastal threats will lead to better predictions, mitigation, and possible solutions to support safe and healthy coastal communities and economies.

Continue reading ‘$11.75M awarded for ocean acidification, coral ecosystems, HABs, and hypoxia research in 2018’

Arctic coralline algae elevate surface pH and carbonate in the dark

Red coralline algae are projected to be sensitive to ocean acidification, particularly in polar oceans. As important ecosystem engineers, their potential sensitivity has broad implications, and understanding their carbon acquisition mechanisms is necessary for making reliable predictions. Therefore, we investigated the localized carbonate chemistry at the surface of Arctic coralline algae using microsensors. We report for the first time carbonate ion concentration and pH measurements ([CO32-]) at and above the algal surface in the microenvironment. We show that surface pH and [CO32-] are higher than the bulk seawater in the light, and even after hours of darkness. We further show that three species of Arctic coralline algae have efficient carbon concentrating mechanisms including direct bicarbonate uptake and indirect bicarbonate use via a carbonic anhydrase enzyme. Our results suggest that Arctic corallines have strong biological control over their surface chemistry, where active calcification occurs, and that net dissolution in the dark does not occur. We suggest that the elevated pH and [CO32-] in the dark could be explained by a high rate of light independent carbon fixation that reduces respiratory CO2 release. This mechanism could provide a potential adaptation to ocean acidification in Arctic coralline algae, which has important implications for future Arctic marine ecosystems.

Continue reading ‘Arctic coralline algae elevate surface pH and carbonate in the dark’

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Ocean acidification in the IPCC AR5 WG II

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