Beth Ravit

A Comparison of Sediment Microbial Communities Associated with Phragmites australis and Spartina alterniflora in Two Brackish Wetlands of New Jersey

The extensive spread ofPhragmites australis throughout brackish marshes on the East Coast of the United States is a major factor governing management and restoration decisions because it is assumed that biogeochemical functions are altered by the invasion. Microbial activity is important in providing wetland biogeochemical functions such as carbon and nitrogen cycling, but there is little known about sediment microbial communities inPhragmites marshes. Microbial populations associated with invasivePhragmites vegetation and with native salt marsh cordgrass,Spartina alterniflora, may differ in the relative abundance of microbial taxa (community structure) and in the ability of this biota to decompose organic substrates (community biogeochemical function). This study compares sediment microbial communities associated withPhragmites andSpartina vegetation in an undisturbed brackish marsh near Tuckerton, New Jersey (MUL), and in a brackish marsh in the anthropogenically affected Hackensack meadowlands (SMC). We use phospholipid fatty acid (PLFA) analysis and enzymataic activity to profile sediment microbial communities associated with both plants in each site. Sediment analyses include bulk density, total organic matter, and root biomass. PLFA profiles indicate that the microbial communities differ between sites with the undisturbed site exhibiting greater fatty acid richness (62 PLFA recovered from MUL versus 38 from SMC). Activity of the 5 enzymes analyzed (β-glucosidase, acid phosphatase, chitobiase, and 2 oxidases) was higher in the undisturbed site. Differences between vegetation species as measured by Principal Components Analysis were significantly greater at the undisturbed MUL site than at SMC, and patterns of enzyme activity and PLFAs did not correspond to patterns of root biomass. We suggest that in natural wetland sediments, macrophyte rhizosphere effects influence the community composition of sediment microbial populations. Physical and chemical site disturbances may impose limits on these rhizosphere effects, decreasing sediment microbial diversity and potentially, microbial biogeochemical functions.

The effects of drainage and nitrogen enrichment on Phragmites australis, Spartina alterniflora, and their root-associated microbial communities.

Salt marshes along the northeastern coast of the United States are increasingly subject to changes in hydrology and enrichment with nitrogen as a result of human activities. We conducted a greenhouse experiment to determine the response of Phragmites australis, Spartina alterniflora, and their root-associated microbial communities to these environmental perturbations. Two sets of treatments were compared: 1) saturated versus drained hydrology under low N enrichment and 2) low versus high N enrichment under drained hydrologic conditions. Unvegetated sediments were planted with either Phragmites australis or Spartina alterniflora, and after one growing season, sediment characteristics, macrophyte biomass, and sediment microbial community structure, as described by phospholipid fatty acids (PLFAs), were analyzed. Under all conditions tested, Spartina root production was significantly greater than Phragmites. While Spartina invested more biomass in roots, Phragmites invested proportionally more biomass in shoots and rhizomes, and Phragmites response to drained hydrology or to an increase in N also differed from that of Spartina. Under N enrichment, the rate of Phragmites stem production doubled, and under drained conditions the ratio of Phragmites shoot:root biomass increased, while Spartina biomass ratios remained unchanged. Although Spartina root biomass was significantly greater than that of Phragmites, under drained conditions the Spartina sediment PLFA diversity was significantly lower than the PLFA diversity in both Phragmites and unvegetated sediments. Under saturated conditions, vegetated sediments exhibited greater PLFA diversity, while no diversity differences were seen in unvegetated sediments under the two hydrologic conditions. Six PLFAs were responsible for 80% of the separation seen within the Principal Components Analysis ordination space. Significant differences in these PLFAs were due to hydrology when comparing saturated vs. drained sediments, and predominantly due to the plant species when comparing N treatments under drained conditions. Our results suggest that macrophyte root association can influence the structure of estuarine sediment microbial communities, but that saturated hydrological conditions may override the plant influences.

ANAEROBIC DEHALOGENATION OF HALOGENATED ORGANIC COMPOUNDS: NOVEL STRATEGIES FOR BIOREMEDIATION OF CONTAMINATED SEDIMENTSOF CONTAMINATED SEDIMENTSOF CONTAMINATED SEDIMENTSOF CONTAMINATED SEDIMENTS

greatest challenges for restoration of estuaries. Halogenated organic compounds constitute one of the largest groups of environmental pollutants and their use has resulted in widespread dissemination and environmental contamination, with freshwater, estuarine and marine sediments as significant sinks. Consequently, the management of sediments contaminated with toxic organic compounds, including polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), polychlorinated biphenyls (PCBs), pesticides and brominated flame retardants, is a major problem with far-reaching economic and ecological consequences. Anaerobic dehalogenating populations appear to be abundant in estuarine and marine sediments and many chlorinated and brominated aromatic compounds are readily dehalogenated, potentially leading to complete degradation and mineralization. For example, dechlorination of chlorinated dioxins and dibenzofurans is readily promoted in sediments from several sites. The biodegradability of organohalides is affected by available electron donors and acceptors, and the dehalogenating microbial populations active in different redox zones are distinct. Co-amendment with halogenated analogues enhanced dechlorination of spiked PCDD/Fs in estuarine sediments under a variety of conditions. Enhancement of microbial dehalogenation is an attractive remediation alternative that could potentially detoxify sediments and avoid the problematic redistribution of contaminants that is associated with dredging. Microbial reductive dechlorination is an important environmental process because it has the potential of decreasing the toxicity of PCDD/Fs if lateral chlorines are removed. These fundamental studies are providing an understanding of how dehalogenation processes are incorporated into a global 505 Remediation of sediments contaminated with toxic chemicals is one of the I. Twardowska et al. (eds.), and Water Pollution Monitoring, Protection and Remediation, 3–23.

ENVIRONMENTAL REVIEW AND CASE STUDIES: Is Urban Marsh Sustainability Compatible with the Clean Water Act?

The United States (US) Army Corps of Engineers and US Environmental Protection Agency share responsibility for regulating placement of fill material in coastal wetlands and open waters. However, achieving the goal of no net wetland loss has been difficult, particularly in urban regions where development pressures and environmental conditions have exacerbated wetland losses. Despite protections provided in the Clean Water Act, one significant wetland category is threatened by adherence to the rules regarding no discharge of fill: low-lying coastal wetlands subject to the effects of a changing climate, including rising sea level, higher storm surges, and flooding. Without inland migration or accretion of new sediments, coastal wetlands will be lost unless marsh surface elevations are raised. The northeastern US coastline is a hot spot that may be especially vulnerable to sea-level rise. To explore current restoration policy, three case studies were examined: Jamaica Bay, New York, disappearing marshes; Jersey City, New Jersey, Lincoln Park West marsh; and Kane Wetland Mitigation Bank in the New Jersey Meadowlands District. Questions related to projected sea-level rise, ecological topography and adjacencies, or the potential for extreme storm events and surges were not addressed in the designs of these recent restorations. Although placement of fill materials in wetlands, marshes, or open water can create unanticipated consequences, if there is stringent regulatory oversight and a transparent public process, allowing placement of fill to preserve coastal wetlands could increase coastal resiliency. We suggest that the greater danger is failing to acknowledge the predicted effects of a changing climate. Permitting decisions must take into account broader geographic areas, expanded time frames, and projected effects of climate change.

RESEARCH ARTICLE: Eastern Oysters ( Crassostrea virginica ) in the Hudson-Raritan Estuary: Restoration Research and Shellfishery Policy

Once-extensive Eastern Oyster (Crassostrea virginica) reefs in the Hudson-Raritan Estuary (HRE) were destroyed almost a century ago as a result of human activities. However, because of improvements in water quality, the potential exists to reintroduce this ecologically extinct species to the ecosystem. For over a decade, New York/New Jersey Baykeeper has conducted oyster restoration activities in support of target ecological goals proposed in the HRE Comprehensive Restoration Plan (CRP). The critical research question is whether existing conditions at a proposed restoration site can actually support long-term Eastern Oyster survival. To determine the feasibility of restoring this native species in Keyport Harbor, New Jersey, juvenile oysters were placed in research field plots, and survivorship and growth were monitored. Data from the first reported oyster restoration research in the New Jersey (NJ) portion of the HRE indicate that oysters could indeed be reintroduced into the ecosystem. After 11 months in situ, research oyster survival rates as high as 60% were observed. Qualitative tissue observations indicated female oysters produced eggs that appeared normal and were ready for spawning. Biodiversity of species collected from the field plots was two- to threefold greater with adult research oysters present, suggesting that oysters increased the density and abundance of other marine species. Sediment deposition patterns indicated that the presence of oysters in support structures may reduce the degree of topographic relief caused by winter storm energies. The research ended abruptly on August 9, 2010, when New Jerseys Department of Environmental Protection rescinded the project permit because of concerns that research oysters were beginning to reach New Jerseys market size of 2.5 inches. Although initial data suggest that oysters can survive and reproduce in Raritan Bay and the potential exists to achieve oyster restoration goals included in the CRP, the project also highlights the current lack of agreement between shellfishery regulators and restoration practitioners with respect to oyster reintroduction in waters where shellfish harvesting is currently prohibited. Different shellfish management approaches are used in New England states (Massachusetts, Rhode Island, and Connecticut), where local control is an important management tool, and in Chesapeake Bay states (Maryland and Virginia), where federal involvement is relatively high. Situated between these two distinct shellfish-producing regions, New Jersey and New York have not supported aggressive reestablishment of historic Eastern Oyster populations in the HRE, and unlike adjacent states, have not developed long-term oyster aquaculture plans. The reluctance to support oyster restoration is due to concerns related to human health and ecological questions. Examples of best management practices currently employed in neighboring states offer potential solutions to address regulatory concerns and could form the basis for developing a productive long-term strategy to reestablish Eastern Oysters in the HRE.

Environmental Reviews and Case Studies: Unique Landfill Restoration Designs Increase Opportunities to Create Urban Open Space

The majority of humans now live in cities where access to usable open space is often limited, causing a reexamination of current practices and values related to reuse of available urban lands. Closed landfills offer an unprecedented opportunity to convert large underutilized land into usable urban open space, as well as habitat for multiple species. However, existing landfill regulations and closure practices do not allow optimal ecological restoration designs for these underutilized properties to be realized, because current regulations focus on methods that protect required caps and prevent water infiltration. Through the exploration of two design case studies, the authors illustrate the opportunities to increase habitat diversity on closed landfills and to more closely approximate a natural topographic/vegetation interaction. Although initially a more costly restoration, unique restoration design elements enhance both long-term environmental and socio-economic values associated with the reuse of closed urban landfills, which are currently underutilized.

Composting of Aged Reed Bed Biosolids for Beneficial Reuse: A Case Study in New Jersey, USA

ABSTRACT Reed beds with Phragmites australis (common reed) have been utilized to decrease the water, nutrient, and volatile solids content of sewage sludge. An efficient disposal/reuse option was sought for reed bed biosolids accumulated over a 15-year period at a wastewater treatment facility in New Jersey, USA. The study facility had 14 reed beds, each with 1000 wet tons capacity, which were full, and so the solids needed to be removed. Because P. australis is considered an invasive species in New Jersey and several other states in the United States, disposal or reuse of solids containing this plant is regulated. Composting was examined as a potential treatment for destroying the plants reproductive rhizomes. The high temperatures achieved during composting were also tested to determine if regulatory criteria for pathogen reduction could be met, making the composted product suitable for unrestricted land application. Preliminary studies indicated the sludge had stabilized to the point where self-heating did not occur. Among the carbon amendments tested in the laboratory to stimulate compositing activity, Phragmites above-ground biomass was determined to be most suitable. In a field test, Phragmites above-ground biomass was mixed with reed bed biosolids at a 1:2 (w/w) ratio. The temperatures achieved resulted in complete mortality of Phragmites rhizomes. In laboratory tests, rhizomes placed in a drying oven at 50°C for 24 h, or 55°C for 12 h, showed 100% plant mortality. However, under field conditions pile temperatures could not be maintained long enough for the sludge to meet the USEPA 503 biosolids time-temperature pathogen rule requirements for unrestricted land application, even though sample fecal coliform counts did meet regulatory limits.