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| Registros recuperados: 24 | |
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| Lookingbill, Todd R; University of Maryland Center for Environmental Science; tlooking@richmond.edu; Kaushal, Sujay S; University of Maryland Center for Environmental Science;; Elmore, Andrew J; University of Maryland Center for Environmental Science;; Gardner, Robert; University of Maryland Center for Environmental Science;; Eshleman, Keith N; University of Maryland Center for Environmental Science;; Hilderbrand, Robert H; University of Maryland Center for Environmental Science;; Morgan, Raymond P; University of Maryland Center for Environmental Science;; Boynton, Walter R; University of Maryland Center for Environmental Science;; Palmer, Margaret A; University of Maryland Center for Environmental Science;; Dennison, William C; University of Maryland Center for Environmental Science;. |
| The relevance of the boundary concept to ecological processes has been recently questioned. Humans in the post-industrial era have created novel lateral transport fluxes that have not been sufficiently considered in watershed studies. We describe patterns of land-use change within the Potomac River basin and demonstrate how these changes have blurred traditional ecosystem boundaries by increasing the movement of people, materials, and energy into and within the basin. We argue that this expansion of ecological commerce requires new science, monitoring, and management strategies focused on large rivers and suggest that traditional geopolitical and economic boundaries for environmental decision making be appropriately revised. Effective mitigation of the... |
| Tipo: Peer-Reviewed Synthesis |
Palavras-chave: Catchment ecology; Chesapeake Bay; Interdisciplinary science; Large river; Potomac River; Restoration; Urban metabolism. |
| Ano: 2009 |
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| Beckensteiner, Jennifer; Kaplan, David; Scheld, Andrew M.. |
| The eastern oyster once provided major societal and ecosystem benefits, but these benefits have been threatened in recent decades by large declines in oyster harvests. In many areas, recovery of oyster aquaculture faces significant societal opposition and spatial constraints limiting its ability to meet expectations regarding future food needs and provision of ecosystem services. In Virginia, oyster aquaculture has begun to expand, concurrent with an increase in subaqueous leased areas (over 130,000 acres of grounds are currently leased). Though private leases must in theory be used for oyster production, in practice, they can be held for other reasons, such as speculation or intentional exclusion of others. These factors have led to large variation over... |
| Tipo: Text |
Palavras-chave: Crassostrea virginica; Oyster aquaculture; Chesapeake Bay; Spatial management; User conflicts. |
| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00611/72337/71162.pdf |
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| Goulletquer, Philippe; Heral, Maurice; Prou, Jean. |
| Oyster landings in the Maryland portion of the Chesapeake Bay have declined by more than 50fold since the early part of the century, despite intensive management efforts. The annual shell repletion program is the most critical programmatic element to effect recovery of the ailing Eastern oyster Crassotrea virginica stock and fishery. The overall efficacy of shell repletion management depends primarily on the success of spat settlement on the planted shell, and furthermore on their survival rate. The Operations Research techniques and mathematical programming developed by Rothschild et al. (1991) attempt to maximize spat recruitment to the oyster stock subject to a series of operational constraints. Allocation and timing of shell deployment are the most... |
| Tipo: Text |
Palavras-chave: Larval; Settlement; USA; Chesapeake Bay; Crassotrea virginica; Oysters. |
| Ano: 1994 |
URL: http://archimer.ifremer.fr/doc/1994/publication-3074.pdf |
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| Dauer, Dm. |
| Long-term trends in subtidal macrobenthic communities of the lower Chesapeake Bay, USA, were examined using data collected quarterly (March, June, September and December) fr om 1985 through 1993 at 16 stations along a salinity gradient from tidal freshwater regions of the major tributaries (James, York and Rappahannock rivers) to the polyhaline region of the mainstem of Chesapeake Bay. In March 1989 two stations were added to the program in the mesohaline region of the Southern Branch of the Elizabeth River, a region characterized by contaminated sediments. A non-parametric trend analysis procedure was applied to five parameters characterizing macrobenthic community structure: community biomass, species richness, abundance of individuals, proportion of... |
| Tipo: Text |
Palavras-chave: Chesapeake Bay; Benthos; Trends; Estuary; Eutrophication. |
| Ano: 1997 |
URL: http://archimer.ifremer.fr/doc/00093/20399/18066.pdf |
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| Marshall, Hg; Alden, Rw. |
| Long term trends in the phytoplankton of the lower Chesapeake Bay were identified using flow corrected and uncorrected data sets, with 22 of 23 significant trends similar under both conditions. The major trends between 1985-1992 were for: 1) reduced phytoplankton concentrations; 2) decreasing numbers of phytoplankton taxa during spring, summer and fall months; and 3) seasonally mixed trends for diatom abundance in waters below the pycnocline, with spring months having decreasing densities, and increasing abundance trends in November and December. The flow patterns had different effects on the trends. Flow diminished the magnitude of the trends for total phytplankton concentrations, so these trends were greater in the flow corrected data. There were mixed... |
| Tipo: Text |
Palavras-chave: Phytoplankton; Chesapeake Bay; Trends; Flow. |
| Ano: 1997 |
URL: http://archimer.ifremer.fr/doc/00093/20383/18051.pdf |
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| Prou, Jean; Goulletquer, Philippe; Bacher, Cedric. |
| In oyster production area the determination of the stock, estimation of mortality and growth rates are determinant for knowledge of the fishery. Growth models can be used to predict the time to reach marketable size (76 mm in Chesapeake Bay). They are also important in term of management, when they can predict the future value of the stock (Askew, 1978). Oyster growth models can be built by analysing growth of natural oysters but absolute age is orten unknown. Many authors report growth data in Chesapeake Bay for suspended oyster culture. Unfortunalely, modelisation of the growth was not developed. In that study oyster, shell growth models have been established at three stations in the Patuxent river. Seasonal eITects on growth were integrated in the model |
| Tipo: Text |
Palavras-chave: Modelisation; Oysters; Crassostrea virginica; Growth; Chesapeake Bay. |
| Ano: 1991 |
URL: http://archimer.ifremer.fr/doc/00200/31109/29512.pdf |
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| Heral, Maurice. |
| This report has been achieved during a work as short-term consultant in Chesapeake Biological Laboratory (University of Maryland) in the Laboratory of Prof. B. J. Rothschild, for a period from July 7 to August 7 1989 and at Ifremer Laboratory of La Tremblade. The terms of reference of the consultance were : to compare the oyster fishery researches between the Chesapeake Bay and Europe, particularly in reference to the French coast. To evaluate the on-going Chesapeake Bay oyster stock assessment project and to provide its comments and recommendations. To work on spat settlement in the Bay. This study was funded by the National Oceanic and Atmospheric Administration, by the Maryland Department of Natural Resources under contract F 1666-89-008 and by the... |
| Tipo: Text |
Palavras-chave: Oyster culture; Oyster production; European countries; Maryland; Chesapeake Bay; Causes; Perspectives. |
| Ano: 1989 |
URL: http://archimer.ifremer.fr/doc/00043/15411/12770.pdf |
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| Registros recuperados: 24 | |
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