Digital Commons Network^™

Phytoplankton Responses To Atmospheric Metal Deposition In The Coastal And Open-Ocean Sargasso Sea, Katherine Mackey, Kristen N. Buck, John Casey, Abigail Cid, Michael Lomas, Yoshiki Sohrin, Adina Paytan

Marine Science Faculty Publications

This study investigated the impact of atmospheric metal deposition on natural phytoplankton communities at open-ocean and coastal sites in the Sargasso Sea during the spring bloom. Locally collected aerosols with different metal contents were added to natural phytoplankton assemblages from each site, and changes in nitrate, dissolved metal concentration, and phytoplankton abundance and carbon content were monitored. Addition of aerosol doubled the concentrations of cadmium (Cd), cobalt (Co), copper (Cu), iron (Fe), manganese (Mn), and nickel (Ni) in the incubation water. Over the 3-day experiments, greater drawdown of dissolved metals occurred in the open ocean water, whereas little metal drawdown …

Benjamin P. Flower (1962–2012), David W. Hastings, Amelia E. Shevenell, James P. Kennett

Marine Science Faculty Publications

Benjamin P. Flower, a gifted paleoceanographer and marine geologist, supportive colleague, and dedicated educator at the University of South Florida (USF) College of Marine Science (CMS) passed away on 1 July 2012 from complications related to a rare genetic immune dysfunction, Common Variable Immunodeficiency. He was 49 years old. During his brief illness, Ben's love of life and boundless high spirits were an inspiration to his family, friends, and colleagues. He exhibited remarkable courage and kept his sense of humor in face of adversity. Ben's intellectualism and enduring love of science remained intact, even in his last hours.

Copper Toxicity In The San Francisco Bay-Delta, Kristen N. Buck

Marine Science Faculty Publications

San Francisco Bay has high dissolved copper concentrations—relative to nearby coastal waters—that often approach federal water quality standards put in place to protect sensitive marine life. But, how toxic is this copper?

Previous studies by other researchers have suggested that metal-binding compounds known as ligands can “grab up” more than 99.9 percent of the total available dissolved copper in seawater, rendering that copper biologically unavailable. Microorganisms that need trace amounts of copper for growth cannot readily obtain it in its ligand-bound form.

Improving Understanding Of Organic Metal‐Binding Ligands In The Ocean, Sylvia Sander, Kristen N. Buck, Maeve Lohan

Marine Science Faculty Publications

Organic Ligands—A Key Control on Trace Metal Biogeochemistry in the Ocean; Salt Lake City, Utah, 25 February 2012

The Organic Complexation Of Iron In The Marine Environment: A Review, Martha Gledhill, Kristen N. Buck

Marine Science Faculty Publications

Iron (Fe) is an essential micronutrient for marine organisms, and it is now well established that low Fe availability controls phytoplankton productivity, community structure, and ecosystem functioning in vast regions of the global ocean. The biogeochemical cycle of Fe involves complex interactions between lithogenic inputs (atmospheric, continental, or hydrothermal), dissolution, precipitation, scavenging, biological uptake, remineralization, and sedimentation processes. Each of these aspects of Fe biogeochemical cycling is likely influenced by organic Fe-binding ligands, which complex more than 99% of dissolved Fe. In this review we consider recent advances in our knowledge of Fe complexation in the marine environment and their …

Mechanisms Of Decadal Sea Level Variability In The Eastern North Atlantic And The Mediterranean Sea, F. M. Calafat, D. P. Chambers, M. N. Tsimplis

Marine Science Faculty Publications

[1] Decadal sea level variations from tide gauge records along the western European coast and in the Mediterranean Sea commencing in the late 19th and early 20th centuries are examined relative to large-scale atmospheric forcing. Recent studies have provided evidence for a link between sea level in the eastern North Atlantic and atmospheric forcing, however the nature of this relationship is still unclear. Here the outputs of a regional barotropic model and a nearly global baroclinic model are used in conjunction with wind stress and heat flux data to explore the physical mechanisms responsible for the observed sea level variability. …

Chlorophyll Aalgorithms For Oligotrophic Oceans: A Novel Approach Based On Three-Band Reflectance Difference, Chuanmin Hu, Zhongping Lee, Bryan Franz

Marine Science Faculty Publications

[1] A new empirical algorithm is proposed to estimate surface chlorophyll a (Chl) concentrations in the global ocean for Chl ≤ 0.25 mg m⁻³(∼78% of the global ocean area). The algorithm is based on a color index (CI), defined as the difference between remote-sensing reflectance (R_rs, sr⁻¹) in the green and a reference formed linearly between R_rsin the blue and red. For low-Chl waters, in situ data showed a tighter (and therefore better) relationship between CI and Chl than between traditional band ratios and Chl, which was further validated using global …

The Metabolic Response Of Pteropods To Acidification Reflects Natural Co2-Exposure In Oxygen Minimum Zones, A. E. Maas, K. F. Wishner, B. A. Seibel

Marine Science Faculty Publications

Shelled pteropods (Thecosomata) are a group of holoplanktonic mollusks that are believed to be especially sensitive to ocean acidification because their aragonitic shells are highly soluble. Despite this concern, there is very little known about the physiological response of these animals to conditions of elevated carbon dioxide. This study examines the oxygen consumption and ammonia excretion of five pteropod species, collected from tropical regions of the Pacific Ocean, to elevated levels of carbon dioxide (0.10%, 1000 ppm). Our results show that pteropods that naturally migrate into oxygen minimum zones, such as Hyalocylis striata, Clio pyramidata, Cavolinia longirostris and Creseis virgula …

Evaluation Of Release-05 Grace Time-Variable Gravity Coefficients Over The Ocean, D. P. Chambers, J. A. Bonin

Marine Science Faculty Publications

The latest release of GRACE (Gravity Recovery and Climate Experiment) gravity field coefficients (Release-05, or RL05) are evaluated for ocean applications. Data have been processed using the current methodology for Release-04 (RL04) coefficients, and have been compared to output from two different ocean models. Results indicate that RL05 data from the three Science Data Centers – the Center for Space Research (CSR), GeoForschungsZentrum (GFZ), and Jet Propulsion Laboratory (JPL) – are more consistent among themselves than the previous RL04 data. Moreover, the variance of residuals with the output of an ocean model is 50–60% lower for RL05 data than for …

Modelling Reef Fish Population Responses To Fisheries Restrictionsin Marine Protected Areas In The Coral Triangle, Divya Varkey, Cameron H. Ainsworth, Tony J. Pitcher

Marine Science Faculty Publications

Marine ecosystem models are used to investigate marine protected area (MPA) benefits for coral reef ecosystems located in Raja Ampat, in the heart of the Coral Triangle. Field data from an integrated and diverse research project is used to develop a spatial ecosystem model using Ecopath, Ecosim, and Ecospace modelling software. The ecological and fisheries responses of a reef ecosystem to different levels of fishing effort restrictions inside MPAs are explored. The trade-offs of allowing some fisheries to operate inside the MPAs versus designating the MPAs as no-take zones are highlighted. The results show that rapid rebuilding of reef fish …

Salinity Gradient Power (Sgp): A Developmental Roadmap Covering Existing Generation Technologies And Recent Investigative Results Into The Feasibility Of Bipolar Membrane-Based Salinity Gradient Power Generation, Clifford R. Merz, Wilfrido A. Moreno, Marilyn Barger, Stephen M. Lipka

Marine Science Faculty Publications

Besides wind and solar-based renewable energy technologies, marine sources are being actively discussed. Sources of marine renewable energy traditionally have included ocean currents, ocean waves, tides, thermal gradients, and salinity gradients. Salinity gradient power (SGP) is an attractive marine renewable resource because it possesses not only the largest energy potential but likely the largest total available resource as well. SGP is instantly available when diluted and concentrated ionic solutions are mixed; is renewable, sustainable, and produces no CO₂ emissions or other significant effluents that may interfere with global climate. The ultimate challenge is in the economics of the recovery …

Energetic Plasticity Underlies A Variable Response To Ocean Acidification In The Pteropod, Limacina Helicina Antarctica, Brad A. Seibel, Amy E. Maas, Heidi M. Dierssen

Marine Science Faculty Publications

Ocean acidification, caused by elevated seawater carbon dioxide levels, may have a deleterious impact on energetic processes in animals. Here we show that high PCO₂ can suppress metabolism, measured as oxygen consumption, in the pteropod, L. helicina forma antarctica, by ∼20%. The rates measured at 180–380 µatm (MO₂  = 1.25 M^−0.25, p = 0.007) were significantly higher (ANCOVA, p  =  0.004) than those measured at elevated target CO₂ levels in 2007 (789–1000 µatm,  =  0.78 M^−0.32, p  =  0.0008; Fig. 1). However, we further demonstrate metabolic plasticity in response to regional …

Direct Measurement Of Riverine Particulate Organic Carbon Age Structure, Brad E. Rosenheim, Valier Galy

Marine Science Faculty Publications

[1] Carbon cycling studies focusing on transport and transformation of terrigenous carbon sources toward marine sedimentary sinks necessitate separation of particulate organic carbon (OC) derived from many different sources and integrated by river systems. Much progress has been made on isolating and characterizing young biologically-formed OC that is still chemically intact, however quantification and characterization of old, refractory rock-bound OC has remained troublesome. Quantification of both endmembers of riverine OC is important to constrain exchanges linking biologic and geologic carbon cycles and regulating atmospheric CO₂ and O₂. Here, we constrain petrogenic OC proportions in suspended sediment from …

Is There A 60-Year Oscillation In Global Mean Sea Level?, Don P. Chambers, Mark A. Merrifield, R. Steven Nerem

Marine Science Faculty Publications

[1] We examine long tide gauge records in every ocean basin to examine whether a quasi 60-year oscillation observed in global mean sea level (GMSL) reconstructions reflects a true global oscillation, or an artifact associated with a small number of gauges. We find that there is a significant oscillation with a period around 60-years in the majority of the tide gauges examined during the 20th Century, and that it appears in every ocean basin. Averaging of tide gauges over regions shows that the phase and amplitude of the fluctuations are similar in the North Atlantic, western North Pacific, and Indian …

Reply To Comment By W. R. Peltier Et Al. On “Ocean Mass From Grace And Glacial Isostatic Adjustment”, D. P. Chambers, John Wahr, Mark E. Tamisiea, R. Steven Nerem

Marine Science Faculty Publications

No abstract provided.

Human Induced Turbidity Changes In Poyang Lake Between 2000 And 2010: Observations From Modis, Lian Feng, Chuanmin Hu, Xiaoling Chen, Liqiao Tian, Liqiong Chen

Marine Science Faculty Publications

A robust retrieval algorithm to estimate concentrations of total suspended sediments (TSS) in Poyang Lake (the largest freshwater lake in China) was developed using Moderate Resolution Imaging Spectroradiometer (MODIS) medium-resolution (250 m) data from 2000 to 2010 and in situ data collected during two cruise surveys. The algorithm was based on atmospherically corrected surface reflectance at 645 nm, with 1240 nm data serving as a reference for aerosols and a nearest-neighbor method was used to avoid land adjacency effect. The algorithm showed an uncertainty of 30–40% for TSS ranging between 3 and 200 mg L⁻¹. Long-term TSS distribution …

Storm-Induced Upwelling Of High PCo2 Waters Onto The Continental Shelf Of The Western Arctic Ocean And Implications For Carbonate Mineral Saturation States, Jeremy T. Mathis, Robert S. Pickart, Robert H. Byrne, Craig L. Mcneil, G. W. Moore, Laurie W. Juranek, Xuewu Liu, Jian Ma, Regina A. Easley, Matthew M. Elliot, Jessica N. Cross, Stacey C. Reisdorph, Frank Bahr, Jamie Morison, Trina Lichendorf, Richard A. Feely

Marine Science Faculty Publications

The carbon system of the western Arctic Ocean is undergoing a rapid transition as sea ice extent and thickness decline. These processes are dynamically forcing the region, with unknown consequences for CO₂ fluxes and carbonate mineral saturation states, particularly in the coastal regions where sensitive ecosystems are already under threat from multiple stressors. In October 2011, persistent wind-driven upwelling occurred in open water along the continental shelf of the Beaufort Sea in the western Arctic Ocean. During this time, cold (<−1.2°C), salty (>32.4) halocline water—supersaturated with respect to atmospheric CO₂ (pCO₂ > 550 μatm) and undersaturated …

Decadal Changes In The Aragonite And Calcite Saturation State Of The Pacific Ocean, Richard A. Feely, Christopher L. Sabine, Robert H. Byrne, Frank J. Millero, Andrew G. Dickson, Rik Wanninkhof, Akihiko Murata, Lisa A. Miller, Dana Greeley

Marine Science Faculty Publications

Based on measurements from the WOCE/JGOFS global CO₂ survey, the CLIVAR/CO₂ Repeat Hydrography Program and the Canadian Line P survey, we have observed an average decrease of 0.34% yr⁻¹ in the saturation state of surface seawater in the Pacific Ocean with respect to aragonite and calcite. The upward migrations of the aragonite and calcite saturation horizons, averaging about 1 to 2 m yr⁻¹, are the direct result of the uptake of anthropogenic CO₂ by the oceans and regional changes in circulation and biogeochemical processes. The shoaling of the saturation horizon is regionally variable, with …

Exploring Trade-Offs Between Fisheries And Conservation Of The Vaquita Porpoise (Phocoena Sinus) Using An Atlantis Ecosystem Model, Hem Nalini Morzaria-Luna, Cameron H. Ainsworth, Isaac C. Kaplan, Phillip S. Levin, Elizabeth A. Fulton

Marine Science Faculty Publications

Background: Minimizing fishery bycatch threats might involve trade-offs between maintaining viable populations and economic benefits. Understanding these trade-offs can help managers reconcile conflicting goals. An example is a set of bycatch reduction measures for the Critically Endangered vaquita porpoise (Phocoena sinus), in the Northern Gulf of California, Mexico. The vaquita is an endemic species threatened with extinction by artisanal net bycatch within its limited range; in this area fisheries are the chief source of economic productivity.

Methodology/Principal Findings: We analyze trade-offs between conservation of the vaquita and fisheries, using an end-to-end Atlantis ecosystem model for the Northern Gulf of California. …

Phisigns: An Online Tool To Identify Signaturegenes In Phages And Design Pcr Primers Forexamining Phage Diversity, Bhakti Dwivedi, Robert Schmieder, Dawn Goldsmith, Robert Edwards, Mya Breitbart

Marine Science Faculty Publications

Background

Phages (viruses that infect bacteria) have gained significant attention because of their abundance, diversity and important ecological roles. However, the lack of a universal gene shared by all phages presents a challenge for phage identification and characterization, especially in environmental samples where it is difficult to culture phage-host systems. Homologous conserved genes (or "signature genes") present in groups of closely-related phages can be used to explore phage diversity and define evolutionary relationships amongst these phages. Bioinformatic approaches are needed to identify candidate signature genes and design PCR primers to amplify those genes from environmental samples; however, there is currently …