Water Quality at Timucuan Ecological and Historic Prese

Baseline Data and Management Implications

Eva DiDonato1, Guy DiDonato2, Amy Kalmbacher3, and Richard Bryant4

1National Park Service: Southeast Coast Network, 2NOAA: Hollings Marine Laboratory, 3Florida Department of Environmental Protection/Office of Coasta

Areas, 4National Park Service: Timucuan Ecological and Historic Preserve.

Background

Tidal creeks contain critical habitat for a variety of fish, 

and wildlife species. They serve as nursery habitats for fish, crustaceans, and shellfish and foraging habitat for birds and mammals while providing a multitude of recreational opportunities including boating, fishing, and bird watching. 

Timucuan Ecological and Historic Preserve (TIMU), 

contains hundreds of miles of tidal creek habitat and covers approximately 46,000 acres between the St. Johns River and the Nassau River. The entire preserve is located within Duval County and the city limits of Jacksonville, FL. Because of its location, TIMU faces many anthropogenic 

threats to water quality including contaminants from agricultural, industrial, and residential land uses. In 2004, TIMU management teamed with the State of Florida Department of Environmental Protection to begin a longterm water quality monitoring program. In March 2004, a water-quality datalogger was deployed off of the Kingsley Plantation dock (Figure 1). This device recorded water temperature, salinity, pH, dissolved oxygen, depth, and turbidity at half-hour intervals. 

Methods and Results

Data were collected beginning in March 2004, with a 

for instrument calibration followed standard manufa(temperature, salinity, pH, dissolved oxygen, depth, aminutes. Sample collection and data analysis followeEstuarine Research Reserve Program (Arendt et al., n

includes data from March 2004 to March 2005.The water-quality datalogger was deployed on averafield deployment was 2 days (July 2004), while the londeployment times, especially during the warmer seasinstrument probes. In total, the device recorded nearl

results include:• pH: pH ranged from 7.2 to 8.2 with values above 8

• Temperature: Water temperatures ranged from 9.7 

in 40% of the measurements. •Depth: Mean depth at this site was 4.0 m and showminimum recorded depth was 2.6 m (December), and • Turbidity: Minimum and maximum turbidities w

Turbidity was greater than 25 NTU (i.e., the federal st• Salinity: Mean daily salinity was 29.4 ppt with the lowest salinity occurred in September immediately afoccurred in March (35.9 ppt).• Dissolved Oxygen (DO): Minimum percent DO sahighest was 139.3% (January). Over the year, several 

These occurred primarily in Summer/Fall but were rof these events lasted longer than 12 hours). 

2004-03 2004-04 2004-05 2004-06 2004-07 2004-08 2004-09 2004-10 2004-11 2004-12 2005-01 2005-02 hypoxia supersaturation

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hypoxiasupersaturation

7.07.27.47.67.88.08.28.48.6

March 2004April 2004May 2004June 2004July 2004 August 2004 September 2004 October 2004 November 2004 December 2004 January 2005 February 2005

pH

Maximum10th %tile

Mean

90th %tileMinimum

Discussion

These data provide baseline water-quality information for TIMU at the Kingsley Plantation site. As development pressures 

adjacent to and within the preserve increase, baseline water quality data like these will be crucial for making informed management decisions aimed towards protecting this valuable resource.

Water quality data collected in this study suggest that the tidal creeks near the Kingsley Plantation site are not well flushed.

Creek pH (Figure 2) falls within a very narrow range (7.2 – 8.2), suggesting a highly buffered system with limited freshwater input. After Hurricane Francis (September 5-7, 2004) passed through the area, salinity remained extremely variable until December (Figure 3). This indicates that freshwater flushing of this system is slow, in this case, several months. Because of the 

protracted flushing time within TIMU tidal creeks, preventing the inflow of contaminants and excess nutrients will be paramount to the long-term management and protection of Park water resources.

There were several short hypoxic events recorded during this year of sampling (Figure 4). The majority of these incidents 

occurred during the summer period, which is very common for tidal creeks in this region. In fact, short hypoxic periods benefitthese valuable nursery habitats by creating a temporary refuge for small crustaceans and crabs from some predators. On the other hand, severe or long-lasting hypoxic events may indicate nutrient enrichment and eutrophication issues. Continued measurement of dissolved oxygen in TIMU creeks can be a useful indicator of environmental degradation. 

ReferencesArendt, M., Snoots, T., and Chen, Y., n.d. A Manual Demonstrating use o

from the NERR System-Wide Monitoring Program. South Ca

Wenner, E., Sanger, D., Arendt, M., Holland, A.F., and Chen, Y., 2004. 

Variables Within the National Estuarine Research Reserve 

Acknowledgements

We would like to thank Fred Holland and Chris Buzzelli for their a

Morgan, and Pamela Chancey for their field assistance, Rick Gleeson 

and Mike Byrne for their constructive editorial suggestions, and Sara 

Figure 2. Monthly Summary of pH at Kingsley 

Plantation Site.

Figure 4. Hypoxia and Supersaturation events at 

Kingsley Plantation Site.

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Timucuan EHPKingsley Datasonde Area

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Map created by the Old Growth Bottomland Forest Research and Education Center

Timucuan EHP

Atlantic

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Southeast Coast NetworkNational Park ServiceU.S. Department of the Interior

Vicinity Map

Map Extent

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303(d) Waters

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h Kingsley Datasonde

Figure 1. Timucuan Ecological and Historic Preserve, 

Kingsley Plantation Site.

00.005.010.015.020.025.030.035.040.0

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Sal (ppt)

Figure 3. Salinity Data from Kingsley 

Plantation Site.