Review of Factors Affecting the Distribution and Abundance of Waterfowl in Shallow-Water Habitats of Chesapeake Bay

Estuaries ◽  
1996 ◽  
Vol 19 (2) ◽  
pp. 272 ◽  
Author(s):  
Matthew C. Perry ◽  
Amy S. Deller
Keyword(s):  
Shallow Water ◽  
Chesapeake Bay ◽  
Factors Affecting

scholarly journals Lagrangian structure of flows in the Chesapeake Bay: challenges and perspectives on the analysis of estuarine flows

2010 ◽  
Vol 17 (2) ◽  
pp. 149-168 ◽  
Author(s):  
M. Branicki ◽  
R. Malek-Madani
Keyword(s):  
Shallow Water ◽  
Transport Properties ◽  
Chesapeake Bay ◽  
Three Dimensional ◽  
Water Model ◽  
Stable And Unstable Manifolds ◽  
Finite Time Lyapunov Exponent ◽  
Potential Benefits ◽  
Shallow Water Models ◽  
Hyperbolic Trajectories

Abstract. In this work we discuss applications of Lagrangian techniques to study transport properties of flows generated by shallow water models of estuarine flows. We focus on the flow in the Chesapeake Bay generated by Quoddy (see Lynch and Werner, 1991), a finite-element (shallow water) model adopted to the bay by Gross et al. (2001). The main goal of this analysis is to outline the potential benefits of using Lagrangian tools for both understanding transport properties of such flows, and for validating the model output and identifying model deficiencies. We argue that the currently available 2-D Lagrangian tools, including the stable and unstable manifolds of hyperbolic trajectories and techniques exploiting 2-D finite-time Lyapunov exponent fields, are of limited use in the case of partially mixed estuarine flows. A further development and efficient implementation of three-dimensional Lagrangian techniques, as well as improvements in the shallow-water modelling of 3-D velocity fields, are required for reliable transport analysis in such flows. Some aspects of the 3-D trajectory structure in the Chesapeake Bay, based on the Quoddy output, are also discussed.

scholarly journals Factors affecting the abundance of age-0 Atlantic menhaden (Brevoortia tyrannus) in Chesapeake Bay

2016 ◽  
Vol 73 (9) ◽  
pp. 2238-2251 ◽  
Author(s):  
Edward D. Houde ◽  
Eric R. Annis ◽  
Lawrence W. Harding ◽  
Michael E. Mallonee ◽  
Michael J. Wilberg
Keyword(s):  
Environmental Factors ◽  
Primary Production ◽  
Chesapeake Bay ◽  
Primary Productivity ◽  
Atlantic Menhaden ◽  
Strongly Correlated ◽  
Brevoortia Tyrannus ◽  
Factors Affecting ◽  
Chl A ◽  
Low Levels

Abstract The abundance of prerecruit, age-0 Atlantic menhaden (Brevoortia tyrannus), declined to low levels in Chesapeake Bay in the 1990s, after two decades of high abundances in the 1970s–1980s. Environmental factors and trophodynamics were hypothesized to control age-0 menhaden abundance. Data on age-0 menhaden abundance from seine and trawl surveys were analysed with respect to primary productivity, chlorophyll a (Chl a), and environmental variables. Abundance from 1989 to 2004 was strongly correlated with metrics of primary production and euphotic-layer Chl a, especially during spring months when larval menhaden transform into filter-feeding, phytoplanktivorous juveniles. Correlation, principal components, and multiple regression analyses were conducted that identified factors associated with age-0 menhaden abundance. Primary production, Chl a, and variables associated with freshwater flow, e.g. Secchi disk depth and zooplankton assemblages, were correlated with age-0 menhaden abundance. Lengths of age-0 menhaden were positively related to mean levels of annual primary production. However, lengths were negatively related to age-0 menhaden abundance, indicating that growth may be density-dependent. The identified relationships suggest that numbers of menhaden larvae ingressing to Chesapeake Bay and environmental factors that subsequently control primary productivity and food for juveniles within the Bay may control recruitment levels of Atlantic menhaden.

Geotechnical and Geological Factors Affecting Offshore Engineering and Seabed Utilization on a Carbonate Margin: St. Croix, V.I.

1984 ◽  
Vol 106 (1) ◽  
pp. 120-129 ◽  
Author(s):  
R. H. Bennett ◽  
F. A. Bowles ◽  
D. N. Lambert ◽  
F. L. Nastav ◽  
G. F. Merrill ◽  
...  
Keyword(s):  
Shallow Water ◽  
Strength Loss ◽  
Steep Slope ◽  
Rock Outcrops ◽  
Sediment Properties ◽  
Factors Affecting ◽  
Northern Margin ◽  
Quantitative Studies ◽  
Average Shear ◽  
Geological Factors

The northern margin of St. Croix, V.I. is characterized by three morphological features: a narrow shallow water carbonate shelf; a steep slope; and a deep-sea basin. Shallow water reef material and carbonate debris occurs along the shelf. A thin carbonate ooze overlies the steep slope where occasionally rock outcrops occur. Trough sediments are clayey silts and turbidite deposits. Average shear strengths range between 3.1–10.0 kPa for the slope and 5.8–28.3 kPa for the trough (1-m cores). Values range as high as 69.1 kPa at sediment depths greater than one meter. Average sensitivities range between 3.2–6.1 for the slope and 4.1–12.1 for the trough (upper 1 m). Higher sensitivities [8–12] indicate the presence of metastable deposits and considerable strength loss upon disturbance. Variation in the sand, silt, and clay sized fractions, the nature of the carbonate particles, and bioturbation strongly affect the variability in the geotechnical properties. Quantitative studies of local morphology, processes and sediment properties reveal the need for detailed data in specific areas of engineering interest.

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