Study of Post-extraction ecological effects in the Kwintebank sand dredging area

SPEEK

Completed: December 2003 - April 2006

<ul><li>Context

SPEEK is a cooperation between three Belgian laboratories (Ghent University/Marine Biology Section; Ghent University/ Renard Centre for Marine Geology; Agricultural Research Centre/ Sea Fisheries Department) and a Spanish Institute (AZTI Foundation). This cooperation aims at joining the expertise present in these groups to gain insight in the possible restoration of the benthic life in the central area of the Kwintebank. This area is closed for sand extraction activities for a period of three years. This ecological information will provide management information necessary for a sustainable management of the sand extraction area on the Belgian Continental Shelf.

<li>Project description

<ul><li>Objectives

The main aims of SPEEK are (1) to describe the long term effects of sand extraction on the benthic life on the Kwintebank; (2) to investigate the possible recovery of the benthic life after cessation of extraction activities in the central part of the Kwintebank; (3) to discriminate appropriate disturbance indicators for the impact assessment of sand extraction and (4) to provide management information with respect to extraction intensity and rotation of possible concession areas at sea.

<li>Methodology

SPEEK is investigating different benthic groups. Within the meiobenthos (all metazoans between 38┬Ám and 1mm), focus is on the dominant taxa. The Marine Biology Section investigates the nematodes, while harpacticoid copepods are studied by AZTI. The Sea Fisheries Department explores the macrobenthos. These biological data will be backed up by geological data collected by RCMG.

In the initial phase of the project, long term effects of sand extraction on the benthic life will be investigated by compiling all available historical data. If possible, more recently collected data, originating from the sand extraction period will be added to the historical data. Analysis of these databases will allow for assessing long term changes in the benthos. This will provide us with the basic information needed to evaluate the possible recovery of the benthic communities.

Further research will evaluate the possible recovery of the different benthic groups in the central area of the Kwintebank, which is closed for sand extraction for a period of three years. The biological data will be combined with geo-acoustic measurements made in the framework of the projects Marebasse and Eumarsand. By combining traditional ecological research (analyzing diversity and community composition) with newly developed techniques at the Marine Biology Section (Nematode Biomass Spectra, MDA-modeling of nematode communities and ecotype approach for harpacticoid copepods), it will be possible to accurately describe the recovery and rate of recovery of the benthos.

By comparing (1) the response time and sensitivity of the different benthic groups to sand extraction/cessation of sand extraction and (2) the accurateness of the different methods of analyzing the data, we will be able to suggest appropriate methods for monitoring the effects of sand extraction on the benthos. The final integration of all tasks will result in the formulation of management options concerning extraction intensity and rotation of extraction areas.