Removing the sands (sins?) of our past: dredge spoil removal and saltmarsh restoration along the Indian River Lagoon, Florida (USA)

Abstract

Estuarine saltmarshes are widely recognized as highly productive and biologically diverse systems. The Indian River Lagoon (IRL) is a 250 km long “Estuary of National Significance” along Florida’s east coast and is known as one of North America’s most diverse estuaries. Like most North American estuaries, the IRL is facing a number of problems, among them loss of emergent wetlands. Between 75 and 90% of the original mangrove and saltmarsh acreage historically bordering the IRL has been lost or impacted, either through direct filling for development or impoundment for mosquito control. This loss has affected IRL water quality and fisheries, since these habitats are now removed from the estuarine system. Active programs are now underway to restore mosquito impoundments by reconnection with culverts or removal of dikes, but restoration of dredge spoil is more problematic, as many of these sites have been developed. However, where undeveloped spoil is found on public lands, restoration is a possibility. One such site, Pine Island Conservation Area (PICA), jointly owned by the Brevard County Environmentally Endangered Lands Program and the St. Johns River Water Management District, contained 25.4 ha of dredge spoil, originating from 1969, when the property was owned by a development company. Following public acquisition in 1996, plans were developed to remove the spoil and restore the site to historic saltmarsh elevation. Between 2003 and 2006 all of the material was removed and the restoration of normal hydrology has resulted in ‘volunteer’ recruitment by appropriate marsh vegetation, without a need for any plantings.