Publication Abstract

Monitoring Of Dredged Material Disposal Sites At Sea And How It Links To Licensing Decisions

A.C.Birchenough*, S.G.Bolam*, G.M. Bowles, B. Hawkins, P. Whomersley, L. Weiss*

There are over 150 sites at sea designated for the disposal of dredged material located in estuaries and up to several miles offshore around England and Wales. On average, 25-40 million wet tonnes of dredged material are disposed at these sites annually. Monitoring of disposal sites is an integral part of managing the disposal of dredged material in the marine environment; the information gleaned feeding back into future national and international policy.

Structured monitoring programmes provide regulatory authorities with data required to make licensing decisions and to re-evaluate assessments made during the licensing process and, if necessary, amend licences to protect the marine environment and human health.

The Centre for the Environment, Fisheries and Aquaculture Science (Cefas) conducts an annual programme of sea disposal site monitoring on behalf of the Marine & Fisheries Agency (MFA), the licensing authority. Due to the number and distribution of disposal sites and the amount disposed to those sites year-on-year, it is unrealistic to undertake regular monitoring of all sites. Therefore, ‘representative’ sites are targeted, along with others where there may be local concern over the potential adverse effects or where disposal activities might have implications for conservation interests.

To assist the selection of disposal sites for monitoring in any one year, Cefas uses a tier-based approach that classifies a number of possible issues or environmental concerns which may be associated with dredged material disposal into a risk-based framework. This paper, firstly, describes this tier-based approach and how this facilitates the prioritisation of dredge material disposal sites for monitoring. Secondly, this paper demonstrates, using case studies, how such monitoring provides information to inform dredged material disposal licensing decisions.