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Articles 1 - 17 of 17

Full-Text Articles in Physical Sciences and Mathematics

Taking The Metabolic Pulse Of The World's Coral Reefs, Tyler Cyronak, Andreas J. Andersson, Chris Langdon, Rebecca Albright, Nicholas R. Bates, Ken Caldeira, Renee Carlton, Jorge E. Corredor, Rob B. Dunbar, Ian Enochs, Jonathan Erez, Bradley D. Eyre, Jean-Pierre Gattuso, Dwight Gledhill, Hajime Kayanne, David I. Kline, David A. Koweek, Coulson Lantz, Boaz Lazar, Derek Manzello, Ashly Mcmahon, Melissa Melendez, Heather N. Page, Isaac R. Santos, Kai G. Schulz, Emily Shaw, Jacob Silverman, Atsushi Suzuki, Lida Teneva, Atsushi Watanabe, Shoji Yamamoto Sep 2019

Taking The Metabolic Pulse Of The World's Coral Reefs, Tyler Cyronak, Andreas J. Andersson, Chris Langdon, Rebecca Albright, Nicholas R. Bates, Ken Caldeira, Renee Carlton, Jorge E. Corredor, Rob B. Dunbar, Ian Enochs, Jonathan Erez, Bradley D. Eyre, Jean-Pierre Gattuso, Dwight Gledhill, Hajime Kayanne, David I. Kline, David A. Koweek, Coulson Lantz, Boaz Lazar, Derek Manzello, Ashly Mcmahon, Melissa Melendez, Heather N. Page, Isaac R. Santos, Kai G. Schulz, Emily Shaw, Jacob Silverman, Atsushi Suzuki, Lida Teneva, Atsushi Watanabe, Shoji Yamamoto

Tyler Cyronak

Worldwide, coral reef ecosystems are experiencing increasing pressure from a variety of anthropogenic perturbations including ocean warming and acidification, increased sedimentation, eutrophication, and overfishing, which could shift reefs to a condition of net calcium carbonate (CaCO3) dissolution and erosion. Herein, we determine the net calcification potential and the relative balance of net organic carbon metabolism (net community production; NCP) and net inorganic carbon metabolism (net community calcification; NCC) within 23 coral reef locations across the globe. In light of these results, we consider the suitability of using these two metrics developed from total alkalinity (TA) and dissolved inorganic carbon (DIC) …


Temperature-Induced Viral Resistance In Emiliania Huxleyi (Prymnesiophyceae), B. Jacob Kendrick, Giacomo R. Ditullio, Tyler Cyronak, James M. Fulton, Benjamin A. S. Van Mooy, Kay D. Bidle Sep 2019

Temperature-Induced Viral Resistance In Emiliania Huxleyi (Prymnesiophyceae), B. Jacob Kendrick, Giacomo R. Ditullio, Tyler Cyronak, James M. Fulton, Benjamin A. S. Van Mooy, Kay D. Bidle

Tyler Cyronak

Annual Emiliania huxleyi blooms (along with other coccolithophorid species) play important roles in the global carbon and sulfur cycles. E. huxleyi blooms are routinely terminated by large, host-specific dsDNA viruses, (Emiliania huxleyi Viruses; EhVs), making these host-virus interactions a driving force behind their potential impact on global biogeochemical cycles. Given projected increases in sea surface temperature due to climate change, it is imperative to understand the effects of temperature on E. huxleyi’s susceptibility to viral infection and its production of climatically active dimethylated sulfur species (DSS). Here we demonstrate that a 3°C increase in temperature induces EhV-resistant phenotypes …


Nitrous Oxide And Methane Dynamics In A Coral Reef Lagoon Driven By Pore Water Exchange: Insights From Automated High‐Frequency Observations, Chiara O'Reilly, Isaac R. Santos, Tyler Cyronak, Ashly Mcmahon, Damien T. Maher Sep 2019

Nitrous Oxide And Methane Dynamics In A Coral Reef Lagoon Driven By Pore Water Exchange: Insights From Automated High‐Frequency Observations, Chiara O'Reilly, Isaac R. Santos, Tyler Cyronak, Ashly Mcmahon, Damien T. Maher

Tyler Cyronak

Automated cavity ring down spectroscopy was used to make continuous measurements of dissolved methane, nitrous oxide, and carbon dioxide in a coral reef lagoon for 2 weeks (Heron Island, Great Barrier Reef). Radon (222Rn) was used to trace the influence of tidally driven pore water exchange on greenhouse gas dynamics. Clear tidal variation was observed for CH4, which correlated to 222Rn in lagoon waters. N2O correlated to 222Rn during the day only, which appears to be a response to coupled nitrification‐denitrification in oxic sediments, fueled by nitrate derived from bird guano. The lagoon was …


Permeable Coral Reef Sediment Dissolution Driven By Elevated Pco2 And Pore Water Advection, Tyler Cyronak, Isaac R. Santos, Bradley D. Eyre Sep 2019

Permeable Coral Reef Sediment Dissolution Driven By Elevated Pco2 And Pore Water Advection, Tyler Cyronak, Isaac R. Santos, Bradley D. Eyre

Tyler Cyronak

Ocean acidification (OA) is expected to drive the transition of coral reef ecosystems from net calcium carbonate (CaCO3) precipitating to net dissolving within the next century. Although permeable sediments represent the largest reservoir of CaCO3 in coral reefs, the dissolution of shallow CaCO3 sands under future pCO2 levels has not been measured under natural conditions. In situ, advective chamber incubations under elevated pCO2 (~800 µatm) shifted the sediments from net precipitating to net dissolving. Pore water advection more than doubled dissolution rates (1.10 g CaCO3 m−2 d−1) when compared to …


Hysteresis Between Coral Reef Calcification And The Seawater Aragonite Saturation State, Ashly Mcmahon, Isaac R. Santos, Tyler Cyronak, Bradley D. Eyre Sep 2019

Hysteresis Between Coral Reef Calcification And The Seawater Aragonite Saturation State, Ashly Mcmahon, Isaac R. Santos, Tyler Cyronak, Bradley D. Eyre

Tyler Cyronak

Some predictions of how ocean acidification (OA) will affect coral reefs assume a linear functional relationship between the ambient seawater aragonite saturation state (Ωa) and net ecosystem calcification (NEC). We quantified NEC in a healthy coral reef lagoon in the Great Barrier Reef during different times of the day. Our observations revealed a diel hysteresis pattern in the NEC versus Ωa relationship, with peak NEC rates occurring before the Ωa peak and relatively steady nighttime NEC in spite of variable Ωa. Net ecosystem production had stronger correlations with NEC than light, temperature, nutrients, pH, …


Groundwater And Porewater As Major Sources Of Alkalinity To A Fringing Coral Reef Lagoon (Muri Lagoon, Cook Islands), Tyler Cyronak, Isaac R. Santos, Dirk V. Erler, Bradley D. Eyre Sep 2019

Groundwater And Porewater As Major Sources Of Alkalinity To A Fringing Coral Reef Lagoon (Muri Lagoon, Cook Islands), Tyler Cyronak, Isaac R. Santos, Dirk V. Erler, Bradley D. Eyre

Tyler Cyronak

To better predict how ocean acidification will affect coral reefs, it is important to understand how biogeochemical cycles on reefs alter carbonate chemistry over various temporal and spatial scales. This study quantifies the contribution of shallow porewater exchange (as quantified from advective chamber incubations) and fresh groundwater discharge (as traced by 222Rn) to total alkalinity (TA) dynamics on a fringing coral reef lagoon along the southern Pacific island of Rarotonga over a tidal and diel cycle. Benthic alkalinity fluxes were affected by the advective circulation of water through permeable sediments, with net daily flux rates of carbonate alkalinity ranging …


Expanding Aquatic Observations Through Recreation, Robert J. W. Brewin, Kieran Hyder, Andreas J. Andersson, Oliver Billson, Philip J. Bresnahan, Thomas G. Brewin, Tyler Cyronak, Giorgio Dall'olmo, Lee De Mora, George Graham, Thomas Jackson, Dionysios E. Raitsos Sep 2019

Expanding Aquatic Observations Through Recreation, Robert J. W. Brewin, Kieran Hyder, Andreas J. Andersson, Oliver Billson, Philip J. Bresnahan, Thomas G. Brewin, Tyler Cyronak, Giorgio Dall'olmo, Lee De Mora, George Graham, Thomas Jackson, Dionysios E. Raitsos

Tyler Cyronak

Accurate observations of the Earth system are required to understand how our planet is changing and to help manage its resources. The aquatic environment—including lakes, rivers, wetlands, estuaries, coastal and open oceans—is a fundamental component of the Earth system controlling key physical, biological, and chemical processes that allow life to flourish. Yet, this environment is critically undersampled in both time and space. New and cost-effective sampling solutions are urgently needed. Here, we highlight the potential to improve aquatic sampling by tapping into recreation. We draw attention to the vast number of participants that engage in aquatic recreational activities and argue, …


Drivers Of Pco2 Variability In Two Contrasting Coral Reef Lagoons: The Influence Of Submarine Groundwater Discharge, Tyler Cyronak, Isaac R. Santos, Dirk V. Erler, Damien T. Maher, Bradley D. Eyre Sep 2019

Drivers Of Pco2 Variability In Two Contrasting Coral Reef Lagoons: The Influence Of Submarine Groundwater Discharge, Tyler Cyronak, Isaac R. Santos, Dirk V. Erler, Damien T. Maher, Bradley D. Eyre

Tyler Cyronak

The impact of groundwater on pCO2 variability was assessed in two coral reef lagoons with distinct drivers of submarine groundwater discharge (SGD). Diel variability of pCO2 in the two ecosystems was explained by a combination of biological drivers and SGD inputs. In Rarotonga, a South Pacific volcanic island, 222Rn‐derived SGD was driven primarily by a steep terrestrial hydraulic gradient, and the water column was influenced by the high pCO2 (5501 µatm) of the fresh groundwater. In Heron Island, a Great Barrier Reef coral cay, SGD was dominated by seawater recirculation through the sediments …


Enhanced Acidification Of Global Coral Reefs Driven By Regional Biogeochemical Feedbacks, Tyler Cyronak, Kai G. Schulz, Isaac R. Santos, Bradley D. Eyre Sep 2019

Enhanced Acidification Of Global Coral Reefs Driven By Regional Biogeochemical Feedbacks, Tyler Cyronak, Kai G. Schulz, Isaac R. Santos, Bradley D. Eyre

Tyler Cyronak

Physical uptake of anthropogenic CO2 is the dominant driver of ocean acidification (OA) in the open ocean. Due to expected decreases in calcification and increased dissolution of CaCO3 framework, coral reefs are thought to be highly susceptible to OA. However, biogeochemical processes can influence the pCO2 and pH of coastal ecosystems on diel and seasonal time scales, potentially modifying the long‐term effects of increasing atmospheric CO2. By compiling data from the literature and removing the effects of short‐term variability, we show that the average pCO2 of coral reefs throughout the globe has increased ~3.5‐fold …


Coral Reef Carbonate Chemistry Variability At Different Functional Scales, Yuichiro Takeshita, Tyler Cyronak, Todd R. Martz, Theodor Kindeberg, Andreas J. Andersson Sep 2019

Coral Reef Carbonate Chemistry Variability At Different Functional Scales, Yuichiro Takeshita, Tyler Cyronak, Todd R. Martz, Theodor Kindeberg, Andreas J. Andersson

Tyler Cyronak

There is a growing recognition for the need to understand how seawater carbonate chemistry over coral reef environments will change in a high-CO2 world to better assess the impacts of ocean acidification on these valuable ecosystems. Coral reefs modify overlying water column chemistry through biogeochemical processes such as net community organic carbon production (NCP) and calcification (NCC). However, the relative importance and influence of these processes on seawater carbonate chemistry vary across multiple functional scales (defined here as space, time, and benthic community composition), and have not been fully constrained. Here, we use Bermuda as a case study to …


Comparing Chemistry And Census-Based Estimates Of Net Ecosystem Calcification On A Rim Reef In Bermuda, Travis A. Courtney, Andreas J. Andersson, Nicholas R. Bates, Andrew R. Collins, Tyler Cyronak, Samantha J. De Putron, Bradley D. Eyre, Rebecca Garley, Eric J. Hochberg, Rodney Johnson, Sylvia Musielewicz, Tim J. Noyes, Christopher L. Sabine, Adrienne J. Sutton, Jessy Toncin, Aline Tribollet Sep 2019

Comparing Chemistry And Census-Based Estimates Of Net Ecosystem Calcification On A Rim Reef In Bermuda, Travis A. Courtney, Andreas J. Andersson, Nicholas R. Bates, Andrew R. Collins, Tyler Cyronak, Samantha J. De Putron, Bradley D. Eyre, Rebecca Garley, Eric J. Hochberg, Rodney Johnson, Sylvia Musielewicz, Tim J. Noyes, Christopher L. Sabine, Adrienne J. Sutton, Jessy Toncin, Aline Tribollet

Tyler Cyronak

Coral reef net ecosystem calcification (NEC) has decreased for many Caribbean reefs over recent decades primarily due to changes in benthic community composition. Chemistry-based approaches to calculate NEC utilize the drawdown of seawater total alkalinity (TA) combined with residence time to calculate an instantaneous measurement of NEC. Census-based approaches combine annual growth rates with benthic cover and reef structural complexity to estimate NEC occurring over annual timescales. Here, NEC was calculated for Hog Reef in Bermuda using both chemistry and census-based NEC techniques to compare the mass-balance generated by the two methods and identify the dominant biocalcifiers at Hog Reef. …


Antagonistic Effects Of Ocean Acidification And Rising Sea Surface Temperature On The Dissolution Of Coral Reef Carbonate Sediments, Daniel Trnovsky, Laura Stoltenberg, Tyler Cyronak, Bradley D. Eyre Sep 2019

Antagonistic Effects Of Ocean Acidification And Rising Sea Surface Temperature On The Dissolution Of Coral Reef Carbonate Sediments, Daniel Trnovsky, Laura Stoltenberg, Tyler Cyronak, Bradley D. Eyre

Tyler Cyronak

Increasing atmospheric CO2 is raising sea surface temperature (SST) and increasing seawater CO2 concentrations, resulting in a lower oceanic pH (ocean acidification; OA), which is expected to reduce the accretion of coral reef ecosystems. Although sediments comprise most of the calcium carbonate (CaCO3) within coral reefs, no in situ studies have looked at the combined effects of increased SST and OA on the dissolution of coral reef CaCO3 sediments. In situ benthic chamber incubations were used to measure dissolution rates in permeable CaCO3 sands under future OA and SST scenarios in a coral reef …


Physiological Integration Of Coral Colonies Is Correlated With Bleaching Resistance, Timothy D. Swain, Emily C. Bold, Phillip C. Osborn, Andrew H. Baird, Mark W. Westneat, Vadim Backman, Luisa A. Marcelino Jul 2019

Physiological Integration Of Coral Colonies Is Correlated With Bleaching Resistance, Timothy D. Swain, Emily C. Bold, Phillip C. Osborn, Andrew H. Baird, Mark W. Westneat, Vadim Backman, Luisa A. Marcelino

Timothy Swain

Inter-module physiological integration of colonial organisms can facilitate colony-wide coordinated responses to stimuli that strengthen colony fitness and stress resistance. In scleractinian corals, whose colonial integration ranges from isolated polyps to a seamless continuum of polyp structures and functions, this coordination improves responses to injury, predation, disease, and stress and may be one of the indications of an evolutionary origin of Symbiodinium symbiosis. However, observations of species-specific coral bleaching patterns suggest that highly integrated coral colonies may be more susceptible to thermal stress, and support the hypothesis that communication pathways between highly integrated polyps facilitate the dissemination of toxic byproducts …


Skeletal Light-Scattering Accelerates Bleaching Response In Reef-Building Corals, Timothy D. Swain, Emily Dubois, Andrew Gomes, Valentina P. Stoyneva, Andrew J. Radosevich, Jillian Henss, Michelle E. Wagner, Justin Derbas, Hannah Grooms, Elizabeth M. Velazquez, Joshua Traub, Brian J. Kennedy, Arabela A. Grigorescu, Mark W. Westneat, Kevin Sanborn, Shoshana Levine, Mark Schick, George Parsons, Brendan C. Briggs, Jeremy D. Rogers, Vadim Backman, Luisa A. Marcelino Jul 2019

Skeletal Light-Scattering Accelerates Bleaching Response In Reef-Building Corals, Timothy D. Swain, Emily Dubois, Andrew Gomes, Valentina P. Stoyneva, Andrew J. Radosevich, Jillian Henss, Michelle E. Wagner, Justin Derbas, Hannah Grooms, Elizabeth M. Velazquez, Joshua Traub, Brian J. Kennedy, Arabela A. Grigorescu, Mark W. Westneat, Kevin Sanborn, Shoshana Levine, Mark Schick, George Parsons, Brendan C. Briggs, Jeremy D. Rogers, Vadim Backman, Luisa A. Marcelino

Timothy Swain

Background At the forefront of ecosystems adversely affected by climate change, coral reefs are sensitive to anomalously high temperatures which disassociate (bleaching) photosynthetic symbionts (Symbiodinium) from coral hosts and cause increasingly frequent and severe mass mortality events. Susceptibility to bleaching and mortality is variable among corals, and is determined by unknown proportions of environmental history and the synergy of Symbiodinium- and coral-specific properties. Symbiodinium live within host tissues overlaying the coral skeleton, which increases light availability through multiple light-scattering, forming one of the most efficient biological collectors of solar radiation. Light-transport in the upper ~200 μm layer …


Modulation Of Light-Enhancement To Symbiotic Algae By Light-Scattering In Corals And Evolutionary Trends In Bleaching, Luisa A. Marcelino, Mark W. Westneat, Valentina P. Stoyneva, Jillian Henss, Jeremy Rogers, Andrew J. Radosevich, Vladimir Turzhitsky, Margaret Siple, Andrew Fang, Timothy D. Swain, Jennifer Fung, Vadim Backman Jul 2019

Modulation Of Light-Enhancement To Symbiotic Algae By Light-Scattering In Corals And Evolutionary Trends In Bleaching, Luisa A. Marcelino, Mark W. Westneat, Valentina P. Stoyneva, Jillian Henss, Jeremy Rogers, Andrew J. Radosevich, Vladimir Turzhitsky, Margaret Siple, Andrew Fang, Timothy D. Swain, Jennifer Fung, Vadim Backman

Timothy Swain

Calcium carbonate skeletons of scleractinian corals amplify light availability to their algal symbionts by diffuse scattering, optimizing photosynthetic energy acquisition. However, the mechanism of scattering and its role in coral evolution and dissolution of algal symbioses during “bleaching” events are largely unknown. Here we show that differences in skeletal fractal architecture at nano/micro-lengthscales within 96 coral taxa result in an 8-fold variation in light-scattering and considerably alter the algal light environment. We identified a continuum of properties that fall between two extremes: (1) corals with low skeletal fractality that are efficient at transporting and redistributing light throughout the colony with …


Language Learning Under Classroom Conditions During The Transition To Hybrid Instruction: A Case-Study Of Student Performance During The Implementation Of Instructional Technology, Lisbeth O. Swain, Timothy D. Swain Jul 2019

Language Learning Under Classroom Conditions During The Transition To Hybrid Instruction: A Case-Study Of Student Performance During The Implementation Of Instructional Technology, Lisbeth O. Swain, Timothy D. Swain

Timothy Swain

We examined the unmanipulated performance of students under real classroom conditions in order to assess the effect of a technology-enhanced hybrid learning approach to second language, (L2) instruction on beginning and advanced Spanish language learners. This research focused on the transition period of technology implementation when the entire section of Spanish of a modern language department of a liberal arts university transitioned from traditional face-to-face instruction, to a technology-enhanced hybrid learning approach with concurrent reduction in face-to-face classroom hours. This implementation provided an opportunity to compare the performance of students prior to and during the transition to hybrid model of …


Scale Up Isolation Of Aaptamine For In Vivo Evaluation Indicates Its Neurobiological Activity Is Linked To The Delta Opioid Receptor, Nicole L. Mcintosh, Eptisam Lambo, Laura Millan-Lobo, Fei Li, Li He, Phillip Crews, Jennifer L. Whistler, Tyler Johnson Mar 2019

Scale Up Isolation Of Aaptamine For In Vivo Evaluation Indicates Its Neurobiological Activity Is Linked To The Delta Opioid Receptor, Nicole L. Mcintosh, Eptisam Lambo, Laura Millan-Lobo, Fei Li, Li He, Phillip Crews, Jennifer L. Whistler, Tyler Johnson

Tyler Johnson

Opioid receptors belong to the large superfamily of seven transmembrane-spanning (7TM) G protein-coupled receptors (GPCRs). As a class, GPCRs are of fundamental physiological importance mediating the actions of the majority of known neurotransmitters and hormones. The Mu, Delta, and Kappa (MOP, DOP, KOP) opioid receptors are particularly intriguing members of this receptor family as they are the targets involved in many neurobiological diseases such as addiction, pain, stress, anxiety, and depression. Recently we discovered that the aaptamine class of marine sponge derived natural products exhibit selective agonist activity in vitro for the DOP versus MOP receptor. Our findings may explain …