MY VIEW
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By Norwood Davis

The following My View is written in response to the "Voices Away from the Bluff" with Blair Perkins published in the Oct. 31 issue of The Nantucket Independent.

I would like to address several of the generalizations Mr. Perkins makes, which are not supported by scientific evidence.

1) Beach nourishment projects have been successful even in high energy environments. We have designed and modeled the project using site-specific

wave and current data from 'Sconset.

While Mr. Perkins states that beach nourishment projects in other locations have had "very limited success," direct observations of beaches and decades of experience with beach nourishment speak otherwise. The success of beach nourishment projects is often most directly apparent after the passage of a significant storm, when beaches without a nourished beach clearly sustain greater damage than those with a designed beach in front of them. This was recently highlighted during the passage of Hurricane Noel along the eastern US, where news reports confirmed less damage along nourished beaches.

While each shoreline is unique, the fundamental concept remains: if you place additional material on the beach that is similar to what is there now, the beach will continue to perform similarly, just farther seaward of the pre-construction position. In the case of 'Sconset, the nourished beach will protect the base of the bluff.

To design this project, we collected actual wave and current data offshore of 'Sconset. This site-specific data was used within the modeling performed for the project site. The models (three different computer models were applied to the project area) assumed multiple size storms from multiple directions, contrary to Mr. Perkin's statement of "little to no wave/swell modeling" that was only from "one vector." This work has been reviewed and deemed technically sound by outside coastal engineering experts. Knowing and understanding the high energy conditions at 'Sconset, our engineers are confident that the beach will perform as designed. Our coastal engineering team has previously worked in high energy environments, including over twenty miles of beach nourishment projects along the New Jersey coast and multiple successful projects along Fire Island in New York.

2) Federal agencies responsible for assessing impacts to endangered species have determined there will be no negative impacts to right whales.

The federal agency charged with protecting endangered species, the National Marine Fisheries Service (NMFS), undertook a comprehensive review of the project and its potential impacts on any endangered species present in the area, including right whales. NMFS determined that the proposed project "is not likely to adversely affect Kemp's ridley, leatherback, or green sea turtles or right, humpback, or fin whales" (NMFS, October 2007). NMFS based their evaluation on over ten years of sightings data, knowledge of species life histories, and government records of species mortality. The project is outside all areas designated as Critical Habitat for right whales. Further, an endangered species observer will be present on the dredge at all times to minimize impacts.

3) Impacts at the offshore borrow site will be minor and short-term.

The observation that the impacts at the borrow site will be permanent is flatly incorrect. Removal of sand at the borrow site will expose the underlying sediment which, due to its burial depth and lack of oxygen, will initially be absent of benthic (bottom-dwelling) organisms. However, sand and organisms will be transported to the disturbed area by natural processes allowing for relatively rapid recolonization. Marine organisms present at the borrow site are adapted to living in a dynamic environment and can survive disruptive events and propagate future generations. For example, many of these organisms are mass-spawners (releasing millions of eggs or larvae at a time) that are capable of dispersing their young over long distances. Studies completed by the National Research Council and the Minerals Management Service demonstrate that benthic communities fully recolonize borrow areas within a 1-3 year period. Further, the rate of recolonization is positively correlated with the amount of ocean energy. A high energy area like that found offshore eastern Nantucket is likely to recolonize on the early side of this range. Fish that feed on the borrow site will be entirely unaffected by the lack of benthic organisms due to the abundance of similar habitats nearby.

Marine waterbirds also will be largely unaffected by the dredging project. As Mr. Perkins states, there are vast numbers of waterbirds present offshore during the winter months; however, multiple surveys have demonstrated that the waterbirds are concentrated at Quidnet Rip and Bass Rip shoal, where we will not be dredging. The project will have no impact on these preferred habitat areas for the waterbirds. While dredging at the borrow site will temporarily remove some bottom-dwelling food sources for the birds, this should not affect the birds as they could easily forage at their nearby, much larger preferred habitats. Finally, construction will take place during the summer and fall, when waterbirds have migrated elsewhere and are virtually absent.

4) The only impact to nearby shorelines from the project will be some slight increases in beach width and storm damage protection.

Beach nourishment was chosen precisely because it does not cause increased erosion along nearby shorelines like other shore protection methods can. We've quantified the existing sediment transport in the project area at ~210,000 cubic yards per year, and we expect that the beach nourishment project will increase sediment transport by approximately 38 percent due to the placement of clean, compatible sand along 'Sconset Beach. Adjacent beaches may expect some slight increases in width and storm damage pro- tection. Thus, the concept of a wider beach causing erosion expressed by Mr. Perkins is incorrect. Finally, our rigorous modeling efforts have consistently shown that offshore dredging impacts are too minor and too far away to propagate to the shoreline - meaning that the project will not change nearshore waves, currents, or sediment transport patterns.

5) Beach nourishment construction will only directly impact a particular area for approximately 2 to 4 days; the beach will be nourished about every 5 years.

Construction is planned during the milder weather conditions of the summer and fall and will be a 24- hour operation (as is typical of all beach nourishment projects); however, the contractor and equipment (bulldozers and one stand containing 4 lights) will move along as the beach is being built. Thus, any particular area will only be directly disturbed for approximately 2 to 4 days. Most of the beach will be open to the public during construction and public access will be available, as the contractor will only close off the immediate construction area for safety reasons. While it is true that renourishment will be required approximately 5 years after the initial construction, renourishment takes only about half as long since much less sediment is needed. Additionally, renourishment intervals typically lengthen over time, meaning that it could eventually be more than 5 years between renourishments. Therefore, disturbances from the project will be limited to only a few days for a given area every 5 years or more, and will not be continuous.

6) Hard bottom mitigation will replicate or improve existing conditions.

We are proposing hard bottom habitat mitigation for the under 5 percent of existing hard bottom habitat in the nearshore area that will be covered by sand from the beach nourishment project. As a result of the mitigation, the project will not result in any net loss in habitat type (as is required by state and federal wetlands laws and policies). The beach nourishment project will cover hard bottom habitat and create sand habitat. The mitigation site will cover sand habitat and create hard bottom habitat. Ecological diversity will be increased by locating the hard bottom mitigation habitat slightly to the north of the existing cobble fields at Sankaty. This will expand the geographic area of hard bottom habitat which is scarcer in Nantucket waters than the abundant sand habitats of Nantucket Shoals.

7) Moving homes is not viable for an entire community.

Moving homes is simply not an option for an entire community. Many homeowners have already moved their homes as far landward as they can on their own lots, or have used most nearby lots that were previously available, such that few unoccupied lots are available for the remaining homeowners. Additionally, merely moving houses does nothing to slow the erosion that will eventually claim Baxter Road, 'Sconset Village, and the town sewer beds.

8) Long-term impacts will be minimal.

Long-term impacts from beach nourishment have been studied and found to be minimal. For example, the US Army Corps of Engineers undertook, with cooperation from the US Fish and Wildlife Service, the National Marine Fisheries Service, the US Environmental Protection Agency, and the New Jersey Division of Fisheries and Wildlife, a 7-year biological monitoring program of a 21 mile beach nourishment project from Manasquan Inlet to Asbury Park New Jersey to assess the potential impacts of the project on benthic communities, fish, and wildlife. The study produced the following findings:

• Nearshore animal life abundance, biomass, and taxa richness declined for a short-term period; recovery was complete within 2 to 6.5 months after construction.

• Fish eggs and larvae were not affected.

• Impacts to surf zone fish were minor: during construction, there was a lower abundance of bluefish and higher abundance of kingfish. After construction, there was no difference in surf zone fish abundance. Food for surf zone fish (as observed in the water column and in fish stomachs) was consistent throughout the study.

• There were no impacts to offshore fish: offshore fish were no different in abundance or species composition during the study. Food for offshore fish measured in the stomachs of specific species (including winter flounder and scup) was consistent during the study.

• Surveys of recreational fishermen fishing from jetties on shore showed that the vast majority thought fishing had improved during and after construction.

• Turbidity and suspended sediment was limited to the nearshore beach; levels above natural conditions were not recorded outside of a narrow area along the beach.

• Biomass at the borrow site reached full recovery in 2 to 2.5 years. Many organisms colonize more quickly but growth of larger organisms such as the sand dollar requires a longer period to reach full growth.

• Overall conclusions of the study are that impacts on the biological community from the beach nourishment project were minor and short-term.

9) Terraces and dewatering were innovative methods.

Unlike the widely-implemented practice of beach nourishment, SBPF's past efforts to control erosion (terraces and dewatering) were very innovative. SBPF was among the first to implement dewatering in the US, yielding mixed results: after the Codfish Park system capacity was doubled in December 1999, the beach in front of it accreted 120 feet over the next 15 months; once it was turned off in 2002 due to beach accretion, erosion resumed. The other dewatering systems faced operational difficulties that make their functionality difficult to assess. The terraces were required by local regulations to be temporary and pervious, and were designed to withstand storm waves for only 2 days; thus, they failed during longer storms. Even so, the terraces provided measurable protection to the bluff compared to areas without terraces. Further, we are working with the Conservation Commission to modify the design to use substantially fewer wooden posts and to retain the fabric on site after it has yielded its sand in future storms.

Beach nourishment has been determined to be the best option for protecting our shoreline and homes by environmental regulators. Our project team has exhaustively reviewed all potential environmental impacts and have found that most are minor or that they can be effectively mitigated (as is the case with the hard bottom habitat). I see no convincing reason for not going

forward with this project. I