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The role of tidal dispersion is reassessed, based on a consideration of the relevant physical mechanisms, particularly those elucidated by numerical simulations of tide-induced dispersion. It appears that the principal influence of tidal currents on dispersion occurs at length scales of the tidal excursion and smaller; thus the effectiveness of tidal dispersion depends on the relative scale of the tidal excursion to the spacing between major bathymetric and shoreline features. In estuaries where the typical spacing of topographic features is less than the tidal excursion, tidal dispersion may contribute significantly to the overall flushing. In estuaries and embayments in which the typical spacing between major...
Categories: Publication; Types: Citation; Tags: Estuaries
Long-term studies were used to examine (1) contrasting time scales and mechanisms of structural variations within two benthic communities and (2) the usefulness of long data sets for evaluating human impact. A 10-year study of a San Francisco Bay mudflat, the details of which are reported elsewhere, has revealed large short-term (on the order of months) variations in species abundances within a community composed predominantly of opportunistic species. The study site, located in a highly urbanized estuary, is subject to the influence of a nearby sewage-treatment facility. However, rapid changes in population size of the common species, in part due to periodic natural habitat disturbance, impedes the detection of...
Categories: Publication; Types: Citation; Tags: Estuaries
This dataset shows the estimated delivered nitrogen load from all sources (livestock manure from confined operations, livestock manure from pasture feeding, livestock manure from feedlots, fertilizer applied to crops, runoff from urban land, combined municipal and wastewater discharge, and from atmospheric deposition)into the estuaries, bays, and sounds along the U.S. Gulf of Mexico coast in 2002.
Categories: Data; Tags: Alabama, Alabama, Apalachee Bay, Apalachee Bay, Apalachicola Bay, All tags...
This dataset was developed as part of the research for a Royal Roads University master's thesis entitled "Assessing the impact of human activities on British Columbia’s estuaries". The work was also published through PLOS One (Robb, 2014). The estuary polygons were created by the Pacific Estuary Conservation Program (PECP). Please see Ryder et al., 2007 for more information on their creation. This dataset includes a subset of the PECP estuary dataset because only those estuary polygons that could be linked to to a unique watershed were considered in the analysis. The attributes for each estuary polygon show the spatial coverage of different human activities within the bounds of the estuary and its upstream watershed....
Coastal Condition (Combined) This layer is one of the South Atlantic LCC indicators in the estuarine ecosystem (both estuarine marsh and estuarine open water). It is an index of coastal condition capturing water quality, sediment quality, and benthic community condition. Reason for Selection This index measures the overall abiotic condition of the system, is well monitored, and is synthesized by the Environmental Protection Agency (EPA) every 5 years. It integrates measures of water quality, sediment quality, and benthic habitat quality. Input Data The EPA Coastal Condition Index (CCI) is a ranking derived from a water quality index, sediment quality index, benthic index, coastal habitat index, and fish tissue...
The diked and freshened Herring River estuary (Wellfleet, Massachusetts) experiences regular summer hypoxia and one- to three-week periods of main stream anoxia, often accompanied by fish kills. Stream hypoxia results from the temperature-dependent increase in oxygen demand of organic matter released by diked salt marsh deposits; periods of total anoxia are induced by heavy rains which increase the runoff of wetland organic matter. Historic reductions in tidal flushing have extended the low salinity region of the estuary normally characterized by high organic loads and minimal flushing. Recurrent main stream anoxia has depressed both migratory and resident aquatic fauna.
Categories: Publication; Types: Citation; Tags: Estuaries

map background search result map search result map BC Estuary Threats Assessment Indicator V 2.0: Estuarine Combined: Coastal Condition Estimates of Total Nitrogen and Phosphorus Delivery to Estuaries, Bays, and Sounds Along the U.S. Gulf of Mexico Coast, 2002 BC Estuary Threats Assessment Estimates of Total Nitrogen and Phosphorus Delivery to Estuaries, Bays, and Sounds Along the U.S. Gulf of Mexico Coast, 2002 Indicator V 2.0: Estuarine Combined: Coastal Condition