Download or read book Natural Cycles and Transfer of Mercury Through Pacific Coastal Marsh Vegetation Dominated by Spartina Foliosa and Salicornia Virginica written by and published by . This book was released on 2008 with total page 1088 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Mercury Uptake by a Dominant Plant Species in San Francisco Bay Tidal Marshes Salicornia Virginica written by Jenny Jensen and published by . This book was released on 2007 with total page 84 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Dynamics of Carbon and Nitrogen in a Southern California Salt Marsh written by Theodore Paul Winfield and published by . This book was released on 1980 with total page 182 pages. Available in PDF, EPUB and Kindle. Book excerpt: This study explores three functional aspects of the salt marsh-estuarine ecosystem in the Tijuana Estuary (southern California): primary productivity of the salt marsh vascular plants, organic carbon cycle, and inorganic nitrogen cycle. The productivity study was designed to test the hypothesis that the salt marsh vascular plants in the Tijuana Estuary are not as productive as those in eastern coastal marshes. Spartina foliosa was found to be the most productive individual species in terms of dry weight and carbon, but succulent plant species as a group contributed more to the overall vascular plant productivity. On a dry weight basis net above-ground primary productivity (NAPP) averaged 0.8kg/m('2)/yr which was approximately 240g C/m('2)/yr. Carbon productivity of vascular plants was low in comparison to Atlantic and Gulf of Mexico marshes, and differences were attributed to the more saline soils of southern California. Standing dead biomass and litter averaged over the total marsh surface were constant throughout the study period. The decomposition rate of selected grass species was slower than that for succulent species and the decomposition rate for all plant material varied with elevation, being faster in the tidal creeks and slowest in the upper marsh. The organic carbon study was designed to provide data on the quality and quantity of the various forms of organic carbon being transported to and from the marsh surface in the tidal waters. The data were used in conjunction with those generated from the productivity study to evaluate the hypothesis that the Tijuana Estuary salt marsh exports a substantial amount (45-50%) of the organic carbon produced and that a major portion of the export is as particulate organic carbon (POC). The concentration of POC, dissolved organic carbon (DOC), ATP and chlorophyll a was measured in water samples collected periodically during a tidal cycle each month. Organic carbon was exported as DOC (40-110g C/m('2)/yr) and showed a slight import of POC (5-6g C/m('2)/yr). POC was mainly detrital carbon as opposed to biomass carbon. The Tijuana Estuary salt marsh exports substantially less than 50% of its NAPP, and export is in the dissolved form as opposed to particulate. Results of this and other recent studies suggest that a re-evaluation of salt marsh carbon flow models is needed. The purpose of the inorganic nitrogen study was to document the distribution of ammonium, nitrate and nitrite in the tidal waters draining the Tijuana Estuary salt marsh and to evaluate the tidal waters as a source of nitrogen for salt marsh vegetation. The inorganic nitrogen cycle was characterized by the annual import of ammonium and slight annual export of nitrate. Ammonium was found to be the dominant form of inorganic nitrogen except in the late spring when nitrate was dominant. Inorganic nitrogen import totalled 1.1 - 2.16g N/m('2)/yr. The import of inorganic nitrogen accounted for 28% of the nitrogen required by salt marsh vascular plants, but only 6% of the combined productivity of vascular plants and benthic algae. Nitrogen regeneration processes within the salt marsh are important in meeting the nitrogen needs of salt marsh vegetation.
Download or read book The Role of Spartina Alterniflora in the Transfer of Mercury in a Salt Marsh Environment written by William R. Rahn and published by . This book was released on 1973 with total page 122 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Cycling of Mercury in Spartina Marshes and Its Availability to Selected Biota written by Ronald Johannes Breteler and published by . This book was released on 1980 with total page 216 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Mercury Cycling in a Wetland dominated Ecosystem written by Nelson J. O'Driscoll and published by Society of Environmental Toxicology & Chemistry. This book was released on 2005 with total page 420 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Global and Regional Mercury Cycles written by W. Baeyens and published by . This book was released on 2014-01-15 with total page 596 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Influence of Sulfate reducing Bacteria and Spartina Alterniflora on Mercury Methylation in Simulated Salt Marsh Systems written by Theresa T. Fu (Hui) and published by . This book was released on 2005 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The interactions of sulfate-reducing bacteria and Spartina alterniflora marsh grass have been established using a simulated salt marsh system and these interactions have been quantified using geochemical and molecular tools. Plant activities have a direct influence on mercury methylators and therefore control mercury transformation in the environment. Biogeochemical data show that sulfate and sulfide profiles change seasonally due to plant growth and senescence. Spartina alterniflora impact the two drivers for sulfate and sulfide transformation. The community of sulfate-reducing bacteria serve as the anaerobic driver and transform sulfate to sulfide (sulfate reduction). Sulfate-reducing bacteria have been identified as the principal methylators of mercury (Andersson, et al., 1990; Compeau and Bartha, 1985; Compeau and Bartha, 1984; Blum and Bartha, 1980; Gilmour and Capone). The aerobic driver is dissolved oxygen present in both porewater and plant root exudates, which transform sulfide back to sulfate (sulfide oxidation). Sulfate is not limiting in the vegetated sediment, even at the lower depths. Therefore, although sulfate reduction rates were high when plant activity was high, oxidative processes were also significant in the upper 4-cm of the sediment. In addition, demethylation of methylmercury to ionic Hg(II) in the porewater can occur through oxidative processes (Oremland et al., 1991). Therefore, the significance of sulfide oxidation may have strong implications for methylmercury demethylation in our marsh system.
Download or read book Biological Interactions Between Hosts Parasites and Mercury written by Laura Christina Lukas and published by . This book was released on 2021 with total page 75 pages. Available in PDF, EPUB and Kindle. Book excerpt: Coastal communities, including regions along the North Carolina coast, have seen impacts of sea level rise. These impacts include wetland salinization, loss of nursery habitat, and decreased protection from major storm events. Wetlands provide ecosystem services for our environment, including filtration of runoff from land pollutants. One of those major pollutants which affects North Carolina biota is the heavy metal, mercury.Mercury pollution in wetlands is mainly due to anthropogenic sources, including the burning of fossil fuels, and also natural sources, such as volcanic activity. Inorganic mercury is released into the atmosphere, where it eventually settles to the ground. Mercury can also be taken up by plants and stored in leaves which eventually fall to the ground. These processes of mercury deposition can ultimately make their way to wetlands through surface water runoff. Inorganic mercury, which is deposited in wetlands, can be converted through sulfate reducing bacteria within the sediment to a bioavailable form known as methyl-mercury. Methyl-mercury (MeHg) production may also depend on salinity concentrations in wetlands; therefore, sea level rise could affect mercury levels in wetlands, possibly leading to increases in MeHg in some locations. In general, mercury is a major health concern for North Carolina residents, especially those living near the coast. In particular, mercury poses a major health concern to animals, and can bioaccumulate and biomagnify through trophic levels, eventually reaching humans.Previous work has shown that parasites can take in pollutants, like mercury, from their host tissues and store those pollutants within their own tissues, thus acting like a sponge to pollutants in the host, and in some cases, lowering the levels of pollutants in the host. However, salinity may also have an impact on the amount of MeHg which gets produced within wetland sediments. One of my objectives looked at the mercury levels of uninfected host tissues compared to infected host tissues, and how this might change over a salinity gradient. In order to determine this, parasite life-cycles were taken into consideration and how parasites and mercury might transfer to different hosts.This study took place in two North Carolina estuaries, the Pamlico and Neuse Rivers. I had five sites along each river, from oligohaline to mesohaline localities. Over a one-year period, I collected three host species (two resident species: naked gobies and white-fingered mud crabs, and one mobile species: blue crabs) and recorded their parasite diversity and abundance. I then preserved host and parasite tissues and analyzed them for total mercury (THg) content. In addition, water samples were collected to measure DOC levels because DOC has also been shown to correlate with THg in biota. Also, sediment samples from each site were measured for THg and MeHg. Finally, I took abiotic measurements (most importantly salinity and temperature) as these measures were predicted to be important physical factors of MeHg concentrated in my study system. I predicted that hosts which were parasitized would have lower levels of THg in their tissues compared to hosts which were unparasitized, and that number of parasites would positively increase with salinity. For one type of parasite in the mud crabs, this prediction was upheld, but I did not observe this pattern for the other parasites in my study. In fact, results from THg analysis showed higher mercury levels in hosts which were parasitized compared to unparasitized hosts. This result could suggest that parasites are influencing the health of these hosts making them more prone to infection by parasites (i.e., susceptibility is higher when mercury levels are higher). In addition, I found THg and MeHg levels in sediments were higher at lower salinities than at higher salinities. In naked gobies, THg levels in tissues from the Neuse River were highest at the lowest salinity site. In the Pamlico River, THg in naked goby tissues showed a slight increase with increasing salinity. With increasing salinity, DOC decreased. Finally, for naked gobies in the Neuse River, parasites were found consistently throughout my sites, and in the Pamlico River parasites were most abundant in the second lowest salinity and at the highest salinity site. Altogether, this study provides important information for how parasite communities and THg levels change throughout an estuary; however, more investigation is needed to determine the THg levels of uninfected and infected hosts, and their parasites.
Download or read book The Seasonal Influence of Saltmarsh Plants Salicornia Virginica and Scirpus Robustus on Methylmercury Production and Degradation Over Small Spatial Scales in South San Francisco Bay written by Le Hue Kieu and published by . This book was released on 2004 with total page 146 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Beach and Salt Marsh Vegetation of the North American Pacific Coast written by Keith B. Macdonald and published by . This book was released on 1974 with total page 114 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Wetland Creation and Restoration written by Jon A. Kusler and published by . This book was released on 1990 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: This is a preliminary evaluation of the status of the science of wetland creation and restoration in the United States. It contains a series of regional reviews. Each review summarizes wetland creation and restoration experiences in broadly defined wetland regions (e.g. Pacific coastal wetlands, wooded wetlands of the Southeast). It also includes a series of theme papers, covering a wide range of topics of general application to wetland creation and restoration (hydrology, management techniques, planning).
Download or read book Wigeongrass Ruppia Maritima L written by Harold A. Kantrud and published by . This book was released on 1991 with total page 64 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Sabkha Ecosystems written by M. Ajmal Khan and published by Springer. This book was released on 2014-05-26 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Sustainable development is the key for the survival in 21st century. The natural resources are finite and cannot be used with impunity because we are the custodian of these resources and have responsibility to pass these to the next generation. This monumental task requires several major commitments and most important of them is to arrest population explosion which has already reached seven billion. Natural resources like air to breath, food to eat, and water to drink, and fossil fuel to maintain this life style are being overexploited. Unrestrained consuming culture will accelerate undesired situation. This situation will have more dire consequences in resource limited ecosystems like dry lands. Given the severe scarcity of water, ever increasing population and soil salinization out of the box solutions for the provision of food and clean energy is required to spare meager fresh water resources for conventional agriculture. This volume contains a number of articles dealing with halophyte ecology, bio-geography, ecophysiology, hyper-saline soils, biofuels, biosaline agriculture, biosaline landscaping, climate change mitigation, and biodiversity. It also contains the communication of innovative ideas, such as the research into floating mangroves, seagrass terraces, as well as a World Halophyte Garden containing all known salt-tolerant plant species. It is hoped that the information provided will not only advance vegetation science, but that it will truly generate more interdisciplinarity, networking, awareness, and inspire farmers, and agricultural and landscaping stakeholders to seriously engage in halophyte cash crop production in coastal hyper-saline areas.
Download or read book Coastal Marine Ecosystems of Latin America written by U. Seeliger and published by Springer Science & Business Media. This book was released on 2000-10-18 with total page 394 pages. Available in PDF, EPUB and Kindle. Book excerpt: Coastal and marine ecosystems, some severely degraded, other still pristine, control rich resources of inshore environments and coastal seas of Latin America's Pacific and Atlantic margins. Conflicts between the needs of the region's nations and diminishing revenues and environmental quality have induced awareness of coastal ecological problems and motivated financial support for restoration and management. The volume provides a competent review on the structure, processes and function of 22 important Latin American coastal marine ecosystems. Each contribution describes the environmental settings, biotic components and structure of the system, considers trophic processes and energy flow, evaluates the modifying influence of natural and human perturbations, and suggests management needs. Although the focus of the book is on basic ecological research, the results have application for coastal managers.
Download or read book Wetland Creation and Restoration Regional reviews written by Jon A. Kusler and published by . This book was released on 1989 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Concepts and Controversies in Tidal Marsh Ecology written by M.P. Weinstein and published by Springer Science & Business Media. This book was released on 2000-10-31 with total page 862 pages. Available in PDF, EPUB and Kindle. Book excerpt: Tidal salt marshes are viewed as critical habitats for the production of fish and shellfish. As a result, considerable legislation has been promulgated to conserve and protect these habitats, and much of it is in effect today. The relatively young science of ecological engineering has also emerged, and there are now attempts to reverse centuries-old losses by encouraging sound wetland restoration practices. Today, tens of thousands of hectares of degraded or isolated coastal wetlands are being restored worldwide. Whether restored wetlands reach functional equivalency to `natural' systems is a subject of heated debate. Equally debatable is the paradigm that depicts tidal salt marshes as the `great engine' that drives much of the secondary production in coastal waters. This view was questioned in the early 1980s by investigators who noted that total carbon export, on the order of 100 to 200 g m-2 y-1 was of much lower magnitude than originally thought. These authors also recognized that some marshes were either net importers of carbon, or showed no net exchange. Thus, the notion of `outwelling' has become but a single element in an evolving view of marsh function and the link between primary and secondary production. The `revisionist' movement was launched in 1979 when stable isotopic ratios of macrophytes and animal tissues were found to be `mismatched'. Some eighteen years later, the view of marsh function is still undergoing additional modification, and we are slowly unraveling the complexities of biogeochemical cycles, nutrient exchange, and the links between primary producers and the marsh/estuary fauna. Yet, since Teal's seminal paper nearly forty years ago, we are not much closer to understanding how marshes work. If anything, we have learned that the story is far more complicated than originally thought. Despite more than four decades of intense research, we do not yet know how salt marshes function as essential habitat, nor do we know the relative contributions to secondary production, both in situ or in the open waters of the estuary. The theme of this Symposium was to review the status of salt marsh research and revisit the existing paradigm(s) for salt marsh function. Challenge questions were designed to meet the controversy head on: Do marshes support the production of marine transient species? If so, how? Are any of these species marsh obligates? How much of the production takes place in situ versus in open waters of the estuary/coastal zone? Sessions were devoted to reviews of landmark studies, or current findings that advance our knowledge of salt marsh function. A day was also devoted to ecological engineering and wetland restoration papers addressing state-of-the-art methodology and specific case histories. Several challenge papers arguing for and against our ability to restore functional salt marshes led off each session. This volume is intended to serve as a synthesis of our current understanding of the ecological role of salt marshes, and will, it is hoped, pave the way for a new generation of research.
