Date of this Version

2012

Document Type

Report

Abstract

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 Mar. 1995 – Sep. 2012 and includes data from 69 quarterly sampling at 155 sampling sites events within the FKNMS, including the Dry Tortugas National Park (DRTO). This annual report reflects funding cutbacks resulting in reduction of spatial sampling to 112 sites, none within DRTO. 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 2012, 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 0.2 micrograms/l and the vertical attenuation coefficient for downward irradiance (Kd, i.e., light attenuation) should be less than or equal to 0.13 per meter. For all monitoring sites in FKNMS, dissolved inorganic nitrogen should be less than or equal to 0.75 micromolar and total phosphorus should be less than or equal to 0.2 micromolar. Table 1 shows the number of sites and percentage of total sites exceeding these Strategic Targets for 2012. 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) has introduced a bias to the dataset which results in a reporting problem, perhaps requiring a revision of SP-47 to correct this deviation.

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