Controls on sediment transport over coral reefs off southwest Puerto Rico: Seasonal patterns and Hurricane Maria

Guánica Bay in southwest Puerto Rico is highly turbid and has some of the highest PCB concentrations in the USA. To investigate how and to what extent the bay waters influence coral reef ecosystem health along the coastline, 6 months of hydrodynamic data were collected at 8 sites on the insular shelf. Bed shear stresses were primarily driven by waves and were weakest at the site closest to La Parguera, located downcoast to the west. Due to the prevailing westward shelf currents, suspended particulate material (SPM) exiting the bay likely settles out at these lower energy sites. We postulate the ecosystem in this area was adversely affected immediately after the hurricane because (1) the source concentration of SPM and PCBs in the bay was greatly increased, and (2) regional waves in the months after the hurricane season were less energetic and, thus, less frequently mobilized and flushed the material.