A multi agency project funded by US EPA's STAR Program
 

Characterizing the sampled sites

 

As part of the process of analyzing the data collected from sites, we must better characterize the environmental variables influencing these areas. The environmental variables that were used in site selection, and others, need to be investigated in more detail.

A second step is to carefully define the area of surrounding land and water that is contributing to the environmental conditions of each site, in other words a zone of influence for each site.

This characterization of the influences on the site requires that we carefully consider both natural and anthropogenic factors, their distance from our sites, and the linkages between the influences on the landscape that affect habitat which in turn affect the biota.

 

 

 

Distal influences on coastal margins

Here is an example of how human activities within the watersheds of Great Lakes streams and rivers can affect the condition of Great Lakes coastal margins, in this case a river-influenced wetland. Uses of the land distant from the coast may still impact coastal conditions because these influences are carried to the coast by streams and rivers. Move your mouse over the image to view pop-up descriptions of potential impacts; this text is repeated below.

Great Lakes coastal margins, including coastal wetlands, receive runoff from land within the Great Lakes watershed. Water carrying the by-products of various human activities may run directly from the land into the lake, or may run into streams and rivers and be carried to the lake from more distant locations. Agricultural runoff may contain nutrients from manure and fertilizers, hormones from animal wastes, pesticides, and sediments. Nutrients and pesticides from lawn treatments often end up in runoff, as do nutrients from leaking septic systems. Industrial runoff may contain chemicals, metals, oil and grease, nutrients, and other contaminants. Urban runoff may contain industrial effluent and nutrients that remain following wastewater treatment, oil, grease, and other contaminants from vehicles, and salt and other chemicals applied to roads. Areas of natural vegetation that occur between human activities and water resources may filter out some contaminants before they can reach the water.

Proximal influences on coastal margins

Human activities right along the Great Lakes coasts can be local sources of stress for coastal ecosystems. Examples include the dredging of channels for boat activity; building of marinas, docks, and boat launches; and the building of shoreline protection structures such as sea walls, dikes, and riprap.

Great Lakes coastal margins receive runoff from land within the Great Lakes watershed Coastal wetlands receive runoff from the land and from rivers and streams Rivers and streams carry runoff from land activities to the Great Lakes coastal margins Rivers and streams carry runoff from land activities to the Great Lakes coastal margins Rivers and streams carry runoff from land activities to the Great Lakes coastal margins Rivers and streams carry runoff from land activities to the Great Lakes coastal margins Agricultural runoff may contain nutrients from manure and fertilizers, hormones from animal wastes, pesticides, and sediments. Industrial runoff may contain chemicals, metals, oil and grease, nutrients, and other contaminants. Nutrients and pesticides from lawn treatments often end up in rivers, as do nutrients from leaking septic systems. These are carried downstream to the lake Nutrients and pesticides from lawn treatments often end up in rivers, as do nutrients from leaking septic systems. These are carried downstream to the lake Nutrients and pesticides from lawn treatments often end up in rivers, as do nutrients from leaking septic systems. These are carried downstream to the lake Runoff from lawn treatments and leaking septic systems of shoreline property owners may run directly into the lake. Urban runoff may contain industrial effluent and nutrients that remain following wastewater treatment, oil, grease, and other contaminants from vehicles, and salt and other chemicals applied to roads. Natural areas between human activities and water resources may filter out some contaminants before they can reach the water. Natural areas between human activities and water resources may filter out some contaminants before they can reach the water. Natural areas between human activities and water resources may filter out some contaminants before they can reach the water. Natural areas between human activities and water resources may filter out some contaminants before they can reach the water.