September 2005 Update - A.R.M. Loxahatchee NWR - Enhanced Water Quality Monitoring and Modeling Program

Prepared by: Matt Harwell, A.R.M. Loxahatchee National Wildlife Refuge
With contributions from Laura Brandt, Leslie MacGregor (NPS), Donatto Surratt, and Mike Waldon

Overview

This update is a summary of activities since the previous status report of April 2005 (Harwell et al. 2005) on the implementation of the Refuge's Enhanced Water Quality Monitoring and Modeling Program. A project overview can be found at: http://sofia.usgs.gov/lox_monitor_model/. The primary objective of this overall program focuses on providing information for use in ecological management of the Refuge (Brandt et al. 2004; Harwell et al. 2005).

The Refuge's monitoring component of this program addresses one of the Consent Decree Principals recommendations (17 December 2003):
B. Enhancing Monitoring of the Refuge
Design and implement an enhanced monitoring program to improve spatial and temporal understanding of factors related to phosphorus dynamics.

The Refuge’s modeling component of this program addresses several of the Consent Decree Principals recommendations (17 December 2003):
C. Modeling of the Refuge

Develop a water quality/hydraulic model for the Refuge with a phosphorus cycling component.
Evaluate issues associated with phosphorus loads and transports within the L-40 and L-7 canals.
Develop and track a simple phosphorus mass-balance model for the Refuge.

Additionally, data from the enhanced water quality monitoring network have been used by FDEP in developing their draft Marsh Monitoring Network (Strawman Everglades P-criterion monitoring networks; 17 August 2005 workshop). It is anticipated that as the FDEP network is refined, data from the Refuge’s enhanced monitoring program will continue to be of value.

Monitoring Update

Sampling of the enhanced water quality monitoring network (shown in Figure 1) occurred at 7 stations in March 2005, 17 stations in April 2005, 22 stations in May 2005, 38 stations in June 2005, and 24 stations in July 2005 (Table 1; Figures 2-6). Final data for monthly samples continue to be publicly posted on DBHYDRO by the SFWMD (http://www.sfwmd.gov/org/ema/dbhydro/index.html).

Total phosphorus data are presented in Table 1.

Conductivity sonde deployment information for 2005 is presented in Table 2.

Modeling Update

Model development (contract with University of Louisiana – Lafayette) continues. A draft model selection report and a draft model data report are currently being finalized. Concurrent with the completion of the model selection report will be the finalization of the first report from the modeling external technical review panel (contract with Tennessee Technological University).

Results from the first canal sediment survey effort (contract with University of Florida-IFAS) have been reviewed. The first canal water quality survey component is anticipated in the next quarter.

Other Updates

Through collaboration with USGS, information from the Refuge’s Enhanced Water Quality Monitoring and Modeling Program is now available on the USGS’ SOFIA website at: http://sofia.usgs.gov/lox_monitor_model/.

Differentially-corrected GPS coordinates of this enhanced network is presently underway, with a complete set of updated coordinates to be available by October 2005.

Data analysis continues as an ongoing process. The Work Plan (Brandt et al. 2004) identifies several potential approaches for refining the network if there are appropriate technical underpinnings for doing so. We are presently examining the potential to eliminate unnecessary or redundant parameters from the monthly monitoring. A draft report for examining parameter elimination has been completed, and a draft report examining potential station reduction is in development. Ultimately, any refinement of the enhanced monitoring network needs to have a sound technical basis before proceeding.

The next steps for this program continue to focus on data collection and analysis and continuing forward with model development.

References
Brandt, L.A., Harwell, M., Waldon, M. (2004) Work Plan: Water Quality Monitoring and Modeling for the A.R.M. Loxahatchee National Wildlife Refuge: 2004-2006.
Prepared for the A.R.M. Loxahatchee National Wildlife Refuge. April, 2004. 33 pp.

Harwell, M. Surratt, D., Waldon, M., Walker, B., Brandt, L. (2005) A.R.M. Loxahatchee National Wildlife Refuge Enhanced Water Quality Monitoring and Modeling Interim Report. April, 2005. 106 pp.

Table 1. Total phosphorus data (ppb) from the Enhanced Water Quality Monitoring Program for (a) marsh, and (b) canal stations for the A.R.M. Loxahatchee National Wildlife Refuge. Graphical representation of station locations are shown in Figure 1.

screen capture image of top portion of Table 1

click here to view Table 1

Enhanced Water Quality Monitoring and Modeling Program for the A.R.M. Loxahatchee National Wildlife Refuge

Quarterly Update Report – September 2005


Figure 1. Location of Enhanced Water Quality Monitoring network stations (LOXA###), in relation to Consent Decree compliance stations (LOX##), for the A.R.M. Loxahatchee National Wildlife Refuge. [larger image]		Figure 2. March 2005 map of the Enhanced Water Quality Monitoring network stations sampled (water drop symbol) in the A.R.M. Loxahatchee National Wildlife Refuge. A primary reason that a station is not sampled is that it has less than 10 cm of clear water column representative of that area. [larger image]


Figure 3. April 2005 map of the Enhanced Water Quality Monitoring network stations sampled (water drop symbol) in the A.R.M. Loxahatchee National Wildlife Refuge. A primary reason that a station is not sampled is that it has less than 10 cm of clear water column representative of that area. [larger image]		Figure 4. May 2005 map of the Enhanced Water Quality Monitoring network stations sampled (water drop symbol) in the A.R.M. Loxahatchee National Wildlife Refuge. A primary reason that a station is not sampled is that it has less than 10 cm of clear water column representative of that area. [larger image]


Figure 5. June 2005 map of the Enhanced Water Quality Monitoring network stations sampled (water drop symbol) in the A.R.M. Loxahatchee National Wildlife Refuge. A primary reason that a station is not sampled is that it has less than 10 cm of clear water column representative of that area. [larger image]		Figure 6. July 2005 map of the Enhanced Water Quality Monitoring network stations sampled (water drop symbol) in the A.R.M. Loxahatchee National Wildlife Refuge. A primary reason that a station is not sampled is that it has less than 10 cm of clear water column representative of that area. [larger image]