Case Studies

Habitat Connections

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Wetlands serve to connect the terrestrial environment with coastal waters and the Gulf through the flows of water, essential materials, and organisms. Any activity that alters one hydrologic facet of a bay and its watersheds will have corresponding effects on the hydrology of other components.

Collectively, impacts from suburban and agricultural landscape alteration have significantly altered surface water quality, quantity and timing in Sarasota Bay and her watersheds. Agricultural activities have ditched, connected, and drained isolated wetlands; deepened, straightened and channelized streams; and redirected historic sheet-flows from the area’s flat upland habitats into manmade ditches. Suburban subdivisions, commercial centers and industrial parks created vast expanses of impervious surfaces which prevent natural filtration and silt control; and add excess nutrients and pollutants to surface water bodies. As a result of these alterations, there is reduced base flow from surficial aquifer to creeks, loss of water storage capacity, increased flashiness (more water faster), significant increases to surface water in some areas, reduced quality of water, fragmented habitats, reduced ecological function and ecosystem services, and loss of resiliency.

Seagrasses are at the downstream end of our altered watersheds. As they respond to changes in water quality, they serve to integrate the effects of changes in the watershed and terrestrial wetlands. Increased nutrients supplied to an estuary generally result in increased drift macroalgae, increased epiphytic organisms growing on seagrass blades, and increased phytoplankton in the water column, all of which reduce the amount of sunlight available at depth, and result in the loss of the deepest grasses. Increased freshwater flow and the associated brown color of the water also reduces light at depth during high rainfall periods, making grasses sensitive to El Niño and La Niña cycles as well.

The overwhelming majority of economically important fishes in the Gulf of Mexico are estuarine-dependent during one or more stages in their life history. Different estuarine-dependent species have different reproductive strategies, occupy the estuary during different life history stages, and have varying lengths of stay, timing of recruitment, and essential habitats. Recruitment to, and movement between estuarine habitats, can be restricted by barriers including structural (e.g., dams, weirs, causeways) and non-structural (e.g., freshwater inflow, dissolved oxygen) barriers. Many opportunities exist for improving the bay and watershed including increasing habitat connectivity, improving filtration and storage capacity of wetlands and other natural habitats in the watershed, improving shorelines with increased buffers and reduced hardening, improving design criteria for development, roads, and existing infrastructure, and creating solutions that will slow water and recreate natural filters.

Roundtable Panel Discussion



An edition of WaterAtlas.org
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An Edition of wateratlas.org