Skidaway Institute of Oceanography

MEPS Marine Ecology Progress Series Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsTheme Sections MEPS 307:273-306 (2006) - doi:10.3354/meps307273 Lipid storage in marine zooplankton Richard F. Lee1,*, Wilhelm Hagen2, Gerhard Kattner3 1Skidaway Institute of Oceanography, 10 Ocean Science Circle, Savannah, Georgia 31406, USA2Marine Zoologie, Universität Bremen (NW2), Postfach 330440, 28334 Bremen, Germany3Alfred-Wegener-Institut für Polar- und Meeresforschung, Postfach 120161, 27515 Bremerhaven, Germany *Email: dick@skio.peachnet.edu ABSTRACT: Zooplankton storage lipids play an important role during reproduction, food scarcity, ontogeny and diapause, as shown by studies in various oceanic regions. While triacylglycerols, the primary storage lipid of terrestrial animals, are found in almost all zooplankton species, wax esters are the dominant storage lipid in many deep-living and polar zooplankton taxa. Phospholipids and diacylglycerol ethers are the unique storage lipids used by polar euphausiids and pteropods, respectively. In zooplankton with large stores of wax esters, triacylglycerols are more rapidly turned over and used for short-term energy needs, while wax esters serve as long-term energy deposits. Zooplankton groups found in polar, westerlies, upwelling and coastal biomes are characterized by accumulation of large lipid stores. In contrast, zooplankton from the trades/tropical biomes is mainly composed of omnivorous species with only small lipid reserves. Diapausing copepods, which enter deep water after feeding on phytoplankton during spring/summer blooms or at the end of upwelling periods, are characterized by large oil sacs filled with wax esters. The thermal expansion and compressibility of wax esters may allow diapausing copepods and other deep-water zooplankton to be neutrally buoyant in cold deep waters, and they can thus avoid spending energy to remain at these depths. Lipid droplets are often noted in zooplankton ovaries, and a portion of these droplets can be transferred to developing oocytes. In addition to lipid droplets, zooplankton eggs have yolks with lipovitellin, a lipoprotein with approximately equal amounts of protein and lipid. The lipovitellin lipid is predominantly phosphatidylcholine, so during reproduction females must convert a portion of their storage lipid into this phospholipid. Developing embryos use their lipovitellin and lipid droplets for energy and materials until feeding begins. The various functions storage lipids serve during the different life history stages of zooplankton are very complex and still not fully understood and hence offer a multitude of fascinating research perspectives. KEY WORDS: Zooplankton · Lipids · Wax esters · Triacylglycerols · Diapause · Reproduction · Ontogeny · Biomes Full text in pdf format PreviousNextExport citation RSS - Facebook - Tweet - linkedIn Cited by Published in MEPS Vol. 307. Online publication date: January 24, 2006 Print ISSN: 0171-8630; Online ISSN: 1616-1599 Copyright © 2006 Inter-Research.

This paper explores the notion that the theoretical basis for contemporary research concerning the structure and function of marine pelagic ecosystems is self-limiting. While some findings such as the microbial food web have extended our knowledge of the biological components of the upper water column and their relationships to fluxes of materials and energy, they have not advanced our understanding of why specific pelagic forms occur in time and space, and why only some attain dominant status and contribute the bulk of biogenic fluxes emanating from the mixed layer. It is argued here that a major impediment to improved conceptual models is the historic focus on resource-dnven or 'bottom-up' factors as being the dominant variables structuring planktonic ecosystems. Evidence is presented that predation or 'top-down' trophic effects may be equally important in specifying the occurrence of particular taxa, the biomass within adjacent trophic levels, and the morphology of dominant herbivores and carnivores. It is suggested that key species, because of unique combinations of life history strategies, metabolic demands, and physiological performance, may exert a dominant role in the extent to which predatory interactions cascade through pelagic food webs. There is considerable evidence of evolution of predation avoidance strategies among phytoplankton and zooplankton. It is proposed that future research might profitably be directed toward the question of how the pelagic environment selects for life histories and morphologles of organisms under conditions when resource availability and predation are both significant structural buttresses. Methodological approaches should include detailed studies of dominant key taxa from different environments, with the goal of identifying the crlt~cal aspects of life history, behavior, or morphology which account for their success.

Unialgal cultures were used to investigate relationships between cell volume and the carbon and nitrogen content of nondiatomaceous marine nanophytoplankton. Cell dimensions were determined by image‐analyzed epifluorescence microscopy and particulate C and N by high‐temperature dry combustion. Volumes were calculated by direct integration with published algorithms (biovolume), but could be estimated equally well from linear dimensions as prolate spheres. Preservation with 0.5% glutaraldehyde reduced cell volumes 29% on average. Correlations were highly significant between biovolume of preserved cells and C and N contents. Nonlinear regression models appeared most appropriate because smaller cells contained more C and N per unit volume than did larger cells. Suggested general C densities for estimating cell C from preserved volume were 0.36 pg µ m −3 for 10 1 µ m 3 cells, 0.24 pg µ m −3 for 10 2 µ m 3 cells, and 0.16 pg C µ m −3 for 10 3 µm 3 cells. Previous regression models substantially underestimated the C densities of nanophytoplankton of 10 1 –10 3 µ m 3 . The explanation for these differences includes the method of determining mean population volumes, the use of preservatives, and the occurrence of significant vacuolar volume in larger phytoplankton.

Dissolving Charcoal Biomass burning produces 40 to 250 million tons of charcoal per year worldwide. Much of this is preserved in soils and sediments for thousands of years. However, the estimated production rate of charcoal is significantly larger than that of decomposition, and Jaffe et al. (p. 345 ; see the Perspective by Masiello and Louchouarn ) calculate that a large fraction of the charcoal produced by fires is lost from the land through dissolution and transport to the oceans.

Abstract. The present paper is the result of a workshop sponsored by the DFG Research Center/Cluster of Excellence MARUM "The Ocean in the Earth System", the International Graduate College EUROPROX, and the Alfred Wegener Institute for Polar and Marine Research. The workshop brought together specialists on organic matter degradation and on proxy-based environmental reconstruction. The paper deals with the main theme of the workshop, understanding the impact of selective degradation/preservation of organic matter (OM) in marine sediments on the interpretation of the fossil record. Special attention is paid to (A) the influence of the molecular composition of OM in relation to the biological and physical depositional environment, including new methods for determining complex organic biomolecules, (B) the impact of selective OM preservation on the interpretation of proxies for marine palaeoceanographic and palaeoclimatic reconstruction, and (C) past marine productivity and selective preservation in sediments. It appears that most of the factors influencing OM preservation have been identified, but many of the mechanisms by which they operate are partly, or even fragmentarily, understood. Some factors have not even been taken carefully into consideration. This incomplete understanding of OM breakdown hampers proper assessment of the present and past carbon cycle as well as the interpretation of OM based proxies and proxies affected by OM breakdown. To arrive at better proxy-based reconstructions "deformation functions" are needed, taking into account the transport and diagenesis-related molecular and atomic modifications following proxy formation. Some emerging proxies for OM degradation may shed light on such deformation functions. The use of palynomorph concentrations and selective changes in assemblage composition as models for production and preservation of OM may correct for bias due to selective degradation. Such quantitative assessment of OM degradation may lead to more accurate reconstruction of past productivity and bottom water oxygenation. Given the cost and effort associated with programs to recover sediment cores for paleoclimatological studies, as well as with generating proxy records, it would seem wise to develop a detailed sedimentological and diagenetic context for interpretation of these records. With respect to the latter, parallel acquisition of data that inform on the fidelity of the proxy signatures and reveal potential diagenetic biases would be of clear value.

Recent studies in the central equatorial Pacific allow a comprehensive assessment of phytoplankton regulation in a high-nutrient, low-chlorophyll (HNLC) ecosystem. Elemental iron enters the euphotic zone principally via upwelling and is present at concentrations (≤30 pM) well below the estimated half-saturation constant (120 pM) for the large cells that bloom with iron enrichment. In addition, the meridional trend in quantum yield of photosynthesis suggests that even the dominant small phytoplankton are held below their physiological potential by iron deficiency. Grazing by microzooplankton dominates phytoplankton losses, accounting for virtually all of the measured phytoplankton production during El Niño conditions and ∼66% during normal upwelling conditions, with mesozooplankton grazing and lateral advection closing the balance. Nitrate uptake is strongly correlated with the pigment biomass of diatoms, which increase in relative abundance during normal upwelling conditions. Nonetheless, the f-ratio remains low (0.07–0.12) under all conditions. Iron budgets are consistent with the notions that new production is determined by the rate of new iron input to the system while total production depends on efficient iron recycling by grazers. Although the limiting substrates differ, the interactions of resource limitation and grazing in HNLC regions are conceptually similar to the generally accepted view for oligotrophic subtropical regions. In both systems, small dominant phytoplankton grow at rapid, but usually less than physiologically maximal, rates; they are cropped to low stable abundances by microzooplankton; and their sustained high rates of growth depend on the remineralized by-products of grazing.

Studies of the decompositional chemistry of 5 types of estuarine macrophyte detritus were undertaken to examine relations among detrital nitrogen, protein, and other decompositional products. Protein and nitrogen contents of the detritus correlated poorly. Although the total mass of protein in all detritus decreased after 150 d of aging, there was a net increase in the mass of detrital nitrogen in some vascular plant detritus. During decomposition, detritus becomes richer in reactive phenolic and carbohydrate groups which may form condensation products with amino acids, yielding precursors to complex nitrogenous humic geopolymers. The existence of a significant positive relation between nitrogen accumulation and the production of humic substances suggests that much of the nitrogen accumulated during detritus decomposition is non-labile humic nitrogen rather than living microbial protein. The process of nitrogen enrichment often observed in detritus studies is consistent wlth the chemical behavior of nitrogen during humification. Biological availability of this humic nitrogen probably depends upon the extent to which proteinoid subunits are retained in the humic macromolecular structure.

The carbon isotopic fractionation accompanying formation of biomass by alkenone‐producing algae in natural marine environments varies systematically with the concentration of dissolved phosphate. Specifically, if the fractionation is expressed by є P ≈ δ e − δ p , where δ e and δ p are the δ 13 C values for dissolved CO 2 and for algal biomass (determined by isotopic analysis of C 37 alkadienones), respectively, and if C e is the concentration of dissolved CO 2 , μmol kg −1 , then b = 38 + 160*[PO 4 ], where [PO 4 ] is the concentration of dissolved phosphate, μM, and b = (25 − є p ) C e . The correlation found between b and [PO 4 ] is due to effects linking nutrient levels to growth rates and cellular carbon budgets for alkenone‐containing algae, most likely by trace‐metal limitations on algal growth. The relationship reported here is characteristic of 39 samples (r 2 = 0.95) from the Santa Monica Basin (six different times during the annual cycle), the equatorial Pacific (boreal spring and fall cruises as well as during an iron‐enrichment experiment), and the Peru upwelling zone. Points representative of samples from the Sargasso Sea ([PO 4 ] ≤ 0.1 μM) fall above the b = f [PO 4 ] line. Analysis of correlations expected between μ (growth rate), є p , and C e shows that, for our entire data set, most variations in є p result from variations in μ rather than C e . Accordingly, before concentrations of dissolved CO 2 can be estimated from isotopic fractionations, some means of accounting for variations in growth rate must be found, perhaps by drawing on relationships between [PO 4 ] and Cd/Ca ratios in shells of planktonic foraminifera.

With the Arctic rapidly changing, the needs to observe, understand, and model the changes are essential. To support these needs, an annual cycle of observations of atmospheric properties, processes, and interactions were made while drifting with the sea ice across the central Arctic during the Multidisciplinary drifting Observatory for the Study of Arctic Climate (MOSAiC) expedition from October 2019 to September 2020. An international team designed and implemented the comprehensive program to document and characterize all aspects of the Arctic atmospheric system in unprecedented detail, using a variety of approaches, and across multiple scales. These measurements were coordinated with other observational teams to explore cross-cutting and coupled interactions with the Arctic Ocean, sea ice, and ecosystem through a variety of physical and biogeochemical processes. This overview outlines the breadth and complexity of the atmospheric research program, which was organized into 4 subgroups: atmospheric state, clouds and precipitation, gases and aerosols, and energy budgets. Atmospheric variability over the annual cycle revealed important influences from a persistent large-scale winter circulation pattern, leading to some storms with pressure and winds that were outside the interquartile range of past conditions suggested by long-term reanalysis. Similarly, the MOSAiC location was warmer and wetter in summer than the reanalysis climatology, in part due to its close proximity to the sea ice edge. The comprehensiveness of the observational program for characterizing and analyzing atmospheric phenomena is demonstrated via a winter case study examining air mass transitions and a summer case study examining vertical atmospheric evolution. Overall, the MOSAiC atmospheric program successfully met its objectives and was the most comprehensive atmospheric measurement program to date conducted over the Arctic sea ice. The obtained data will support a broad range of coupled-system scientific research and provide an important foundation for advancing multiscale modeling capabilities in the Arctic.

Dissolved organic matter (DOM) is a master variable in aquatic systems. Modern fluorescence techniques couple measurements of excitation emission matrix (EEM) spectra and parallel factor analysis (PARAFAC) to determine fluorescent DOM (FDOM) components and DOM quality. However, the molecular signatures associated with PARAFAC components are poorly defined. In the current study we characterized river water samples from boreal Québec, Canada, using EEM/PARAFAC analysis and ultrahigh resolution mass spectrometry (FTICR-MS). Spearman's correlation of FTICR-MS peak and PARAFAC component relative intensities determined the molecular families associated with 6 PARAFAC components. Molecular families associated with PARAFAC components numbered from 39 to 572 FTICR-MS derived elemental formulas. Detailed molecular properties for each of the classical humic- and protein-like FDOM components are presented. FTICR-MS formulas assigned to PARAFAC components represented 39% of the total number of formulas identified and 59% of total FTICR-MS peak intensities, and included significant numbers compounds that are highly unlikely to fluoresce. Thus, fluorescence measurements offer insight into the biogeochemical cycling of a large proportion of the DOM pool, including a broad suite of unseen molecules that apparently follow the same gradients as FDOM in the environment.

Abstract Climate change induced permafrost thaw in the Arctic is mobilizing ancient dissolved organic carbon (DOC) into headwater streams; however, DOC exported from the mouth of major arctic rivers appears predominantly modern. Here we highlight that ancient (>20,000 years B.P.) permafrost DOC is rapidly utilized by microbes (~50% DOC loss in <7 days) and that permafrost DOC decay rates (0.12 to 0.19 day −1 ) exceed those for DOC in a major arctic river (Kolyma: 0.09 day −1 ). Permafrost DOC exhibited unique molecular signatures, including high levels of aliphatics that were rapidly utilized by microbes. As microbes processed permafrost DOC, its distinctive chemical signatures were degraded and converged toward those of DOC in the Kolyma River. The extreme biolability of permafrost DOC and the rapid loss of its distinct molecular signature may explain the apparent contradiction between observed permafrost DOC release to headwaters and the lack of a permafrost signal in DOC exported via major arctic rivers to the ocean.

Differences in methylmercury (CH(3)Hg) production normalized to the sulfate reduction rate (SRR) in various species of sulfate-reducing bacteria (SRB) were quantified in pure cultures and in marine sediment slurries in order to determine if SRB strains which differ phylogenetically methylate mercury (Hg) at similar rates. Cultures representing five genera of the SRB (Desulfovibrio desulfuricans, Desulfobulbus propionicus, Desulfococcus multivorans, Desulfobacter sp. strain BG-8, and Desulfobacterium sp. strain BG-33) were grown in a strictly anoxic, minimal medium that received a dose of inorganic Hg 120 h after inoculation. The mercury methylation rates (MMR) normalized per cell were up to 3 orders of magnitude higher in pure cultures of members of SRB groups capable of acetate utilization (e.g., the family Desulfobacteriaceae) than in pure cultures of members of groups that are not able to use acetate (e.g., the family Desulfovibrionaceae). Little or no Hg methylation was observed in cultures of Desulfobacterium or Desulfovibrio strains in the absence of sulfate, indicating that Hg methylation was coupled to respiration in these strains. Mercury methylation, sulfate reduction, and the identities of sulfate-reducing bacteria in marine sediment slurries were also studied. Sulfate-reducing consortia were identified by using group-specific oligonucleotide probes that targeted the 16S rRNA molecule. Acetate-amended slurries, which were dominated by members of the Desulfobacterium and Desulfobacter groups, exhibited a pronounced ability to methylate Hg when the MMR were normalized to the SRR, while lactate-amended and control slurries had normalized MMR that were not statistically different. Collectively, the results of pure-culture and amended-sediment experiments suggest that members of the family Desulfobacteriaceae have a greater potential to methylate Hg than members of the family Desulfovibrionaceae have when the MMR are normalized to the SRR. Hg methylation potential may be related to genetic composition and/or carbon metabolism in the SRB. Furthermore, we found that in marine sediments that are rich in organic matter and dissolved sulfide rapid CH(3)Hg accumulation is coupled to rapid sulfate reduction. The observations described above have broad implications for understanding the control of CH(3)Hg formation and for developing remediation strategies for Hg-contaminated sediments.

The in situ or authigenic formation of calcium phosphate minerals in marine sediments is a major sink for the vital nutrient phosphorus. However, because typical sediment chemistry is not kinetically conducive to the precipitation of these minerals, the mechanism behind their formation has remained a fundamental mystery. Here, we present evidence from high-sensitivity x-ray and electrodialysis techniques to describe a mechanism by which abundant diatom-derived polyphosphates play a critical role in the formation of calcium phosphate minerals in marine sediments. This mechanism can explain the puzzlingly dispersed distribution of calcium phosphate minerals observed in marine sediments worldwide.

Dissolved organic matter (DOM) in the oceans is one of the largest pools of reduced carbon on Earth, comparable in size to the atmospheric CO2 reservoir. A vast number of compounds are present in DOM, and they play important roles in all major element cycles, contribute to the storage of atmospheric CO2 in the ocean, support marine ecosystems, and facilitate interactions between organisms. At the heart of the DOM cycle lie molecular-level relationships between the individual compounds in DOM and the members of the ocean microbiome that produce and consume them. In the past, these connections have eluded clear definition because of the sheer numerical complexity of both DOM molecules and microorganisms. Emerging tools in analytical chemistry, microbiology, and informatics are breaking down the barriers to a fuller appreciation of these connections. Here we highlight questions being addressed using recent methodological and technological developments in those fields and consider how these advances are transforming our understanding of some of the most important reactions of the marine carbon cycle.

The goal of these studies was to improve our understanding of how Oithonidae and Oncaeidae can exist in nearly every part of the ocean. In particular, it was intended to obtain quantitative information on reproduction rates and the longevity of adult females, and on feeding and growth rates of Oncaeidae. When feeding at relatively high food levels, early copepodids of Oncaea mediterranea ingested ∼100% of their body weight daily and had an exponential growth rate of r = 0.26. Average reproduction rates of field-collected O.mediterranea females ranged from 5.3 to 13.3 nauplii day −1 and those of females of Oithona plumifera were 3.8 nauplii day −1 . However, females of the latter reproduced for longer periods than those of the former. Average longevity of females of O.mediterranea ranged from 29 to 41 days, and that of O.plumifera was 71 days on average. Their reproductive output per lifetime was similar to those of small calanoid species like Paracalanus parvus , for example, which reproduce at higher rates, but over a shorter adult female lifespan. It is assumed that predator avoidance, especially of early juveniles, extended egg production and female longevity, and relatively low metabolic expenditures contribute to the nearly ubiquitous occurrence of the two genera. The limited specialization of the two genera, when compared to calanoids, could be seen as an advantage to survival over an extended range of environmental conditions. It is hypothesized that the relatively low rates of food consumption, growth, reproduction and, possibly, mortality contribute to stabilizing planktonic communities in the ocean.

It is acknowledged that marine invertebrates produce bioactive natural products that may be useful for developing new drugs. By exploring untapped geographical sources and/or novel groups of organisms one can maximize the search for new marine drugs to treat human diseases. The goal of this paper is to analyse the trends associated with the discovery of new marine natural products from invertebrates (NMNPI) over the last two decades. The analysis considers different taxonomical levels and geographical approaches of bioprospected species. Additionally, this research is also directed to provide new insights into less bioprospected taxa and world regions. In order to gather the information available on NMNPI, the yearly-published reviews of Marine Natural Products covering 1990-2009 were surveyed. Information on source organisms, specifically taxonomical information and collection sites, was assembled together with additional geographical information collected from the articles originally describing the new natural product. Almost 10000 NMNPI were discovered since 1990, with a pronounced increase between decades. Porifera and Cnidaria were the two dominant sources of NMNPI worldwide. The exception was polar regions where Echinodermata dominated. The majority of species that yielded the new natural products belong to only one class of each Porifera and Cnidaria phyla (Demospongiae and Anthozoa, respectively). Increased bioprospecting efforts were observed in the Pacific Ocean, particularly in Asian countries that are associated with the Japan Biodiversity Hotspot and the Kuroshio Current. Although results show comparably less NMNPI from polar regions, the number of new natural products per species is similar to that recorded for other regions. The present study provides information to future bioprospecting efforts addressing previously unexplored taxonomic groups and/or regions. We also highlight how marine invertebrates, which in some cases have no commercial value, may become highly valuable in the ongoing search for new drugs from the sea.

Abstract. Dissolved black carbon (DBC), defined here as condensed aromatics isolated from seawater via PPL solid phase extraction and quantified as benzenepolycarboxylic acid (BPCA) oxidation products, is a significant component of the oceanic dissolved organic carbon (DOC) pool. These condensed aromatics are widely distributed in the open ocean and appear to be tens of thousands of years old. As such DBC is regarded as highly refractory. In the current study, the photo-lability of DBC, DOC and coloured dissolved organic matter (CDOM; ultraviolet-visible absorbance) were determined over the course of a 28 day irradiation of North Atlantic Deep Water under a solar simulator. During the irradiation DBC fell from 1044 ± 164 nM-C to 55 ± 15 nM-C, a 20-fold decrease in concentration. Dissolved black carbon photo-degradation was more rapid and more extensive than for bulk CDOM and DOC. The concentration of DBC correlated with CDOM absorbance and the quality of DBC indicated by the ratios of different BPCAs correlated with CDOM absorbance spectral slope, suggesting the optical properties of CDOM may provide a proxy for both DBC concentrations and quality in natural waters. Further, the photo-lability of components of the DBC pool increased with their degree of aromatic condensation. These trends indicate that a continuum of compounds of varying photo-lability exists within the marine DOC pool. In this continuum, photo-lability scales with aromatic character, specifically the degree of condensation. Scaling the rapid photo-degradation of DBC to rates of DOC photo-mineralisation for the global ocean leads to an estimated photo-chemical half-life for oceanic DBC of less than 800 years. This is more than an order of magnitude shorter than the apparent age of DBC in the ocean. Consequently, photo-degradation is posited as the primary sink for oceanic DBC and the apparent survival of DBC molecules in the oceans for millennia appears to be facilitated not by their inherent inertness but by the rate at which they are cycled through the surface ocean's photic zone.

A physical model based on determining the fraction of the tidal prism that returns to the estuary on the next high tide is used to estimate the flushing time of the Okatee River estuary. The return flow factor ( b ) of 0.81 yields a flushing time of 2 days. A mass balance model of 228 Ra and salinity is also used to estimate b . This model yields an average b = 0.79, virtually the same as the physical model. A third model based on the decay of 224 Ra relative to 228 Ra is used to determine the apparent age of water in the estuary. These ages range from 1.6 to 5 days, with an average of 3.4 days. These three independent estimates are in remarkably close agreement, certainly within the error of each estimate. We use these residence times to develop a mass balance model for the radium isotopes in the Okatee estuary. We consider decay, mixing, sedimentary input, river input, and submarine groundwater discharge (SGD). The major loss term for each isotope is mixing with water in Port Royal Sound; the major input for each isotope is SGD. At steady state these terms must balance. Knowing the water age and the radium isotope composition of groundwater entering the Okatee allows us to estimate an average SGD flux of 1 m 3 /s. The SGD flux is a factor of 3–4 greater during the summer relative to the winter. This SGD supplies a considerable quantity of nutrients and carbon into the Okatee system.

Atmospheric deposition is a source of potentially bioavailable iron (Fe) and thus can partially control biological productivity in large parts of the ocean. However, the explanation of observed high aerosol Fe solubility compared to that in soil particles is still controversial, as several hypotheses have been proposed to explain this observation. Here, a statistical analysis of aerosol Fe solubility estimated from four models and observations compiled from multiple field campaigns suggests that pyrogenic aerosols are the main sources of aerosols with high Fe solubility at low concentration. Additionally, we find that field data over the Southern Ocean display a much wider range in aerosol Fe solubility compared to the models, which indicate an underestimation of labile Fe concentrations by a factor of 15. These findings suggest that pyrogenic Fe-containing aerosols are important sources of atmospheric bioavailable Fe to the open ocean and crucial for predicting anthropogenic perturbations to marine productivity.

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTNew Developments in the Marine Nitrogen CycleJay A. Brandes, Allan H. Devol, and Curtis DeutschView Author Information Skidaway Institute of Oceanography, 10 Ocean Science Circle, Savannah, Georgia 31411, and School of Oceanography, University of Washington, Seattle, Washington 98195 Cite this: Chem. Rev. 2007, 107, 2, 577–589Publication Date (Web):February 14, 2007Publication History Received16 May 2006Published online14 February 2007Published inissue 1 February 2007https://pubs.acs.org/doi/10.1021/cr050377thttps://doi.org/10.1021/cr050377tresearch-articleACS PublicationsCopyright © 2007 American Chemical SocietyRequest reuse permissionsArticle Views4938Altmetric-Citations197LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access optionsGet e-Alertsclose SUBJECTS:Anions,Cations,Geological materials,Nitrogen,Oxidation Get e-Alerts