Petit Manan Island

This 10-acre island lies 2.5 miles south of Petit Manan Point in the Town of Steuben, Washington County. It was acquired in 1974 by transfer from the U.S. Coast Guard. The Coast Guard continues to maintain the 119’ lighthouse tower and navigational aids, and the Service maintains several historical structures on the island. Petit Manan has long been considered one of the most important islands in the Gulf of Maine for colonial nesting seabirds.

Botanical inventories, including those for rare plants, were conducted in 1995, 2001, and 2002 (Widrig 1996 and Mittelhauser 2002). Vegetation on the north and east side of the island includes a variety of grasses, Angelica, raspberry, asters, meadowrue, blueberry, and beachpea. The southwestern and central areas of the island are dominated by a dense stand of raspberry which is rapidly expanding each year. Calamagrostis occupies a large portion of the western half of the island. The invasive species dodder established a strong foothold on the northern end of the island in 2000. Extensive vegetation management occurs, utilizing a variety of techniques such as burning, herbicide, and mechanical treatment to improve nesting seabird habitat. Annual monitoring of this vegetation and its response to treatment dictates what to do in forthcoming years.

Significant numbers of terns had historically nested on the island, including 1,500 nesting pairs observed in 1971. However, when human presence on the island ended with automation of the light station in 1972, the numbers of nesting gulls gradually increased to the point they excluded all nesting terns by 1983. Tern restoration was initiated in 1984 in partnership with the College of the Atlantic. One of the first actions was the removal of herring and black-backed gulls. Within one week of the gull control effort, terns returned to nest on Petit Manan Island. The seabird colony has continued to grow, and the island now supports nesting by eight species of seabirds and waterfowl. Razorbill and common murre also routinely visit the island, however no nesting efforts have been documented. Leach’s storm-petrels and black guillemots also nest on the island. The island also supports migrating songbirds, shorebirds and raptors. Table 3-30 presents the nesting seabirds known on the island. An annual report is available upon request from Refuge Complex Headquarters.

Biological technicians live on the island each nesting season and conduct biological surveys (food and productivity studies), predator control and banding. Our staff and seasonal technicians conduct a complete census of the island each year; and record observations of all species observed on or adjacent to the island. Habitat restoration work continues as a cooperative

endeavor with the Gulf of Maine Seabird Working Group and MDIFW. The Refuge is currently participating in Arctic tern and Atlantic puffin metapopulation studies with the University of New Brunswick.

The results of a spider inventory (Jennings 2000) and botanical inventory (Mittlehauser 2000) for this island is also available at Refuge Complex Headquarters.

The island is a popular tour boat destination. Several tour boats per day pause offshore to observe the island’s seabirds during June – August. Refuge Complex staff meet annually with the tour boat companies to discuss issues of concern, and we provide them with periodic updates throughout the seabird nesting season.