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Articles 1 - 12 of 12
Full-Text Articles in Life Sciences
Late Afternoon Seasonal Transition To Dissolution In A Coral Reef: An Early Warning Of A Net Dissolving Ecosystem?, Laura Stoltenberg, Kai G. Schulz, Coulson A. Lantz, Tyler Cyronak, Bradley D. Eyre
Late Afternoon Seasonal Transition To Dissolution In A Coral Reef: An Early Warning Of A Net Dissolving Ecosystem?, Laura Stoltenberg, Kai G. Schulz, Coulson A. Lantz, Tyler Cyronak, Bradley D. Eyre
Marine & Environmental Sciences Faculty Articles
There are concerns that reefs will transition from net calcifying to net dissolving in the near future due to decreasing calcification and increasing dissolution rates. Here we present in situ rates of net ecosystem calcification (NEC) and net ecosystem production (NEP) on a coral reef flat using a slack-water approach. Up until dusk, the reef was net calcifying in most months but shifted to net dissolution in austral summer, coinciding with high respiration rates and a lower aragonite saturation state (Ωarag). The estimated sediment contribution to NEC ranged from 8 – 21 % during the day and 45 …
Porewater Carbonate Chemistry Dynamics In A Temperate And A Subtropical Seagrass System, Theodor Kindeberg, Nicholas R. Bates, Travis A. Courtney, Tyler Cyronak, Alyssa Griffin, Fred T. Mackenzie, May-Linn Paulsen, Andreas J. Andersson
Porewater Carbonate Chemistry Dynamics In A Temperate And A Subtropical Seagrass System, Theodor Kindeberg, Nicholas R. Bates, Travis A. Courtney, Tyler Cyronak, Alyssa Griffin, Fred T. Mackenzie, May-Linn Paulsen, Andreas J. Andersson
Marine & Environmental Sciences Faculty Articles
Seagrass systems are integral components of both local and global carbon cycles and can substantially modify seawater biogeochemistry, which has ecological ramifications. However, the influence of seagrass on porewater biogeochemistry has not been fully described, and the exact role of this marine macrophyte and associated microbial communities in the modification of porewater chemistry remains equivocal. In the present study, carbonate chemistry in the water column and porewater was investigated over diel timescales in contrasting, tidally influenced seagrass systems in Southern California and Bermuda, including vegetated (Zostera marina) and unvegetated biomes (0–16 cm) in Mission Bay, San Diego, USA …
Will Shark Skin Dissolve Under High Co2?, Emily K. Witt
Will Shark Skin Dissolve Under High Co2?, Emily K. Witt
Scientific Communication News
No abstract provided.
Thresholds And Drivers Of Coral Calcification Responses To Climate Change, Niklas Kornder, Bernhard Riegl, Joana Figueiredo
Thresholds And Drivers Of Coral Calcification Responses To Climate Change, Niklas Kornder, Bernhard Riegl, Joana Figueiredo
Marine & Environmental Sciences Faculty Articles
Increased temperature and CO2 levels are considered key drivers of coral reef degradation. However, individual assessments of ecological responses (calcification) to these stressors are often contradicting. To detect underlying drivers of heterogeneity in coral calcification responses, we developed a procedure for the inclusion of stress–effect relationships in ecological meta‐analyses. We applied this technique to a dataset of 294 empirical observations from 62 peer‐reviewed publications testing individual and combined effects of elevated temperature and pCO2 on coral calcification. Our results show an additive interaction between warming and acidification, which reduces coral calcification by 20% when pCO2 levels exceed …
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
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
Marine & Environmental Sciences Faculty Articles
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) …
Effects Of Ocean Warming And Acidification On Fertilization Success And Early Larval Development In The Green Sea Urchin, Lytechinus Variegatus, Brittney L. Lenz
Effects Of Ocean Warming And Acidification On Fertilization Success And Early Larval Development In The Green Sea Urchin, Lytechinus Variegatus, Brittney L. Lenz
HCNSO Student Theses and Dissertations
Climate change is predicted to affect the larval stages of many marine organisms. Ocean warming can reduce larval survival and hasten larval development, whereas ocean acidification can delay larval development. Ocean acidification is especially concerning for marine organisms that develop and grow calcified shells or skeletons in an environment undersaturated with calcium carbonate minerals. This study assessed the effects of ocean warming and acidification on the fertilization and larval development of the green sea urchin, Lytechinus variegatus, a tropical species common in Florida and the Caribbean. After spawning, gametes were fertilized and embryos/larvae were reared at: 1) 28°C and …
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
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
Marine & Environmental Sciences Faculty Articles
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 …
Effects Of Elevated Pco2 And Irradiance On Growth, Photosynthesis And Calcification In Halimeda Discoidea, K. E. Peach, M. S. Koch, Patricia Blackwelder
Effects Of Elevated Pco2 And Irradiance On Growth, Photosynthesis And Calcification In Halimeda Discoidea, K. E. Peach, M. S. Koch, Patricia Blackwelder
Marine & Environmental Sciences Faculty Articles
Ocean acidification (OA) effects on photophysiology and calcification were examined in Halimeda discoidea, a calcifying macroalga that produces tropical reef sediments. Photosynthetic parameters, including maximum photosynthetic rate (Pmax), photosynthetic efficiency (α) and compensating irradiance (Ic) were determined in short-term assays on live thalli after a 10 d exposure to 4 levels of CO2 partial pressures (pCO2; 491, 653, 982 and 1201 µatm) under saturating (300 µmol photons m-2 s-1) and sub-saturating (90 µmol photons m-2 s-1) irradiance in an aquaria study. Morphology …
Enhanced Acidification Of Global Coral Reefs Driven By Regional Biogeochemical Feedbacks, Tyler Cyronak, Kai G. Schulz, Isaac R. Santos, Bradley D. Eyre
Enhanced Acidification Of Global Coral Reefs Driven By Regional Biogeochemical Feedbacks, Tyler Cyronak, Kai G. Schulz, Isaac R. Santos, Bradley D. Eyre
Marine & Environmental Sciences Faculty Articles
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 …
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
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
Marine & Environmental Sciences Faculty Articles
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 …
Permeable Coral Reef Sediment Dissolution Driven By Elevated Pco2 And Pore Water Advection, Tyler Cyronak, Isaac R. Santos, Bradley D. Eyre
Permeable Coral Reef Sediment Dissolution Driven By Elevated Pco2 And Pore Water Advection, Tyler Cyronak, Isaac R. Santos, Bradley D. Eyre
Marine & Environmental Sciences Faculty Articles
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
Hysteresis Between Coral Reef Calcification And The Seawater Aragonite Saturation State, Ashly Mcmahon, Isaac R. Santos, Tyler Cyronak, Bradley D. Eyre
Marine & Environmental Sciences Faculty Articles
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, …