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Full-Text Articles in Life Sciences
Relative And Interactive Effects Of Plant And Grazer Richness In A Benthic Marine Community, Jf Bruno, Ke Boyer, Je Duffy, Sc Lee
Relative And Interactive Effects Of Plant And Grazer Richness In A Benthic Marine Community, Jf Bruno, Ke Boyer, Je Duffy, Sc Lee
VIMS Articles
The interactive effects of changing biodiversity of consumers and their prey are poorly understood but are likely to be important under realistic scenarios of biodiversity loss and gain. We performed two factorial manipulations of macroalgal group (greens, reds, and browns) and herbivore species (amphipods, sea urchin, and fish) composition and richness in outdoor mesocosms simulating a subtidal, hard-substratum estuarine community in North Carolina, USA. In the experiment where grazer richness treatments were substitutive, there were no significant effects of algal or herbivore richness on final algal biomass. However, in the experiment in which grazer treatments were additive (i.e., species-specific densities …
Influence Of Sea Ice On Primary Production In The Southern Ocean: A Satellite Perspective, Walker O. Smith Jr., Josefino C. Comiso
Influence Of Sea Ice On Primary Production In The Southern Ocean: A Satellite Perspective, Walker O. Smith Jr., Josefino C. Comiso
VIMS Articles
Sea ice in the Southern Ocean is a major controlling factor on phytoplankton productivity, but the relationship is modified by regional differences in atmospheric and oceanographic conditions. We used the phytoplankton biomass, photosynthetically active radiation (PAR), and cloud cover data from Sea-viewing Wide Field of View Sensor (SeaWiFS), ice concentrations data from Special Sensor Microwave Imager (SSM/I) and Advanced Microwave Scanning Radiometer-EOS (AMSR-E), sea-surface temperature data from advanced very high resolution radiometer (AVHRR), and a vertically integrated model to estimate primary productivity south of 60 degrees S. We also selected six areas within the Southern Ocean and analyzed the variability …
Trophic Interactions Under Stress: Hypoxia Enhances Foraging In An Estuarine Food Web, William Christopher Long, Rochelle D. Seitz
Trophic Interactions Under Stress: Hypoxia Enhances Foraging In An Estuarine Food Web, William Christopher Long, Rochelle D. Seitz
VIMS Articles
Ecosystem-level effects of stressors are critical to understanding community regulation, and environmental stress models are useful in describing such effects. Hypoxia is an important stressor in aquatic ecosystems that usually decreases abundance and biomass of benthic fauna. In field surveys, predator abundance is low in hypoxic areas, and in lab experiments, predators reduce their feeding rates under hypoxic conditions, leading to the hypothesis that consumer stress models (CSMs), rather than prey stress models (PSMs), apply to the systems. We tested predictions from these models with manipulative field experiments wherein we varied predator access to marked Macoma balthica clams at deep …
Effects Of Coastal Development On Nearshore Estuarine Nekton Communities, Donna M. Bilkovic, Molly Mitchell
Effects Of Coastal Development On Nearshore Estuarine Nekton Communities, Donna M. Bilkovic, Molly Mitchell
VIMS Articles
Coastal development affects estuarine resources by severing terrestrial-aquatic linkages, reducing shallow water habitats, and degrading ecosystem services, which is predicted to result in measurable declines in nekton community integrity. We assessed the effects of landscape features on nearshore habitats and biological communities, relating subtidal habitat, shoreline condition, upland land use and nearshore fish communities in a Chesapeake Bay tributary, the James River, Virginia. Both upland development and the placement of erosion control structures on the shoreline were associated with reduced fish community integrity, and shoreline alterations were linked with the amount of subtidal structural habitat in the nearshore. Ecological thresholds …
Feeding Patterns And Predation Potential Of Scyphomedusae In A Highly Productive Upwelling Region, Cynthia L. Suchman, Elizabeth A. Daly, Julie E. Keister, William T. Peterson
Feeding Patterns And Predation Potential Of Scyphomedusae In A Highly Productive Upwelling Region, Cynthia L. Suchman, Elizabeth A. Daly, Julie E. Keister, William T. Peterson
VIMS Articles
We quantified diet and predation rates for large scyphomedusae from a coastal upwelling region. In the Northern California Current, early stages of euphausiids, gelatinous taxa, and cladocerans were particularly vulnerable to predation by Chrysaora fuscescens, Aurelia labiata, and Phacellophora camtschatica, whereas copepods were not. Moreover, C. fuscescens had the potential to deplete the standing stock of euphausiid eggs where predator and prey overlapped. During August 2002, C. fuscescens ingested an average 32.5% of the standing stock of euphausiid eggs each day at stations close to shore and north of Cape Blanco (42.9 degrees N, 126.6 degrees W) where maximum abundances …
Development, Biological Regulation, And Fate Of Ctenophore Blooms In The York River Estuary, Chesapeake Bay, Robert H. Condon, Deborah K. Steinberg
Development, Biological Regulation, And Fate Of Ctenophore Blooms In The York River Estuary, Chesapeake Bay, Robert H. Condon, Deborah K. Steinberg
VIMS Articles
Blooms of the lobate ctenophore Mnemiopsis leidyi proliferate in estuaries and coastal regions worldwide. However, their role in food web structure and carbon flow between trophic levels is not fully understood. During 2003-2006, we conducted field surveys along a salinity gradient in the lower York River, a sub-estuary of the Chesapeake Bay, to determine factors controlling the timing and magnitude of M leidyi blooms, and to evaluate effects of gelatinous zooplankton on carbon cycling. Samples for density, biovolume, and carbon content of ctenophores, scyphomedusae, and mesozooplankton were collected using surface net tows and quantified in the laboratory. Historical published records …