June 21, 2017

MIT Sea Grant Ocean Acidification Seminar Tuesday June 27th at 12:00

Please join us Tuesday June 27 at MIT Sea Grant for presentations by six MIT Sea Grant funded researchers on their ocean acidification projects.

Tuesday June 27th
12:00-3:00
NW98-152 MIT Sea Grant Large Conference Room
Please note that our location has changed
MIT Sea Grant is now located at 12 Emily St. Cambridge, MA

We encourage attendees to bring their lunch to the seminar. The seminar is open to the public. Please pass this announcement along to interested parties. Questions can be sent to KBaltes@mit.edu.

If you are unable to attend in person, the seminar will be streamed live: https://www.youtube.com/user/mitseagrant2/live


Quantification of the Contribution of Wastewater Effluent to Coastal Ocean Acidification
Scott Doney and Jennie Rheuban
Woods Hole Oceanographic Institution

The objective of our SeaGrant project is to determine the influence of wastewater treatment facility effluent on coastal acidification in Buzzards Bay. Over the past few decades, estuaries around Buzzards Bay have experienced degrading water quality due to coastal nutrient eutrophication that can also lead to acidification. Our study combines hydrodynamic/plume modeling with a field sampling campaign to characterize the dispersion and biogeochemical impact of wastewater discharge. The talk will present new results from Fall, 2016 field sampling and model results for the Wareham River near the Wareham Wastewater Treatment Plant discharge.


How warming and acidifying oceans are impacting shell development in young American lobsters
Dean Robyn Hannigan
University of Massachusetts Boston

The American lobster fishery is a significant component of the coastal New England economy and community; in 2016, it landed over $530 million in Maine alone. The epicenter of this fishery, the Gulf of Maine (GoM), is warming faster than 99% of the world’s oceans due to shifting deep sea currents and changes in the Atlantic Multidecadal Oscillation (AMO) as a result of climate change. The GoM is also acidifying from increased carbon flux to coastal waters and increasing CO2 transfer across the boundary layer into the surface waters. Acidification is not only increasing the hydrogen ion content of the waters but decreasing availability of carbonate ions and changing, as a result, the saturation state of calcite and aragonite. Changes in the saturation state of carbonate minerals, particularly calcite, impacts the stability of exoskeletons such as that of the lobster whose shell is comprised of chitin proteins and calcite with strategic crystallization of calcium apatite Ca5(PO4)3(OH). We are examining the combined effects of ocean warming and acidification on shell development in larval and juvenile American lobsters. These life stages are inherently stressful due to the energetic demands on rapid growth and associated molting. Increased stress due to warming and acidification, we hypothesize, will compromise the structural integrity of the shell leading to deformation and potential increased incidence of epizootic shell disease. Similarly, we expect that changes in the carbonate chemistry of the water will alter the mineralogy of the carbonate-apatite in the shells leading to loss of calcium apatite at the opening of organule canals. This mineral appears to maintain a basic pH at the shell surface acting as a deterrent for bacterial incursion into the canals. Larvae and juveniles reared under variable conditions of temperature and pH show little difference in growth rate or survival. However, differences in mineralogy, as evaluated by spatial distributions of Ca and Mg using energy dispersive x-ray spectroscopy, do occur. Structural deformation of thorax shell structure also occurs in lobsters reared under experimental conditions. Lesions associated with bacterial infestation of the shell were also evident with morphology of the lesions as well as abundance and location on the shell differing across treatments and life stages. In addition to evaluation of shell structure and mineralogy we isolated RNA from the shells created a new reference transcriptome for the American lobster. Using this, we will determine differential expression of genes essential to biomineralization under future climate conditions. These data in combination with shell mineralogy, structure, and disease data will enable us to understand how disease susceptibility might change because of warming and acidification. Ultimately, the results of this work will inform the management of the lobster fishery so it remains sustainable into the future.


Impact of ocean acidification on calcification rate, shell properties, pallial fluid pH, and epigenetics of commercially important mollusks across critical life stages
Justin B. Ries
Northeastern University

This project aims to investigate the vulnerability of commercially important calcifying marine mollusks to ocean acidification (OA) at various stages of their life history. Specific projects include investigating: (1) impact of OA on calcification rates of limpets (Crepidula fornicata) and eastern oysters (Crassostrea virginica) during juvenile vs. adult stages; (2) impact of OA on shell structure of limpets (Crepidula fornicata), quahogs (Mercenaria mercenaria), soft shell clams (Mya arenaria), bay scallops (Argopecten irradians), sea scallops (Placopecten magellanicus), eastern oysters (C. virginica), and mussels (Mytilus edulis); (3) impacts of OA and warming on dissolution kinetics of mollusk shells; and (4) development of a novel pH microelectrode approach to measuring impact of OA on extrapallial calcifying fluid pH of mollusks. Although experimental studies are ongoing, initial results suggest that early-life-stage limpets are more vulnerable to OA than during their adult stage, while early-life-stage oysters are more resistant to OA than during their adult stage. Results also show that OA negatively impacts calcification rate and shell microstructure of a range of aragonitic (quahogs, soft-shell clams, limpets) and calcitic (oysters, bay scallops, sea scallops) mollusks, but has no impact on calcification rate or shell microstructure of blue mussels. Controlled dissolution experiments reveal that dissolution rates of mollusk shells will be faster under warmer conditions predicted for the future, and that baseline dissolution of mollusk shells occurs even in oversaturated conditions. Finally, a novel microelectrode approach was developed for measuring extrapallial calcifying fluid pH of scallops—an approach that we will utilize in the future to explore mollusks’ surprisingly disparate responses to OA across species and life-stages.


Towards a Cost-Effective Monitoring System of Coastal Ocean Acidification in the US North East
Themistoklis Sapsis
Massachusetts Institute of Technology

It is important to accurately monitor coastal acidification (COA) in the coastal environment as this area is particularly affected by anthropogenic inputs. However, distributing pH sensors throughout Boston Harbor, Mass Bay or the Gulf of Maine with pH sensors would be impractical and very expensive. Computer simulations can help alleviate much of the cost and increase accurate predictions but requires validated, biochemical simulation models for the Northeast. We propose an integrated methodology that will combine and analyze all available information from monitoring stations in Mass Bay, Boston Harbor and their tributaries. We will use deep Gaussian Processe to blend information from diverse sources at variable fidelity in a multi-fidelity Bayesian framework, where all uncertainties are accounted for in the final prediction. Increased development of coastal communities has brought more runoff, sedimentation, nutrients and contaminants, and habitat degradation in coastal areas. Integrating multi-fidelity data with the biogeochemical-augmented coastal model (FVCOM-ERSEM) will result in highly accurate predictions of COA that will enable improved, cost-effective management of coastal resources, and support environmental preservation and remediation efforts.


Developing a Miniaturized In-situ Sensor Technology for Simultaneous Measurements of Seawater Dissolved Inorganic Carbon and pCO2
Zhaohui 'Aleck' Wang
Woods Hole Oceanographic Institution

The development of carbon sensors to monitor and study ocean acidification is widely recognized as a research priority at this time in history. Dissolved inorganic carbon (DIC) and partial pressure of CO2 (pCO2) are desirable parameters for accurately characterizing the marine CO2 system. This project will develop a miniaturized, in-situ sensor, Channelized Optical System II (CHANOS II) for simultaneous, spectrophotometric measurements of seawater DIC and pCO2 with high frequency (~1 Hz) for up to 1000 m of water depth. Built on the success of the original CHANOS, CHANOS II will develop a miniaturized fluidic CO2 equilibrating manifold for both DIC and pCO2 channels, applying miniature pumps and switches to dramatically reduce sensor size, power consumption, and cost, and improve robustness. CHANOS II will be capable of making high-quality measurements on both stationary and mobile platforms, such as buoys, profilers, and autonomous underwater vehicles (AUVs). The deployable time depends on what platforms it will be on. For stationary platforms, it can be up to 4 months at hourly sampling interval; for mobile platforms, it can be up to one week continuous measurements.


Sensors for Measuring Carbon Dioxide, Bicarbonate, and pH in the Ocean
Timothy Manning Swager,
Massachusetts Institute of Technology

This proposal seeks to develop small, economical, low-power sensors to be deployed in networks in coastal marine eco-systems to record levels of CO2, CO3H-, and pH. The sensors will use a hybrid of silicon-based, field-effect transistors and electroactive organic molecules/polymers. These organic materials are designed to have variable Fermi levels that change with pH and CO3H- concentrations. The new sensors can be used for persistent, distributed monitoring of coastal waters needed to understand the effects of river emissions and atmospheric perturbations on ocean ecology. Shallow regions are particularly sensitive to these chemical changes in the water; they are habitat to abundant shell fish populations and also provide a breeding ground for economically important fish species and other sea life. The sensors will allow for the collection of critical spatial-temporal data to be used in models that can explain the origins of chemical changes.

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