Evaluating the sensor-equipped autonomous surface vehicle C-Worker 4 as a tool for identifying coastal ocean acidification and changes in carbonate chemistry

The interface between land and sea is a key environment for biogeochemical carbon cycling, yet these dynamic environments are traditionally under sampled. Logistical limitations have historically precluded a comprehensive understanding of coastal zone processes, including ocean acidification. Using sensors on autonomous platforms is a promising approach to enhance data collection in these environments. Here, we evaluate the use of an autonomous surface vehicle (ASV), the C-Worker 4 (CW4), equipped with pH and pCO2 sensors and with the capacity to mount additional sensors for up to 10 other parameters, for the collection of high-resolution data in shallow coastal environments. We deployed the CW4 on two occasions in Belizean coastal waters for 2.5 and 4 days, demonstrating its capability for high-resolution spatial mapping of surface coastal biogeochemistry. This enabled the characterisation of small-scale variability and the identification of sources of low pH/high pCO2 waters as well as identifying potential controls on coastal pH. We demonstrated the capabilities of the CW4 in both pre-planned “autonomous” mission mode and remote “manually” operated mode. After documenting platform behaviour, we provide recommendations for further usage, such as the ideal mode of operation for better quality pH data, e.g., using constant speed. The CW4 has a high power supply capacity, which permits the deployment of multiple sensors sampling concurrently, a shallow draught, and is highly controllable and manoeuvrable. This makes it a highly suitable tool for observing and characterising the carbonate system alongside identifying potential drivers and controls in shallow coastal regions.

Continue reading ‘Evaluating the sensor-equipped autonomous surface vehicle C-Worker 4 as a tool for identifying coastal ocean acidification and changes in carbonate chemistry’

Coastal acidification adaption and mitigation strategies, webinars

Ocean and coastal acidification (OCA) threatens marine ecosystems and the coastal communities that rely on them. Actions and best practices to adapt to and mitigate impacts of OCA, such as buffering sediments, restoring seagrasses and conserving refugia is an area of active research. Hear from five speakers about strategies to mitigate impacts of OCA on coral reefs and shellfish resources.

Continue reading ‘Coastal acidification adaption and mitigation strategies, webinars’

Autonomous minisubmarine measures seawater conditions

Forecasts of carbonate chemistry in coastal ecosystems determined from seasonal robotic measurements can improve fisheries management and help mitigate short-term ocean acidification events.

A yellow submarine glider floats on the ocean surface.
A Slocum glider operated by Rutgers University is deployed off the coast of New Jersey. Underwater gliders equipped with sensors provide live data that help scientists understand in real time how acidity is changing in Earth’s oceans. Credit: Liza Wright-Fairbanks, Rutgers University

Since the Industrial Revolution began in the mid-18th century, Earth’s oceans have absorbed about one third of the carbon dioxide emitted through human activities. The ensuing roughly 30% increase in ocean acidity has reduced the amount of carbonate available for calcifying organisms such as corals and oysters to construct their skeletons and shells. As ocean acidity continues to climb, these biological structures could begin to dissolve or cost organisms extra energy to maintain, potentially disrupting marine food webs.

Continue reading ‘Autonomous minisubmarine measures seawater conditions’

State legislation on ocean & coastal acidification webinar (video)

March 19, 2020, from 2pm – 4 pm Eastern

Holly GalavottiU.S. Environmental Protection Agency; Mike MolnarCoastal States OrganizationJustine KimballPh.D, Senior Program Manager, California Ocean Protection CouncilCaren Braby, Marine Resources Program Manager, Oregon Department of Fish and WildlifeDonald WitherillDirector, Division of Environmental Assessment, Maine Department of Environmental Protection

Summary: Ocean and coastal acidification threatens marine ecosystems and the coastal communities that rely on them. The U.S. EPA’s Ocean and Coastal Acidification Program promotes awareness and conducts research and long-term monitoring to mitigate impacts of acidification and develop solutions. States play a critical role in guarding their coastlines against local causes of acidification.

Hear from three states who have successfully enacted state legislation on ocean and coastal acidification as they share their experience and discuss actions that have been implemented to address acidification in their state.

Flyer for the State Legislation on Ocean & Coastal Acidification Webinar

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IGS global seminar series: glacial water impacts on the chemical characteristics of sea ice and seawater and ocean acidification in Svalbard Fjords

Speaking: Agneta Fransson, Norwegian Polar Institute, Oslo, Norway

Event Type: Webinars and Virtual Events

When: 9 December 2020

Where: Online: 12:00 pm AKST, 4:00 pm EST

International Glaciological Society Global Seminar:

Speaking: Agneta Fransson, Norwegian Polar Institute, Oslo, Norway, “Glacial Water Impacts on the Chemical Characteristics of Sea Ice and Seawater and Ocean Acidification in Svalbard Fjords”.

Continue reading ‘IGS global seminar series: glacial water impacts on the chemical characteristics of sea ice and seawater and ocean acidification in Svalbard Fjords’

Event: dive deeper – ocean acidification

Friday, 18 December 2020, 15:00

WonderLab Museum


In this edition of Dive Deeper we will talk about what ocean acidification, the problems it causes and what we can do to minimize our impact. To participate in the activity you will want, RED cabbage water (you can get this by boiling a head of cabbage in water for 15-20 minutes then allowing it to cool), white vinegar, 2 jars, a star and some water. We will be covering Indiana academic standards for 1st, 4th, and 5th grade Earth and Atmospheric Science, 3rd and 4th grade Life Science.

Click here to register for Zoom LIVE: https://zoom.us/meeting/register/tJMvc–sqD4jGdBpSa87JqQFl14E8stSGa83

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DNA damage and oxidative stress responses of mussels Mytilus galloprovincialis to paralytic shellfish toxins under warming and acidification conditions – elucidation on the organ-specificity

Commonly affected by changes in climate and environmental conditions, coastal areas are very dynamic environments where shellfish play an important ecological role. In this study, the oxidative stress and genotoxic responses of mussels (Mytilus galloprovincialis) exposed to paralytic shellfish toxin (PST) – producing dinoflagellates Gymnodinium catenatum were evaluated under i) current conditions (CC: 19 °C; pH 8.0), ii) warming (W: 24 °C; pH 8.0), iii) acidification (A:19 °C; pH 7.6) and iv) combined effect of warming and acidification (WA: 24 °C; pH 7.6). Mussels were fed with G. catenatum for 5 days, and to a non-toxic diet during the following 10 days. A battery of oxidative stress biomarkers and comet assay was performed at the peak of toxin accumulation and at the end of the post-exposure phase. Under CC, gills and hepatopancreas displayed different responses/vulnerabilities and mechanisms to cope with PST. While gills presented a tendency for lipid peroxidation (LPO) and genetic damage (expressed by the Genetic Damage Indicator – GDI), hepatopancreas seems to better cope with the toxins, as no LPO was observed. However, the mechanisms involved in hepatopancreas protection were not enough to maintain DNA integrity. The absence of LPO, and the antioxidant system low responsiveness, suggests DNA damage was not oxidative. When exposed to toxic algae under W, toxin-modulated antioxidant responses were observed in both gills and hepatopancreas. Simultaneous exposure to the stressors highlighted gills susceptibility with a synergistic interaction increasing DNA damage. Exposure to toxic algae under A led to genotoxicity potentiation in both organs. The combined effect of WA did not cause relevant interactions in gills antioxidant responses, but stressors interactions impacted LPO and GDI. Antioxidant responses and LPO pointed out to be modulated by the environmental conditions in hepatopancreas, while GDI results support the dominance of toxin-triggered process. Overall, these results reveal that simultaneous exposure to warming, acidification and PSTs impairs mussel DNA integrity, compromising the genetic information due to the synergetic effects. Finally, this study highlights the increasing ecological risk of harmful algal blooms to Mytilus galloprovinciallis populations.

Continue reading ‘DNA damage and oxidative stress responses of mussels Mytilus galloprovincialis to paralytic shellfish toxins under warming and acidification conditions – elucidation on the organ-specificity’

Assessing coral reef condition indicators for local and global stressors using Bayesian networks

Coral reefs are highly valued ecosystems currently threatened by both local and global stressors. Given the importance of coral reef ecosystems, a Bayesian network approach can benefit an evaluation of threats to reef condition. To this end, we used data to evaluate the overlap between local stressors (overfishing and destructive fishing, watershed‐based pollution, marine‐based pollution, and coastal development threats), global stressors (acidification and thermal stress) and management effectiveness with indicators of coral reef health (live coral index, live coral cover, population bleaching, colony bleaching and recently killed corals). Each of the coral health indicators had Bayesian networks constructed globally and for Pacific, Atlantic, Australia, Middle East, Indian Ocean, and Southeast Asia coral reef locations. Sensitivity analysis helped evaluate the strength of the relationships between different stressors and reef condition indicators. The relationships between indicators and stressors were also evaluated with conditional analyses of linear and nonlinear interactions. In this process, a standardized direct effects analysis was emphasized with a target mean analysis to predict changes in the mean value of the reef indicator from individual changes to the distribution of the predictor variables. The standardized direct effects analysis identified higher risks in the Middle East for watershed‐based pollution with population bleaching and Australia for overfishing and destructive fishing with living coral. For thermal stress, colony bleaching and recently killed coral in the Indian Ocean were found to have the strongest direct associations. For acidification threat, Australia had a relatively strong association with colony bleaching and the Middle East had the strongest overall association with recently killed coral although extrapolated spatial data were used for the acidification estimates. The Bayesian network approach helped to explore the relationships among existing databases used for policy development in coral reef management by examining the sensitivity of multiple indicators of reef condition to spatially‐distributed stress.

Continue reading ‘Assessing coral reef condition indicators for local and global stressors using Bayesian networks’

Retrieving monthly and interannual total-scale pH (pHT) on theEast China Sea shelf using an artificial neural network:ANN-pHT-v1 (update)

While our understanding of pH dynamics has strongly progressed for open-ocean regions, for marginal seas such as the East China Sea (ECS) shelf progress has been constrained by limited observations and complex interactions between biological, physical and chemical processes. Seawater pH is a very valuable oceanographic variable but not always measured using high-quality instrumentation and according to standard practices. In order to predict total-scale pH (pH(T)) and enhance our understanding of the seasonal variability of pHT on the ECS shelf, an artificial neural network (ANN) model was developed using 11 cruise datasets from 2013 to 2017 with coincident observations of pHT, temperature (T), salinity (S), dissolved oxygen (DO), nitrate (N), phosphate (P) and silicate (Si) together with sampling position and time. The reliability of the ANN model was evaluated using independent observations from three cruises in 2018, and it showed a root mean square error accuracy of 0.04. The ANN model responded to T and DO errors in a positive way and S errors in a negative way, and the ANN model was most sensitive to S errors, followed by DO and T errors. Monthly water column pHT for the period 2000-2016 was retrieved using T, S, DO, N, P and Si from the Changjiang biology Finite-Volume Coastal Ocean Model (FVCOM). The agreement is good here in winter, while the reduced performance in summer can be attributed in large part to limitations of the Changjiang biology FVCOM in simulating summertime input variables.

Continue reading ‘Retrieving monthly and interannual total-scale pH (pHT) on theEast China Sea shelf using an artificial neural network:ANN-pHT-v1 (update)’

Presentation: Ocean acidification on the Great Barrier Reef: the future is now

Thursday 26th of November 11:00 to 12:00hrs (AEST)

https://jcu.zoom.us/j/88350515490 Password: 730762

Abstract:Ocean acidification, the increase in seawater CO2 with all its associated consequences, is relatively well understood in open oceans. In shelf seas such as the Great Barrier Reef, processes are much less understood, due to complex interactions with water quality and biological processes. I will show new data how ocean acidification has been progressing in the Great Barrier Reef, and its direct and indirect effects on coral reefs of the GBR, including shifts from corals to seaweed, impaired coral recruitment, and increasing bioerosion. Our new data from the Great Barrier Reef suggest that functional changes are already occurring, measurably affecting coralline algae, and coral recruitment and promoting macroalgae. Although most reefs are still net accreting, some reefs in marginal locations and high latitudes have started to dissolve in winter. The future integrity of GBR reefs under increasing ocean acidification will depend on their specific biophysical properties, and effective mitigation of the cumulative stressors from nutrient pollution. Unlike a clean-up of water quality, OA is irreversible on time scales of thousands of years, and there is no latitudinal escape, re-emphasising the imperative for rapid action on atmospheric CO2 pollution.

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Ocean acidification in the IPCC AR5 WG II

OUP book