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VIMS Articles

2021

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Articles 61 - 67 of 67

Full-Text Articles in Life Sciences

Morphological And Mitochondrial Dna Analyses Of Oysters In The Northern Bay Of Bengal, Bangladesh, Mohammed S. N. Chowdhury, Kimberly S. Reece, Sourav S. Joy, Loren D. Coen, Aad C. Smaal Jan 2021

Morphological And Mitochondrial Dna Analyses Of Oysters In The Northern Bay Of Bengal, Bangladesh, Mohammed S. N. Chowdhury, Kimberly S. Reece, Sourav S. Joy, Loren D. Coen, Aad C. Smaal

VIMS Articles

The geographic boundaries of many important habitat-building shallow estuarine oyster (Family Ostreidae) species are poorly understood, especially in subtropical and tropical waters. These keystone species often have extensive historical and extant ranges, in part because of their ability to adapt to diverse environmental conditions and the transfer and introduction of a few species worldwide for aquaculture production. In addition, oysters exhibit morphological plasticity additionally confounding species identification and taxonomy. Molecular techniques have led to significant improvements in oyster systematics and taxonomy but have not been applied to oysters from many tropical regions, including the coastal areas of the Indian Ocean …


Effects Of A Natural Precipitation Gradient On Fish And Macroinvertebrate Assemblages In Coastal Streams, Sean Kinard, Christopher J. Patrick, Fernando Carvallo Jan 2021

Effects Of A Natural Precipitation Gradient On Fish And Macroinvertebrate Assemblages In Coastal Streams, Sean Kinard, Christopher J. Patrick, Fernando Carvallo

VIMS Articles

Anthropogenic climate change is expected to increase the aridity of many regions of the world. Surface water ecosystems are particularly vulnerable to changes in the water-cycle and may suffer adverse impacts in affected regions. To enhance our understanding of how freshwater communities will respond to predicted shifts in water-cycle dynamics, we employed a space for time approach along a natural precipitation gradient on the Texas Coastal Prairie. In the spring of 2017, we conducted surveys of 10 USGS-gauged, wadeable streams spanning a semi-arid to sub-humid rainfall gradient; we measured nutrients, water chemistry, habitat characteristics, benthic macroinvertebrates, and fish communities. Fish …


The Extent Of Seasonally Suitable Habitats May Limit Forage Fish Production In A Temperate Estuary, Mary C. Fabrizio, Troy D. Tuckey, Aaron J. Bever, Michael L. Macwilliams Jan 2021

The Extent Of Seasonally Suitable Habitats May Limit Forage Fish Production In A Temperate Estuary, Mary C. Fabrizio, Troy D. Tuckey, Aaron J. Bever, Michael L. Macwilliams

VIMS Articles

The sustained production of sufficient forage is critical to advancing ecosystem-based management, yet factors that affect local abundances and habitat conditions necessary to support aggregate forage production remain largely unexplored. We quantified suitable habitat in the Chesapeake Bay and its tidal tributaries for four key forage fishes: juvenile spotted hake Urophycis regia, juvenile spot Leiostomus xanthurus, juvenile weakfish Cynoscion regalis, and bay anchovy Anchoa mitchilli. We used information from monthly fisheries surveys from 2000 to 2016 coupled with hindcasts from a spatially interpolated model of dissolved oxygen and a 3-D hydrodynamic model of the Chesapeake Bay …


Temporal And Spatial Variability Of Phytoplankton And Mixotrophs In A Temperate Estuary, Nicole C. Millette, Marcella Da Costa, Jordan W. Mora, Rebecca J. Gast Jan 2021

Temporal And Spatial Variability Of Phytoplankton And Mixotrophs In A Temperate Estuary, Nicole C. Millette, Marcella Da Costa, Jordan W. Mora, Rebecca J. Gast

VIMS Articles

A significant proportion of phototrophic species are known to be mixotrophs: cells that obtain nutrients through a combination of photosynthesis and prey ingestion. Current methods to estimate mixotroph abundance in situ are known to be limited in their ability to help identify conditions that favor mixotrophs over strict autotrophs. For the first time, we combine microscopic analysis of phototrophic taxa with immunoprecipitated bromodeoxyuridine (BrdU)labeled DNA amplicon sequencing to identify and quantify active and putative mixotrophs at 2 locations in a microtidal temperate estuary. We analyze these data to examine spatial and temporal variability of phytoplankton and mixotrophs. Microscopy-based phototrophic diversity …


Environmentally-Determined Production Frontiers And Lease Utilization In Virginia's Eastern Oyster Aquaculture Industry, Jennifer Beckensteiner, Andrew M. Scheld, Pierre St-Laurent, Marjorie A.M. Friedrichs, David M. Kaplan Jan 2021

Environmentally-Determined Production Frontiers And Lease Utilization In Virginia's Eastern Oyster Aquaculture Industry, Jennifer Beckensteiner, Andrew M. Scheld, Pierre St-Laurent, Marjorie A.M. Friedrichs, David M. Kaplan

VIMS Articles

During the last decade, oyster aquaculture has rebounded in Virginia and has been associated with an increase in subaqueous leased area. Production levels remain historically low, however, and many leases are thought to be underutilized. This study uses a novel approach leveraging high-resolution environmental data to evaluate lease utilization and identify constraints on aquaculture development. Stochastic Frontier Analysis (SFA) and Data Envelopment Analysis (DEA) were used to define environmentally-determined production frontiers, i.e. production possibilities based on empirical observations of aquaculture production, available space, and environmental conditions. Both methods estimated Lease Capacity Utilization (LCU, from 0 to 1) for leases producing …


Effects Of Climate Change On Metabolite Accumulation In Freshwater And Marine Cyanobacteria, I-Shuo Huang, Xinping Hu, Hussain Abdulla, Paul V. Zimba Jan 2021

Effects Of Climate Change On Metabolite Accumulation In Freshwater And Marine Cyanobacteria, I-Shuo Huang, Xinping Hu, Hussain Abdulla, Paul V. Zimba

VIMS Articles

Global climate change and anthropogenic nutrient inputs are responsible for increased frequency of cyanobac- terial blooms that potentially contain 55 classes of bioactive metabolites. This study investigated the effects of CO2 availability and concomittant pH levels on two cyanobacteria that produce microcystins: a marine cf. Syne- chocystis sp. and a freshwater Microcystis aeruginosa. Cyanobacterial strains were semi-continuously cultured in mesotrophic growth media at pH 7.5, 7.8, 8.2, and 8.5 via a combination of CO2 addition and control of alkalinity. The cell concentration between treatments was not significantly different and nutrient availability was not lim- ited. Concentration of most known cyanobacterial …


Determinants Of Community Compositional Change Are Equally Affected By Global Change, Meghan L. Avolio, Kimberley J. Komatsu, (...), David S. Johnson, Et Al Jan 2021

Determinants Of Community Compositional Change Are Equally Affected By Global Change, Meghan L. Avolio, Kimberley J. Komatsu, (...), David S. Johnson, Et Al

VIMS Articles

Global change is impacting plant community composition, but the mechanisms underlying these changes are unclear. Using a dataset of 58 global change experiments, we tested the five fundamental mechanisms of community change: changes in evenness and richness, reordering, species gains and losses. We found 71% of communities were impacted by global change treatments, and 88% of communities that were exposed to two or more global change drivers were impacted. Further, all mechanisms of change were equally likely to be affected by global change treatments— species losses and changes in richness were just as common as species gains and reordering. We …