Impact/Purpose:

Coastal dune lakes are fresh water basins that are delicately perched above the coastal salt water fringe, making them wonderfully unique locations all over the world. Over the past decade, a series of such lakes in the Choctawhatchee basin of Florida’s panhandle has attracted vast urban development. With changing land-use practices, these lakes are under a constant threat of deteriorating water quality and loss of a diverse ecosystem. As a result, these lakes have been identified as globally rare and imperiled (S1/G2) by the Florida Natural Areas Inventory. Only a few hundred such lakes are in existence world wide, and similar ecosystems can only be found in the Florida Panhandle, Madagascar, Australia, New Zealand and the Northwest Pacific Coast of the United States. The U.S. lakes are almost exclusively found along the Gulf Coast.

Description:

Scattered along a 30 mile coastline just east of Destin, Florida, lies a series of 18 named coastal dune lakes distributed between Walton and Bay County. The lakes are irregularly shaped, typically shallow (2-6 m deep), located within a mile inland from the coast. The water is composed of a mix of fresh and salt water, accumulated from runoff, groundwater seepage, direct precipitation, and storm surges. The lake water is generally colored (tea or black colored) due to watershed contributions of dissolved organic matter. While these lakes are typically exposed to sub-tropical weather conditions they are also impacted by hurricane activity.

The lakes are unique in their intermittent connection (outfalls) to the Gulf. This periodic connection serves as control for flood-level waters when the dunes are breached, and lake water flows via a conduit to the Gulf. Depending on tides and weather conditions, salt water and biota from the Gulf fills the void left behind by the lowered water level of the lake until equilibrium is reached. This exchange forms a brackish water-body, creating a temporary estuarine ecosystem. Each of the coastal dune lakes is individually characteristic, with outfall openings varying in length, frequency and duration. As a result, some of the lakes can be completely freshwater (salinity < 0.2 ppt), some brackish and/or salty, with varying degrees between stages (0.5-12.1 ppt). This changing condition of water makes these lakes biologically diverse systems with a dynamic nature. The nutrient concentration (primarily TP and TN) fluctuates seasonally and spatially from one lake to another, possibly related to the density of urban development surrounding the lakes, and the runoff associated with it.

With the ever rising demand in lake front properties, Walton and Bay counties has seen an increase in population growth over the last decade. Using GIS applications we were able to gauge this increase in urban development surrounding the lakes. If this trend continues, concerns over issues such as, water quality, outfall management, land-use practices, and greater public awareness, need to be addressed.

URLs/Downloads:

Final Progress Report

Record Details:

Record Type:PROJECT( ABSTRACT )

Start Date:09/30/2007

Completion Date:03/31/2008

Record ID: 200805

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Related Organizations:

Role :OWNER

Organization Name :UNIVERSITY OF FLORIDA

Citation :Gainesville

State :FL

Zip Code :32611

Project Information:

Approach :

In an attempt to preserve these lakes from degradation, we pose (a) to survey these lakes so as to produce a baseline against which any future anthropogenic impacts may be compared; (b) based on the survey, suggest alternative management/land-use practice strategies that strikes a balance between the natural ecosystem and the communities that live around it. Surveying will include tasks such as identify and map the lakes; locate sources of potential water pollutants, and collect data, including hydrology, water quality, soil/sediment, vegetation, animal habitation, and land-use practices.

Cost :$9,941.42

Research Component :Nanotechnology

Approach :

In an attempt to preserve these lakes from degradation, we pose (a) to survey these lakes so as to produce a baseline against which any future anthropogenic impacts may be compared; (b) based on the survey, suggest alternative management/land-use practice strategies that strikes a balance between the natural ecosystem and the communities that live around it. Surveying will include tasks such as identify and map the lakes; locate sources of potential water pollutants, and collect data, including hydrology, water quality, soil/sediment, vegetation, animal habitation, and land-use practices.

Cost :$9,941.42

Research Component :P3 Challenge Area - Water

Approach :

In an attempt to preserve these lakes from degradation, we pose (a) to survey these lakes so as to produce a baseline against which any future anthropogenic impacts may be compared; (b) based on the survey, suggest alternative management/land-use practice strategies that strikes a balance between the natural ecosystem and the communities that live around it. Surveying will include tasks such as identify and map the lakes; locate sources of potential water pollutants, and collect data, including hydrology, water quality, soil/sediment, vegetation, animal habitation, and land-use practices.

Cost :$9,941.42

Research Component :Pollution Prevention/Sustainable Development

Project IDs:

ID Code :SU833550

Project type :EPA Grant