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Assessing Tidal Marsh Resilience To Sea-Level Rise At Broad Geographic Scales With Multi-Metric Indices, Kb Raposa, K Wasson, E Smith, Ja Crooks, P Delgado, S Lerberg, Et Al. Jan 2016

Assessing Tidal Marsh Resilience To Sea-Level Rise At Broad Geographic Scales With Multi-Metric Indices, Kb Raposa, K Wasson, E Smith, Ja Crooks, P Delgado, S Lerberg, Et Al.

VIMS Articles

Tidal marshes and the ecosystem services they provide may be at risk from sea-level rise (SLR). Tidal marsh resilience to SLR can vary due to differences in local rates of SLR, geomorphology, sediment availability and other factors. Understanding differences in resilience is critical to inform coastal management and policy, but comparing resilience across marshes is hindered by a lack of simple, effective analysis tools. Quantitative, multi-metric indices are widely employed to inform management of benthic aquatic ecosystems, but not coastal wetlands. Here, we develop and apply tidal marsh resilience to sea-level rise (MARS) indices incorporating ten metrics that contribute to ...


Saltmarsh Plant Responses To Eutrophication, Ds Johnson, Rs Warren, La Deegan, Tj Mozdzer Jan 2016

Saltmarsh Plant Responses To Eutrophication, Ds Johnson, Rs Warren, La Deegan, Tj Mozdzer

VIMS Articles

In saltmarsh plant communities, bottom-up pressure from nutrient enrichment is predicted to increase productivity, alter community structure, decrease biodiversity, and alter ecosystem functioning. Previous work supporting these predictions has been based largely on short-term, plot-level (e.g., 1-300 m(2)) studies, which may miss landscape-level phenomena that drive ecosystem-level responses. We implemented an ecosystem-scale, nine-year nutrient experiment to examine how saltmarsh plants respond to simulated conditions of coastal eutrophication. Our study differed from previous saltmarsh enrichment studies in that we applied realistic concentrations of nitrate (70-100 mu M NO3-), the most common form of coastal nutrient enrichment, via tidal water ...


Beyond The Benchtop And The Benthos: Dataset Management Planning And Design For Time Series Of Ocean Carbonate Chemistry Associated With Durafet (R)-Based Ph Sensors, Eb Rivest, M O'Brien, L Kapsenberg, Cc Gotschalk, Ca Blanchette, U Hoshijima, Ge Hofmann Jan 2016

Beyond The Benchtop And The Benthos: Dataset Management Planning And Design For Time Series Of Ocean Carbonate Chemistry Associated With Durafet (R)-Based Ph Sensors, Eb Rivest, M O'Brien, L Kapsenberg, Cc Gotschalk, Ca Blanchette, U Hoshijima, Ge Hofmann

VIMS Articles

To better understand the impact of ocean acidification on marine ecosystems, an important ongoing research priority for marine scientists is to characterize present-day pH variability. Following recent technological advances, autonomous pH sensor deployments in shallow coastal marine environments have revealed that pH dynamics in coastal oceans are more variable in space and time than the discrete, open-ocean measurements that are used for ocean acidification projections. Data from these types of deployments will benefit the research community by facilitating the improved design of ocean acidification studies as well as the identification or evaluation of natural and human-influenced pH variability. Importantly, the ...


Marine Phytophthora Species Can Hamper Conservation And Restoration Of Vegetated Coastal Ecosystems, Ll Govers, Wam In 'T Veid, Jp Meffert, Tj Bouma, Pcj Van Rijswick, Jht Heusinkveld, Rj Orth, Mm Van Katwijk, T Van Der Heide Jan 2016

Marine Phytophthora Species Can Hamper Conservation And Restoration Of Vegetated Coastal Ecosystems, Ll Govers, Wam In 'T Veid, Jp Meffert, Tj Bouma, Pcj Van Rijswick, Jht Heusinkveld, Rj Orth, Mm Van Katwijk, T Van Der Heide

VIMS Articles

Phytophthora species are potent pathogens that can devastate terrestrial plants, causing billions of dollars of damage yearly to agricultural crops and harming fragile ecosystems worldwide. Yet, virtually nothing is known about the distribution and pathogenicity of their marine relatives. This is surprising, as marine plants form vital habitats in coastal zones worldwide (i.e. mangrove forests, salt marshes, seagrass beds), and disease may be an important bottleneck for the conservation and restoration of these rapidly declining ecosystems. We are the first to report on widespread infection of Phytophthora and Halophytophthora species on a common seagrass species, Zostera marina (eelgrass), across ...


Effects Of Sediment And Salinity On The Growth And Competitive Abilities Of Three Submersed Macrophytes, Erin C. Shields, Kenneth A. Moore Jan 2016

Effects Of Sediment And Salinity On The Growth And Competitive Abilities Of Three Submersed Macrophytes, Erin C. Shields, Kenneth A. Moore

VIMS Articles

Submersed macrophytes are generally found in multispecies beds, with the dominance of individual species varying in both space and time. In estuarine environments, these plants can grow across a range of environmental conditions which may alter species interactions. Three species common to the Chesapeake Bay region, Vallisneria americana (wild celery), Heteranthera dubia (water stargrass), and Stuckenia pectinata (sago pondweed), were planted in a microcosm designed to test their growth and interactions (relative yielding) under a range of conditions of salinity (0, 5, or 10), sediment type (mud or sand), and species combinations. H. dubia was most sensitive to elevated salinity ...


Millennial-Scale Sustainability Of The Chesapeake Bay Native American Oyster Fishery, Tc Rick, La Reeder-Myers, Ca Hofman, D Breitburg, R Lockwood, G Henkes, L Kellogg, D Lowery, Mw Luckenbach, R Mann, Mb Ogburn, Mj Southworth, J Wah, J Wesson, Ah Hines Jan 2016

Millennial-Scale Sustainability Of The Chesapeake Bay Native American Oyster Fishery, Tc Rick, La Reeder-Myers, Ca Hofman, D Breitburg, R Lockwood, G Henkes, L Kellogg, D Lowery, Mw Luckenbach, R Mann, Mb Ogburn, Mj Southworth, J Wah, J Wesson, Ah Hines

VIMS Articles

Estuaries around the world are in a state of decline following decades or more of overfishing, pollution, and climate change. Oysters (Ostreidae), ecosystem engineers in many estuaries, influence water quality, construct habitat, and provide food for humans and wildlife. In North America's Chesapeake Bay, once-thriving eastern oyster (Crassostrea virginica) populations have declined dramatically, making their restoration and conservation extremely challenging. Here we present data on oyster size and human harvest from Chesapeake Bay archaeological sites spanning similar to 3,500 y of Native American, colonial, and historical occupation. We compare oysters from archaeological sites with Pleistocene oyster reefs that ...


Virtualspecies, An R Package To Generate Virtual Species Distributions, B Leroy, Cn Meynard, C Bellard, F Courchamp Jan 2016

Virtualspecies, An R Package To Generate Virtual Species Distributions, B Leroy, Cn Meynard, C Bellard, F Courchamp

VIMS Articles

virtualspecies is a freely available package for R designed to generate virtual species distributions, a procedure increasingly used in ecology to improve species distribution models. This package combines the existing methodological approaches with the objective of generating virtual species distributions with increased ecological realism. The package includes 1) generating the probability of occurrence of a virtual species from a spatial set of environmental conditions (i.e. environmental suitability), with two different approaches; 2) converting the environmental suitability into presence-absence with a probabilistic approach; 3) introducing dispersal limitations in the realised virtual species distributions and 4) sampling occurrences with different biases ...


Biodiversity Enhances Reef Fish Biomass And Resistance To Climate Change, Je Duffy, Js Lefcheck, Rd Stuart-Smith, Sa Navarrete, Gj Edgar Jan 2016

Biodiversity Enhances Reef Fish Biomass And Resistance To Climate Change, Je Duffy, Js Lefcheck, Rd Stuart-Smith, Sa Navarrete, Gj Edgar

VIMS Articles

Fishes are the most diverse group of vertebrates, play key functional roles in aquatic ecosystems, and provide protein for a billion people, especially in the developing world. Those functions are compromised by mounting pressures on marine biodiversity and ecosystems. Because of its economic and food value, fish biomass production provides an unusually direct link from biodiversity to critical ecosystem services. We used the Reef Life Survey's global database of 4,556 standardized fish surveys to test the importance of biodiversity to fish production relative to 25 environmental drivers. Temperature, biodiversity, and human influence together explained 47% of the global ...


Global Analysis Of Seagrass Restoration: The Importance Of Large-Scale Planting, Mm Van Katwijk, A Thorhaug, N Marba, Rj Orth, Cm Duarte, Et Al. Jan 2016

Global Analysis Of Seagrass Restoration: The Importance Of Large-Scale Planting, Mm Van Katwijk, A Thorhaug, N Marba, Rj Orth, Cm Duarte, Et Al.

VIMS Articles

In coastal and estuarine systems, foundation species like seagrasses, mangroves, saltmarshes or corals provide important ecosystem services. Seagrasses are globally declining and their reintroduction has been shown to restore ecosystem functions. However, seagrass restoration is often challenging, given the dynamic and stressful environment that seagrasses often grow in. From our world-wide meta-analysis of seagrass restoration trials (1786 trials), we describe general features and best practice for seagrass restoration. We confirm that removal of threats is important prior to replanting. Reduced water quality (mainly eutrophication), and construction activities led to poorer restoration success than, for instance, dredging, local direct impact and ...


Overcoming Restoration Paradigms: Value Of The Historical Record And Metapopulation Dynamics In Native Oyster Restoration, Romauld N. Lipcius, Russell P. Burke, Danielle N. Mcculloch, Sebastian J. Schreiber, David M. Schulte, Rochelle D. Seitz, Jian Shen Sep 2015

Overcoming Restoration Paradigms: Value Of The Historical Record And Metapopulation Dynamics In Native Oyster Restoration, Romauld N. Lipcius, Russell P. Burke, Danielle N. Mcculloch, Sebastian J. Schreiber, David M. Schulte, Rochelle D. Seitz, Jian Shen

VIMS Articles

Restoration strategies for native oyster populations rely on multiple sources of information, which often conflict due to time- and space-varying patterns in abundance and distribution. For instance, strategies based on population connectivity and disease resistance can differ, and extant and historical records of abundance and distribution are often at odds, such that the optimal strategy is unclear and valuable restoration sites may be excluded from consideration. This was the case for the Lynnhaven River subestuary of lower Chesapeake Bay, which was deemed unsuitable for Eastern Oyster (Crassostrea virginica) restoration based on physical conditions, disease challenge, and extant oyster abundance. Consequently ...


Trophic Cascades In The Western Ross Sea, Antarctica: Revisited, David G. Ainley, Grant Ballard, Randolph M. Jones, Dennis Jongsomjit, Stephen D. Pierce, Walker O. Smith, Sam Veloz Aug 2015

Trophic Cascades In The Western Ross Sea, Antarctica: Revisited, David G. Ainley, Grant Ballard, Randolph M. Jones, Dennis Jongsomjit, Stephen D. Pierce, Walker O. Smith, Sam Veloz

VIMS Articles

We investigated mesopredator effects on prey availability in the Ross Sea, Antarctica, as - sessing the reasons why Adélie penguin Pygoscelis adeliae foraging trip duration (FTD) increases and diet changes from krill to fish as numbers of foraging penguins and competing cetaceans increase in the penguins’ foraging area. To investigate penguins’ seasonally changing FTD as a function of foraging-population size—previously investigated indirectly—we used bio-logging to determine the penguins’ 3-dimensional foraging volume, while an autonomous glider quantified the depth, abundance, and distribution of potential prey. As numbers of foraging penguins and cetaceans increased, penguins spent more time on foraging trips ...


Abstracts Of Technical Papers, Presented At The 107th Annual Meeting, National Shellfisheries Association, Monterey, California, March 22–26, 2015, National Shellfisheries Association Aug 2015

Abstracts Of Technical Papers, Presented At The 107th Annual Meeting, National Shellfisheries Association, Monterey, California, March 22–26, 2015, National Shellfisheries Association

VIMS Articles

No abstract provided.


Copepod Carcasses As Microbial Hot Spots For Pelagic Denitrification, Rn Glud, Hp Grossart, M Larsen, Kw Tang, Ke Arendt, Et Al. Jan 2015

Copepod Carcasses As Microbial Hot Spots For Pelagic Denitrification, Rn Glud, Hp Grossart, M Larsen, Kw Tang, Ke Arendt, Et Al.

VIMS Articles

Copepods are exposed to a high non-predatory mortality and their decomposing carcasses act as microniches with intensified microbial activity. Sinking carcasses could thereby represent anoxic microenvironment sustaining anaerobic microbial pathways in otherwise oxic water columns. Using non-invasive O-2 imaging, we document that carcasses of Calanus finmarchicus had an anoxic interior even at fully air-saturated ambient O-2 level. The extent of anoxia gradually expanded with decreasing ambient O-2 levels. Concurrent microbial sampling showed the expression of nitrite reductase genes (nirS) in all investigated carcass samples and thereby documented the potential for microbial denitrification in carcasses. The nirS gene was occasionally expressed ...


Influence Of Central Pacific Oceanographic Conditions On The Potential Vertical Habitat Of Four Tropical Tuna Species, Al Deary, S Moret-Ferguson, M Engels, E Zettler, G Jaroslow Jan 2015

Influence Of Central Pacific Oceanographic Conditions On The Potential Vertical Habitat Of Four Tropical Tuna Species, Al Deary, S Moret-Ferguson, M Engels, E Zettler, G Jaroslow

VIMS Articles

Climate change has resulted in the geographic and vertical expansion of oxygen minimum zones but their impact on the vertical distribution of commercially important species, such as tunas, is not well understood. Although La Nina events are characterized by increased upwelling along the equator, the increased primary productivity and bacterial proliferation drive the expansion of oxygen minimum zones. Vertical habitat of four tropical tuna species were characterized using direct observations of the oceanographic conditions of the Central Pacific Ocean during the 2008 La Nina event and existing primary literature on temperature and dissolved oxygen physiological tolerances for these tunas. Concentrations ...


Visual Acuity In Pelagic Fishes And Mollusks (Vol 92, Pg 1, 2013), Yl Gagnon, Tt Sutton, S Johnsen Jan 2015

Visual Acuity In Pelagic Fishes And Mollusks (Vol 92, Pg 1, 2013), Yl Gagnon, Tt Sutton, S Johnsen

VIMS Articles

No abstract provided.


Dissolved Oxygen Dynamics During A Phytoplankton Bloom In The Ross Sea Polynya, By Queste, Kj Heywood, Wo Smith, De Kaufman, Td Jickells, Ms Dinniman Jan 2015

Dissolved Oxygen Dynamics During A Phytoplankton Bloom In The Ross Sea Polynya, By Queste, Kj Heywood, Wo Smith, De Kaufman, Td Jickells, Ms Dinniman

VIMS Articles

The Ross Sea polynya is one of the most productive regions in the Southern Ocean. However, limited access and high spatio-temporal variability of physical and biological processes limit the use of conventional oceanographic methods to measure early season primary productivity. High-resolution observations from two Seagliders provide insights into the timing of a bloom in the southern Ross Sea polynya in December 2010. Changes in chlorophyll and oxygen concentrations are used to assess bloom dynamics. Using a ratio of dissolved oxygen to carbon, net primary production is estimated over the duration of the bloom showing a sensitive balance between net autotrophy ...


Vertical Mixing, Critical Depths, And Phytoplankton Growth In The Ross Sea, Wo Smith, Rm Jones Jan 2015

Vertical Mixing, Critical Depths, And Phytoplankton Growth In The Ross Sea, Wo Smith, Rm Jones

VIMS Articles

Phytoplankton growth and biomass accumulation vary spatially and temporally in the Ross Sea, largely as a function of ice concentrations, vertical mixing depths, and iron concentrations. To assess the role of vertical mixing in bloom initiation, we used a high-resolution numerical model to estimate changes in mixed layer depths from October 1 through early December, the period where phytoplankton growth begins and biomass accumulates, and estimate critical depths for this period. Mixed layers in October ranged from the complete water column (>600 m) to ca. 200 m; over a 60-day period, the mixed layers decreased on average by 70%. Estimated ...


Biodiversity Mediates Top-Down Control In Eelgrass Ecosystems: A Global Comparative-Experimental Approach, Je Duffy, Pl Reynolds, C Bostrom, Ja Coyer, M Cusson, Et Al. Jan 2015

Biodiversity Mediates Top-Down Control In Eelgrass Ecosystems: A Global Comparative-Experimental Approach, Je Duffy, Pl Reynolds, C Bostrom, Ja Coyer, M Cusson, Et Al.

VIMS Articles

Nutrient pollution and reduced grazing each can stimulate algal blooms as shown by numerous experiments. But because experiments rarely incorporate natural variation in environmental factors and biodiversity, conditions determining the relative strength of bottom-up and top-down forcing remain unresolved. We factorially added nutrients and reduced grazing at 15 sites across the range of the marine foundation species eelgrass (Zostera marina) to quantify how top-down and bottom-up control interact with natural gradients in biodiversity and environmental forcing. Experiments confirmed modest top-down control of algae, whereas fertilisation had no general effect. Unexpectedly, grazer and algal biomass were better predicted by cross-site variation ...


Reproductive Skew Drives Patterns Of Sexual Dimorphism In Sponge-Dwelling Snapping Shrimps, Stc Chak, Je Duffy, Dr Rubenstein Jan 2015

Reproductive Skew Drives Patterns Of Sexual Dimorphism In Sponge-Dwelling Snapping Shrimps, Stc Chak, Je Duffy, Dr Rubenstein

VIMS Articles

Sexual dimorphism is typically a result of strong sexual selection on male traits used in male male competition and subsequent female choice. However, in social species where reproduction is monopolized by one or a few individuals in a group, selection on secondary sexual characteristics may be strong in both sexes. Indeed, sexual dimorphism is reduced in many cooperatively breeding vertebrates and eusocial insects with totipotent workers, presumably because of increased selection on female traits. Here, we examined the relationship between sexual dimorphism and sociality in eight species of Synalpheus snapping shrimps that vary in social structure and degree of reproductive ...


Mapping Diversity Indices: Not A Trivial Issue, V Granger, N Bez, Jm Fromentin, C Meynard, A Jadaud Jan 2015

Mapping Diversity Indices: Not A Trivial Issue, V Granger, N Bez, Jm Fromentin, C Meynard, A Jadaud

VIMS Articles

Mapping diversity indices, that is estimating values in all locations of a given area from some sampled locations, is central to numerous research and applied fields in ecology. Two approaches are used to map diversity indices without including abiotic or biotic variables: (i) the indirect approach, which consists in estimating each individual species distribution over the area, then stacking the distributions of all species to estimate and map a posteriori the diversity index, (ii) the direct approach, which relies on computing a diversity index in each sampled locations and then to interpolate these values to all locations of the studied ...


Marine Biodiversity And Ecosystem Functioning: What's Known And What's Next?, L Gamfeldt, Js Lefcheck, Jek Byrnes, Bj Cardinale, Je Duffy Jan 2015

Marine Biodiversity And Ecosystem Functioning: What's Known And What's Next?, L Gamfeldt, Js Lefcheck, Jek Byrnes, Bj Cardinale, Je Duffy

VIMS Articles

Marine ecosystems are experiencing rapid and pervasive changes in biodiversity and species composition. Understanding the ecosystem consequences of these changes is critical to effectively managing these systems. Over the last several years, numerous experimental manipulations of species richness have been performed, yet existing quantitative syntheses have focused on a just a subset of processes measured in experiments and, as such, have not summarized the full data available from marine systems. Here, we present the results of a meta-analysis of 110 marine experiments from 42 studies that manipulated the species richness of organisms across a range of taxa and trophic levels ...


Detection And Diversity Of Copper Containing Nitrite Reductase Genes (Nirk) In Prokaryotic And Fungal Communities Of Agricultural Soils, A Long, B Song, K Fridey, A Silva Jan 2015

Detection And Diversity Of Copper Containing Nitrite Reductase Genes (Nirk) In Prokaryotic And Fungal Communities Of Agricultural Soils, A Long, B Song, K Fridey, A Silva

VIMS Articles

Microorganisms are capable of producing N-2 and N2O gases as the end products of denitrification. Copper-containing nitrite reductase (NirK), a key enzyme in the microbial N-cycle, has been found in bacteria, archaea and fungi. This study seeks to assess the diversity of nirK genes in the prokaryotic and fungal communities of agricultural soils in the United States. New primers targeting the nirK genes in fungi were developed, while nirK genes in archaea and bacteria were detected using previously published methods. The new primers were able to detect fungal nirK genes as well as bacterial nirK genes from a group that ...


Evaluating The Predictive Performance Of Empirical Estimators Of Natural Mortality Rate Using Information On Over 200 Fish Species, Ay Then, Jm Hoenig, Ng Hall, Da Hewitt Jan 2015

Evaluating The Predictive Performance Of Empirical Estimators Of Natural Mortality Rate Using Information On Over 200 Fish Species, Ay Then, Jm Hoenig, Ng Hall, Da Hewitt

VIMS Articles

Many methods have been developed in the last 70 years to predict the natural mortality rate, M, of a stock based on empirical evidence from comparative life history studies. These indirect or empirical methods are used in most stock assessments to (i) obtain estimates of M in the absence of direct information, (ii) check on the reasonableness of a direct estimate of M, (iii) examine the range of plausible M estimates for the stock under consideration, and (iv) define prior distributions for Bayesian analyses. The two most cited empirical methods have appeared in the literature over 2500 times to date ...


Genetic And Biogeochemical Investigation Of Sedimentary Nitrogen Cycling Communities Responding To Tidal And Seasonal Dynamics In Cape Fear River Estuary, Ja Lisa, B Song, Cr Tobias, De Hines Jan 2015

Genetic And Biogeochemical Investigation Of Sedimentary Nitrogen Cycling Communities Responding To Tidal And Seasonal Dynamics In Cape Fear River Estuary, Ja Lisa, B Song, Cr Tobias, De Hines

VIMS Articles

Tidal and seasonal fluctuations in the oligohaline reaches of estuaries may alter geochemical features that influence structure and function of microbial communities involved in sedimentary nitrogen (N) cycling. In order to evaluate sediment community responses to short-term (tidal) and long-term (seasonal) changes in different tidal regimes, nitrogen cycling rates and genes were quantified in three sites that span a range of tidal influence in the upper portion of the Cape Fear River Estuary. Environmental parameters were monitored during low and high tides in winter and spring. N-15 tracer incubation experiments were conducted to measure nitrification, denitrification, anaerobic ammonium oxidation (anammox ...


Projected Impacts Of Climate Warming On The Functional And Phylogenetic Components Of Coastal Mediterranean Fish Biodiversity, C Albouy, F Leprieur, F Le Loc'h, N Mouquet, Cn Meynard, Et Al. Jan 2015

Projected Impacts Of Climate Warming On The Functional And Phylogenetic Components Of Coastal Mediterranean Fish Biodiversity, C Albouy, F Leprieur, F Le Loc'h, N Mouquet, Cn Meynard, Et Al.

VIMS Articles

Climate warming affects biodiversity distribution across all ecosystems. However, beyond changes in species richness, impacts on other biodiversity components are still overlooked, particularly in the marine realm. Here we forecasted the potential effect of climate warming on the phylogenetic and functional components of coastal Mediterranean fish biodiversity. To do so, we used species distribution models to project the potential distribution of 230 coastal fish species by the end of the 21st century based on the IPCC A2 scenario implemented with the Mediterranean climatic model NEMOMED8. From these projections, we assessed the changes in phylogenetic (PD) and functional diversity (FD) of ...


Properties Of Age Compositions And Mortality Estimates Derived From Cohort Slicing Of Length Data, Le Ailloud, Mw Smith, Ay Then, Kl Omori, Gm Ralph, Jm Hoenig Jan 2015

Properties Of Age Compositions And Mortality Estimates Derived From Cohort Slicing Of Length Data, Le Ailloud, Mw Smith, Ay Then, Kl Omori, Gm Ralph, Jm Hoenig

VIMS Articles

Cohort slicing can be used to obtain catch-at-age data from length frequency distributions when directly measured age data are unavailable. The procedure systematically underestimates the relative abundance of the youngest age groups and overestimates abundance at older ages. Cohort-sliced catch-at-age data can be used to estimate total mortality rate (Z) using a regression estimator or the Chapman-Robson estimator for right truncated data. However, the effect of cohort slicing on accuracy and precision of resulting Z estimates remains to be determined. We used Monte Carlo simulation to estimate the per cent bias and per cent root mean square error of the ...


Biogeochemical Variability In The Southern Ross Sea As Observed By A Glider Deployment, De Kaufman, Mam Friedrichs, Wj Smith Jr., By Queste, Kj Heywood Jan 2014

Biogeochemical Variability In The Southern Ross Sea As Observed By A Glider Deployment, De Kaufman, Mam Friedrichs, Wj Smith Jr., By Queste, Kj Heywood

VIMS Articles

High-resolution autonomous glider data (including temperature, salinity, fluorescence, and optical backscatter) collected during the 2010-2011 austral summer identified variations in phytoplankton biomass along two glider sections near 76 degrees 40'S. Sea surface temperatures were warmer during the latter, westward section, while mixed layer depths were deeper. Substantial quantities of Modified Circumpolar Deep Water, identified by neutral density criteria, were located within both sections. Chlorophyll (Chl) concentrations computed from fluorescence exhibited daily quenching near the surface, and deep chlorophyll concentrations at 200 m became periodically elevated, suggesting substantial export on small space and time scales. The concentrations of particulate organic ...


Multifunctionality Does Not Imply That All Functions Are Positively Correlated, J Byrnes, Js Lefcheck, L Gamfeldt, Jn Griffin, F Isbell Jan 2014

Multifunctionality Does Not Imply That All Functions Are Positively Correlated, J Byrnes, Js Lefcheck, L Gamfeldt, Jn Griffin, F Isbell

VIMS Articles

No abstract provided.


Zooplankton Carcasses And Non-Predatory Mortality In Freshwater And Inland Sea Environments, Kw Tang, Mi Gladyshev, Op Dubovskaya, G Kirillin, Hp Grossart Jan 2014

Zooplankton Carcasses And Non-Predatory Mortality In Freshwater And Inland Sea Environments, Kw Tang, Mi Gladyshev, Op Dubovskaya, G Kirillin, Hp Grossart

VIMS Articles

Zooplankton carcasses are ubiquitous in marine and freshwater systems, implicating the importance of non-predatory mortality, but both are often overlooked in ecological studies compared with predatory mortality. The development of several microscopic methods allows the distinction between live and dead zooplankton in field samples, and the reported percentages of dead zooplankton average 11.6 (minimum) to 59.8 (maximum) in marine environments, and 7.4 (minimum) to 47.6 (maximum) in fresh and inland waters. Common causes of non-predatory mortality among zooplankton include senescence, temperature change, physical and chemical stresses, parasitism and food-related factors. Carcasses resulting from non-predatory mortality may ...


Field Experimental Evidence That Grazers Mediate Transition Between Microalgal And Seagrass Dominance, Pl Reynolds, Jp Richardson, Je Duffy Jan 2014

Field Experimental Evidence That Grazers Mediate Transition Between Microalgal And Seagrass Dominance, Pl Reynolds, Jp Richardson, Je Duffy

VIMS Articles

We tested the relative effects of nutrient loading, reduced predation, and reduced grazing on eelgrass community dynamics in Chesapeake Bay and found evidence supporting the "mutualistic mesograzer model" in which small invertebrate grazers control accumulation of epiphytic algae, buffer eutrophication effects, and thus facilitate seagrass dominance. Experimental reduction of crustacean grazers in the field stimulated a nearly sixfold increase in epiphytic algae, and reduced seagrass biomass by 65% compared to controls with grazers. Nutrient fertilization generally had much weaker effects, but an interaction with mesograzers was key in changing the sign of fertilization effects on the system: aboveground eelgrass biomass ...