Wetlands Evaluation for Philbrick\u27s Pond Marsh Drainage Evaluation North Hampton, NH

Philbrick’s Pond is a lagoon type estuary that formed landward of barrier beach spits in North Hampton, NH. Its inlet was stabilized and restricted by the road that is now Route 1A or Ocean Boulevard. Water flow from the Gulf of Maine passes through a culvert running under Route 1A and into a small waterway and is further restricted as it runs through a clay pipe under an old trolley berm. The lagoon is characterized as a 29 acre tidal marsh. The goal of the overall project is to evaluate the condition and hydrology of the two restrictions recognizing the conflicting needs for improved drainage from upstream flooding and limiting tidal flooding associated with extreme (i.e., storm surge) and normal flooding events due to sea level rise. The tidal marsh itself is a resource held in the public trust and therefore should be protected from any negative impacts associated with current conditions or predicted impacts due to future alternatives that may be chosen by the Town and its residents. Ditching of the marsh in the mid twentieth century rerouted drainage paths (e.g., Chapel Brook) and has resulted in large areas of vegetation loss between ditches in the past 60 years, as first reported by Short in 1984. The objectives of this report on the tidal marsh are threefold: 1) to evaluate the health of the tidal marsh by comparing existing and new data in Philbrick’s Pond with conditions found in the Little River tidal marsh just to the south; 2) characterize the relative benefits to the tidal marsh for the hydraulic alternatives evaluated by the hydrologic modeling; and 3) recommend management actions to restore marsh health using small scale drainage improvements (also known as runneling)

Eelgrass Habitat Creation in Nantucket Harbor, Massachusetts

In response to eelgrass habitat losses associated with development and marine activities in and around Nantucket Harbor, a plan to restore a meadow by transplanting eelgrass to previously vegetated areas was developed in conjunction with the Nantucket Land Council. Over 6,000 eelgrass shoots were sustainably harvested from an extensive bed within the Harbor that was located just west of First Point and near the inlet to Nantucket Sound. Four weeks following collection, impacts from our collection were shown by a 24% decline in shoot density, but live eelgrass cover did not decline significantly. After 12 weeks, no effects of collecting could be measured at the donor site for shoot density or cover. Plants had difficulty establishing within the restoration area due in part to extensive phytoplankton and macroalgal blooms that dramatically shaded the transplants for the initial three months following transplanting. After the first growing season, few of the 6,000 plants had survived, but those plants that survived became well established and grew through the second growing season in 2011. The significance of the macroalgae was documented through estimates of percentage cover, whereas light measurements showed the decline in water clarity from phytoplankton blooms to less than 10% ambient. Combined with our planting and monitoring results, our observations suggest that reestablishment of eelgrass beds in Nantucket Harbor is not limited by the distribution of seedlings, but by shading from phytoplankton and macroalgal blooms that resulted in levels of light too low to support eelgrass establishment during the summer months in 2010

Macroalgal Monitoring in the Great Bay Estuary: 2018 Annual Report

Since 2013, the abundance and taxa of intertidal macroalgae have been assessed at fixed locations throughout the Great Bay Estuary in New Hampshire. Algal abundance may be influenced by environmental conditions such as nutrient levels, water temperature, light and invasive species. Therefore, abundance of different algal groups can provide insights into the overall health of the estuary and signal ecological change. In 2018, intertidal abundance data for percentage cover and biomass were collected, as planned, from five of the eight sites. For the first time, subtidal sampling arrays were also incorporated at all four sites in Great Bay proper to monitor macroalgae at lower elevations and to collect data on eelgrass communities coexisting with the algae

Seaweed Monitoring in the Great Bay Estuary: 2019 Annual Report

As global warming increases temperature and nitrogen inputs change—either due to greater inputs associated with growing populations in the Great Bay or with nitrogen reductions at wastewater treatment plants—it is important to understand how these changes are impacting the estuary. To that end, the abundance and taxa of intertidal seaweeds have been assessed at fixed locations throughout the estuary since 2013. Seaweed abundance may be influenced by environmental conditions such as nutrient levels, water temperature, light availability, and invasive species. Therefore, seaweed communities can provide insights into the overall health of the estuary and signal ecological change. In 2019, abundance data (percent cover and biomass) were collected from five of the eight intertidal sampling locations and four subtidal locations. Data from 2013-2019 show appreciable cover and biomass of nuisance seaweeds (reds and greens), including several introduced species. Green seaweeds decreased in cover at the two intertidal sites that are sampled annually (Depot Road and Adams Point), and cover of red seaweed decreased at one site (Depot Road)

Leveraging Natural Resources Toward Resilience: Outreach, Restoration, and Monitoring for a Resilient NH Coast

Both sound science and meaningful community engagement are critical to creating resilient coastlines given that important natural resources and high population densities coexist in these areas. Salt marshes and sand dunes provide important benefits to the people who live near them, such as mitigating flood impacts, when the condition of the ecosystem is robust enough to support such functions. To enhance the ability of these systems to perform ecosystem services, the goals of this project were to 1. Empower landowners to sustainably manage their own property to support coastal ecosystems and the benefits they provide, 2. Restore eroded sand dunes to increase resilience, and 3. Monitor change in sand dune and salt marsh systems to understand coastal ecosystem condition and response to storms and sea level rise. The status and results of activities for each of eight tasks is outlined and presented with data, as appropriate

Impacts of Marine Docks on Eelgrass in New England: A Spreadsheet-Based Model for Managers and Planners

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Searching for tidal tails - investigating galaxy harassment

Galaxy harassment has been proposed as a physical process that morphologically transforms low surface density disc galaxies into dwarf elliptical galaxies in clusters. It has been used to link the observed very different morphology of distant cluster galaxies (relatively more blue galaxies with 'disturbed' morphologies) with the relatively large numbers of dwarf elliptical galaxies found in nearby clusters. One prediction of the harassment model is that the remnant galaxies should lie on low surface brightness tidal streams or arcs. We demonstrate in this paper that we have an analysis method that is sensitive to the detection of arcs down to a surface brightness of 29 B mag/arcsec^2 and then use this method to search for arcs around 46 Virgo cluster dwarf elliptical galaxies. We find no evidence for tidal streams or arcs and consequently no evidence for galaxy harassment as a viable explanation for the relatively large numbers of dwarf galaxies found in the Virgo cluster.Comment: Accepted for publication in MNRA