Piermont Marsh Research Articles

Climate and Vegetation Change in a Coastal Marsh: Two Snapshots of Groundwater Dynamics and Tidal Flooding at Piermont Marsh, NY Spanning 20 Years

Climate and Vegetation Change in a Coastal Marsh: Two Snapshots of Groundwater Dynamics and Tidal Flooding at Piermont Marsh, NY Spanning 20 Years

Coastal marshes provide valuable protection for coastal communities from storm-induced wave, flood, and structural loss in a changing climate

Wetlands such as tidal marshes and mangroves are known to buffer coastal communities from wave, flood, and structural loss during storms. Coastal communities and resource managers seek to understand the ecosystem service value of coastal wetlands for reducing storm-induced flood loss in a changing climate. A recent modeling study found that a tall and dense Phragmites-dominated Piermont Marsh reduced the flood loss in the Village of Piermont, New York, U.S.A. during Superstorm Sandy and the 1% annual chance flood and wave event by 8% and 11%, respectively. Here we used the same modeling approach to examine the marsh’s buffering capacity in a changing climate (from 2020 to 2100), considering a potential marsh restoration plan (from 2020 to 2025) and potential marsh loss due to sea-level rise. Results showed that from 2020 to 2100, the 1% annual chance flood, wave, and structural loss would increase due to sea-level rise, storms, and marsh loss. However, the marsh will buffer ~ 11–12% of structural loss until 2050. Under the extreme SLR scenario of 2.89 m and a low accretion rate, Piermont Marsh is expected to lose its buffering capacity by 2080–2100 but will retain some buffering capacity with a high accretion rate of 10 mm/year and marsh growth. The marsh’s buffering capacity will remain during extra-tropical storms during winter and spring unless the wind has a significant northerly component. Lessons learned from this study can be used by coastal communities and marsh managers to develop coastal resiliency and marsh restoration plan.

Invasive Phragmites provides superior wave and surge damage protection relative to native plants during storms

Phragmites marshes, which are found in every continent except in Antarctica, are being removed by resource managers in the US because it is considered an invasive species with little ecosystem service value. Here we present a comprehensive study on the ecosystem service value of an invasive Phragmites marsh vs a native Typha marsh for flood protection during tropical cyclones. Using a vegetation-resolving three-dimensional surge-wave model and observed vegetation and building data, we assessed the value of the Piermont Marsh in buffering Piermont Village, New York, USA from wave, flood, and structural damage during Superstorm Sandy in October 2012. Observed and simulated wind and water level data along the Hudson River were used as boundary conditions. Model results showed that the Marsh, with predominantly invasive Phragmites australis, dissipated more than half of the wave energy, but negligible flood, at the Village during Sandy. River-borne debris could not be transported across the Marsh to the Village. If Phragmites were replaced with the shorter, native cattail, Typha angustifolia, simulations of Sandy suggested that Piermont Marsh’s wave and debris buffering capacity would be preserved. However, had Sandy occurred in non-growth season when Typha is much shorter and sparser, the Marsh would be unable to buffer the wave and debris. Simulated residential structure damage during Sandy (>$10 M) agreed well with reported losses. If the Marsh were absent, the total loss would have increased by 26%. Since damage is dependent on the storm characteristics, we estimated the protective value of the Phragmites marsh for a 1% annual chance flood and wave event to be more than $2 M. This confirms the significant value of Piermont Marsh in protecting Piermont Village from flood and wave damage. To develop a balanced restoration plan, marsh managers should consider biodiversity as well as the significant ecosystem service value of Phragmites-dominated marsh for flood protection.

Invertebrate Communities of Low-Salinity Wetlands: Overview and Comparison between Phragmites and Typha Marshes Within the Hudson River Estuary

Benthic macroinvertebrate abundance, taxonomic composition, and surface flooding dynamics were compared among high and low elevation stands of narrow-leaved cattail (Typha angustifolia) and invasive common reed (Phragmites australis) at Iona Island Marsh, an oligohaline wetland, and Piermont Marsh, a mesohaline wetland, within the Hudson River National Estuarine Research Reserve during 1999 and 2000. Overall, the benthic macroinvertebrate community at both sites was similar in composition and abundance to those documented from other low-salinity systems. Macroinvertebrate taxa richness was lowest in mesohaline common reed, but similar among common reed and cattail habitats in oligohaline wetlands. Total macroinvertebrate densities were greater at high-elevation compared to low-elevation reed stands at the mesohaline site during summer 1999 and spring 2000. Total macroinvertebrate densities were similar among both oligohaline vegetation types during all seasons, except for spring 2000, when lower densities were observed in low-elevation common reed. A weak positive relationship between macroinvertebrate density and depth of flooding suggests that surface hydrology may be influencing the observed patterns of macroinvertebrate density among the vegetation stands. These results suggest that benthic macroinvertebrate abundance and diversity may not necessarily be impaired in low-salinity wetlands experiencing invasion by common reed unless the change in vegetation is accompanied by a measurable alteration to physical conditions on the marsh surface (i.e., elevation and flooding dynamics).

Diffusional losses of amended anaerobic electron acceptors in sediment field microcosms

Hudson River sediment microcosms from Piles Creek (PC), Piermont Marsh (PM), and Iona Island (II) were amended with ∼100mM nitrate or sulfate to stimulate anaerobic bioremediation. Nitrate and sulfate decreased over two years of field incubation and the fraction of these losses due to diffusion to the water column was predicted using Fick’s law. Apparent diffusion (Dapp) values of 1–4×10−10m2s−1 predicted the majority of loss/gain from/to the sediments by 700 d, but not at all times. Effective diffusion (Deff) values predicted by the porosity function (Deff=Dmolε4/3) were larger than those observed in the field, and field data indicates a cube power relationship: Deff=Dmolε3. Dapp greatly increased in surficial layers at PM and PC in year two, suggesting that bioadvection caused by bioturbating organisms had occurred. The effects of bioturbation on transport to/from the sediments are modeled, and results can be applied to various sediment treatment scenarios such as capping.

A simple model for predicting water table fluctuations in a tidal marsh

Wetland restoration efforts are ongoing in many urban estuaries. In this context the hydrologic characteristics of restored wetlands are of paramount importance since the spatially and temporally variable position of the water table and of soil saturation establishes the oxidation state of the substrate, which, in turn, affects the wetland's biogeochemical composition and the biological communities it is capable of supporting. A relatively simple analytical model developed here describes tidal marsh hydrology from creek bank to interior, considering transient drainage, net meteorological inputs, and tidal effects. Given a series of physical and time‐dependent inputs, the analytical solution derived predicts the position of the water table at points along a transect perpendicular to a tidal creek. Validation of the model using water table time series data collected along three transects at Piermont Marsh, a tidal wetland on the Hudson River in the New York/New Jersey Estuary, indicates good general agreement between observations and predictions, although it may not be precise enough for some kinds of ecological applications. A sensitivity analysis on the model indicates that a range of pairs of transmissivity and specific yield values that increase with distance from the creek results in the same spatial and temporal fluctuations in the water table. This equifinality result is discussed as it relates to the predictive capacity of the model presented.

The hydrology of Piermont Marsh, a reference for tidal marsh restoration in the Hudson river estuary, New York

The topography, hydroperiod, water table, and selected edaphic characteristics are described for Piermont Marsh, an irregularly flooded tidal marsh in the Hudson River Estuary, New York, USA. Despite variations in microtopography, overall the marsh is flat, and although the observations were conducted at a high point in the Estuary's 18.6 year metonic cycle, its surface was only inundated 10–12 times a month. Observations of spatial differences in the saturated hydraulic conductivity and surface infiltration rates are also discussed. ‘Edge’ portions of the marsh are characterized by a slightly higher, more uniform, more structured, less organic, and less hydrologically conductive substrate than found in the marsh interior. Preferential flow is facilitated by macropores in the creekbank wall. The water table is close to the marsh surface for a lesser percentage of the lunar month in the marsh ‘edge’ when compared to the interior, where it is almost always within 10 cm of the surface. The extent to which the spatial variability of these hydrologic characteristics determines the marsh's ability to provide various ecosystem services is also discussed and the implications of these observations on tidal marsh restoration efforts briefly presented.

Dissolved Inorganic Nitrogen Pools and Surface Flux under Different Brackish Marsh Vegetation Types, Common Reed (Phragmites australis) and Salt Hay (Spartina patens)

The current expansion of Phragmites australis into the high marsh shortgrass (Spartina patens, Distichlis spicata) communities of eastern U.S. salt marshes provided an opportunity to identify the influence of vegetation types on pools and fluxes of dissolved inorganic nitrogen (DIN). Two brackish tidal marshes of the National Estuarine Research Reserve system were examined, Piermont Marsh of the Hudson River NERR in New York and Hog Island in the Jacques Coustaeu NERR of New Jersey. Pools of DIN in porewater and rates of DIN surface flux were compared in replicated pairs of recently-expanded P. australis and neighboring S. patens-dominated patches on the high marsh surface. Both marshes generally imported nitrate (NO3−) and exported ammonium (NH4+), such that overall DIN was exported. No differences in surface exchange of NO3− or NH4+ were observed between vegetation types. Depth-averaged porewater NH4+ concentrations over the entire growing season were 56% lower under P. australis than under S. patens (average 1.4 vs. 3.2 mg NH4+ L−1) with the most profound differences in November. Porewater profiles showed an accumulation of NH4+ at depth in S. patens and constant low concentrations in P. australis from the soil surface to 50 cm depth, with no significant differences in porewater salinity. Despite these profound differences in porewater, NH4+ diffusion from soils of P. australis and S. patens were not measurably different, were similar to other published rates, and were well below estimated rates based on passive diffusion alone. Rapid adsorption and uptake by litter and microbes in surface soils of both communities may buffer NH4+ loss to flooding tides in both communities, thereby reducing the impact of P. australis invasion on NH4+ flux to flooding waters.

NEW DISTRIBUTION RECORDS FOR THE SPOTFIN KILLIFISH, FUNDULUS LUCIAE (BAIRD), IN THE LOWER HUDSON RIVER ESTUARY AND ADJACENT WATERS

The spotfin killifish, Fundulus luciae, occurs in salt and brackish marshes of the east coast of the United States from Georgia to Massachusetts. The purpose of this study was to provide additional information on the distribution and habitat preferences of spotfin killifish in the lower Hudson River Estuary, where prior to 2000, this species had not been reported. The primary study site was Piermont Marsh, Rockland County, NY. Additional collection sites included Ralph Creek, Brooklyn, NY; Saw Mill Creek, Staten Island, NY; and Lincoln Park, Jersey City, NJ. Twenty-five spotfin killifish were collected at Piermont Marsh and Ralph Creek during 2001. All specimens were collected from the upper intertidal zone, in accordance with the reported habitat preferences and life history of this species. Samples from previous studies in northeastern U.S. brackish/salt marshes were examined, and spotfin killifish were identified from samples collected at Branford, CT in 1999; Milford, CT in 2000; and Larchmont, NY in 1976. These findings indicate that spotfin killifish may not necessarily be rare; however, their cryptic lifestyle and preference for high intertidal brackish/salt marsh habitat has often precluded detailed assessments of their life history and geographic distribution.

DoesPhragmites expansion alter the structure and function of marsh landscapes? Patterns and processes revisited

We assess the probability and importance of different spatial distributions ofPhragmites australis (Trin Ex Steud) within brackish tidal marshes of the mid-Atlantic United States coast. The comparative impact ofPhragmites expansion on the larger coupled marsh-estuary system may partially be a function of the landscape area dominated byPhragmites, the landscape position occupied byPhragmites, the landscape pattern created byPhragmites expansions, and the resulting impact on tidal drainage networks. We find evidence thatPhragmites establishment can occur at many landscape positions, and thatPhragmites spread within a marsh can occur via colonization (new patches), linear clonal growth (along a preferred axis), or circular clonal growth (non-directional, random spread). Early intervals ofPhragmites spread were dominated by colonization for all sites except for Piermont Marsh (which appeared to be dominated by linear clonal growth) and Lang Tract (which appeared to be dominated by circular clonal growth). Although 46–100% of new patches ofPhragmites occurred within 5 m of drainages, at only one site (Piermont Marsh, New York) didPhragmites populations remain concentrated along creek banks. Except for Iona Island, New York, which appears to be in an early stage ofPhragmites invasion, patch dynamics at all sites showed an increase followed by a decrease in patch number, as independent patches became established, expanded, and coalesced. We also found some evidence for a loss of first order streams at later stages ofPhragmites invasions in several sites (Hog Island, Lang Tract, Silver Run).

PCB congener distributions in muscle, liver and gonad of Fundulus heteroclitus from the lower Hudson River Estuary and Newark Bay

Gradients in sediment polychlorinated biphenyl (PCB) concentrations and PCB congener profiles exist along the Hudson River (NY, USA). We evaluated site and tissue differences in PCB concentration and congener profiles in resident mummichog ( Fundulus heteroclitus) collected from PCB-contaminated sites in the lower Hudson River and the New York/New Jersey Harbor Estuary. Fish were collected from three PCB-contaminated sites Piermont Marsh (P), Iona Marsh (I), and Newark Bay (NB), and from two reference sites (Flax Pond, NY; Succotash Salt Marsh, RI). Congener profiles were statistically analyzed using principal component analysis (PCA) and general linear model (GLM) profile analysis. Contaminated fish had PCB tissue concentrations approximately 10-fold higher than those of reference fish. There were no site differences in PCB body burden (all tissues combined) among the contaminated site fish. However, relative PCB concentration did differ between organs: NB fish (gonad=liver > muscle); I and P fish (gonad > liver > muscle). In contrast to PCB content, PCB congener profiles did show site differences; NB mummichog being depleted in the less chlorinated congeners relative to I and P fish, likely reflecting different PCB sources to these populations. Within a site, however, PCB congener patterns were similar between liver, gonad and muscle. In conclusion, PCA and GLM analyses gave complementary results, both analyses indicating differences in site, but not tissue, distributions of PCB congeners. This study also demonstrates that unlike congener profiles, total PCB content does differ dramatically amongst tissues and further, that PCB differences among tissues (gonad vs. liver vs. muscle) can vary with site.

Nekton use of a Phragmites australis marsh on the Hudson River, New York, USA

Recently, Phragmites australis (common reed) in North American wetlands has changed from a species with limited distribution to an invasive species producing dense monospecific stands. This expansion has forced out other wetland vegetation, potentially changing the functions of these ecosystems. Little research has focused on whether P. australis stands serve as valuable wetland habitat and foraging areas for terrestrial animals and resident marsh nekton. This study addressed the effect of different hydrologic and geomorphic conditions among P. australis stands on abundance of resident nekton in Piermont Marsh, located on the lower Hudson River Estuary. Three P. australis-dominated sites (erosional creekbank, depositional creekbank, interior) were sampled for nekton using bottomless lift nets during day and night spring high tides during the months of July, August, and September, 1998. Hydrology data were collected for ten continuous days during each sampling period and included mean flooding depth, duration, and frequency for the three sites. Species captured on the marsh surface included Fundulus heteroclitus (common mummichog), Palaemonetes pugio (dagger-blade grass shrimp), Callinectes sapidus (blue crab), and Uca minax (brackish water fiddler crab). Results indicate that nekton and macrobenthos are using all areas sampled, and measured densities are comparable to those measured in some non-P. australis dominant wetlands elsewhere on the Hudson River. Although no strong correlation was made between nekton densities and hydrology, definite patterns were observed in the data. The results indicated that additional variables, such as geomorphology, might interact with hydrology to influence nekton use of the marsh surface. Although exact mechanisms controlling spatial variation of nekton use within P. australis stands still need to be elucidated, P. australis does seem to serve as nekton habitat.

Interactions among plant species and microorganisms in salt marsh sediments.

The interactions among Spartina patens and sediment microbial populations and the interactions among Phragmites australis and sediment microbial populations were studied at monotypic sites in Piermont Marsh, a salt marsh of the Hudson River north of New York, N.Y., at key times during the growing season. Arbuscular mycorrhizal fungi (AMF) effectively colonized S. patens but not P. australis, and there were seasonal increases and decreases that coincided with plant growth and senescence (17 and 6% of the S. patens root length were colonized, respectively). In sediment samples from the Spartina site, the microbial community and specific bacterial populations were at least twice as large in terms of number and biomass as the microbial community and specific bacterial populations in sediment samples from the Phragmites site, and peak values occurred during reproduction. Members of the domain Bacteria, especially members of the alpha-, gamma-, and delta-subdivisions of the Proteobacteria, were the most abundant organisms at both sites throughout the growing season. The populations were generally more dynamic in samples from the Spartina site than in samples from the Phragmites site. No differences between the two sites and no differences during the growing season were observed when restriction fragment length polymorphism analyses of nifH amplicons were performed in an attempt to detect shifts in the diversity of nitrogen-fixing bacteria. Differences were observed only in the patterns generated by PCR or reverse transcription-PCR for samples from the Spartina site, suggesting that there were differences in the overall and active populations of nitrogen-fixing bacteria. Regression analyses indicated that there was a positive interaction between members of the delta-subdivision of the Proteobacteria and root biomass but not between members of the delta-subdivision of the Proteobacteria and macroorganic matter at both sites. In samples from the Spartina site, there were indications that there were bacterium-fungus interactions since populations of members of the alpha-subdivision of the Proteobacteria were negatively associated with AMF colonization and populations of members of the gamma-subdivision of the Proteobacteria were positively associated with AMF colonization.

The Diamondback Terrapins of Piermont Marsh, Hudson River, New York

We investigated the size and structure of a population of diamondback terrapins (Malaclemys terrapin) inhabiting Piermont Marsh on the lower Hudson River, New York. From 6 June through 24 August 1997, 39 trapping periods were completed using trammel nets set in and around the marsh complex. Only eight terrapins were captured six males and two females indicative of a small or broadly-dispersed population. Terrapins were trapped near a sandbar area outside of the marsh but never seen or trapped in two marsh creeks, suggesting the creeks were not used by terrapins during the time of the study. Instead, terrapins were observed basking and swimming around the rocky piers and breakwaters in the Hudson River. Recent development, soil subsidence, and Phragmites australis growth may have deteriorated traditional terrapin nesting sites in the region.