UK study on seabed smothering from dredging

A paper giving insight into the damage created by dredging, specifically the smothering settlement of suspended ‘wash off’ sediments over the seabed, impacting the animals and plants that live on and within it, can be read here.

It stresses how animals with delicate feeding or breathing apparatus, e.g. bivalve shellfish, can be intolerant to increased siltation, so giving reduced growth or fatality. MaerlMaerl Maerl is a collective term for several species of red seaweed, with hard, chalky skeletons. It is rock hard and, unlike other seaweeds, it grows as unattached rounded nodules or short, branched shapes on the seabed. Like all seaweeds, maerl needs sunlight to grow, and it only occurs to a depth of about 20m. beds (calcified seaweed) are reported to be particularly sensitive to smothering emanating from channel dredging. It describes how important spawning and/or nursery areas are for fish and other marine animals, and how dredging can result in smothering their eggs and larvae. Shellfish are said to be particularly susceptible during spring when spatfall occurs, and when smothering of intertidal areas occurs, there may be subsequent effects on the availability of animals and plants in bird/fish feeding areas.

The treatise further points out how the blanketing or smothering of benthic animals and plants may also cause stress and reduced rates of growth or reproduction, relating to how sediments are distributed more widely within the estuary or coastal area and may settle over adjacent subtidal or intertidal habitats some distance from the dredged area.

More information on the marine and seabed species impacted may be found on UK Marine SACsSAC Special Areas of Conservation Project

Please do share this

  • Facebook
  • Twitter
  • Delicious
  • StumbleUpon
  • Add to favorites
  • Email
  • RSS