Wildlife of
American Samoa

Primary Threats

• Rising sea surface temperatures drive coral bleaching and reduced reef resilience; ocean acidification impairs coral growth; sea-level rise and stronger storms/cyclones increase coastal erosion and damage reefs and turtle nesting areas, while heavier rainfall events increase landslide risk and sediment runoff into lagoons.
• Land-based runoff (sediment and nutrients) from steep watersheds, unpaved/eroding roads, construction, and some agriculture degrades nearshore reefs by smothering corals and fueling algal growth. Solid waste and marine debris (including plastics and lost fishing gear) accumulate on beaches and reef flats, affecting turtles and seabirds. Wastewater infrastructure limitations can contribute to localized water-quality problems in embayments.
• Nearshore reef fisheries that communities rely on can experience localized depletion, particularly for vulnerable or slow-growing species and invertebrates. Fishing pressure can increase around accessible reefs and during periods when offshore fishing is constrained by weather or costs, reducing reef fish biomass and ecosystem function.
• Introduced predators (e.g., rats and feral cats) and invasive ants can impact native forest birds and other wildlife, while invasive plants alter rainforest structure and regeneration. Invasive marine organisms and coral predators/disease interactions (including outbreaks that can follow warming events) can further stress already heat-impacted reefs.
• Limited flat land concentrates housing and services along the coast; clearing for homes, roads, and small agriculture can fragment lowland forests and riparian buffers. Coastal modification and encroachment reduce natural shoreline vegetation that stabilizes sediment and provides habitat.
• Road building and upgrades on steep terrain can trigger erosion and chronic sediment delivery to reefs if drainage and slope stabilization are inadequate. Coastal facilities (harbors, seawalls, shoreline hardening) can alter currents and sediment movement, degrading adjacent reef and beach habitats.
• Shoreline armoring, stream channel alterations, and land grading can change hydrology and increase peak flows that transport sediment to lagoons. Changes in coastal vegetation (clearing mangrove-like wet areas where present, removing native strand plants) reduce natural protection and habitat complexity.
• Boating, anchoring, trampling on reef flats, and concentrated recreation in accessible bays can physically damage corals and seagrass/algal beds. Disturbance at beaches can affect turtle nesting success, especially where lighting or frequent human presence occurs.
• Coral disease risks rise when reefs are stressed by heat and poor water quality; outbreaks can reduce coral cover and diversity. Wildlife health can also be affected by pollutants and debris ingestion/entanglement, particularly for sea turtles.
• Historically and occasionally, take of certain wildlife (e.g., fruit bats or sea turtles) can pressure populations if not controlled; even low levels can be significant for slow-reproducing species and small local populations, especially when combined with habitat stressors.
• Direct wildlife trade is not a dominant driver, but illegal retention or movement of protected species/parts (e.g., turtle products) can occur and requires enforcement and public outreach to prevent impacts and deter trafficking pathways through U.S.-linked transport.