Water quality surveys in Culebra: comprehensive assessment of inorganic nutrient and human dietary tracer concentrations 2023-05-03 to 2024-05-21

This record provides dissolved inorganic nutrient and human dietary tracer (caffeine and sucralose) concentration metrics collected monthly between May 2023 to May 2024 to provide reference data of nearshore and watershed water quality on the island of Culebra, Puerto Rico. The water quality monitoring was conducted at 18 fixed stations. Five stations were selected to quantify Land Based Sources of Pollution (LBSP) stressor loads at key point and non-point sources in the Cabra, Coronel, and Aeropuerto watersheds. Levels of LBSP exposure were measured at 13 nearshore stations co-located with long-term seagrass monitoring sites. Nearshore monitoring sites were selected to identify watershed discharge points, coastal hydrodynamics, as well as the existing level of LBSP exposure and anticipated changes to LBSP exposure due to management actions. Nearshore monitoring stations were designated based on their land based sources of pollution management implementation status (LBSP Treatment Group), as follows: 1) LBSP Restoration stations: Located downstream where land-based pollutant management has or is being implemented. 2) LBSP Control stations: Representing a range of land-based pollutant impairments, including sites with no LBSP management and no known direct discharge of LBSP but are representative of the range of external factors that may be encountered at the LBSP Restoration stations. 3) Negative Reference stations of know significant -anecdotal and quantified- LBSP impairment. 4) Positive Reference stations of low LBSP impairment.

Nearshore water quality samples for nutrients were collected at two depths: surface (10-25 cm ) and bottom (2 m deep). Human dietary tracer water samples were collected at surface, only collected at the 13 nearshore monitoring stations. Watershed water quality samples were collected only at surface. Metrics include: Nitrite, nitrate, ammonium, total nitrogen, orthophosphate, total phosphorus, and silicate; caffeine and sucralose. The data presented herein was collected with financial support from NOAA Restoration Center and NOAA Coral Reef Conservation Program, and the National Fish and Wildlife Foundation (NFWF). The research questions, survey design and monitoring localities were specific to this study and the associated water quality data is unsuitable in a regulatory framework.