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Full-Text Articles in Marine Biology

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 …


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 …


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. …


High-Resolution Habitat And Bathymetry Maps For 65,000 Sq. Km Of Earth’S Remotest Coral Reefs, Samuel J. Purkis, Arthur C. R. Gleason, Charlotte R. Purkis, Alexandra C. Dempsey, Philip Renaud, Mohamed Faisal, Steven Saul, Jeremy M. Kerr Apr 2019

High-Resolution Habitat And Bathymetry Maps For 65,000 Sq. Km Of Earth’S Remotest Coral Reefs, Samuel J. Purkis, Arthur C. R. Gleason, Charlotte R. Purkis, Alexandra C. Dempsey, Philip Renaud, Mohamed Faisal, Steven Saul, Jeremy M. Kerr

Marine & Environmental Sciences Faculty Articles

With compelling evidence that half the world’s coral reefs have been lost over the last four decades, there is urgent motivation to understand where reefs are located and their health. Without such basic baseline information, it is challenging to mount a response to the reef crisis on the global scale at which it is occurring. To combat this lack of baseline data, the Khaled bin Sultan Living Oceans Foundation embarked on a 10-yr survey of a broad selection of Earth’s remotest reef sites—the Global Reef Expedition. This paper focuses on one output of this expedition, which is meter-resolution seafloor habitat …


Detection Of Adsorbed Chlordecone On Microplastics In Marine Sediments In Guadeloupe: A Preliminary Study, Fidji Sandre, Charlotte R. Dromard, Karyn Le Menach, Yolande Bouchon-Navaro, Sébastien Cordonnier, Nathalie Tapie, Hélène Budzinski, Claude Bouchon Jan 2019

Detection Of Adsorbed Chlordecone On Microplastics In Marine Sediments In Guadeloupe: A Preliminary Study, Fidji Sandre, Charlotte R. Dromard, Karyn Le Menach, Yolande Bouchon-Navaro, Sébastien Cordonnier, Nathalie Tapie, Hélène Budzinski, Claude Bouchon

Gulf and Caribbean Research

Plastic pollution in the oceans is recognized as a worldwide problem. Since the 1950s, the production of plastics has been increasing and the first reports of microplastics (particles < 500 μm) in the marine environment began to appear in the 1970s. These particles represent a growing environmental problem due to their dispersion in seawater and marine organisms. Additionally, microparticles in general can adsorb pollutants that will then become bioavailable to organisms by being desorbed during digestion, which could be an important pathway for the contamination of organisms. In Guadeloupe and Martinique, an organochlorine pesticide called “chlordecone” was used from 1972 to 1993 in banana plantations and this very persistent pollutant contaminates soils, rivers, and coastal marine areas and accumulates in marine foodwebs. To examine these issues, we had two goals: 1) to assess the contamination of marine sediments by microplastics surrounding Guadeloupe; and 2) to determine the ability of microplastics to adsorb chlordecone, as has been demonstrated for other organochlorine pollutants. To do so, marine sediments were collected in triplicate from 12 sites in coral reef environments around the island. Microplastics from each sample were then enumerated by size, color and shape under a binocular microscope. The results indicate that microplastics are found in all the studied sites and that their distribution could be linked to marine currents or proximity to areas of significant human activities (port activities, agglomeration, etc.). Finally, our preliminary results indicated that chlordecone could be adsorbed onto microplastics, with a concentration ranging from 0.00036—0.00173 µg/µg of microfilter.