The Anastasia Island beach mouse (AIBM) (Peromyscus polionotus phasma) is a subspecies of oldfield mouse. While its natural range historically stretched for about 50 miles north of the Matanzas Inlet (St. Johns County, Florida), it is currently found only on Anastasia Island, a 14-mile long barrier island whose southern tip is located at the inlet. Its population is largely relegated to two remaining natural preserves- Anastasia State Park at the north end of the island, and Fort Matanzas National Monument (FMNM) at the southern end. Both parks preserve remnants of coastal sand dune ecosystems, the primary habitat required by AIBM. Due to its highly restricted range and vulnerability to hurricanes and coastal development, the subspecies is listed as endangered by the U.S. Fish and Wildlife Service.

In 2016, Hurricane Matthew severely impacted the coastline of St. Johns County, including FMNM. Upwards of fifty feet of dunes were washed away, while overwash inundated lower lying habitat proximate to the inlet. Hurricanes Irma (2017), Dorian (2019), Ian (2022), and Nicole (2022), in addition to numerous interspersed nor’easters, have all exacerbated the continuing erosion of primary sand dunes and backdune habitat. Today, it is estimated that there is no more than 25 acres of quality dune habitat remaining within the Anastasia Island portion of the park upon which AIBM rely.

Goal:
Maximize the chances that AIBM will persist and recover from storm-induced negative impacts by achieving a sustainable population size and habitat within FMNM.
Objectives:

1. Assess the current condition and extent of potential AIBM habitat at FMNM.
2. Develop a species management strategy for AIBM that will include short and long-term management actions that can be implemented and sustained by park staff without causing unacceptable impacts to other park resources.

Major tasks will include- but are not limited to- remote sensing research, on-site surveying, preparation of a draft strategy for NPS review, and final strategy preparation and submittal based upon NPS comments.