Like many other activities, dredging produces underwater sound. Recently, the issue of effects of underwater sound on aquatic life has received broader attention within the scientific community, with stakeholders and the general public.
This position paper, produced by a CEDA Working Group on Underwater Sound:
– Summarises the effects of sound on aquatic life to set the scene,
– Describes in detail the underwater sounds generated by various components of the dredging process,
– Summarises what is known about potential effects of dredging sounds,
– Identifies options for managing dredging-related sound, and
– Provides conclusions and an outline of future areas of research.
The position paper includes excellent illustrations of sources of dredging induced underwater sound for different types of equipment: cutter suction dredger, trailing suction hopper dredger, grab dredger and backhoe dredger.
The Position paper has been prepared by the CEDA Working Group on Underwater Sound (WG UWS) under the remit of the CEDA Environment Commission, and reviewed by experts on dredging from various professional groups.
CEDA will continue its work on this subject. By providing independent expert advice, Dr. Frank Thomsen (DHI, Denmark), the chairman of the WG UWS will continue to represent CEDA in the Technical Subgroup Underwater Noise, that has been set up by the European Commission as part of the Common Implementation Strategy of the Marine Strategy Framework Directive, MSFD (2008/56/EC). This ambitious Directive (adopted in June 2008) aims to protect the marine environment across Europe. One of the 11 descriptors in MSFD that define “Good Environmental Status” to be achieved by 2020 is “underwater noise”.
CEDA will set up an Underwater Sound Expert Group with participation of experts also from CEDA’s sister association, WEDA, Western Dredging Association and EADA, the Eastern Dredging Association to:
– Produce further state-of-the-art review of ambient sound, dredging induced underwater sound and impact of this on aquatic biota,
– Develop an underwater sound monitoring protocol/procedure in conjunction with initiatives (D-UK-NL cooperation on setting standards/ANSI) and
– Provide guidance on how to assess underwater sound by dredging.
About CEDA
The Central Dredging Association (CEDA) is an international professional membership organisation for all those involved in dredging related activities and who live or work in Europe, Africa, or the Middle East. CEDA provides an independent forum for the exchange of knowledge in fields related to dredging, maritime construction and dredged material management. Members are drawn from many fields and include consultants, research and educational institutes, port authorities, government agencies, dredging contractors, builders of dredging vessels, and suppliers of ancillary equipment. CEDA encompasses a wide range of disciplines and activities and does not represent the interests of any particular industry sector
More info: Underwater sound and Presentation
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Dredging Today Staff, November 17, 2011; Image: dredging