Carbon manipulations and measurements for a changing ocean /

In this dissertation, I present several tools to assist the community in making accurate and precise manipulations and measurements of carbonate chemistry parameters, which are essential for understanding, interpreting, and predicting the anthropogenic impact on the chemistry of our oceans. As the frequency of carbonate chemistry measurements increases with interest in the ocean's response to climate change, there is a continued need for confidence in the measurements to ensure data quality and consequent data usefulness. First, I explain the results of an international inter-laboratory comparison of various carbonate chemistry measurements. The majority of the results exhibit agreement within 0.5% of the assigned value for total alkalinity and total dissolved inorganic carbon, with significantly more variability in pH measurements. In many cases there is evidence of significant loss of CO₂ from the seawater samples, a particularly alarming bias given how critical these measurements are to the understanding of increasing anthropogenic carbon in our oceans. Carbonate chemistry measurements can also be compromised when taken from environments such as coastal and estuarine seawater, as well as laboratory cultures and aquaria, containing large numbers of suspended biogenic particles. The presence of these particles in a seawater sample may alter the results of the analysis for carbonate chemistry parameters including total alkalinity, total dissolved inorganic carbon, and pH. In this dissertation, I present the verification of a filtration method using a peristaltic pump and enclosed filter housing, which does not alter the dissolved CO₂ content of the seawater sample, and thus is suitable for filtration of samples before analysis. Finally, manipulation of carbonate chemistry in the laboratory is a crucial tool for studying the impacts of increasing CO₂ on organisms and communities, however is not always straightforward. I developed a carefully controlled aquarium system capable of manipulating the carbonate chemistry, oxygen levels, and temperature of seawater. The multi-stressor nature of the control is critical, particularly regarding the investigation of coastal ocean conditions, which are unique in the magnitude of range and temporal variability possible in these parameters. The aquarium system is dynamically controlled such that variability in pH may be introduced across many time scales. The novel tools presented in this dissertation for the manipulation and measurements of carbonate chemistry will assist in ensuring greater accuracy and understanding of the impacts of changes in carbon dioxide on our ocean

Carbon manipulations and measurements for a changing ocean /

In this dissertation, I present several tools to assist the community in making accurate and precise manipulations and measurements of carbonate chemistry parameters, which are essential for understanding, interpreting, and predicting the anthropogenic impact on the chemistry of our oceans. As the frequency of carbonate chemistry measurements increases with interest in the ocean's response to climate change, there is a continued need for confidence in the measurements to ensure data quality and consequent data usefulness. First, I explain the results of an international inter-laboratory comparison of various carbonate chemistry measurements. The majority of the results exhibit agreement within 0.5% of the assigned value for total alkalinity and total dissolved inorganic carbon, with significantly more variability in pH measurements. In many cases there is evidence of significant loss of CO₂ from the seawater samples, a particularly alarming bias given how critical these measurements are to the understanding of increasing anthropogenic carbon in our oceans. Carbonate chemistry measurements can also be compromised when taken from environments such as coastal and estuarine seawater, as well as laboratory cultures and aquaria, containing large numbers of suspended biogenic particles. The presence of these particles in a seawater sample may alter the results of the analysis for carbonate chemistry parameters including total alkalinity, total dissolved inorganic carbon, and pH. In this dissertation, I present the verification of a filtration method using a peristaltic pump and enclosed filter housing, which does not alter the dissolved CO₂ content of the seawater sample, and thus is suitable for filtration of samples before analysis. Finally, manipulation of carbonate chemistry in the laboratory is a crucial tool for studying the impacts of increasing CO₂ on organisms and communities, however is not always straightforward. I developed a carefully controlled aquarium system capable of manipulating the carbonate chemistry, oxygen levels, and temperature of seawater. The multi-stressor nature of the control is critical, particularly regarding the investigation of coastal ocean conditions, which are unique in the magnitude of range and temporal variability possible in these parameters. The aquarium system is dynamically controlled such that variability in pH may be introduced across many time scales. The novel tools presented in this dissertation for the manipulation and measurements of carbonate chemistry will assist in ensuring greater accuracy and understanding of the impacts of changes in carbon dioxide on our ocean

EFFECTS OF INCREASED pCO2 ON URCHIN, MUSSELS AND ABALONE

participantAs more carbon dioxide is added to the atmosphere, increasing amounts are absorbed into the oceans. This increase in total carbon, and consequent lowering of the ocean pH, has a variety of effects, many of which are only just beginning to be thoroughly studied. Preliminary results suggest that organisms with calcium carbonate shells may be particularly impacted by increasingly acidic seawater. We will be studying the impact of ocean acidification on marine organisms of the California coast, including the sea urchin, abalone and mussel. Beyond the scientific interest in trying to understand the affects of acidification on them, these organisms are of additional interest due to their economic and social value. The project will include the design and creation of a system, which can accurately monitor the carbonate chemistry of seawater, as well as the temperature and oxygen concentration. Some problems have been identified with many of the methods used in the past to change the composition of the seawater, such as bubbling with gas or acid additions. To avoid these and try to mimic the natural changes as closely as possible, we will pre-equilibrate the seawater using a membrane contactor between a mixture of the desired gases and seawater. Autonomous monitoring will ensure the tanks are at the desired level and the technique will allow for easy and non-intrusive adjustments to the carbon system

Controlled experimental aquarium system for multi-stressor investigation: carbonate chemistry, oxygen saturation, and temperature

"El Internet está en constante crecimiento, las aplicaciones Web y las nuevas tecnologías móviles tienen un gran impacto en la vida diaria, así como en los procedimientos de programación y métodos de desarrollo. En el País si bien no se ha dado como en países del primer mundo, el servicio de los proveedores de Internet también ha mejorado en los últimos años. Todo esto ha causado que los diferentes sectores (privado, público y gubernamental) consideren a Internet como un canal importante de comunicación. En el presente proyecto de Tesis se desarrolla una aplicación Web que permite a los usuarios de manera sencilla y segura puedan gestionar sus gastos personales. Se presenta una aplicación que cumple con todos los requisitos del análisis y diseño del Proceso Unificado de Desarrollo. La aplicación fue diseñada, desarrollada y probada de acuerdo a los requisitos generados por los usuarios garantizando una aplicación Web totalmente funcional y fácil de usar.

Advancing Ocean Acidification Biology Using Durafet® pH Electrodes

Research assessing the biological impacts of global ocean change often requires a burdensome characterization of seawater carbonate chemistry. For laboratory-based ocean acidification research, this impedes the scope of experimental design. Honeywell Durafet® III pH electrodes provide precise and continuous seawater pH measurements. In addition to use in oceanographic sensor packages, Durafets can also be used in the laboratory to track and control seawater treatments via Honeywell Universal Dual Analyzers (UDAs). Here we provide performance data, instructions, and step-by-step recommendations for use of multiple UDA-Durafets. Durafet pH measurements were within ±0.005 units pHT of spectrophotometric measurements and agreement among eight Durafets was better than ±0.005 units pHT. These results indicate equal performance to Durafets in oceanographic sensor packages, but methods for calibration and quality control differ. Use of UDA-Durafets vastly improves time-course documentation of experimental conditions and reduces person-hours dedicated to this activity. Due to the versatility of integrating Durafets in laboratory seawater systems, this technology opens the door to advance the scale of questions that the ocean acidification research community aims to address

Detecting the Unexpected: A Research Framework for Ocean Acidification

The threat that ocean acidification (OA) poses to marine ecosystems is now recognized and U.S. funding agencies have designated specific funding for the study of OA. We present a research framework for studying OA that describes it as a biogeochemical event that impacts individual species and ecosystems in potentially unexpected ways. We draw upon specific lessons learned about ecosystem responses from research on acid rain, carbon dioxide enrichment in terrestrial plant communities, and nitrogen deposition. We further characterize the links between carbon chemistry changes and effects on individuals and ecosystems, and enumerate key hypotheses for testing. Finally, we quantify how U.S. research funding has been distributed among these linkages, concluding that there is an urgent need for research programs designed to anticipate how the effects of OA will reverberate throughout assemblages of species. © 2014 American Chemical Society