A5023629550- Marine and coastal ecosystems
- Microbial Community Ecology and Physiology
- Marine Biology and Ecology Research
- Photosynthetic Processes and Mechanisms
- Algal biology and biofuel production
- Coral and Marine Ecosystems Studies
- Isotope Analysis in Ecology
- Water Quality Monitoring and Analysis
- Spectroscopy and Quantum Chemical Studies
- Photoreceptor and optogenetics research
- Ocean Acidification Effects and Responses
- Biocrusts and Microbial Ecology
- Marine Sponges and Natural Products
- Marine and coastal plant biology
- Oceanographic and Atmospheric Processes
- Arctic and Antarctic ice dynamics
- Food Industry and Aquatic Biology
- Remote Sensing in Agriculture
- Polar Research and Ecology
- Atmospheric and Environmental Gas Dynamics
- Light effects on plants
- Plant Water Relations and Carbon Dynamics
- Plant responses to elevated CO2
- Geology and Paleoclimatology Research
- Atmospheric chemistry and aerosols
Rutgers, The State University of New Jersey
2015-2024
Samara Federal Research Scientific Center
2021
Rutgers Sexual and Reproductive Health and Rights
1999-2020
Physical Sciences (United States)
2004
Moss Landing Marine Laboratories
2004
Monterey Bay Aquarium Research Institute
2004
Woods Hole Oceanographic Institution
2004
Duke University
2004
University of California, Santa Barbara
2004
Lomonosov Moscow State University
1992-2002
Comparison of eight iron experiments shows that maximum Chl a , the DIC removal, and overall DIC/Fe efficiency all scale inversely with depth wind mixed layer (WML) defining light environment. Moreover, lateral patch dilution, sea surface irradiance, temperature, grazing play additional roles. The Southern Ocean were most influenced by very deep WMLs. In contrast, conditions favorable during SEEDS SERIES as well IronEx‐2. two extreme experiments, EisenEx SEEDS, can be linked via bottle...
Over the past three decades, massive bleaching events of zooxanthellate corals have been documented across range global distribution. Although phenomenon is correlated with relatively small increases in sea-surface temperature and enhanced light intensity, underlying physiological mechanism remains unknown. In this article we demonstrate that thylakoid membrane lipid composition a key determinate thermal-stress sensitivity symbiotic algae cnidarians. Analyses membranes reveal critical...
The availability of iron is known to exert a controlling influence on biological productivity in surface waters over large areas the ocean and may have been an important factor variation concentration atmospheric carbon dioxide glacial cycles. effect Southern Ocean particularly because its area abundant nitrate, yet iron-enhanced growth phytoplankton be differentially expressed between with high silicic acid south low north, where diatom limited by both iron. Two mesoscale experiments,...
Colonies of the Caribbean coral Montastraea cavernosa exhibit a solar-stimulated orange-red fluorescence that is spectrally similar to variety fluorescent proteins expressed by corals. The source this phycoerythrin in unicellular, nonheterocystis, symbiotic cyanobacteria within host cells coral. coexist with dinoflagellates (zooxanthellae) and express nitrogen-fixing enzyme nitrogenase. presence prokaryotic symbiont nitrogen-limited zooxanthellate suggests nitrogen fixation may be an...
In zooxanthellate corals, excess excitation energy can be dissipated as heat (nonphotochemical quenching), thereby providing protection against oxidative damage by supraoptimal light in shallow reefs. To identify and quantify the photoprotective mechanisms, we studied diel variability of chlorophyll fluorescence yields photosynthetic parameters situ using moored SCUBA‐based fast‐repetition‐rate fluorometers. The results reveal that nonphotochemical quenching is triggered prior to saturation...
EisenEx—the second in situ iron enrichment experiment the Southern Ocean—was performed Atlantic sector over 3 weeks November 2000 with overarching goal to test hypothesis that primary productivity Ocean is limited by availability austral spring. Underwater irradiance, chlorophyll a (Chl a), photochemical efficiency, and were measured inside outside of an iron‐enriched patch order quantify response phytoplankton fertilization. Chl concentration photosynthetic rate (14C uptake simulated...
During the past several decades, numerous reports from disparate geographical areas have documented an increased frequency of “bleaching” in reef-forming corals. The phenomenon, triggered by sea surface temperatures, occurs when cnidarian hosts digest and/or expel their intracellular, photosynthetic dinoflagellate symbionts (“zooxanthellae” genus Symbiodinium ). Although coral bleaching is often followed death animal hosts, some cases, survives and can be repopulated with viable...
Abstract. Iron is an essential nutrient involved in a variety of biological processes the ocean, including photosynthesis, respiration and dinitrogen fixation. Atmospheric deposition aerosols recognized as main source iron for surface ocean. In high nutrient, low chlorophyll areas, it now clearly established that limits phytoplankton productivity but its biogeochemical role environments has been poorly studied. We investigated this question unexplored southeast Pacific, arguably most...
Abstract Diatoms possess an impressive capacity for rapidly inducible thermal dissipation of excess absorbed energy (qE), provided by the xanthophyll diatoxanthin and Lhcx proteins. By knocking out Lhcx1 Lhcx2 genes individually in Phaeodactylum tricornutum strain 4 complementing knockout lines with different proteins, multiple mutants varying qE capacities are obtained, ranging from zero to high values. We demonstrate that is entirely dependent on concerted action Lhcx1, Lhcx3 having...
Abstract The Southern Ocean contributes substantially to the global biological carbon pump (BCP). Salps in Ocean, particular Salpa thompsoni , are important grazers that produce large, fast-sinking fecal pellets. Here, we quantify salp bloom impacts on microbial dynamics and BCP, by contrasting locations differing presence/absence. Salp blooms coincide with phytoplankton dominated diatoms or prymnesiophytes, depending water mass characteristics. Their grazing is comparable microzooplankton...
Using solar energy suboptimally How efficient are phytoplankton at converting sunlight into the products of photosynthesis? The two other pathways that absorbed can take emission back to environment by fluorescence or conversion heat. Lin et al. measured lifetimes in laboratory and combined them with satellite measurements variable chlorophyll fluorescence. Combined, they determined quantum yields photochemistry four ocean basins. Approximately 60% is converted heat, a figure 50% higher than...
In many species of symbiotic corals, spawning occurs synchronously several nights after the full moon. This process is correlated with level lunar irradiance, but mechanism by which these cnidarian/zooxanthellate symbioses can detect such low levels light remains unknown. Here we report first biophysical evidence that host animal exhibits extraordinarily sensitive photoreception in blue region spectrum. Using a high‐resolution laser‐induced signal to tentacle scattering, measured effect...
The evolution of multicellularity in animals required the production extracellular matrices that serve to spatially organize cells according function. In corals, three are involved spatial organization: (i) an organic ECM, which facilitates cell-cell and cell-substrate adhesion; (ii) a skeletal matrix (SOM), controlled deposition calcium carbonate skeleton; (iii) skeleton itself, provides structural support for 3D organization coral colonies. this report, we examine these by using vitro...
Abstract Amundsen Sea polynyas are among the most productive, yet climate‐sensitive ecosystems in Southern Ocean and host massive annual phytoplankton blooms. These blooms believed to be controlled by iron fluxes from melting ice icebergs intrusion of nutrient‐rich Circumpolar Deep Water, however interplay between effects other controls, such as light availability, has not been quantified. Here, we examine photophysiology relation Fe stress physical forcing two largest polynyas, Polynya...
Abstract Variable fluorescence techniques are increasingly used to assess phytoplankton photosynthesis. All and models for photosynthetic electron transport rates (ETRs) amplitude‐based subject errors, especially when growth is nutrient‐limited. Here we develop a new, kinetic‐based approach measure, directly in absolute units, ETRs estimate phytoplankton. We applied this investigate the effects of nitrogen limitation on photophysiology rates. Nutrient stress leads decrease quantum yield...
Abstract Phytoplankton in the Arctic Ocean are subject to nitrogen limitation summer, however, how severely stress affects phytoplankton physiology remains largely unknown. In summers of 2015–2018, we examined distribution photophysiological properties across two contrasting regions with distinctly different levels availability upper water column. We quantified extent using a highly sensitive fluorescence induction and relaxation system obtain continuous underway measurements via discrete...
Approximately 45% of the photosynthetically fixed carbon on Earth occurs in oceans phytoplankton, which account for less than 1% world's photosynthetic biomass. This amazing empirical observation implies a very high energy conversion efficiency, but how efficiently is solar actually used? The photon budget photosynthesis can be divided into three terms: quantum yields photochemistry, fluorescence, and heat. Measuring two these processes closes budget. development ultrasensitive, seagoing...
Fluorescent pigments in several Indo‐Pacific and Caribbean anthozoans have recently been identified as proteins related to the Green‐fluorescent protein (GFP) of hydromedusa Aequorea victoria . Here we show that GFP is widely distributed many species. The fluorescence excitation emission spectra for pigment are similar those reported elsewhere coral noncoral quantum yield estimated be 35%. Spectral molecular characterization isolated clearly it GFP, laboratory situ measurements Western blot...
Benthic photoautotrophic organisms significantly contribute to the productivity of shallow tropical coastal ecosystems. However, measurements photosynthetic light use and dissipation in benthic are complicated by taxonomic diversity, spatial heterogeneity, natural variability local nutrient, irradiance, temperature regimes, as well destructive sampling protocols. To help overcome these problems, we developed a SCUBA‐based fast repetition rate (FRR) fluorometer for variable chlorophyll...
Significance Diatoms are unicellular eukaryotic phytoplankton responsible for nearly one-half of total marine primary productivity. We identified a plastid-targeted protein in the coastal diatom Thalassiosira pseudonana (TpDSP1) that enhances growth during iron limitation under low light. Clone lines overexpressing TpDSP1 had lower quantum requirements growth, increased levels photosynthetic and carbon fixation proteins, cyclic electron flow around photosystem I, an energy-producing pathway...
Constraining photosynthetic energy conversion efficiency in nature is challenging. In principle, two yield measurements must be made simultaneously: photochemistry, fluorescence and/or thermal dissipation. We constructed different, extremely sensitive and precise active fluorometers: one measures the quantum of photochemistry from changes variable fluorescence, other lifetimes picosecond time domain. By deploying pair instruments on eight transoceanic cruises over six years, we obtained 200...
When diatoms are stressed for inorganic nitrogen they remodel their intermediate metabolism and redirect carbon towards lipid biosynthesis. However, this response comes at a significant cost reflected in decreased photosynthetic energy conversion efficiency growth. Here we explore molecular genetics approach to restrict the assimilation of by knocking down nitrate reductase (NR). The transformant strain, NR21, exhibited about 50% lower expression activity enzyme but simultaneously...