A5087722654- Marine and coastal ecosystems
- Marine Biology and Ecology Research
- Microbial Community Ecology and Physiology
- Oceanographic and Atmospheric Processes
- Isotope Analysis in Ecology
- Ocean Acidification Effects and Responses
- Marine and fisheries research
- Marine Bivalve and Aquaculture Studies
- Wastewater Treatment and Nitrogen Removal
- Arctic and Antarctic ice dynamics
- Protist diversity and phylogeny
- Aquatic Ecosystems and Phytoplankton Dynamics
- Algal biology and biofuel production
- Methane Hydrates and Related Phenomena
- Diatoms and Algae Research
- Atmospheric and Environmental Gas Dynamics
- Genomics and Phylogenetic Studies
- Coral and Marine Ecosystems Studies
- Marine and coastal plant biology
- Water Quality Monitoring and Analysis
- Geochemistry and Elemental Analysis
- Geology and Paleoclimatology Research
- Paleontology and Stratigraphy of Fossils
- Ionosphere and magnetosphere dynamics
- Seismic Waves and Analysis
Bigelow Laboratory for Ocean Sciences
2016-2025
University of Sheffield
2024
Irvine University
2023
University of California, Irvine
2018-2023
Maine Department of Marine Resources
2017-2021
Bermuda Institute of Ocean Sciences
2008-2019
Woods Hole Oceanographic Institution
2018
University of Maryland Center for Environmental Science
1996-2004
J. Craig Venter Institute
2004
University of Southern California
2004
We have applied "whole-genome shotgun sequencing" to microbial populations collected en masse on tangential flow and impact filters from seawater samples the Sargasso Sea near Bermuda. A total of 1.045 billion base pairs nonredundant sequence was generated, annotated, analyzed elucidate gene content, diversity, relative abundance organisms within these environmental samples. These data are estimated derive at least 1800 genomic species based relatedness, including 148 previously unknown...
The Cyanobacteria Prochlorococcus and Synechococcus account for a substantial fraction of marine primary production. Here, we present quantitative niche models these lineages that assess future global abundances distributions. These are the result neural network, nonparametric, parametric analyses, they rely on >35,000 discrete observations from all major ocean regions. cell abundance based temperature photosynthetically active radiation, but individual responses to environmental...
The eukaryotic green alga Dunaliella tertiolecta acclimates to decreased growth irradiance by increasing cellular levels of light-harvesting chlorophyll protein complex apoproteins associated with photosystem II (LHCIIs), whereas increased elicits the opposite response. Nuclear run-on transcription assays and measurements cab mRNA stability established that light intensity-dependent changes in LHCII are controlled at level transcription. gene high-intensity was partially enhanced reducing...
Abstract. Inorganic phosphorus (SRP) concentrations in the subtropical North Atlantic are some of lowest global ocean and have been hypothesized to constrain primary production. Based upon data from several transect cruises this region, it has that dissolved organic (DOP) supports a significant fraction production Atlantic. In study, time-series biogeochemistry is presented for Bermuda Time-series Study site, including rates export. Most parameters seasonal pattern, although year-over-year...
Abstract. The smallest marine phytoplankton, collectively termed picophytoplankton, have been routinely enumerated by flow cytometry since the late 1980s during cruises throughout most of world ocean. We compiled a database 40 946 data points, with separate abundance entries for Prochlorococcus, Synechococcus and picoeukaryotes. use average conversion factors each three groups to convert carbon biomass. After gridding 1° spacing, covers 2.4% ocean surface area, best coverage in North...
Diatoms, but not flagellates, have been shown to increase rates of nitrogen release after a shift from low growth irradiance much higher experimental irradiance. We compared NO 3 − uptake kinetics, internal inorganic storage, and the temperature dependence reduction enzymes, nitrate (NR) nitrite reductase (NiR), in nitrogen‐replete cultures diatoms ( Chaetoceros sp., Skeletonema costatum , Thalassiosira weissflogii ) flagellates Dunaliella tertiolecta Pavlova lutheri Prorocentrum minimum...
Marine diatoms generally form large blooms during periods of cool temperature (<20°C), high NO 3 − fluxes (>25 μM‐N), and turbulent mixing, but the adaptations that allow to bloom under these conditions are not well understood. We have conducted both uptake kinetics direct short‐term manipulation studies on field diatom‐dominated populations from Chesapeake Delaware Bays spring fall blooms. Absolute rates by a Rhizoseleni ‐dominated population did appear saturate even at concentrations...
As intermediary in a number of key biological processes, the dynamics oceanic NO2- concentrations have historically been used as an indicator balance between oxidative and reductive pathways marine nitrogen cycle. appreciation role cycle grew through 1960s 1970s, data sets from different ocean basins became available, common feature was observed stratified water columns: peak at base euphotic zone, with near zero both shallower deeper. These are significant; they commonly range 10 400 nmol...
The performance of 36 models (22 ocean color and 14 biogeochemical circulation (BOGCMs)) that estimate depth‐integrated marine net primary productivity (NPP) was assessed by comparing their output to in situ C data at the Bermuda Atlantic Time series Study (BATS) Hawaii Ocean (HOT) over nearly two decades. Specifically, skill based on models' ability observed mean, variability, trends NPP. At both sites, more than 90% underestimated mean NPP, with average bias BOGCMs being twice models....
Phytoplankton alter their biochemical composition according to nutrient availability, such that bulk elemental varies across oceanic provinces. However, the links between plankton and variation in biogeochemical cycling of nutrients remain largely unknown. In a survey phytoplankton phosphorus stress western North Atlantic, we found phosphorus-depleted subtropical Sargasso Sea were enriched polyphosphate (polyP) compared with nutrient-rich temperate waters, contradicting canonical...
Knowledge of concentrations and elemental ratios suspended particles are important for understanding many biogeochemical processes in the ocean. These include patterns phytoplankton nutrient limitation as well linkages between cycles carbon nitrogen or phosphorus. To further enable studies ocean biogeochemistry, we here present a global dataset consisting 100,605 total measurements particulate organic carbon, nitrogen, phosphorus analyzed part 70 cruises time-series. The data globally...
Abstract The concept of constant elemental ratios in plankton communities—the Redfield ratio—is central importance to ocean biogeochemistry. Recently, several studies have demonstrated regional differences the C:P and N:P ratio. However, less is known about potential systematic variations C:N Here we present an analysis particulate organic carbon nitrogen ratio 40,482 globally distributed samples from upper 200 m water column. Particulate concentrations are highly correlated ( R 2 = 0.86)...
Abstract. Pico-plankton and nano-plankton are generally thought to represent a negligible fraction of the total particulate organic carbon (POC) export flux in oligotrophic gyres due their small size, slow individual sinking rates, tight grazer control that leads high rates recycling euphotic zone. Based upon recent inverse modeling network analysis however, it has been hypothesized pico-plankton, including cyanobacteria Synechococcus Prochlorococcus, contribute significantly POC export, via...
High-sensitivity measurements reveal variation in surface ocean phosphate, leading to a new model for nutrient cycles.