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Full-Text Articles in Life Sciences
Temporal Shifts In Top-Down Vs. Bottom-Up Control Of Epiphytic Algae In A Seagrass Ecosystem, Ma Whalen, Je Duffy, Jb Grace
Temporal Shifts In Top-Down Vs. Bottom-Up Control Of Epiphytic Algae In A Seagrass Ecosystem, Ma Whalen, Je Duffy, Jb Grace
VIMS Articles
In coastal marine food webs, small invertebrate herbivores (mesograzers) have long been hypothesized to occupy an important position facilitating dominance of habitat-forming macrophytes by grazing competitively superior epiphytic algae. Because of the difficulty of manipulating mesograzers in the field, however, their impacts on community organization have rarely been rigorously documented. Understanding mesograzer impacts has taken on increased urgency in seagrass systems due to declines in seagrasses globally, caused in part by widespread eutrophication favoring seagrass overgrowth by faster-growing algae. Using cage-free field experiments in two seasons (fall and summer), we present experimental confirmation that mesograzer reduction and nutrients can promote …
Multiple Predator Species Alter Prey Behavior, Population Growth, And A Trophic Cascade In A Model Estuarine Food Web, Pl Reynolds, Jf Bruno
Multiple Predator Species Alter Prey Behavior, Population Growth, And A Trophic Cascade In A Model Estuarine Food Web, Pl Reynolds, Jf Bruno
VIMS Articles
Predators can influence prey population dynamics by affecting prey behaviors with strong fitness consequences, with cascading effects on lower trophic levels. Here, we demonstrate that multiple predator species can nonconsumptively influence prey population growth and the strength of a trophic cascade in a model marine community. We exposed the herbivorous amphipod Ampithoe longimana to olfactory and visual cues from three common predators (pinfish, mud crabs, brown shrimp) singly and together in a multiple-predator assemblage to quantify the nonconsumptive effects (NCEs) of predator identity and the presence of multiple predators on prey population and community-level metrics. The presence of predator cues, …
Fish Species Distribution In Seagrass Habitats Of Chesapeake Bay Are Structured By Abiotic And Biotic Factors, Jason J. Schaffler, Jacques Van Montfrans, Cynthia M. Jones, R J. Orth
Fish Species Distribution In Seagrass Habitats Of Chesapeake Bay Are Structured By Abiotic And Biotic Factors, Jason J. Schaffler, Jacques Van Montfrans, Cynthia M. Jones, R J. Orth
VIMS Articles
Seagrass habitats have long been known to serve as nursery habitats for juvenile fish by providing refuges from predation and areas of high forage abundance. However, comparatively less is known about other factors structuring fish communities that make extensive use of seagrass as nursery habitat. We examined both physical and biological factors that may structure the juvenile seagrass-associated fish communities across a synoptic-scale multiyear study in lower Chesapeake Bay. Across 3years of sampling, we collected 21,153 fish from 31 species. Silver Perch Bairdiella chrysoura made up over 86% of all individuals collected. Nine additional species made up at least 1% …
Revision Of The Genus Centrophorus (Squaliformes: Centrophoridae): Part 1-Redescription Of Centrophorus Granulosus (Bloch & Schneider), A Senior Synonym Of C-Acus Garman And C-Niaukang Teng, Wt White, Da Ebert, Gjp Naylor, Hc Ho, P Clerkin, A Verissimo, Cf Cotton
Revision Of The Genus Centrophorus (Squaliformes: Centrophoridae): Part 1-Redescription Of Centrophorus Granulosus (Bloch & Schneider), A Senior Synonym Of C-Acus Garman And C-Niaukang Teng, Wt White, Da Ebert, Gjp Naylor, Hc Ho, P Clerkin, A Verissimo, Cf Cotton
VIMS Articles
The genus Centrophorus is one of the most taxonomically complex and confusing elasmobranch groups. A revision of this group is currently underway and this first paper sets an important foundation in this process by redescribing the type species of the genus-Centrophorus granulosus. This taxon name has been previously applied to two different morphotypes: a large species > 1.5 m TL and a smaller species similar to 1 m TL. Centrophorus acus and C. niaukang are the most commonly used names applied to the larger morphotype. The original description of C. granulosus was based on a large specimen of similar to 1.5 …
Penguin Biogeography Along The West Antarctic Peninsula Testing The Canyon Hypothesis With Palmer Lter Observations, O Schofield, H Ducklow, K Bernard, S Doney, D Patterson-Fraser, Et Al.
Penguin Biogeography Along The West Antarctic Peninsula Testing The Canyon Hypothesis With Palmer Lter Observations, O Schofield, H Ducklow, K Bernard, S Doney, D Patterson-Fraser, Et Al.
VIMS Articles
No abstract provided.
Contribution Of Sea Ice In The Southern Ocean To The Cycling Of Volatile Halogenated Organic Compounds, A Granfors, A Karlsson, E Mattsson, Walker O. Smith Jr., K Abrahamsson
Contribution Of Sea Ice In The Southern Ocean To The Cycling Of Volatile Halogenated Organic Compounds, A Granfors, A Karlsson, E Mattsson, Walker O. Smith Jr., K Abrahamsson
VIMS Articles
The contribution of sea ice to the flux of biogenic volatile halogenated organic compounds to the atmosphere in the Southern Ocean is currently not known. To approach this question, we measured halocarbons in sea ice, sea ice brine, and surface water of the Amundsen and Ross Seas. Concentrations in sea ice of these compounds, normalized to seawater salinity, ranged from 0.2 to 810 pmol L-1. Salinity-normalized chlorophyll a concentrations in the ice ranged from 3.5 to 190 mu gL(-1). Our results suggest biological production of halocarbons in sea ice, with maxima of halogenated organics and chlorophyll a commonly found in …
Krill Biomass And Aggregation Structure In Relation To Tidal Cycle In A Penguin Foraging Region Off The Western Antarctic Peninsula, Ks Bernard, Deborah K. Steinberg
Krill Biomass And Aggregation Structure In Relation To Tidal Cycle In A Penguin Foraging Region Off The Western Antarctic Peninsula, Ks Bernard, Deborah K. Steinberg
VIMS Articles
Antarctic krill are a key component of the diet of Adlie penguins inhabiting the Western Antarctic Peninsula (WAP), yet our understanding of the variability of krill distribution patterns within nearshore penguin feeding grounds is limited. A recent study of the foraging patterns of penguins breeding in the northern WAP suggests that tidal phase plays a role in foraging distance. We used acoustics to examine biomass and aggregation structure of krill in the penguin foraging grounds off Palmer Station during diurnal and semi-diurnal tides. Nearshore, integrated krill biomass during diurnal tides was significantly higher than during semi-diurnal tides. Krill aggregations were …
Effects Of Microalgal Exudates And Intact Cells On Subtropical Marine Zooplankton, Nj Silva, Kw Tang, Rm Lopes
Effects Of Microalgal Exudates And Intact Cells On Subtropical Marine Zooplankton, Nj Silva, Kw Tang, Rm Lopes
VIMS Articles
Harmful algal blooms (HABs) affect coastal waters worldwide and very often lead to the disruption of seafood harvesting and commercial activities, because of potential hazards to human health associated with the consumption of contaminated mussels, crustaceans and fish. HAB events are frequently caused by outbreaks of toxin-producing dinoflagellates, which are subject to top-down control by zooplankton. The aim of this study was to analyze the effects of dinoflagellate exudates and intact cells on the survivorship and mobility of zooplankton taxa from a subtropical location (Ubatuba, Brazil). Lethal effects were observed in five out of six taxa investigated, three of which …
Envisioning A Marine Biodiversity Observation Network, Je Duffy, La Amaral-Zettler, Dg Fautin, G Paulay, Ta Rynearson, Et Al.
Envisioning A Marine Biodiversity Observation Network, Je Duffy, La Amaral-Zettler, Dg Fautin, G Paulay, Ta Rynearson, Et Al.
VIMS Articles
Humans depend on diverse ocean ecosystems for food, jobs, and sustained well-being, yet many stressors threaten marine life. Extensive research has demonstrated that maintaining biodiversity promotes ocean health and service provision; therefore, monitoring the status and trends of marine biodiversity is important for effective ecosystem management. However, there is no systematic sustained program for evaluating ocean biodiversity. Coordinating existing monitoring and building a proactive marine biodiversity observation network will support efficient, economical resource management and conservation and should be a high priority. A synthesis of expert opinions suggests that, to be most effective, a marine biodiversity observation network should integrate …
Physiological Effects Of Diet Mixing On Consumer Fitness: A Meta-Analysis, Js Lefcheck, Ma Whalen, Tm Davenport, Jp Stone, Je Duffy
Physiological Effects Of Diet Mixing On Consumer Fitness: A Meta-Analysis, Js Lefcheck, Ma Whalen, Tm Davenport, Jp Stone, Je Duffy
VIMS Articles
The degree of dietary generalism among consumers has important consequences for population, community, and ecosystem processes, yet the effects on consumer fitness of mixing food types have not been examined comprehensively. We conducted a meta-analysis of 161 peer-reviewed studies reporting 493 experimental manipulations of prey diversity to test whether diet mixing enhances consumer fitness based on the intrinsic nutritional quality of foods and consumer physiology. Averaged across studies, mixed diets conferred significantly higher fitness than the average of single-species diets, but not the best single prey species. More than half of individual experiments, however, showed maximal growth and reproduction on …
Effects Of Seasonal Hypoxia On Macrobenthic Production And Function In The Rappahannock River, Virginia, Usa, Sk Sturdivant, Rochelle D. Seitz, R. J. Diaz
Effects Of Seasonal Hypoxia On Macrobenthic Production And Function In The Rappahannock River, Virginia, Usa, Sk Sturdivant, Rochelle D. Seitz, R. J. Diaz
VIMS Articles
Since colonial times, anthropogenic effects have eroded Chesapeake Bay’s health, resulting in an increase in the extent and severity of hypoxia (≤ 2 mg O2 l-1), adversely affecting community structure and secondary production of macrobenthos in the Bay and its tributaries. The influence of hypoxia on macrobenthic communities is well documented, but less well known is the regulatory effect of hypoxia on macrobenthic production. Changes in macrobenthic production were assessed in the lower Rappahannock River, a sub-estuary of Chesapeake Bay, in an area known to experience seasonal hypoxia. During the spring, summer, fall, and following spring of …
Internal Versus External Drivers Of Periodic Hypoxia In A Coastal Plain Tributary Estuary: The York River, Virginia, Sj Lake, Mark Brush, Iris C. Anderson, Hi Kator
Internal Versus External Drivers Of Periodic Hypoxia In A Coastal Plain Tributary Estuary: The York River, Virginia, Sj Lake, Mark Brush, Iris C. Anderson, Hi Kator
VIMS Articles
The formation of periodic hypoxia within tributary estuaries, and its relationship to the spring-neap tidal cycle, has been well documented in several systems along the US east coast. However, the importance and scale of other physical and biological processes, which ultimately control the frequency and spatial extent of hypoxia, are less well understood. This study synthesized in situ measurements, metabolic incubations, and high-resolution water quality monitoring into a spatially explicit, temporally integrated mass balance to examine the significance of multiple organic matter sources and oxygen sinks in relation to hypoxia in the York River estuary (YRE), Virginia, USA. Results highlight …
Biodiversity In A Changing Climate: A Synthesis Of Current And Projected Trends In The Us, Md Staudinger, Sl Carter, Ms Cross, Ns Dubois, Je Duffy, Et Al.
Biodiversity In A Changing Climate: A Synthesis Of Current And Projected Trends In The Us, Md Staudinger, Sl Carter, Ms Cross, Ns Dubois, Je Duffy, Et Al.
VIMS Articles
This paper provides a synthesis of the recent literature describing how global biodiversity is being affected by climate change and is projected to respond in the future. Current studies reinforce earlier findings of major climate-change-related impacts on biological systems and document new, more subtle after-effects. For example, many species are shifting their distributions and phenologies at faster rates than were recorded just a few years ago; however, responses are not uniform across species. Shifts have been idiosyncratic and in some cases counterintuitive, promoting new community compositions and altering biotic interactions. Although genetic diversity enhances species' potential to respond to variable …
Seed Burial In Eelgrass Zostera Marina: The Role Of Infauna, Nj Blackburn, R J. Orth
Seed Burial In Eelgrass Zostera Marina: The Role Of Infauna, Nj Blackburn, R J. Orth
VIMS Articles
Seed burial is a vital process that influences small- and large-scale plant population patterns and is frequently mediated by soil-dwelling invertebrates. Despite its importance in terrestrial systems, very little is known about seed burial in seagrasses. The goal of this work was to determine the role that benthic infauna play in the burial of Zostera marina seeds. Mesocosm experiments studying seed burial depth, seed burial rate, and particle burial and redistribution using beads, were conducted in defaunated sediment cores populated with single specimens of infauna with different modes of feeding and thus bioturbation effects: Amphitrite ornata (downward conveyor deposit feeder), …
Oyster-Mediated Benthic-Pelagic Coupling Modifies Nitrogen Pools And Processes, Ar Smyth, Nr Geraldi, Mf Piehler
Oyster-Mediated Benthic-Pelagic Coupling Modifies Nitrogen Pools And Processes, Ar Smyth, Nr Geraldi, Mf Piehler
VIMS Articles
Removal of nitrogen through enhanced denitrification has been identified as an ecosystem service provided by oysters. In this study, we assessed the effects of an individual oyster (Crassostrea virginica) on nitrogen dynamics. Fluxes of N-2, O-2, nitrate/nitrite (NOx) and ammonium (NH4+) were measured from continuous-flow microcosms that contained a live oyster, sediment, or a live oyster + sediment. Net N-2 fluxes were indicative of nitrogen fixation in the sediment treatment and denitrification in the oyster and oyster + sediment treatments. Organic matter de position and ammonium production associated with oyster biodeposits and excretion likely decreased N limitation, and …
Modeling The Effect Of Hypoxia On Macrobenthos Production In The Lower Rappahannock River, Chesapeake Bay, Usa, Samuel Kersey Sturdivant, Mark Brush, Robert J. Diaz
Modeling The Effect Of Hypoxia On Macrobenthos Production In The Lower Rappahannock River, Chesapeake Bay, Usa, Samuel Kersey Sturdivant, Mark Brush, Robert J. Diaz
VIMS Articles
Hypoxia in Chesapeake Bay has substantially increased in recent decades, with detrimental effects on macrobenthic production; the production of these fauna link energy transfer from primary consumers to epibenthic and demersal predators. As such, the development of accurate predictive models that determine the impact of hypoxia on macrobenthic production is important. A continuous-time, biomass-based model was developed for the lower Rappahannock River, a Bay tributary prone to seasonal hypoxia. Phytoplankton, zooplankton, and macrobenthic state variables were modeled, with a focus on quantitatively constraining the effect of hypoxia on macrobenthic biomass. This was accomplished through regression with Z': a sigmoidal function …
Sperm Swimming Speeds In The Eastern Oyster Crassostrea Virginica (Gmelin, 1791), Roger L. Mann, Mark Luckenbach
Sperm Swimming Speeds In The Eastern Oyster Crassostrea Virginica (Gmelin, 1791), Roger L. Mann, Mark Luckenbach
VIMS Articles
Oysters, like the vast majority of sessile marine invertebrates, shed sperm and eggs into the water column where fertilization subsequently occurs. The fate of the gametes depends on their passive movements at various scales in a high-viscosity environment, the longevity of the sperm's ability to affect oriented movement, the rate of sperm movement toward the egg target, and the ability of sperm to effect fertilization. Oyster sperm swim in a helical pattern with a mean forward progression velocity of 0.057 +/- 0.010 mm/sec (SE; n = 25) with the 95 percentile range extending from 0.036-0.078 mm/sec, a value comparable with …
Microzooplankton Grazing Along The Western Antarctic Peninsula, Lm Garzio, Deborah K. Steinberg, M Erickson, Hw Ducklow
Microzooplankton Grazing Along The Western Antarctic Peninsula, Lm Garzio, Deborah K. Steinberg, M Erickson, Hw Ducklow
VIMS Articles
The significance of microzooplankton as grazers in pelagic ecosystems has been established, yet relatively few studies of microzooplankton grazing, compared to that of macrozooplankton, have been conducted in the Southern Ocean. We report phytoplankton and bacterial growth and grazing mortality rates along the Western Antarctic Peninsula (WAP), a region of rapid climate change. Growth and grazing rates were determined by dilution experiments at select stations along the WAP in January of 2009 to 2011 and in the nearshore waters near Palmer Station in February and March 2011. Microzooplankton exerted higher grazing pressure on bacteria compared to phytoplankton along the WAP …
Broad-Scale Association Between Seagrass Cover And Juvenile Blue Crab Density In Chesapeake Bay, Gina M. Ralph, Rochelle D. Seitz, R J. Orth, Kathleen E. Knick, Rom Lipcius
Broad-Scale Association Between Seagrass Cover And Juvenile Blue Crab Density In Chesapeake Bay, Gina M. Ralph, Rochelle D. Seitz, R J. Orth, Kathleen E. Knick, Rom Lipcius
VIMS Articles
Although numerous small-scale laboratory, mesocosm, and field experiments have demonstrated that abundance, survival, and growth of juvenile fish and invertebrates are higher in vegetated than in unvegetated habitats, the effect of habitat quality (i.e. habitat complexity) within vegetated habitats has not been documented at a broad spatial scale. We examined the relationship between percent cover in seagrass beds (eelgrass Zostera marina, widgeon grass Ruppia maritima, and associated macroalgae) and juvenile blue crab Callinectes sapidus density at a broad spatial scale. We quantified the functional relationship between juvenile density and percent cover of vegetation by sampling in Chesapeake Bay (USA) seagrass …
Microphytobenthos And Benthic Macroalgae Determine Sediment Organic Matter Composition In Shallow Photic Sediments, Ak Hardison, Elizabeth A. Canuel, Iris C. Anderson, C. R. Tobias, B. Veuger, M. N. Waters
Microphytobenthos And Benthic Macroalgae Determine Sediment Organic Matter Composition In Shallow Photic Sediments, Ak Hardison, Elizabeth A. Canuel, Iris C. Anderson, C. R. Tobias, B. Veuger, M. N. Waters
VIMS Articles
Microphytobenthos and benthic macroalgae play an important role in system metabolism within shallow coastal bays. However, their independent and interactive influences on sediment organic matter (SOM) are not well understood. We investigated the influence of macroalgae and microphytobenthos on SOM quantity and quality in an experimental mesocosm system using bulk and molecular level (total hydrolyzable amino acids, THAA; phospholipid linked fatty acids, PLFA; pigment) analyses. Our experiment used an incomplete factorial design made up of two factors, each with two levels: (1) light (ambient vs. dark) and (2) macroalgae (presence vs. absence of live macroalgae). Over the course of the …
Denitrification And Nutrient Assimilation On A Restored Oyster Reef, M. Lisa Kellogg, Jeffery Cornwell, Michael S. Owens, Kennedy Paynter
Denitrification And Nutrient Assimilation On A Restored Oyster Reef, M. Lisa Kellogg, Jeffery Cornwell, Michael S. Owens, Kennedy Paynter
VIMS Articles
At a restored reef site and a control site in the Choptank River, Maryland, USA, we partially quantified the effect of oyster reef restoration on the removal of nutrients from the water column by determining seasonal fluxes of oxygen (O2), ammonium (NH4 +), combined nitrate and nitrite (NO2+ 3), di-nitrogen (N2) and soluble reactive phosphorus (SRP) and by assessing the assimilation of nutrients by macrofauna. Fluxes of O2, NH4 +, NO2+ 3 and SRP at the restored site were enhanced by at least one order of magnitude during all seasons. Seasonal denitrification rates at the restored site, measured as flux …
Carbon Fluxes And Pelagic Ecosystem Dynamics Near Two Western Antarctic Peninsula Adélie Penguin Colonies: An Inverse Model Approach, Sevrine F. Sailley, Hugh W. Ducklow, Holly V. Moeller, William R. Fraser, Oscar M. Schofield, Deborah K. Steinberg, Lori M. Garzio, Scott C. Doney
Carbon Fluxes And Pelagic Ecosystem Dynamics Near Two Western Antarctic Peninsula Adélie Penguin Colonies: An Inverse Model Approach, Sevrine F. Sailley, Hugh W. Ducklow, Holly V. Moeller, William R. Fraser, Oscar M. Schofield, Deborah K. Steinberg, Lori M. Garzio, Scott C. Doney
VIMS Articles
An inverse food-web model for the western Antarctic Peninsula (WAP) pelagic food web was constrained with data from Palmer Long Term Ecological Research (PAL-LTER) project annual austral summer sampling cruises. Model solutions were generated for 2 regions with Adélie penguin Pygoscelis adeliae colonies presenting different population trends (a northern and a southern colony) for a 12 yr period (1995−2006). Counter to the standard paradigm, comparisons of carbon flow through bacteria, microzooplankton, and krill showed that the diatom−krill−top predator food chain is not the dominant pathway for organic carbon exchanges. The food web is more complex, including significant contributions by microzooplankton …
Combining Observations And Numerical Model Results To Improve Estimates Of Hypoxic Volume Within The Chesapeake Bay, Usa, A.J. Bever, Marjorie A.M. Friedrichs, Carl T. Friedrichs, M. E. Scully, Lyon Lanerolle
Combining Observations And Numerical Model Results To Improve Estimates Of Hypoxic Volume Within The Chesapeake Bay, Usa, A.J. Bever, Marjorie A.M. Friedrichs, Carl T. Friedrichs, M. E. Scully, Lyon Lanerolle
VIMS Articles
The overall size of the dead zone within the main stem of the Chesapeake Bay and its tidal tributaries is quantified by the hypoxic volume (HV), the volume of water with dissolved oxygen (DO) less than 2 mg/L. To improve estimates of HV, DO was subsampled from the output of 3-D model hindcasts at times/locations matching the set of 2004-2005 stations monitored by the Chesapeake Bay Program. The resulting station profiles were interpolated to produce bay-wide estimates of HV in a manner consistent with nonsynoptic, cruise-based estimates. Interpolations of the same stations sampled synoptically, as well as multiple other combinations …
Nondaily Deposition Of Striae In The Bay Scallop Argopecten Irradians (Concentricus) In The Laboratory, P Hollyman, Mark Luckenbach, Ca Richardson
Nondaily Deposition Of Striae In The Bay Scallop Argopecten Irradians (Concentricus) In The Laboratory, P Hollyman, Mark Luckenbach, Ca Richardson
VIMS Articles
Small (similar to 15 mm) and large (similar to 30 mm) calcein-marked bay scallops, Argopecten irradians, held for 2, 4, and 6 wk in the laboratory under natural illumination and conditions of high and low flow rates deposited significantly more striae on the surface of the left (dark) shell valve compared with the right (light) shell valve. Small scallops deposited an average of 0.55 stria per day, 0.42 stria per day, and 0.34 stria per day, respectively, during the 2-, 4-, and 6-wk experiments, whereas large scallops had a lower frequency of stria formation (0.20 stria per day, 0.18 stria …
Molecular And Functional Ecology Of Aquatic Microbial Symbionts, Hans-Peter Grossart, Lasse Riemann, Kam W. Tang
Molecular And Functional Ecology Of Aquatic Microbial Symbionts, Hans-Peter Grossart, Lasse Riemann, Kam W. Tang
VIMS Articles
No abstract provided.
The Maredat Global Database Of High Performance Liquid Chromatography Marine Pigment Measurements, J. Peloquin, Walker O. Smith Jr.
The Maredat Global Database Of High Performance Liquid Chromatography Marine Pigment Measurements, J. Peloquin, Walker O. Smith Jr.
VIMS Articles
A global pigment database consisting of 35 634 pigment suites measured by high performance liquid chromatography was assembled in support of the MARine Ecosytem DATa (MAREDAT) initiative. These data originate from 136 field surveys within the global ocean, were solicited from investigators and databases, compiled, and then quality controlled. Nearly one quarter of the data originates from the Laboratoire d'Oceanographie de Villefranche (LOV), with an additional 17% and 19% stemming from the US JGOFS and LTER programs, respectively. The MAREDAT pigment database provides high quality measurements of the major taxonomic pigments including chlorophylls a and b, 19'-butanoyloxyfucoxanthin, 19'-hexanoyloxyfucoxanthin, alloxanthin, divinyl …
Age, Growth, And Reproductive Biology Of Cownose Rays In Chesapeake Bay, Robert A. Fisher, Garrett C. Call, R. Dean Grubbs
Age, Growth, And Reproductive Biology Of Cownose Rays In Chesapeake Bay, Robert A. Fisher, Garrett C. Call, R. Dean Grubbs
VIMS Articles
The Cownose Ray Rhinoptera bonasus is an opportunistic predator of benthic invertebrates and has had a long history of negative interactions with commercial shellfish industries. Most recently, Cownose Rays have been implicated in negatively affecting the recovery of bay scallop Argopecten irradians stocks in North Carolina and oyster restoration and commercial aquaculture efforts in Chesapeake Bay. A mitigation attempt to decrease predation on shellfish has resulted in an unregulated fishery for Cownose Rays. Cownose Ray life history suggests that they are highly susceptible to overexploitation. We determined age, growth, and size at maturity for Cownose Rays collected in Chesapeake Bay. …
The Importance Of Dissimilatory Nitrate Reduction To Ammonium (Dnra) In The Nitrogen Cycle Of Coastal Ecosystems, Ae Giblin, Cr Tobias, Bk Song, N Weston, Gt Banta
The Importance Of Dissimilatory Nitrate Reduction To Ammonium (Dnra) In The Nitrogen Cycle Of Coastal Ecosystems, Ae Giblin, Cr Tobias, Bk Song, N Weston, Gt Banta
VIMS Articles
Until recently, it was believed that biological assimilation and gaseous nitrogen (N) loss through denitrification were the two major fates of nitrate entering or produced within most coastal ecosystems. Denitrification is often viewed as an important ecosystem service that removes reactive N from the ecosystem. However, there is a competing nitrate reduction process, dissimilatory nitrate reduction to ammonium (DNRA), that conserves N within the ecosystem. The recent application of nitrogen stable isotopes as tracers has generated growing evidence that DNRA is a major nitrogen pathway that cannot be ignored. Measurements comparing the importance of denitrification vs. DNRA in 55 coastal …