Mangroves support a wide range of biodiversity within the submerged root systems and among the trunks and canopy including sponge communities, shrimp, insects, fish, frogs, turtles, lizards, snakes, and birds (Kathiresan & Bingham 2001, Nagelkerken et al. 2001). Mangrove wetlands support a variety of wetland and migratory birds (Wauer and Sladen 1992). Submerged red mangrove prop roots are colonized by a variety of organisms, including sponges, oysters, and an abundance of coral species among the prop roots (Rogers 2009). The complexity of these prop root communities support a range of fish species and are known as a nursery ground for commercially important species (Tobias 2001).
Of the USVI SGCN, 20 rely on mangroves, including eight insects, two freshwater invertebrates, two landbirds, two plants, and six waterbirds. See table below for the list of these species.
In the USVI, two LANDFIRE classification type (Existing Vegetation Type) corresponds with mangroves: Caribbean Coastal Mangroves and Caribbean Estuary Mangroves found primarily
In 2021, the Grimes Lab of the University of the Virgin Islands developed the Territory Mangrove Monitoring Program (TMMP) that involves annual monitoring at specific sites. Monitoring includes the collection of environmental metrics such as water quality, groundwater temperature and light, Blue Carbon and soil characteristics, all of which will inform management through TMMP (Grimes et al., 2024). The Grimes Lab has also focused on mangrove recovery after Hurricane Irma through sediment sample collection in salt ponds and flats containing mangroves. Preliminary findings highlight the importance of salt pond sites for natural mangrove regeneration (Grimes, n.d.).
The Virgin Islands Established Program to Stimulate Competitive Research (VI-EPSCoR), funded by the National Science Foundation (NSF) applies advanced tools, such as 3D modeling of mangroves and high-resolution maps of mangrove habitats to monitor ecosystem changes and recovery across the territory. One of VI-EPSCoR's most significant achievements has been the establishment of mangrove nurseries and the outplanting of seedlings at degraded mangrove habitats in St. Thomas.
In the last decade, mangrove restoration efforts have been expanded across the territory by University of the Virgin Islands' Growing Research, Restoration, Outreach, and Education (GRROE) USVI Mangrove Program. Through community workshops, outreach, and engagement activities, the program has increased environmental education in coastal communities most affected by tropical storms and hurricanes (Grace-McCaskey et al., 2026). These Nature-based Solutions (NBS) have also fostered community participation through surveys and questionnaires in understanding local awareness, perceptions, and interests related to mangrove conservation and restoration activities (Bloem, 2025; Grace-McCaskey et al., 2026).
Mangrove mapping and assessments within the Puerto Rican Bank, including the USVI and BVI, have enabled researchers to identify previously unmapped areas for restoration. Kotikot et al. (2024) has recently developed a mangrove monitoring and mapping tool using Sentinel-2 satellite imagery, Google Earth Engine (GEE), and a machine-learning algorithm called Random Forest to assess mangrove distribution and temporal changes between 2020 and 2022. Using imagery with a 10-meter spatial resolution, the researchers achieved classification accuracies greater than 85% for mangrove patches and identified evidence
of mangrove loss, recovery, disturbance, and restoration responses.
Mangrove assessments after the dual Category 5 Hurricanes Irma and Maria (2017) in St. John showed that after 2 years, mangrove forests had little natural recovery, Neither seedlings nor young mangrove trees grew at the rate expected.
Anthropogenic sources of stress to mangroves include siltation, surface runoff, oil pollution, sewage effluent, and cooling water discharge from power plants. The threat of pollution can come in the form of large marine debris, including derelict vessels and fishing gear, but also as soluble pollution such as oil and gas. Movement of abandoned vessels during storms harm prop roots and tree growth and can leak pollutants and trap wildlife (Lord-Boring et al. 2004). Oils and gases negatively impact mangrove health and seedling survival (Kathiresan and Bingham 2001). Increased nutrients from agricultural areas and sewage decreases mangrove root system growth (Lovelock et al. 2009). In the USVI, mangrove wetlands are located on prime coastal real estate (Tobias 1996). As a result, they are often threatened by commercial and residential development.