Brief about dredging
There is a general prohibition of dumping in the Baltic Sea according to the Helsinki Convention, except for dredged material; however, dumping of dredged material containing harmful substances is only permitted according to HELCOMGuidelines. The Contracting Parties are obliged to regulate and also report about the material that has been deposited in the Baltic Sea Area.
Photo: Michael Layefsky/Flickr
In addition, the countries should inform the Secretariat of their monitoring activities and submit reports when they are available, states the HELCOM Guidelines for management of dredged material at sea. The Guidelines are a part of the HELCOM Recommendation (36/2), newly adopted in March 2015.
The analysed data on dredging activities until the end of 2013, reported by the Baltic coastal countries, has been reviewed by the HELCOM Pressure group meeting held on 7-10 October 2015. The deadline for sending in the most recent data of 2014 was 1 October 2015 and has not yet been duly processed. The meeting document concerning dredging and depositing management can be viewed here.
Dredging and depositing of dredged materials is one of the environmental pressures on the seafloor and its inhabitants, with even a cumulative impact on benthic biotopes. Furthermore, as dredging releases suspended particles from the sediments into the water column, the water transparency is impaired. The sediments may also release nutrients and hazardous substances, such as heavy metals and organic contaminants, to the water column and affect marine life. The dredging activities also usually generate impulsive underwater noise, which is an additional harmful factor for marine organisms. Dredging and depositing of dredged materials is the most severe pressure in most of the northern areas of the Baltic Sea.
On the other hand, dredging is essential to maintain navigation to, in and from ports and harbours; for the development of port facilities as well as for remediation construction of artificial land and flood management.
The HELCOM Guidelines for management of dredged material at sea urges the data on dredging activities to be submitted to HELCOM Secretariat by 1 October of the year following the dredging activity. The recent data were reported by the HELCOM member states in accordance with the requirements of the Guidelines, including data on chemical analysis of reallocated dredged material and spatial data on the activities.
The latest information will be published to the dredging database and made available online via HELCOM website. The compiled data enables long term observations on the scale of the environmental impact of dredging, and also help in the development of a forthcoming pressure indicator, ‘Cumulative impact on benthic biotopes’.
The most recent complete reporting by the coastal states from 2013 can be viewed here.