The lagoon is separated from Great Pond Bay on its southern side by a vegetated baymouth bar about 1,100 m long, with a maximum width of 105 m. It connects with the sea by a narrow channel at its south-eastern corner. The perimeter of the lagoon is vegetated with black mangroves, and extensive mudflats are exposed when water levels are low. The salinity of the water in the lagoon varies between 20 and 40 parts per thousand, depending on rainfall and groundwater runoff in the 470 ha catchment. There is a small settlement of about 100 houses in the watershed of the lagoon, mainly on its north-eastern side.[2]
History
Great Pond and its surrounding mudflats were historically used by the people of St. Croix to fish, crab and gather salt.[3] The area has had human inhabitants in the area for centuries. Excavations have uncovered human remains in the Great Pond area from 300-700 A.D. as well as 700-900 A.D.[1] In the 18th century, a 430-acre (170 ha) plantation called Great Pond plantation occupied the area around the Great Pond.[4][5] A map from 1920 indicates a fan mill (labeled "Great Pond Bay Mill") located just north of Great Pond.[1] The name of the mill suggests it may have been part of the Great Pond plantation.[1]
Beginning in the 1990s, the mangroves in the Great Pond began expanding coverage, adding small islands of mangrove trees within the pond. The pond transitioned from an open-water system to a closed salt pond.[3][6] In 2015, mangroves in the interior of the pond died off.[3] This resulted in a grey-colored landscape within the pond.[3] The channel that had supplied the pond with its saltwater closed up, due to accumulation of sand and buildup of organic debris.[3]