Artificial Structures

Artificial structures are found throughout the estuary and include a wide variety of human-built objects designed to protect shorelines and shoreline structures, transportation, recreation, and more recently, for restoration (oyster shell and artificial reefs).

Artificial structures were built to protect shorelines and shoreline structures (seawalls, jetties, revetments), for transportation (bridge and pier pilings, wharfs, moorings, wrecks, derelict vessels, the reserve or “mothball” fleet in Suisun Bay) and recreation (fishing piers, boat ramps, marinas, duck blinds), to support industry (shore-side buildings, water intakes or outfalls, transmission towers, pipelines, cables), and more recently for restoration (oyster shell and artificial reef structures). Artificial structures are similar to rocky habitats in that they alter local wave and current patterns and provide physical habitat for a variety of species. However, artificial structures differ from rocky habitats in their spatial distribution in the estuary, and contain structural features that do not occur on rock outcrops. Thus, the fish and invertebrate assemblages on natural rocks may differ from those on artificial substrates.

While artificial structures support some valued ecosystem services, they are not in short supply, and they can have some detrimental effects. The Subtidal Goals Project recommends further study of the advantages and disadvantages of removing abandoned pier pilings, and if removal is decided upon, using an adaptive management approach. It also recommends using a pilot project approach, and if creosote pilings are removed, providing eelgrass as a substitute substrate for attracting spawning herring. Goals for artificial structures focus on protecting the habitat values of existing active structures, removing and preventing structures that harm the subtidal system, and improving understanding of the role of these structures in the subtidal system.

To read more, download the artificial structures section of our report.






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