2015 Annual Report of the Water Quality Monitoring Project for the Water Quality Protection Program of the Florida Keys National Marine Sanctuary

摘要

This report serves as a summary of our efforts to date in the execution of the Water Quality Monitoring Project for the FKNMS as part of the Water Quality Protection Program. The period of record for this report is Apr. 1995 – Dec. 2015 and includes data from 82 quarterly sampling events within the FKNMS (20.5 years). This annual report reflects funding cutbacks in 2012 resulting in reduction of spatial sampling from 155 to 112 sites. Field parameters measured at each station (surface and bottom at most sites) include salinity (practical salinity scale), temperature (ºC), dissolved oxygen (DO, mg l-1), turbidity (NTU), relative fluorescence, and light attenuation (Kd, m-1). Water quality variables include the dissolved nutrients nitrate (NO3-), nitrite (NO2-), ammonium (NH4+), and soluble reactive phosphorus (SRP). Total unfiltered concentrations include those of nitrogen (TN), organic carbon (TOC), phosphorus (TP), silicate (SiO2) and chlorophyll a (CHLA, μg l-1). The EPA developed Strategic Targets for the Water Quality Monitoring Project (SP-47) which state that beginning in 2008 through 2015, they shall annually maintain the overall water quality of the near shore and coastal waters of the FKNMS according to 2005 baseline. For reef sites, chlorophyll a should be less than or equal to 0.35 μg l-1 and the vertical attenuation coefficient for downward irradiance (Kd, i.e., light attenuation) should be less than or equal to 0.20 m-1. For all monitoring sites in FKNMS, dissolved inorganic nitrogen should be less than or equal to 0.75 μM (0.010 ppm) and total phosphorus should be less than or equal to 0.25 μM (0.0077 ppm). Table 1 shows the number of sites and percentage of total sites exceeding these Strategic Targets for 2015. We must recognize that the reduction of sampling sites in western FKNMS (less human-impacted sites) and the increase in inshore sites (heavily human-impacted sites) introduces a bias to the dataset which results in a reporting problem, perhaps requiring a revision of SP-47 to correct this deviation. To avoid such complications, we have not included the recently added locations (#500 to #509) in the calculation of compliances. For reef stations, chlorophyll less than or equal to 0.35 micrograms liter-1 (ug l-1) and vertical attenuation coefficient for downward irradiance (Kd, i.e., light attenuation) less than or equal to 0.20 per meter; for all stations in the FKNMS, dissolved inorganic nitrogen less than or equal to 0.75 micromolar and total phosphorus less than or equal to 0.25 micromolar; water quality within these limits is considered essential to promote coral growth and overall health. The “number of samples” exceeding these targets is tracked and reported annually. Values in green are those years with % compliance greater than 1995-2005 baseline. Values in yellow are those years with % compliance less than 1995-2005 baseline.