Patterns and Processes of Mercury Release from Leaves of Two Dominant Salt Marsh Macrophytes, Phragmites australis and Spartina alterniflora

Windham, Lisamarie; Weis, Judith S.; Weis, Peddrick

doi:10.2307/1353170

Cited by 72 publications

(39 citation statements)

References 32 publications

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“…These amounts are expected to be at least 10 percent of the internal THg and MeHg concentrations in the aboveground plant material per day, values commonly published for nutrients. Far higher values for Hg-leaching have been found for another plant species commonly found in saltmarshes, S. alterniflora (Windham et al 2001). Based on the 10-percent leaching values, leaching amounts of 0.029 g THg/day and 0.00015 MeHg/day are expected.…”

Section: Chapter 3 Haaf Sediment Mercury Pool Sizes and Dynamics In Rmentioning

confidence: 90%

Pre-Construction Biogeochemical Analysis of Mercury in Wetlands Bordering the Hamilton Army Airfield Wetlands Restoration Site

Best¹,

Fredrickson²,

McFarland³

et al. 2005

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ABSTRACT:Over 90 percent of the coastal wetlands in San Francisco Bay have been lost since the industrial revolution. The U.S. Army Corps of Engineers (USACE) is working with the California State Coastal Conservancy and the San Francisco Bay Conservation and Development Commission (BCDC) to reconstruct wetlands at Hamilton Army Airfield (HAAF) and restore 203 ha of tidal habitat to endangered species such as the clapper rail and the saltmarsh harvest mouse. HAAF has subsided below mean sea level and will require 10 million cu yd of fill material to elevate the site to the point where typical marsh vegetation can colonize and the natural sediment trapping, marsh-building physical dynamics can proceed. Wetlands are believed to be sources of methylmercury (MeHg) production and export, and HAAF represents only 203 ha of the additional 23,300 ha of wetlands to be established around the bay by 2055. Means to mitigate MeHg magnification in bay aquatic food webs are needed but currently unknown. This interim report describes site-specific information collected in 2003 on the geochemical/geophysical, microbial, predominant plant-and animal-related interactions that affect stabilization and mobilization of Hg and MeHg in the sediments/soils of the area.Total mercury (THg) and MeHg levels were measured in June 2003 in the sediment in relation to depth at intertidal sites at HAAF and the China Camp State Park (as a reference), as well as at inland sites at HAAF and Bel Marin Creek. Other parameters important for the cycling of Hg and MeHg in sediments were determined also to establish site-specific relationships between these parameters and THg and MeHg. The highest MeHg concentrations (range 0.8-4.4 mg g -1 DW) were found in the upper 2.5-5.1 cm of the cores and levels decreased with depth. THg levels (range 160-550 ng g -1 ) increased with depth, correlating inversely with MeHg. MeHg correlated directly with redox potential (E h ), total organic carbon, and phosphorus. Net MeHg production is the result of methylation and demethylation rates in the sediment. Methylation and demethylation rates were determined by on-site incubations of mud-and vegetated-mud cores with stable Hg isotopes at the HAAF and China Camp sites. Methylation rates were 1.44 ng MeHg g -1 per day in nonvegetated sediments of HAAF. Rates were usually lower in vegetated than in nonvegetated sediments. Rates were usually higher in the light than in darkness. Methylation rates varied with location within the bay on bare and epipelon-vegetated sites and were lower at HAAF than at China Camp. Epipelon is the complex of microalgae, bacteria, and detritus on the sediment surface. Demethylation rates were 1.281 ng MeHg g -1 per day in nonvegetated sediments at HAAF and 0.78 ng MeHg g -1 per day at China Camp. Mean THg concentrations in the macrophytic vegetation, predominated by Spartina foliosa and Salicornia virginica, ranged from 13 to 158 ng g -1 in shoots and from 217 to 297 ng g -1 in roots. Mean MeHg concentration ranged from 0.55 to 4.75 ng g -1 in shoo...

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Section: Chapter 3 Haaf Sediment Mercury Pool Sizes and Dynamics In Rmentioning

confidence: 90%

Pre-Construction Biogeochemical Analysis of Mercury in Wetlands Bordering the Hamilton Army Airfield Wetlands Restoration Site

Best¹,

Fredrickson²,

McFarland³

et al. 2005

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“…The adaptations of halophytes for dealing with salt stress, such as cellular compartmentalization of solutes and excretion through salt glands, may allow for higher tolerance of metals (Williams et al 1994, Windham et al 2001. Several scientists, noting the capacity of P. australis to take up and store belowground a variety of metals, have recommended P. australis as a phytoremediator of Hg, Mg, and Cr contamination (Weis & Weis 2004, Windham et al 2001.…”

Section: Pollution and Eutrophicationmentioning

confidence: 99%

Centuries of Human-Driven Change in Salt Marsh Ecosystems

Gedan

Silliman

Bertness

2009

Annu. Rev. Mar. Sci.

779

436

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Salt marshes are among the most abundant, fertile, and accessible coastal habitats on earth, and they provide more ecosystem services to coastal populations than any other environment. Since the Middle Ages, humans have manipulated salt marshes at a grand scale, altering species composition, distribution, and ecosystem function. Here, we review historic and contemporary human activities in marsh ecosystems-exploitation of plant products; conversion to farmland, salt works, and urban land; introduction of non-native species; alteration of coastal hydrology; and metal and nutrient pollution. Unexpectedly, diverse types of impacts can have a similar consequence, turning salt marsh food webs upside down, dramatically increasing top down control. Of the various impacts, invasive species, runaway consumer effects, and sea level rise represent the greatest threats to salt marsh ecosystems. We conclude that the best way to protect salt marshes and the services they provide is through the integrated approach of ecosystem-based management.

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“…The accumulation and potential for translocation of metals depend on shoot or root uptake at a particular site (Hietz 1992). Leaves of P. australis released 2-3 times less Hg than those of Spartina alterniflora (Windham et al 2001a). quantified the seasonal pattern of metal accumulation in different tissues of P. australis and S. alterniflora in New Jersey marshes.…”

Section: Growth and Developmentmentioning

confidence: 99%

The biology of Canadian weeds. 129. Phragmites australis (Cav.) Trin. ex Steud.

Mal¹,

Narine²

2004

Can. J. Plant Sci.

100

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-common reed, is a perennial, emergent aquatic plant with annual cane-like stems developed from an extensive rhizome system. It grows in low-lying wet areas such as fresh and salt-water marshes, drainage ditches, shallow lake edges, sandy banks, roadsides, woodlands and rocky places. Stems can reach up to 6.0 m in height, vary in diameter from 4 to10 mm and have 10 to 25 cm long hollow internodes. Clones are extended by perennial rhizomes with extensive aerenchymatous tissue that supplies oxygen. Roots develop from rhizomes and other submerged parts of shoots. Leaves are smooth, alternate with narrow-lanceolate laminae, 20 to 70 cm long and 1 to 5 cm broad, and tapering to long slender points. The inflorescence is a terminal panicle, often 30 cm long, dull purple to yellow, with main branches bearing many spikelets. Seed production and germination are extremely variable and comparatively rare in many populations. Phragmites australis carries out photosynthesis through the C 3 pathway (or a variation thereof). Studies of genetic variation through isozyme and other molecular methods suggest that the populations are very closely related, and that variation in the metapopulation is small. Chloroplast DNA sequences of two non-coding regions indicate that non-native introduced genotypes of P. australis have displaced native genotypes in parts of North America. Phragmites australis often forms extensive monocultures in North America. As a consequence, habitat quality and species diversity have been documented to decline. However, in roadside populations it is effective in taking up many typical heavy metals that originate from nearby highways and buildings. Phragmites australis is found in all Canadian provinces and the Northwest Territories, but not in the Yukon Territory or Nunavut. The infestation of P. australis is most severe in the Great Lakes region and its migration is primarily mediated through rivers, canals and waterways but roadways are increasingly becoming important. Changes in the water regime have been linked to its success and could ultimately result in changes to the floristic composition of a habitat. Rodeo™, an aqueous solution of the isopropylamine salt of glyphosate, is most frequently used to control P. australis populations. Other methods of control include cutting, burning, and drainage of the species' habitat. As P. australis is considered to be invasive in North America, introduction of biological control agents is now being investigated. Can. J. Plant Sci. 84: 365-396. Le roseau commun Phragmites australis (Cav.) Trin. ex Steud. est une vivace aquatique dont le vaste système de rhizomes donne chaque année des tiges ressemblant à des cannes. L'espèce pousse dans les dépressions humides comme les marais d'eau douce et salants, les fossés de drainage, la rive des lacs peu profonds, les berges sablonneuses, le bord des routes, les boisés et les endroits rocailleux. Les tiges atteignent parfois jusqu'à 6,0 m de hauteur et leur diamètre varie de 4 à 10 mm, avec de longues sections creuses de 10 à ...

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Patterns and Processes of Mercury Release from Leaves of Two Dominant Salt Marsh Macrophytes, Phragmites australis and Spartina alterniflora

Cited by 72 publications

References 32 publications

Pre-Construction Biogeochemical Analysis of Mercury in Wetlands Bordering the Hamilton Army Airfield Wetlands Restoration Site

Pre-Construction Biogeochemical Analysis of Mercury in Wetlands Bordering the Hamilton Army Airfield Wetlands Restoration Site

Centuries of Human-Driven Change in Salt Marsh Ecosystems

The biology of Canadian weeds. 129. Phragmites australis (Cav.) Trin. ex Steud.

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