Increased sediment loads over coral reefs in Saint Lucia in relation to land use change in contributing watersheds

Watershed- and island wide-scale land cover changes in Puerto Rico (1930s–2004) and their potential effects on coral reef ecosystems

“…Coral reef ecosystems are particularly susceptible to the indirect effects of land cover change (Hunter and Evans, 1995;Wolanski et al, 2004;Bartley et al, 2014) as a result of increased pollutant levels that alter the oligotrophic and low-turbidity conditions in which these systems tend to thrive (Fabricius, 2005;Erftemeijer et al, 2012). Land cover changes have been associated with the deterioration of coral reef ecosystems throughout the world including Australia (Lewis et al, 2007), islands of the Pacific (Hodgson and Dixon, 1988;Prouty et al, 2010Prouty et al, , 2014Stender et al, 2014), Madagascar and Africa (McClanahan and Obura, 1997;Maina et al, 2012), Central, South and North America (Dutra et al, 2006;Jaap et al, 2008;Carilli et al, 2009), and the Insular Caribbean (Oliver et al, 2011;Bégin et al, 2014), among others.…”

Elemental signature of terrigenous sediment runoff as recorded in coastal salt ponds: US Virgin Islands

“…High-relief tropical volcanic islands, such as St. John, U.S. Virgin Islands (USVI), are naturally susceptible to terrigenous (land-derived) sediment weathering, erosion, and rapid down-slope transport to coastal environments during rainfall events. The ultimate fate of these sediments include: 1) deposition within the watershed; 2) coastal buffer zones such as salt ponds, which trap sediments and prevent input into the marine environment; 3) nearshore marine environments (coral reefs, seagrasses, algal flats), many of which are adversely affected by terrigenous sedimentation (Begin et al, 2014;Yates et al, 2014;Brooks et al, 2007;Ralph et al, 2007;Rogers et al, 2007;Thomas and Devine, 2005); and, 4) offshore marine environments. Terrigenous sediment delivery to the coast is magnified in areas where human activities have altered land uses such as removing vegetation, exposing rocks and soils and creating impermeable surfaces (e.g., road and building construction) (Brooks et al, 2007;Ramos-Scharrón and MacDonald 2005;and Brooks et al, 2004).…”

“…Historical rainfall records are generally short (decades), discontinuous, and geographically limited. Archives such as sediment cores can be directly compared to historical records for the past ~50 years to develop proxies for runoff events, which can provide insight into variability beyond the time-frame of historical databases (Begin et al, 2014;Brooks et al, 2004). This is important as runoff likely varies on multiple time-scales.…”

Contributions of human activities to suspended sediment yield during storm events from a small, steep, tropical watershed

“…The steep topography and small floodplains on small volcanic islands limits sediment storage and the buffering capacity of the watershed against increased hillslope sediment supply (Walling, 1999). Such environments characterize many volcanic islands in the South Pacific and elsewhere where many coral reefs are sediment-stressed (Bégin et al, 2014;Fallon et al, 2002;Hettler et al, 1997;Rotmann and Thomas, 2012).…”