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Raposa K.B.,Narragansett Bay National Estuarine Research Reserve | Cole Ekberg M.L.,Save The Bay | Burdick D.M.,University of New Hampshire | Ernst N.T.,Rhode Island National Wildlife Refuge Complex | Adamowicz S.C.,Rachel Carson National Wildlife Refuge
Regional Environmental Change | Year: 2016

Salt marshes persist within the intertidal zone when marsh elevation gains are commensurate with rates of sea-level rise (SLR). Monitoring changes in marsh elevation in concert with tidal water levels is therefore an effective way to determine if salt marshes are keeping pace with SLR over time. Surface elevation tables (SETs) are a common method for collecting precise data on marsh elevation change. Southern New England is a hot spot for SLR, but few SET elevation change datasets are available for the region. Our study synthesizes elevation change data collected from 1999 to 2015 from a network of SET stations throughout Rhode Island (RI). These data are compared to accretion and water level data from the same time period to estimate shallow subsidence and determine whether marshes are tracking SLR. Salt marsh elevation increased at a mean overall rate of 1.40 mm year−1 and ranged from −0.33 to 3.36 mm year−1 at individual stations. Shallow subsidence dampened elevation gain in mid-Narragansett Bay marshes, but in other areas of coastal RI, subsurface processes may augment surface accretion. In all cases, marsh elevation gain was exceeded by the 5.26 mm year−1 rate of increase in sea levels during the study period. Our study provides the first SET elevation change data from RI and shows that most RI marshes are not keeping pace with short- or long-term rates of SLR. It also lends support to previous research that implicates SLR as a primary driver of recent changes to southern New England salt marshes. © 2016 Springer-Verlag Berlin Heidelberg Source

Mateo I.,University of Rhode Island | Durbin E.G.,University of Rhode Island | Bengtson D.A.,University of Rhode Island | Kingsley R.,University of Rhode Island | And 2 more authors.
Northeastern Naturalist | Year: 2012

Elemental concentrations and stable (δ18O, δ13C) isotopic ratios in otoliths of young-of-the year (YOY) Tautoga onitis (Tautog) captured in nurseries in Rhode Island, Connecticut, New Jersey, and Virginia were determined using otolith micro-chemistry. Multi-chemical signatures differed significantly among the distinct nurseries among regions (MANOVA: P < 0.001) and between years (MANOVA: P < 0.001). Classification accuracy for Tautog nurseries among regions ranged from 92% to 96% for each of the two years. Since accurate classification of juvenile Tautog to their nursery sites was achieved, otolith chemistry can potentially be used as a natural habitat tag in assigning adult Tautog to their respective estuarine nurseries, but it is important to consider that the chemical signals may change annually. Source

McKinney R.A.,Public Health England | Raposa K.B.,Narragansett Bay National Estuarine Research Reserve
Urban Ecosystems | Year: 2013

Urban marine habitats are often utilized by wildlife for foraging and other activities despite surrounding anthropogenic impact or disturbance. However little is known of the ecological factors that determine habitat value of these and other remnant natural habitats. We examined the preferential use of urban marine habitats in a northeast US estuary to try to elucidate the factors driving enhanced foraging activity at these sites. Using a bioenergetic model, we compared energy intake to energy expenditure and examined differences in behavior and foraging success of great egrets Ardea alba at three urban and three rural salt marshes in Narragansett Bay, Rhode Island USA. Mean per site available nekton energy averaged 4.44 ± 0.97 GJ site-1 and was significantly higher at urban than at rural sites. While energy expenditure by birds was similar across all sites, mean strike and prey capture rate were significantly greater at urban sites, and 70.1 ± 12.2 % of strikes by egrets at urban sites were successful. Egrets foraging at urban sites consumed significantly more energy (23.2 ± 6.62 W bird-1) than those at rural sites. Model results indicated a net energy gain by egrets foraging at urban sites, versus a net energy loss at rural sites. Our results may help explain previously observed increases in the numbers of egrets foraging at urban marine habitats, and help provide input into decisions about the extent to which these areas should be considered for restoration or protection. © 2012 Springer Science+Business Media New York (outside the USA). Source

Mateo I.,University of Rhode Island | Durbin E.G.,University of Rhode Island | Bengtson D.A.,University of Rhode Island | Kingsley R.,University of Rhode Island | And 2 more authors.
Fishery Bulletin | Year: 2010

The elemental composition of otoliths may provide valuable information for establishing connectivity between fish nursery grounds and adult fish populations. Concentrations of Rb, Mg, Ca, Mn, Sr, Na, K, Sr, Pb, and Ba were determined by using solution-based inductively coupled plasma mass spectrometry in otoliths of young-of-the year tautog (Tautoga onitis) captured in nursery areas along the Rhode Island coast during two consecutive years. Stable oxygen (ä 18O) and carbon (ä 13C) isotopic ratios in young-of-the year otoliths were also analyzed with isotope ratio mass spectrometry. Chemical sig natures dif fered sig nif icantly among the distinct nurseries within Narragansett Bay and the coastal ponds across years. Significant differences were also observed within nurseries from year to year. Classification accuracy to each of the five tautog nursery areas ranged from 85% to 92% across years. Because accurate classification of juvenile tautog nursery sites was achieved, otolith chemistry can potentially be used as a natural habitat tag. Source

McKinney R.A.,U.S. Environmental Protection Agency | Raposa K.B.,Narragansett Bay National Estuarine Research Reserve | Kutcher T.E.,101 Coastal Institute Kingston
Urban Ecosystems | Year: 2010

Wading birds (i.e, Ardeidae: herons, egrets, and bitterns) are a guild of waterbirds that forage in coastal habitats which in the US and Europe are often located in close proximity to urban centers. However, the use of urban marine habitats may have consequences for bird populations, as birds can be subject to stress from increased levels of passive and active human disturbance. We examined the effects of human disturbance, available foraging habitat, and prey abundance on wading bird density and species richness at 17 urban coastal sites in Narragansett Bay, Rhode Island USA. The sites represented a gradient of immediately adjacent residential and commercial land use (e.g., 0.0-67.7% urban land use within a 30.5 m buffer of the sites) within an urban matrix (i.e., all sites were located within a suburban center with a population of about 85,000 people). Wading bird density (0.62 ± 0.12 birds ha-1) and species richness (average 4.49 ± 0.37 species across all sites) were not influenced by passive human disturbance as measured by the extent of urban land surrounding a site. However, wading bird density and species richness both decreased significantly as active disturbance (i.e., number of boats moored or docked upstream of the site) increased (r = -0.56, F = 6.85, p = 0.019 and r = -0.73, F = 16.6, p = 0.001, respectively). In addition, both density (r = 0.72, F = 16.2, p = 0.001) and species richness (r = 0.72, F = 16.2, p = 0.001) increased concomitantly with a prey index that combines the density of fish and invertebrates on which the birds feed with the amount of available shallow water foraging habitat at a site. Our results suggest that wading birds i) may not be negatively affected by urban land surrounding estuarine foraging areas in and of itself; and ii) may be utilizing urban areas in the absence of high levels of active disturbance to take advantage of potentially enhanced prey resources. In the case where the benefits of foraging at a site outweigh the costs related to human disturbance, urban marine habitats may need to be considered for restoration or protection from further increases in active human disturbance. © 2009 US Government. Source

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