Start date

24 September 2009

End date

31 December 2010

Seabed restoration: Do the benefits justify the costs?

Reference:
09/P115
Organisation:
Cefas
Amount Funded:
£123,085
Status:
Current

To date, relatively few marine aggregate extraction licences have been relinquished.  As a result, there is currently no clear policy, from the regulatory perspective, on how to deal with these sites post extraction.  For example:

 Is the current requirement for the seabed to be left in a similar physical condition realistic?

  • Are persistent impacts significant in terms of ecosystem health?
  • What action is required by the legislation
  • What is the purpose of the final seabed survey undertaken post extraction?
  • should it be undertaken immediately, or left for a suitable period to allow for natural recovery?
  • should its focus be on assessing the physical or biological status of the site (or both)?
  • is it possible to adequately distinguish between natural and dredging induced changes?
  • what constitutes a suitable survey design?
  • where impacts remain, should further monitoring be required?
  • Where the final survey shows major persistent impacts (i.e. changes beyond the limits of natural variability), what should happen?
  • Is it technically possible to restore the seabed in response to these impacts (see Bellew & Drabble, 2004; Cooper et al., (in prep) and Collins, K and Mallinson, J., 2008)?
  • Can the benefits of restoration justify the costs (financial and environmental)?       

 A likely future increase in the number of licences being given up means there is a clear and urgent need to provide an unbiased assessment of the questions raised above.  The output from this study, in the form of a position paper, will help the regulator, and their advisors to formulate sensible policy on how to deal with extraction sites on cessation of dredging.