Biological Monitoring of Open-Water Dredged Material Disposal Sites

Environmental monitoring of open-water disposal sites is too frequently a process of sampling as many ecosystem components as possible in the hope that project-induced impacts will be detected. This approach has two major shortcomings: (1) there usually has been no attempt to predict impacts or set levels at which impacts are considered adverse; and (2) attempts to study as many ecosystem components as possible usually dilutes available monetary resources resulting in weak and/or inadequate overall study designs. Monitoring programs for open-water dredged material disposal sites should be designed in a tiered approach around predictions of impacts to specifically identified resources of interest, and the thresholds at which impacts will be adverse should be clearly defined prior to monitoring. Resource concerns, adverse impact thresholds, and tiered monitoring plans should be products of a technical committee formed to advise the resource manager.