Dredging

About: Dredging is a research topic. Over the lifetime, 3300 publications have been published within this topic receiving 28325 citations.

Evaluating effects of dredging-induced underwater sound on aquatic species : a literature review

Abstract: At any given moment, there may be multiple underwater sounds emanating from both natural and anthropogenic sources. Dredging activities such as the excavation, transit, and placement of material generate underwater sound. This report documents research into the biological effects of underwater sound from dredging and other anthropogenic sources to help evaluate the potential ecological risks of dredging activities. Effects data generated from exposures to anthropogenic sound sources indicate that dredging-induced sounds do not pose a significant risk of direct injury or mortality to aquatic biota. A notable exception, and much less common, is blasting activities used to remove rock and other hard substrata in navigation channels. In terms of potential non-lethal responses, low-frequency sounds produced by dredging overlap with the hearing frequency ranges of select fish and mammal species, which may pose risks for auditory temporary threshold shifts, auditory masking, and behavioral responses. To better understand the ecological risk associated with dredging sounds, a risk-based approach is needed that utilizes the available data and other site-specific information appropriate for evaluating underwater sound. The information reported herein can be used in an exposure assessment as part of a broader framework for evaluating and managing underwater sound effects on aquatic life. DISCLAIMER: The contents of this report are not to be used for advertising, publication, or promotional purposes. Citation of trade names does not constitute an official endorsement or approval of the use of such commercial products. All product names and trademarks cited are the property of their respective owners. The findings of this report are not to be construed as an official Department of the Army position unless so designated by other authorized documents. DESTROY THIS REPORT WHEN NO LONGER NEEDED. DO NOT RETURN IT TO THE ORIGINATOR. ERDC/EL TR-19-18 iii

Economic Burden of Sand Dredging on Artisanal Fishing in Lagos State, Nigeria

Abstract: Increasing demand for sand for construction purposes has made river/sea sand dredging a major threat to aquatic habitat and fishing. The study compared the cost and returns of artisanal fishermen in river sand dredging and non-dredging in selected fishing communities in Lagos state. The study showed that there were no significant differences in the average ages and experience in fishing of fishermen in sand dredging and non-dredging areas. However, there were significant differences in the average turbidity of river water and quantity of fish caught per labour hour by fishermen in dredging and non-dredging areas. The low productivity in sand dredging area is attributed to the negative effect sand dredging. Fishermen in non-sand dredging areas earned higher gross profit per day. The need for government to control the activities of the sand dredgers in fishing communities is recommended for the sustainability of the environment and fishing in the study area.

Investigations on the dynamics of particle clouds in stagnant water using response surface methodology

Abstract: Disposal of sediments during land reclamation and dredging is an important component in many environmental engineering projects. Dredged material can be discharged into the ambient water either ins...

Dredging in sediments containing munitions and explosives of concern (MEC)

Abstract: : This document provides guidance to personnel (e.g., planners, cost estimators, specification writers, engineers, managers, and dredging contractors) involved in dredging projects with sediment containing Munitions and Explosives of Concern (MEC). The guidance is primarily in the form of compiled information gained from experiences on past dredging projects involving MEC and was compiled from a variety of sources. This report describes the different types of dredges and dredging projects that can encounter MEC, describes how these dredges' operational methodologies can be impacted by MEC, and summarizes past project methodology modifications that have been used to deal with MEC. Technical aspects of past MEC/dredging projects are presented with regard to engineering controls to mitigate detonation hazards, underwater MEC detection and discrimination technologies, contracting, public awareness, safety requirements, and MEC separation techniques and (where available) subsequent impacts on production rates and costs.

New Bedford Harbor Superfund Project, Acushnet River Estuary Engineering Feasibility Study of Dredging and Dredged Material Disposal Alternatives. Report 12. Executive Summary

Abstract: : Sediments in New Bedford Harbor, Massachusetts, have been contaminated with polychlorinated biphenyl compounds and heavy metals. The high levels of contamination have resulted in the New Bedford site being placed on the National Priorities List of the Nation's worst hazardous waste sites. The US Army Corps of Engineers has been working since 1986 in efforts to evaluate remedial action alternatives for this site. The purpose of the EFS was to evaluate the engineering feasibility of dredging and selected disposal alternatives for removal and disposal of contaminated sediment from the New Bedford Superfund Site. Results of the EFS are presented in a series fo 12 reports. Reports 1-11 present detailed results of field investigations, laboratory studies, and engineering analyses. This executive summary highlights information from the first 11 reports and presents results of the EFS. Keywords: Confined disposal facility; Contained aquatic disposal; Contaminant migration; Sediment transport.