Ecological Impacts Resulting from Structural Shading/Shadowing on Wetlands and Essential Fish Habitat

Focus Area

Wildlife & Ecosystems


Natural Resources




Under $99k


1-2 years

Research Idea Scope

Objective of research would be to provide verifiable data demonstrating effects of elevated structures in various ecosystems to help accurately identify impacts for permitting and NEPA studies. Impacts to freshwater and tidal systems are of particular interest in relation to secondary versus direct impacts, EFH, marine mammals. Impacts to terrestrial non-aquatic resources may also be covered but require multiple studies to accomplish. Anticipate following tasks to be components of research: –literature review (scientific and grey literature) –survey of current practices of DOTs, MPOs, other industries (such as shipping, oil & gas lines, rail, and other types of river or coastal shoreline development) –field study and analysis of effects in freshwater and tidal systems, and terrestrial non-aquatic areas

Urgency and Payoff

Specifically related to 404, Section 10 and EFH, structural shading effects/impacts can be difficult to quantify and thereby difficult to appropriately mitigate. This is especially relevant to coastal states whose transportation systems are ever increasing capacity and requiring larger, wider structures to accommodate volume increases in these types of ecosystems. New highways, capacity expansions or replacements are pressing projects that can be and are being delayed because of permitting/agency coordination efforts not being able to address adequately these types of impacts. This study could provide solid, verifiable data that state DOTs, in particular, could use in accurately determining impacts that may result from elevated structure construction in these various ecosystems. Non-aquatic feature impacts also play a role as secondary/cumulative impacts in permitting and agency coordination. Being able to provide similar verifiable and documented data can assist in those coordination efforts to keep projects from stalling.

Suggested By

Will McGoldrick South Carolina DOT 803-737-1326

[email protected]