28 April 2016
Mayor Sefatia Romeo Theken
City of Gloucester
9 Dale Avenue Gloucester, MA 01930
Re: Ten Pound Island
Mayor Romeo Theken,
At your invitation, Mass Audubon staff members Jeff Collins, Chris Leahy, and I visited Ten Pound Island on April 8th with assistance from your harbormaster staff. Jeff is our Director of Ecological Management, Chris holds the Gerard Bertrand Chair of Ornithology and Natural History and is a Gloucester resident. I direct our Ecological Extension Service through which we offer technical assistance to conservation partners such as municipalities and land trusts.
We spent approximately one hour exploring the island, conducting a very brief plant and wildlife inventory, and discussing ways that we could assist the City in evaluating potential uses of the island including wildlife habitat enhancements and improvements to permit greater public access. Our immediate takeaways were as follows:
The island appears to serve as nesting habitat for several bird species including Black-crowned Night Heron, Herring Gull, and Common Eider. Other heron species have also been observed investigating the island during the pre-breeding period. Ten Pound is part of a constellation of North Shore rocky islands that provide critical nesting habitat for a number of bird species that have evolved to use the historically predator-free setting.
Norway Rats, a non-native invasive species, appear to be present on the island, based on presence of burrows. Rats are egg predators and can severely reduce reproductive success of a bird nesting colony.
While non-native species are the dominant plants, the vegetation structure is representative of other rocky islands with a few trees of medium height, dense shrubby areas, and some open areas of low ground cover and grasses, all ringed by bare rock.
There is currently no improved access to the island, in either the form of a protected landing or a distinct trail.
Unmanaged human access and any dog presence during bird nesting season would have a very negative impact on breeding success of the nesting birds.
Wildlife habitat could be dramatically improved with an effort to reduce invasive plant species and eradicate the rat population.
We observed no endangered or threatened plant, animal or bird species during our visit.
Any improved public a access to the island should be strictly managed to protect wildlife habitat.
Under appropriate management and professional interpretation, the educational and passive recreational value of the island could conceivably be enhanced, while protecting the natural resources it contains.
Additional Detail: No active Common Eider nests were seen, but old nest bowls and one predated egg from a previous nesting year was observed. Three Black-crowned Night Herons were seen including one nest that appeared to be active. Herring and Great Black-backed Gulls were present, but no evidence of their nesting on the island was observed. Our visit was early in the breeding season, and birds may be setting up nests now or in coming weeks.
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Several ground burrows were observed in the expected nesting areas of eiders or gulls. These ground burrows are assumed to be nests of the invasive Norway Rat, the exact population size of the rat infestation is undetermined at this time but we would assume that their presence is a serious threat to nesting success of the island’s ground nesting birds.
Sycamore maple (Acer pseudoplatanus) and Japanese knotweed (Fallopia japonica) are the dominant invasive plants observed on the island with Japanese knotweed most common near the lighthouse and Sycamore maple as the canopy species in forested areas on the island. Dominant plant species covering the rocky areas were Mossy Stonecrop (Sedum acre) and Winter Creeper (Euonymous fotunei radicans). Both species are non-native and although are not currently listed as invasive in Massachusetts, are both being evaluated once more information is acquired about these species. The island also has extensive thickets of (native) Poison Ivy.
We observed evidence of human use at the western end of the island, including burned wood and litter. Boaters appear to access the island from a narrow cobble beach near the seawall at this end of the island. There are no stairs up the seawall nor any open or flat clearing that provides a picnic spot.
As you may know, Ten Pound Island falls within the Eastern Point-Gloucester Harbor and Essex County Coastal Bird Islands Important Bird Areas (IBA). The IBA program is an international effort to identify areas significant to bird species worldwide. In Massachusetts, 79 sites have been identified. The Eastern Point-Gloucester Harbor IBA is 400-500 acres and it encompasses adjacent tidal flats and open water of Gloucester Harbor to the west and Brace’s Cove and nearshore waters of the Atlantic Ocean to the east. It is well known as an important site for migrating bird species where over 250 different species have been recorded along this 2 mile long peninsula. The Essex County Coastal Bird Islands IBA is 250-300 acres and contains all islands from Nahant to Cape Ann which contain populations of seabirds or wading birds. These coastal bird islands range in individual importance to birds – from several islands that support a few nesting pairs of birds to Mass Audubon’s Kettle Island in Magnolia which is identified as the single most important breeding site for wading birds in Massachusetts. However, in the long term, each of these islands contributes to the health of our bird populations as conditions change and the nesting colonies periodically take up on a new island. Ten Pound Island has significant wildlife value especially for nesting and year-round roosting areas for Common Eiders and possible breeding site for egrets or herons.
To develop a specific management plan, we would need to visit the island several more times to more fully describe the current ecological conditions. We recommend at least 6 site visits during the 2016 field season from May-October to record migratory as well as breeding bird species utilizing the island. We would conduct an extensive plant inventory of the island during the summer months when plants Ecological Extension Service 3 Massachusetts Audubon Society are fully leafed out as well as an initial assessment of the extent of the Norway Rat infestation on the island. Based on this data, we would develop management recommendations including invasive plant control, Norway rat control, and potential improvements that might enable public visitation while avoiding impacts to wildlife. We would also be able to participate in a moderated public discussion of potential uses of the island or any other public participating process you might find helpful in developing a comprehensive plan for the island. While a detailed budget would be established based on the services most needed, I would estimate that the scope of work I describe here would range from $10,000- $15,000.
Thank you once again for arranging our earlier visit, which we all enjoyed. Please contact me or Jack Clarke if you have any questions regarding next steps.
Amber Carr Director,