Catlett Islands encompass 280 ha (690acres) and displays a ridge-and-swale geomorphology. The islands consist of multiple parallel ridges of forested wetland hammocks, forested upland hammocks, emergent wetlands and tidal creeks surrounded by shallow subtidal areas that once supported beds of submerged aquatic vegetation.

In cross-section, the ridges are characterized by a marsh/shrub wetland ecotone, a shrub wetland/forested wetland ecotone, a ridge terrace, and an interior forested high ground. Plants found in the marsh/shrub wetland ecotone include salt marsh cordgrass (Spartina alterniflora), salt meadow hay (Spartina patens). Marsh elder and groudsel tree bushes thrive towards higher ground of the saltmarsh. The shrub wetland/forested wetland is characterized by a sparsely forested overstory dominated by young and/or stressed loblolly pine, red cedar and the occasional American holly and black cherry. The shrub layer in this ecotone contains wax myrtle, bayberry and saplings of loblolly pine, cedar, holly and black cherry plus a variety of vines.

The overstory of the ridge terrace is usually dominated by larger, densely distributed loblolly pine. Red cedar, holly, black cherry, red maple and persimmon grow in the subcanopy. The understory consists primarily of American holly and the shrub layer is dominated by wax myrtle, poison ivy, trumpet vine, bull briar, greenbriar and Japanese honeysuckle. Interior high ground of the forested wetlands contains more hardwood species than the ridge terrace although loblolly pine is always present. Several species of oak and tulip poplar, sourwood, black gum, sassafras, sweetgum, dogwood, red maple, black cherry, black locust, persimmon and holly are found here.

Location and Access:

The Catlett Islands (37° 18' N; 76° 33' W) are located approximately 35 km from the mouth of the York River and 7 km from VIMS on the North side of the York River in Gloucester County, Virginia. Timberneck Creek flows into the York River on the eastern side of the Catlett Islands and Cedarbush Creek enters the river on the western side. Poplar Creek bisects the two large areas of the Catlett Islands. The site is accessible primarily by boat. Permission for all activities on the island is mandatory. Please contact Reserve staff for information.

Monitoring Programs:

Water Quality Monitoring - There are no water quality or weather stations at the Catlett Islands component of the CBNERRVA. Weekly volunteer citizen water quality monitoring has been ongoing since the incorporation of the site in 1990. Surface water temperatures range from 5.4 °C to 27.4 °C. Salinity is indicative of mesohaline conditions, ranging from 14-18 ppt in the fall to 8.2-12 ppt in the spring. Dissolved oxygen concentration ranges from 4.2 to 14.0 mg/L. Beginning in 2002, water column inorganic nutrients (ammonium, nitrate, nitrite, ortho-phosphate), total dissolved nitrogen and phosphorus, and chlorophyll are measured monthly adjacent to Catlett Islands.

Biological Monitoring - Catlett Island is a sampling site for the CBNERRVA York River shallow water seine survey. Fish, blue crab and grass shrimp size and density data have been collected since February 2001 from this site. Nekton sampling occurs monthly from February through July. Contact Reserve staff for more information regarding this or any other CBNERRVA monitoring program.