Academic literature on the topic 'Estuarine mudflats'

Abstract In previous chapters we have emphasized the variety of habitats within estuaries. These habitats do not, of course, exist in isolation, but interact with each other, both physically and biologically. For example, mangroves and salt marshes provide organic detritus that may fuel food webs on adjacent flats, while fish and crustaceans move backwards and forwards between the mudflats and the marshes. Indeed, fish may spend much of their time outside estuarine areas, providing a link with the open sea.

Abstract On their upper tidal levels, most marine and estuarine mudflats are hidden by vegetation. In temperate zones, salt-tolerant grasses and other herbaceous plants form what is called salt marsh. Here in spring and summer the white flowers of scurvy grass or the yellow of asters and the purple of sea lavender form colourful swathes against a background of cordgrass, while in winter the vegetation dies back to brown remnants.

Abstract During winter, the intertidal mudflats of the Chesapeake Bay, a large estuarine system on the east coast of North America, are crowded with wading birds. Dunlin (Calidris alpma), dowitchers (Limnodromus spp.), and oystercatchers (Haematopus spp.) accumulate in large feeding flocks. Meanwhile, mudflats in the Severn estuary, in southwest England, are visited by up to 2000 curlew (Numenius arcata), 2000 redshank (Tringa totanus), and 50 000 dunlin. As well as these mobile armies, the richness of the habitats is emphasized by the extensive fringing salt marshes, where cordgrasses (Spartina spp.) dominate meadows that are flooded by sea water at high spring tides. These salt marshes are some of the most productive areas in the world, vying with tropical rain forests and coral reefs for the highest rates at which carbon is fixed.

<em>Abstract.</em> —To satisfy the essential fish habitat (EFH) mandate of the reauthorized Magnuson-Stevens Fishery Conservation and Management Act, the Mid-Atlantic Fishery Management Council (MAFMC) and the National Marine Fisheries Service (NMFS) are developing objective, generic criteria to describe and identify the essential habitats for their managed species. Summer flounder or fluke <em>Paralichthys dentatus </em> is an important commercial and recreational species that occurs from shallow estuaries to the outer continental shelf from Nova Scotia to Florida. It is most abundant within the Middle Atlantic Bight from New England to Cape Hatteras, and this region is the focus of this paper. Summer flounder make seasonal inshore–offshore migrations; adults and juveniles normally inhabit shallow coastal and estuarine waters during the warmer months of the year and mostly move offshore with declining water temperature and day length during autumn. Adults spawn during the fall and winter migrations. The best habitat information available on summer flounder is for the estuarinedependent transforming larvae and juveniles. They use several different estuarine habitats as nursery areas, including salt-marsh creeks, sea grass beds, mudflats, and open bay areas. In these habitats, water temperature affects the seasonal occurrence of summer flounder, drives the inshore–offshore migration, and, particularly during winter and spring, affects first-year growth and survival and thus subsequent year-class strength. The distribution of transforming larvae and juveniles within the estuaries is significantly influenced by salinity gradients and substrate. Transforming larvae and juveniles show a preference for sandy substrates in the laboratory but also have been captured on mud or mixed substrates. Juveniles are attracted to eelgrass and macroalgae habitats because of the presence of prey but remain in nearby sand to avoid predators as well as conceal themselves from the prey. The MAFMC used the life history and habitat parameter information developed by the NMFS Northeast Fisheries Science Center (NEFSC) to precisely describe the EFH of summer flounder by life stage. Because summer flounder are overexploited, the MAFMC wanted to be conservative in its EFH identification. Therefore, 90% of the areas where each life history stage has been collected from offshore surveys were identified as EFH. The MAFMC proposed that 100% of the estuaries where larvae and juveniles were identified as being present be identified as EFH because these life stages are estuarine dependent. Nursery habitats within the estuaries are essential because they provide the best conditions for growth and survival of the transforming larvae and juveniles. Submerged aquatic vegetation beds are especially vulnerable and were identified as habitat areas of particular concern. As more habitatrelated density data become available from various local, state, and federal fishery-independent surveys, updated maps of distribution and abundance will be produced.

<em>Abstract.</em> —To satisfy the essential fish habitat (EFH) mandate of the reauthorized Magnuson-Stevens Fishery Conservation and Management Act, the Mid-Atlantic Fishery Management Council (MAFMC) and the National Marine Fisheries Service (NMFS) are developing objective, generic criteria to describe and identify the essential habitats for their managed species. Summer flounder or fluke <em>Paralichthys dentatus </em> is an important commercial and recreational species that occurs from shallow estuaries to the outer continental shelf from Nova Scotia to Florida. It is most abundant within the Middle Atlantic Bight from New England to Cape Hatteras, and this region is the focus of this paper. Summer flounder make seasonal inshore–offshore migrations; adults and juveniles normally inhabit shallow coastal and estuarine waters during the warmer months of the year and mostly move offshore with declining water temperature and day length during autumn. Adults spawn during the fall and winter migrations. The best habitat information available on summer flounder is for the estuarinedependent transforming larvae and juveniles. They use several different estuarine habitats as nursery areas, including salt-marsh creeks, sea grass beds, mudflats, and open bay areas. In these habitats, water temperature affects the seasonal occurrence of summer flounder, drives the inshore–offshore migration, and, particularly during winter and spring, affects first-year growth and survival and thus subsequent year-class strength. The distribution of transforming larvae and juveniles within the estuaries is significantly influenced by salinity gradients and substrate. Transforming larvae and juveniles show a preference for sandy substrates in the laboratory but also have been captured on mud or mixed substrates. Juveniles are attracted to eelgrass and macroalgae habitats because of the presence of prey but remain in nearby sand to avoid predators as well as conceal themselves from the prey. The MAFMC used the life history and habitat parameter information developed by the NMFS Northeast Fisheries Science Center (NEFSC) to precisely describe the EFH of summer flounder by life stage. Because summer flounder are overexploited, the MAFMC wanted to be conservative in its EFH identification. Therefore, 90% of the areas where each life history stage has been collected from offshore surveys were identified as EFH. The MAFMC proposed that 100% of the estuaries where larvae and juveniles were identified as being present be identified as EFH because these life stages are estuarine dependent. Nursery habitats within the estuaries are essential because they provide the best conditions for growth and survival of the transforming larvae and juveniles. Submerged aquatic vegetation beds are especially vulnerable and were identified as habitat areas of particular concern. As more habitatrelated density data become available from various local, state, and federal fishery-independent surveys, updated maps of distribution and abundance will be produced.

Southern LNG Inc. (SLNG), located near Savannah, Georgia, is one of only four LNG import terminals currently operating in the continental United States. In 1999, SLNG proposed to increase their existing turning basin to alleviate a navigation bottleneck and to accommodate safer docking for the tankers of ever-increasing size that navigate the Savannah River. Additionally, in 2001, SLNG proposed an expansion project which included the creation of a new slip. The expansion of the existing turning basin and the creation of the slip was predicted to permanently impact 3.29-acres of saltmarsh and 0