Open Access. Powered by Scholars. Published by Universities.®

Life Sciences Commons

Open Access. Powered by Scholars. Published by Universities.®

Articles 1 - 27 of 27

Full-Text Articles in Life Sciences

Increased Feeding And Nutrient Excretion Of Adult Antarctic Krill, Euphausia Superba, Exposed To Enhanced Carbon Dioxide (Co2), Gk Saba, O Schofield, Jj Torres, Eh Ombres, Deborah K. Steinberg Dec 2012

Increased Feeding And Nutrient Excretion Of Adult Antarctic Krill, Euphausia Superba, Exposed To Enhanced Carbon Dioxide (Co2), Gk Saba, O Schofield, Jj Torres, Eh Ombres, Deborah K. Steinberg

VIMS Articles

Ocean acidification has a wide-ranging potential for impacting the physiology and metabolism of zooplankton. Sufficiently elevated CO2 concentrations can alter internal acid-base balance, compromising homeostatic regulation and disrupting internal systems ranging from oxygen transport to ion balance. We assessed feeding and nutrient excretion rates in natural populations of the keystone species Euphausia superba (Antarctic krill) by conducting a CO2 perturbation experiment at ambient and elevated atmospheric CO2 levels in January 2011 along the West Antarctic Peninsula (WAP). Under elevated CO2 conditions (similar to 672 ppm), ingestion rates of krill averaged 78 mu g C individual(-1) d(-1) and were 3.5 times …


Global Patterns In The Impact Of Marine Herbivores On Benthic Primary Producers, Alistair G.B. Poore, Alexandra H. Campbell, Ross Coleman, Graham J. Edgar, Veijo Jormalainen, Pamela L. Reynolds, Erik E. Sotka, John J. Stachowicz, Richard Taylor, Mathew A. Vanderklift, J. Emmett Duffy May 2012

Global Patterns In The Impact Of Marine Herbivores On Benthic Primary Producers, Alistair G.B. Poore, Alexandra H. Campbell, Ross Coleman, Graham J. Edgar, Veijo Jormalainen, Pamela L. Reynolds, Erik E. Sotka, John J. Stachowicz, Richard Taylor, Mathew A. Vanderklift, J. Emmett Duffy

VIMS Articles

Despite the importance of consumers in structuring communities, and the widespread assumption that consumption is strongest at low latitudes, empirical tests for global scale patterns in the magnitude of consumer impacts are limited. In marine systems, the long tradition of experimentally excluding herbivores in their natural environments allows consumer impacts to be quantified on global scales using consistent methodology. We present a quantitative synthesis of 613 marine herbivore exclusion experiments to test the influence of consumer traits, producer traits and the environment on the strength of herbivore impacts on benthic producers. Across the globe, marine herbivores profoundly reduced producer abundance …


Effects Of Trophic Skewing Of Species Richness Onecosystem Functioning In A Diverse Marine Community, Pamela L. Reynolds, John F. Bruno May 2012

Effects Of Trophic Skewing Of Species Richness Onecosystem Functioning In A Diverse Marine Community, Pamela L. Reynolds, John F. Bruno

VIMS Articles

Widespread overharvesting of top consumers of the world's ecosystems has "skewed" food webs, in terms of biomass and species richness, towards a generally greater domination at lower trophic levels. This skewing is exacerbated in locations where exotic species are predominantly low-trophic level consumers such as benthic macrophytes, detritivores, and filter feeders. However, in some systems where numerous exotic predators have been added, sometimes purposefully as in many freshwater systems, food webs are skewed in the opposite direction toward consumer dominance. Little is known about how such modifications to food web topology, e.g., changes in the ratio of predator to prey …


Bioturbation In A Declining Oxygen Environment, In Situ Observations From Wormcam, S. Kersey Sturdivant, Robert J. Diaz, George R. Cutter Apr 2012

Bioturbation In A Declining Oxygen Environment, In Situ Observations From Wormcam, S. Kersey Sturdivant, Robert J. Diaz, George R. Cutter

VIMS Articles

Bioturbation, the displacement and mixing of sediment particles by fauna or flora, facilitates life supporting processes by increasing the quality of marine sediments. In the marine environment bioturbation is primarily mediated by infaunal organisms, which are susceptible to perturbations in their surrounding environment due to their sedentary life history traits. Of particular concern is hypoxia, dissolved oxygen (DO) concentrations ≤2.8 mg l−1, a prevalent and persistent problem that affects both pelagic and benthic fauna. A benthic observing system (Wormcam) consisting of a buoy, telemetering electronics, sediment profile camera, and water quality datasonde was developed and deployed in the …


Abstracts Of Technical Papers, Presented At The 104th Annual Meeting, National Shellfisheries Association, Seattle, Washington, March 24–29, 2012, National Shellfisheries Association Apr 2012

Abstracts Of Technical Papers, Presented At The 104th Annual Meeting, National Shellfisheries Association, Seattle, Washington, March 24–29, 2012, National Shellfisheries Association

VIMS Articles

No abstract provided.


Historical Ecology With Real Numbers: Past And Present Extent And Biomass Of An Imperilled Estuarine Habitat, Psez Ermgassen, Md Spalding, B Blake, Ld Coen, B Dumbauld, Mark Luckenbach, Et Al. Jan 2012

Historical Ecology With Real Numbers: Past And Present Extent And Biomass Of An Imperilled Estuarine Habitat, Psez Ermgassen, Md Spalding, B Blake, Ld Coen, B Dumbauld, Mark Luckenbach, Et Al.

VIMS Articles

Historic baselines are important in developing our understanding of ecosystems in the face of rapid global change. While a number of studies have sought to determine changes in extent of exploited habitats over historic timescales, few have quantified such changes prior to late twentieth century baselines. Here, we present, to our knowledge, the first ever large-scale quantitative assessment of the extent and biomass of marine habitat-forming species over a 100-year time frame. We examined records of wild native oyster abundance in the United States from a historic, yet already exploited, baseline between 1878 and 1935 (predominantly 1885-1915), and a current …


Genetic Structure Of Eurasian Badgers Meles Meles (Carnivora: Mustelidae) And The Colonization History Of Ireland, Db O'Meara, Cj Edwards, Dp Sleeman, Tf Cross, Mj Statham, Jr Mcdowell, Et Al. Jan 2012

Genetic Structure Of Eurasian Badgers Meles Meles (Carnivora: Mustelidae) And The Colonization History Of Ireland, Db O'Meara, Cj Edwards, Dp Sleeman, Tf Cross, Mj Statham, Jr Mcdowell, Et Al.

VIMS Articles

The present study examined the contemporary genetic composition of the Eurasian badger, Meles meles, in Ireland, Britain and Western Europe, using six nuclear microsatellite loci and a 215-bp fragment of the mitochondrial DNA control region. Significant population structure was evident within Europe (global multilocus microsatellite FST = 0.205, P < 0.001; global mitochondrial control region FST = 0.399, P < 0.001). Microsatellite-based cluster analyses detected one population in Ireland, whereas badgers from Britain could be subdivided into several populations. Excluding the island populations of Ireland and Britain, badgers from Western Europe showed further structuring, with evidence of discrete Scandinavian, Central European, and Spanish populations. Mitochondrial DNA cluster analysis grouped the Irish population with Scandinavia and Spain, whereas the majority of British haplotypes grouped with those from Central Europe. The findings of the present study suggest that British and Irish badger populations colonized from different refugial areas, or that there were different waves of colonization from the source population. There are indications for the presence of an Atlantic fringe element, which has been seen in other Irish species. We discuss the results in light of the controversy about natural versus human-mediated introductions. (c) 2012 The Linnean Society of London, Biological Journal of the Linnean Society, 2012, , .


Ciliate Epibionts Associated With Crustacean Zooplankton In German Lakes: Distribution, Motility, And Bacterivory, Samantha L. Bickel, Kam W. Tang, Hans-Peter Grossart Jan 2012

Ciliate Epibionts Associated With Crustacean Zooplankton In German Lakes: Distribution, Motility, And Bacterivory, Samantha L. Bickel, Kam W. Tang, Hans-Peter Grossart

VIMS Articles

Ciliate epibionts associated with crustacean zooplankton are widespread in aquatic systems, but their ecological roles are little known. We studied the occurrence of ciliate epibionts on crustacean zooplankton in nine German lakes with different limnological features during the summer of 2011. We also measured the detachment and re-attachment rates of the ciliates, changes in their motility, and the feeding rates of attached vs. detached ciliate epibionts. Epibionts were found in all lakes sampled except an acidic lake with large humic inputs. Epibiont prevalence was as high as 80.96% on the cladoceran Daphnia cucullata, 67.17% on the cladoceran Diaphanosoma brachyurum, and …


Characterization And Ecological Implication Of Eelgrass Life History Strategies Near The Species' Southern Limit In The Western North Atlantic, Jessie C. Jarvis, Ken Moore, W. Judson Kenworthy Jan 2012

Characterization And Ecological Implication Of Eelgrass Life History Strategies Near The Species' Southern Limit In The Western North Atlantic, Jessie C. Jarvis, Ken Moore, W. Judson Kenworthy

VIMS Articles

Eelgrass Zostera marina L. populations located near the species southern limit in the western North Atlantic were assessed monthly from July 2007 through November 2008. We identified (1) dominant life history strategies and local environmental conditions in southern Z. marina populations, (2) quantified differences in reproductive phenology between populations and different local environmental conditions, and (3) compared reproductive strategies to established annual and perennial life history paradigms. Observed populations expressed both life history strategies with one Z. marina population completely losing aboveground biomass and reestablishing from seeds (annual model) while another population retained aboveground biomass throughout the year (perennial model). …


Genetic Diversity Of The Caribbean Spiny Lobster Virus, Panulirus Argus Virus 1 (Pav1), And The Discovery Of Pav1 In Lobster Postlarvae, Ja Moss, Mj Butler, Dc Behringer, Jeffrey D. Shields Jan 2012

Genetic Diversity Of The Caribbean Spiny Lobster Virus, Panulirus Argus Virus 1 (Pav1), And The Discovery Of Pav1 In Lobster Postlarvae, Ja Moss, Mj Butler, Dc Behringer, Jeffrey D. Shields

VIMS Articles

Panulirus argus virus 1 (PaV1) is an unclassified, pathogenic virus first discovered in Caribbean spiny lobsters Panulirus argus from the Florida Keys, USA, and has since been confirmed in lobsters in other parts of the Caribbean. Several studies have examined the prevalence, pathogenicity, and population dynamics of the pathogen in the lobster host, but little is known about the genetic diversity of the virus. We analyzed a fragment of viral DNA from lobsters collected in the Florida Keys, which provided the first insight into the genetic diversity of PaV1. The variation in viral sequences, both within and between individual lobsters, …


Changes In Biodiversity And Environmental Stressors Influence Community Structure Of An Experimental Eelgrass Zostera Marina System, Rachael E. Blake, J. Emmett Duffy Jan 2012

Changes In Biodiversity And Environmental Stressors Influence Community Structure Of An Experimental Eelgrass Zostera Marina System, Rachael E. Blake, J. Emmett Duffy

VIMS Articles

Changes in biodiversity can result in decreased ecosystem functioning and loss of ecosystem services, but altered biodiversity is only one of many stressors impacting ecosystems. In many estuaries, environmental stressors such as warming water temperatures and eutrophication are increasing and negatively impacting biological communities, particularly seagrasses such as the important habitat-forming species Zostera marina (eelgrass). These negative impacts may change the diversity, composition, and functioning of this important ecosystem, but the interactions of stressors with changes in biodiversity are poorly understood. We manipulated eelgrass communities in a factorial experiment to test how changes in crustacean grazer diversity, warmer water temperatures, …


Interannual Variability Of Primary Production And Dissolved Organic Nitrogen Storage In The North Pacific Subtropical Gyre, Ya-Wei Luo, Hugh W. Ducklow, Marjorie A.M. Friedrichs, Matthew Church, David Karl, Scott C. Doney Jan 2012

Interannual Variability Of Primary Production And Dissolved Organic Nitrogen Storage In The North Pacific Subtropical Gyre, Ya-Wei Luo, Hugh W. Ducklow, Marjorie A.M. Friedrichs, Matthew Church, David Karl, Scott C. Doney

VIMS Articles

The upper ocean primary production measurements from the Hawaii Ocean Time series (HOT) at Station ALOHA in the North Pacific Subtropical Gyre showed substantial variability over the last two decades. The annual average primary production varied within a limited range over 1991-1998, significantly increased in 1999-2000 and then gradually decreased afterwards. This variability was investigated using a one-dimensional ecosystem model. The long-term HOT observations were used to constrain the model by prescribing physical forcings and lower boundary conditions and optimizing the model parameters against data using data assimilation. The model reproduced the general interannual pattern in the observed primary production, …


Eelgrass Survival In Two Contrasting Systems: Role Of Turbidity And Summer Water Temperatures, Ken Moore, Erin C. Shields, David B. Parrish, R J. Orth Jan 2012

Eelgrass Survival In Two Contrasting Systems: Role Of Turbidity And Summer Water Temperatures, Ken Moore, Erin C. Shields, David B. Parrish, R J. Orth

VIMS Articles

Eelgrass Zostera marina L. distribution patterns in the mid-Atlantic region of the USA have shown complex changes, with recovery from losses in the 1930s varying between the coastal lagoons and Chesapeake Bay. Restoration efforts in the coastal bays of Virginia introduced Z. marina back to this system, and expansion since 2005 has averaged 66% yr(-1). In contrast, Chesapeake Bay has experienced 2% expansion and has undergone 2 significant die-off events, in 2005 and 2010. We used a temperature-dependent light model to show that from 2005 to 2010 during daylight periods in the summer, coastal bay beds received at least 100% …


The Ross Sea In A Sea Of Change, Walker O. Smith Jr., Pn Sedwick, Kr Arrigo, Dg Ainley, Ah Orsi Jan 2012

The Ross Sea In A Sea Of Change, Walker O. Smith Jr., Pn Sedwick, Kr Arrigo, Dg Ainley, Ah Orsi

VIMS Articles

The Ross Sea, the most productive region in the Antarctic, reaches farther south than any body of water in the world. While its food web is relatively intact, its oceanography, biogeochemistry, and sea ice coverage have been changing dramatically, and likely will continue to do so in the future. Sea ice cover and persistence have been increasing, in contrast to the Amundsen-Bellingshausen sector, which has resulted in reduced open water duration for its biota. Models predict that as the ozone hole recovers, ice cover will begin to diminish. Currents on the continental shelf will likely change in the coming century, …


Two Decades Of Pelagic Ecology Of The Western Antarctic Peninsula, Deborah K. Steinberg, D G. Martinson, D P. Costa Jan 2012

Two Decades Of Pelagic Ecology Of The Western Antarctic Peninsula, Deborah K. Steinberg, D G. Martinson, D P. Costa

VIMS Articles

Significant strides in our understanding of the marine pelagic ecosystem of the Western Antarctic Peninsula (WAP) region have been made over the past two decades, resulting from research conducted aboard ARSV Laurence M. Gould and RVIB Nathaniel B. Palmer. These advances range from an understanding of the physical forcing on biology, to food web ecology (from microbes to top predators), to biogeochemical cycling, often in the larger context of rapid climate warming in the region. The proximity of the WAP to the Antarctic Circumpolar Current and WAP continental shelf bathymetry affects the hydrography and helps structure the biological community. Seasonal, …


Abundance, Composition, And Sinking Rates Of Fish Fecal Pellets In The Santa Barbara Channel, Grace K. Saba, Deborah K. Steinberg Jan 2012

Abundance, Composition, And Sinking Rates Of Fish Fecal Pellets In The Santa Barbara Channel, Grace K. Saba, Deborah K. Steinberg

VIMS Articles

Rapidly sinking fecal pellets are an important component of the vertical flux of particulate organic matter (POM) from the surface to the ocean's interior; however, few studies have examined the role fish play in this export. We determined abundance, size, prey composition, particulate organic carbon/nitrogen (POC/PON), and sinking rates of fecal pellets produced by a forage fish, likely the northern anchovy, in the Santa Barbara Channel. Pellet abundance ranged from 0.1-5.9 pellets m(-3). POC and PON contents averaged 21.7 mu g C pellet(-1) and 2.7 mu g N pellet(-1). The sinking rate averaged 787 m d(-1); thus pellets produced at …


Biotic Dispersal In Eelgrass Zostera Marina, Sarah E. Sumoski, R J. Orth Jan 2012

Biotic Dispersal In Eelgrass Zostera Marina, Sarah E. Sumoski, R J. Orth

VIMS Articles

Dispersal is a critical process in the life history of nearly all plant species and can be facilitated by both abiotic and biotic mechanisms. Despite an abundance of vertebrate fauna utilizing seagrass meadows as a feeding area and thus capable of consuming and excreting seeds, little work has been conducted on biotic seed dispersal mechanisms. The objectives of this study were to (1) determine whether seeds of the seagrass Zostera marina could pass through the digestive systems of resident and transient vertebrates of a seagrass bed and remain viable and (2) determine seed retention times in the guts of each …


Time Series Of Vertical Flux Of Zooplankton Fecal Pellets On The Continental Shelf Of The Western Antarctic Peninsula, Miram R. Gleiber, Deborah K. Steinberg, Hugh W. Ducklow Jan 2012

Time Series Of Vertical Flux Of Zooplankton Fecal Pellets On The Continental Shelf Of The Western Antarctic Peninsula, Miram R. Gleiber, Deborah K. Steinberg, Hugh W. Ducklow

VIMS Articles

Zooplankton fecal pellet contribution to particulate organic carbon (POC) flux over the continental shelf of the western Antarctic Peninsula (WAP) was investigated to better understand the possible effects of changes in zooplankton community structure, due to climate change, on carbon export. Fecal pellets were collected at 170 m depth in a moored sediment trap from January 2004 to January 2009. Fecal pellet shape and size (i.e., carbon content) were quantified to assess flux of pellets from different zooplankton taxa and compared between seasons and years. Fecal pellet POC constituted the dominant proportion of total POC flux, with summer (November to …


Seedling Establishment In Eelgrass: Seed Burial Effects On Winter Losses Of Developing Seedlings, Scott R. Marion, R J. Orth Jan 2012

Seedling Establishment In Eelgrass: Seed Burial Effects On Winter Losses Of Developing Seedlings, Scott R. Marion, R J. Orth

VIMS Articles

Constraints on the transition of seeds to seedlings have the potential to control plant dispersal and persistence. We investigated the processes leading to low initial seedling establishment in eelgrass Zostera marina through a manipulative field experiment assessing the relative importance of germination failure and seedling loss during the winter. Seed plots were established in October at 3 unvegetated sites in the Chesapeake Bay (USA) region, with seeds either at the sediment surface or buried at 2 to 3 cm. Emerging seedlings were monitored at 6 wk intervals between December and April using a video camera, and seed germination was tracked …


Ecosystem Metabolism In Shallow Coastal Lagoons: Patterns And Partitioning Of Planktonic, Benthic, And Integrated Community Rates, Juliette C. P. Giordano, Mark Brush, Iris C. Anderson Jan 2012

Ecosystem Metabolism In Shallow Coastal Lagoons: Patterns And Partitioning Of Planktonic, Benthic, And Integrated Community Rates, Juliette C. P. Giordano, Mark Brush, Iris C. Anderson

VIMS Articles

Net ecosystem metabolism (NEM) provides a quantifiable and integrative method for assessing the ecological responses of aquatic ecosystems to anthropogenic disturbance and has been shown to positively relate to nutrient enrichment in some systems. We measured NEM to determine the trophic status of 4 coastal lagoons receiving a range of nutrient loads on the Virginia/Maryland portion of the Delmarva Peninsula, USA. From July 2007 to July 2008, we used the component technique to assess NEM by developing photosynthesis-irradiance curves for both the water column and sediments approximately monthly; we added macroalgal incubations in the summer of 2008. We also measured …


Eelgrass Recovery In The Coastal Bays Of The Virginia Coast Reserve, Usa, R J. Orth, Karen J. Mcglathery Jan 2012

Eelgrass Recovery In The Coastal Bays Of The Virginia Coast Reserve, Usa, R J. Orth, Karen J. Mcglathery

VIMS Articles

Coastal bay systems are prominent features of coastlines on nearly all continents and are vulnerable to long-term environmental changes related to climate and nutrient over-enrichment. Eelgrass Zostera marina disappeared in the 1930s from the coastal bays of the Virginia Coast Reserve, USA, primarily due to a wasting disease and the effects of a hurricane. It has been re-established recently as a result of a large-scale seeding and restoration effort. The contributions to this Theme Section provide the most comprehensive account available of large-scale recovery of an eelgrass ecosystem, the consequences of the state change from a bare-sediment system to eelgrass …


Eelgrass Restoration By Seed Maintains Genetic Diversity: Case Study From A Coastal Bay System, Laura K. Reynolds, Michelle Waycott, Karen J. Mcglathery, R J. Orth Jan 2012

Eelgrass Restoration By Seed Maintains Genetic Diversity: Case Study From A Coastal Bay System, Laura K. Reynolds, Michelle Waycott, Karen J. Mcglathery, R J. Orth

VIMS Articles

Genetic diversity is positively associated with plant fitness, stability, and the provision of ecosystem services. Preserving genetic diversity is therefore considered an important component of ecosystem restoration as well as a measure of its success. We examined the genetic diversity of restored Zostera marina meadows in a coastal bay system along the USA mid-Atlantic coast using microsatellite markers to compare donor and recipient meadows. We show that donor meadows in Chesapeake Bay have high genetic diversity and that this diversity is maintained in meadows restored with seeds in the Virginia coastal bays. No evidence of inbreeding depression was detected (F-IS-0.2 …


Seed Addition Facilitates Eelgrass Recovery In A Coastal Bay System, R J. Orth, Ken Moore, Scott R. Marion, David J. Wilcox Jan 2012

Seed Addition Facilitates Eelgrass Recovery In A Coastal Bay System, R J. Orth, Ken Moore, Scott R. Marion, David J. Wilcox

VIMS Articles

Eleven years of eelgrass Zostera marina seed additions conducted in a coastal bay system where Z. marina had not been reported since 1933 have resulted in rapid Z. marina expansion beyond the initially seeded plots. From 1999 through 2010, 37.8 million viable seeds were added to 369 individual plots ranging in size from 0.01 to 2 ha totaling 125.2 ha in 4 coastal bays. Subsequent expansion from these initial plots to approximately 1700 ha of bay bottom populated with Z. marina through 2010 is attributable to seed export from the original plots and subsequent generations of seedlings originating from those …


Recovery Trajectories During State Change From Bare Sediment To Eelgrass Dominance, Karen J. Mcglathery, Laura K. Reynolds, Luke W. Cole, R J. Orth Jan 2012

Recovery Trajectories During State Change From Bare Sediment To Eelgrass Dominance, Karen J. Mcglathery, Laura K. Reynolds, Luke W. Cole, R J. Orth

VIMS Articles

Seagrasses are important foundation species in shallow coastal ecosystems that provide critical ecosystem services including stabilizing sediment, sequestering carbon and nutrients, and providing habitat and an energy source for a diverse fauna. We followed the recovery of functional (primary productivity, carbon and nitrogen sequestration, sediment deposition) and structural (shoot density, biomass, plant morphometrics) attributes of Zostera marina (eelgrass) meadows in replicate large plots (0.2 to 0.4 ha) restored by seeding in successive years, resulting in a chrono sequence of sites from 0 (unvegetated) to 9 yr since seeding. Shoot density was the structural metric that changed most significantly, with an …


Two Decades Of Pelagic Ecology Of The Western Antarctic Peninsula, Deborah K. Steinberg, Dg Martinson, Dp Costa Jan 2012

Two Decades Of Pelagic Ecology Of The Western Antarctic Peninsula, Deborah K. Steinberg, Dg Martinson, Dp Costa

VIMS Articles

Significant strides in our understanding of the marine pelagic ecosystem of the Western Antarctic Peninsula (WAP) region have been made over the past two decades, resulting from research conducted aboard ARSV Laurence M. Gould and RVIB Nathaniel B. Palmer. These advances range from an understanding of the physical forcing on biology, to food web ecology (from microbes to top predators), to biogeochemical cycling, often in the larger context of rapid climate warming in the region. The proximity of the WAP to the Antarctic Circumpolar Current and WAP continental shelf bathymetry affects the hydrography and helps structure the biological community. Seasonal, …


The Relationship Between Biophysical Variables And Halocarbon Distributions In The Waters Of The Amundsen And Ross Seas, Antarctica, E Mattson, A Karlsson, Walker O. Smith Jr., K Abrahamsson Jan 2012

The Relationship Between Biophysical Variables And Halocarbon Distributions In The Waters Of The Amundsen And Ross Seas, Antarctica, E Mattson, A Karlsson, Walker O. Smith Jr., K Abrahamsson

VIMS Articles

Little is known regarding the distribution of volatile halogenated organic compounds (halocarbons) in Antarctic waters and their relation to biophysical variables. During the austral summer (December to January) in 2007-08 halocarbon and pigment concentrations were measured in the Amundsen (100-130 degrees W) and Ross Sea (158 degrees W-160 degrees E). In addition, halocarbons were determined in air, snow and sea ice. The distribution of halocarbons was influenced to a large extent by sea ice, and to a much lesser extent by pelagic biota. Concentrations of naturally produced halocarbons were elevated in the surface mixed layer in ice covered areas compared …


Long-Term Increase In Mesozooplankton Biomass In The Sargasso Sea: Linkage To Climate And Implications For Food Web Dynamics And Biogeochemical Cycling, Deborah K. Steinberg, Mw Lomas, Js Cope Jan 2012

Long-Term Increase In Mesozooplankton Biomass In The Sargasso Sea: Linkage To Climate And Implications For Food Web Dynamics And Biogeochemical Cycling, Deborah K. Steinberg, Mw Lomas, Js Cope

VIMS Articles

Changes in zooplankton biomass and species composition over long time scales can have significant effects on biogeochemical cycling and transfer of energy to higher trophic levels. We analyzed size-fractionated mesozooplankton biomass (>200 mu m) from biweekly to monthly day and night tows taken from 1994 to 2010 in the epipelagic zone at the Bermuda Atlantic Time series Study (BATS) site in the oligotrophic North Atlantic subtropical gyre. During this 17-year period total mesozooplankton biomass increased 61% overall, although a few short-term downturns occurred over the course of the time series. The overall increase was higher in the nighttime compared …