Grabb Kalina C.

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Last Name
Grabb
First Name
Kalina C.
ORCID
0000-0001-8771-7191

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  • Article
    Design optimization of a submersible chemiluminescent sensor (DISCO) for improved quantification of reactive oxygen species (ROS) in surface waters
    (MDPI, 2022-09-03) Grabb, Kalina C. ; Pardis, William A. ; Kapit, Jason ; Wankel, Scott D. ; Hayden, Eric B. ; Hansel, Colleen M.
    Reactive oxygen species (ROS) are key drivers of biogeochemical cycling while also exhibiting both positive and negative effects on marine ecosystem health. However, quantification of the ROS superoxide (O2−) within environmental systems is hindered by its short half-life. Recently, the development of the diver-operated submersible chemiluminescent sensor (DISCO), a submersible, handheld instrument, enabled in situ superoxide measurements in real time within shallow coral reef ecosystems. Here, we present a redesigned and improved instrument, DISCO II. Similar to the previous DISCO, DISCO II is a self-contained, submersible sensor, deployable to 30 m depth and capable of measuring reactive intermediate species in real time. DISCO II is smaller, lighter, lower cost, and more robust than its predecessor. Laboratory validation of DISCO II demonstrated an average limit of detection in natural seawater of 133.1 pM and a percent variance of 0.7%, with stable photo multiplier tube (PMT) counts, internal temperature, and flow rates. DISCO II can also be optimized for diverse environmental conditions by adjustment of the PMT supply voltage and integration time. Field tests showed no drift in the data with a percent variance of 3.0%. Wand tip adaptations allow for in situ calibrations and decay rates of superoxide using a chemical source of superoxide (SOTS-1). Overall, DISCO II is a versatile, user-friendly sensor that enables measurements in diverse environments, thereby improving our understanding of the cycling of reactive intermediates, such as ROS, across various marine ecosystems.
  • Article
    Measuring Protons with Photons: A Hand-Held, Spectrophotometric pH Analyzer for Ocean Acidification Research, Community Science and Education
    (MDPI, 2022-10-18) Pardis, William ; Grabb, Kalina C. ; DeGrandpre, Michael D. ; Spaulding, Reggie ; Beck, James ; Pfeifer, Jonathan A. ; Long, David M.
    Ocean Acidification (OA) is negatively affecting the physiological processes of marine organisms, altering biogeochemical cycles, and changing chemical equilibria throughout the world’s oceans. It is difficult to measure pH broadly, in large part because accurate pH measurement technology is expensive, bulky, and requires technical training. Here, we present the development and evaluation of a hand-held, affordable, field-durable, and easy-to-use pH instrument, named the pHyter, which is controlled through a smartphone app. We determine the accuracy of pH measurements using the pHyter by comparison with benchtop spectrophotometric seawater pH measurements, measurement of a certified pH standard, and comparison with a proven in situ instrument, the iSAMI-pH. These results show a pHyter pH measurement accuracy of ±0.046 pH or better, which is on par with interlaboratory seawater pH measurement comparison experiments. We also demonstrate the pHyter’s ability to conduct both temporal and spatial studies of coastal ecosystems by presenting data from a coral reef and a bay, in which the pHyter was used from a kayak. These studies showcase the instrument’s portability, applicability, and potential to be used for community science, STEM education, and outreach, with the goal of empowering people around the world to measure pH in their own backyards.
  • Article
    Development of a deep-sea submersible chemiluminescent analyzer for sensing short-lived reactive chemicals
    (MDPI, 2022-02-22) Taenzer, Lina ; Grabb, Kalina C. ; Kapit, Jason ; Pardis, William A. ; Wankel, Scott D. ; Hansel, Colleen M.
    Based on knowledge of their production pathways, and limited discrete observations, a variety of short-lived chemical species are inferred to play active roles in chemical cycling in the sea. In some cases, these species may exert a disproportionate impact on marine biogeochemical cycles, affecting the redox state of metal and carbon, and influencing the interaction between organisms and their environment. One such short-lived chemical is superoxide, a reactive oxygen species (ROS), which undergoes a wide range of environmentally important reactions. Yet, due to its fleeting existence which precludes traditional shipboard analyses, superoxide concentrations have never been characterized in the deep sea. To this end, we have developed a submersible oceanic chemiluminescent analyzer of reactive intermediate species (SOLARIS) to enable continuous measurements of superoxide at depth. Fluidic pumps on SOLARIS combine seawater for analysis with reagents in a spiral mixing cell, initiating a chemiluminescent reaction that is monitored by a photomultiplier tube. The superoxide in seawater is then related to the quantity of light produced. Initial field deployments of SOLARIS have revealed high-resolution trends in superoxide throughout the water column. SOLARIS presents the opportunity to constrain the distributions of superoxide, and any number of chemiluminescent species in previously unexplored environments.
  • Thesis
    Exploring the role of reactive oxygen species (ROS) in marine ecosystem health and function
    (Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 2022-09) Grabb, Kalina C. ; Hansel, Colleen M.
    With the rapid decline of coastal ecosystems such as coral reefs and seagrasses, it is crucial to better understand the health of these ecosystem to prevent future loss. Reactive oxygen speices (ROS), such as superoxide and hydrogen peroxide, play an underappreciated role in both organism health and ecosystem biogeochemical cycles. This thesis lays the foundation to measure and identify ROS production by coral in situ and through genomic analysis while also highlighting the important role that ROS can play within biogeochemical cycling within seagrass ecosystems. To measure in situ extracellular superoxide, we develop the first DIver-operated Submersible Chemiluminescent sensOr (DISCO), enabling high resolution, non-invasive measurements in real time. We further refine DISCO by making it more compact, user-friendly, adaptable, and robust, enabling measurements of superoxide across a diversity of environments. Using DISCO, I observe species-specific variation in extracellular superoxide concentrations associated with healthy coral. Despite these variations across species, bioinformatic analysis of coral proteins reveal that nearly all coral species have the extracellular superoxide-producing enzyme NADPH oxidase (NOX), and thus the genetic potential to produce extracellular superoxide. This suggests that coral species likely exhibit differential NOX regulation and expression as a function of physiological responses to external stressors, which may play a role in coral immunity. I then turn to seagrass ecosystems, where I observe rapid hydrogen peroxide production and decay through predominantly reductive pathways. This has implications on the environmental redox state and biogeochemical cycling, impacting the ecosystem services that seagrasses provide to marine environments and coastal communities. Overall, this thesis highlights the potential role that ROS may be playing in organism and ecosystem health and lays the groundwork to further develop ROS as a tool to protect these coastal ecosystems against further degradation.
  • Article
    Spatial heterogeneity in particle-associated, light-independent superoxide production within productive coastal waters
    (American Geophysical Union, 2020-10-06) Sutherland, Kevin M. ; Grabb, Kalina C. ; Karolewski, Jennifer S. ; Plummer, Sydney ; Farfan, Gabriela A. ; Wankel, Scott D. ; Diaz, Julia M. ; Lamborg, Carl H. ; Hansel, Colleen M.
    In the marine environment, the reactive oxygen species (ROS) superoxide is produced through a diverse array of light‐dependent and light‐independent reactions, the latter of which is thought to be primarily controlled by microorganisms. Marine superoxide production influences organic matter remineralization, metal redox cycling, and dissolved oxygen concentrations, yet the relative contributions of different sources to total superoxide production remain poorly constrained. Here we investigate the production, steady‐state concentration, and particle‐associated nature of light‐independent superoxide in productive waters off the northeast coast of North America. We find exceptionally high levels of light‐independent superoxide in the marine water column, with concentrations ranging from 10 pM to in excess of 2,000 pM. The highest superoxide concentrations were particle associated in surface seawater and in aphotic seawater collected meters off the seafloor. Filtration of seawater overlying the continental shelf lowered the light‐independent, steady‐state superoxide concentration by an average of 84%. We identify eukaryotic phytoplankton as the dominant particle‐associated source of superoxide to these coastal waters. We contrast these measurements with those collected at an off‐shelf station, where superoxide concentrations did not exceed 100 pM, and particles account for an average of 40% of the steady‐state superoxide concentration. This study demonstrates the primary role of particles in the production of superoxide in seawater overlying the continental shelf and highlights the importance of light‐independent, dissolved‐phase reactions in marine ROS production.
  • Article
    Corals and sponges are hotspots of reactive oxygen species in the deep sea
    (National Academy of Sciences, 2023-11-15) Taenzer, Lina ; Wankel, Scott D. ; Kapit, Jason ; Pardis, William A. ; Herrera, Santiago ; Auscavitch, Steven R. ; Grabb, Kalina C. ; Cordes, Erik ; Hansel, Colleen M.
    Reactive oxygen species (ROS) are central to diverse biological processes through which organisms respond to and interact with their surroundings. Yet, a lack of direct measurements limits our understanding of the distribution of ROS in the ocean. Using a recently developed in situ sensor, we show that deep-sea corals and sponges produce the ROS superoxide, revealing that benthic organisms can be sources and hotspots of ROS production in these environments. These findings confirm previous contentions that extracellular superoxide production by corals can be independent of the activity of photosynthetic symbionts. The discovery of deep-sea corals and sponges as sources of ROS has implications for the physiology and ecology of benthic organisms and introduces a previously overlooked suite of redox reactants at depth.
  • Other
    Coastal resilience and sea level rise workshop report
    (Woods Hole Oceanographic Institution, 2024-09-17) Grabb, Kalina C. ; Ramakrishna, Kilaparti
    To predict and adapt to future sea levels, we need to understand where and why the sea levels are rising now and have risen in the past. Institutions whether large or small, coastal communities whether rich or poor, cannot control sea level rise by their actions alone. But they can prepare well through a variety of adaptation measures. The goal of this workshop was to review the latest scientific findings on sea level rise and coastal resilience to discuss community approaches to increase resilience and adaptation. While examples abound, the participants focused on what has been attempted in Woods Hole, a small coastal town in southeastern Massachusetts, and in the Commonwealth of Massachusetts at the regional and state level. A goal of this exercise was to assess the lessons learned and how they translate to other communities as participants critically reviewed what else is needed to increase coastal resilience. A select group of leading specialists from science institutions within Woods Hole, partnering organizations, coastal community members, the Commonwealth of Massachusetts, as well as those involved in policy formulation at the national and international levels were invited to discuss progress and plans while also sharing lessons learned with representatives from other states.