The economic costs to fisheries from marine sediment disposal: Case study of Providence, RI, USA

Ports worldwide are under pressure to dredge channels and berths to accommodate deep-draft vessels. Marine disposal of the dredged sediments, however, often is a controversial issue due, in part, to potential impacts on commercial and recreational fisheries. We use an integrated framework employing engineering, economic, and biological data and concepts to estimate the economic costs to fisheries from disposal of clean dredged sediments from in and around Providence Harbor, RI, USA. The fishery impacts considered include short-term, direct effects that occur during disposal, long-term effects that arise during the recovery period following disposal, and indirect effects that occur through the food web. Economic damages to commercial and recreational fisheries are assessed for seven potential disposal sites, using conservative assumptions that tend to overstate costs. Damages across sites range from about $256 thousand to $1.9 million. A series of sensitivity analyses is done in recognition of the many uncertainties involved. The sensitivity analyses increase the estimated disposal costs, but do not affect to relative sizes of costs across sites. Considering all sensitivity analyses simultaneously, estimated damages range from about $460 thousand to $3.4 million between the lowest- and highest-cost sites.