Skip common site navigation and headers
United States Environmental Protection Agency
Great Lakes Ecosystem
Begin Hierarchical Links EPA Home > Great Lakes EcosystemsWetlands > Abiotic & Floristic Characterization: Plate 2 End Hierarchical Links
Introduction
Methods
Major Findings: Abiotic Factors
Major Findings: Vegetation Analysis
References
List of Tables
List of Figures
List of Plates

 

Great Lakes Coastal Wetlands: Abiotic and Floristic Characterization

Plate 2.  Wetland Site Types of the Great Lakes Shoreline

Barrier-beach lagoons are formed when nearshore currents deposit a sand or gravel barrier bar across the mouth of an embayment. The resulting shallow pond or lagoon is sheltered from the lake's wave energy; sediments accumulate in the lagoon basin and vegetation can become rooted. Although water levels in the lagoon may be augmented by tributary streams and groundwater seepage, coastal lagoon wetlands are also partially controlled by the Great Lakes, through permanent or intermittent connecting channels, wave overwash, or cross-bar seepage.

Barrier-Beach Lagoon at Big Bay, Madeline Island, Apostle Islands, WisconsinPlate 2a. Barrier-Beach Lagoon at Big Bay, Madeline Island, Apostle Islands, WI. Barrier beach lagoons are frequently bounded by steep, irregular topography in areas down-current from major sand-producing features where deep embayments trap sands moved by longshore currents. The irregular coastline along the till bluffs of the Bayfield Peninsula and Apostle Islands features numerous well-developed lagoons. Here, the two beaches reflect different lake levels and periods of barrier formation. (Photo by Eric Epstein, 1996).

Barrier-Beach Lagoon at Rainbow Shores/Sandy Pond, New YorkPlate 2b. Barrier-Beach Lagoon at Rainbow Shores/Sandy Pond, NY. Along the eastern end of Lake Ontario, predominant wind and water currents have accumulated sands eroded from glacial moraines to the west, creating a nearly continuous stretch of lagoons and wetlands between the barrier and the irregular moraine upland to the east. (Photo by John Griebsch 1990).


Barrier-Beach Lagoon at Lakeview Pond Wildlife Management Area, Jefferson County, New YorkPlate 2c. Barrier-Beach Lagoon at Lakeview Pond Wildlife Management Area, Jefferson Co., NY. The barrier beach reduces wind and wave energies, allowing for the accumulation of fine sediments and the development of submergent and emergent vegetation communities behind the protective barrier. (Photo by D. Klein 1994).

 
Begin Site Footer

EPA Home | Privacy and Security Notice | Contact Us