Letter from America — Dredging and Erosion — Comparisons of Mis-management
Jerry Berne of Sustainable Coastlines wrote this philosophical treatise comparing the dredging and erosion situation (mal)practised in the USA and in the UK.
Coastal Mis-management
Dr. Barry Drucker, the US Minerals Management Service scientist responsible for studying the offshore sand mining process recently wrote to me stating that, as dredging operations become more efficient, offshore sand mining was moving towards deep waters (which, in many areas of the US, means many miles offshore). More importantly, he continues, “Some of this shift is definitely due to the realization that exploiting too much of deposit in close proximity to the beach can actually have a devastating effect on the shoreline and subsequent increases in erosion.”
This means the erosion caused by this is ongoing as once protective shoalsshoal A sandbank or sandbar that makes the water shallow are obliterated by earlier mining or the resulting huge cavities become offshore sand traps from gravitational forces literally pulling sand offshore. What he does not say, and what is becoming painfully evident in areas such as Florida and the US Gulf coast, is that much of our easily exploitable nearshore shoals have already been mined so that the move to mine deep water deposits are now required. This means more expense, a spreading destruction of the seabed habitat and further harm to onshore and nearshore ecosystems.
Unfortunately for the UK as well as the US, many officials continue to depend on “independent” reports to say that this dredging does no harm as did Carwyn Jones recently in the efforts of the Llanelli mining company to dredge the nearshore in Helwick Bay. Most of these reports, however, are sponsored by the companies or the agencies benefiting in profit or power from finding no link between dredging and erosion/environmental harm. As a just released US report in BioScience (October, 2005) on studies of offshore sand mining for beach nourishment states, its authors’ survey, “…discovered that monitoring is typically conducted by project promoters with no independent peer review.” This results in “…expensive, multi-decadal monitoring, the majority of studies of the ecological impacts of beach nourishment are scientifically inadequate and suffer from critical flaws, improper analyses, and unjustified interpretations.”
Offshore mining must be carefully monitored for the harm it does and the often un-calculated expense of damaged ecosystems, infrastructure, private/public property and the loss of historic and cultural treasures both in the immediate and distant future. In the meanwhile, there are methods of coastal protection with long term evidence of success, environmental soundness and sustainability as Holmberg Technologies (www.erosion.com). There are also new methods under going study, even a biochemical method to mitigate a certain class of pollutant which seems to make beach sand particles less adherent and more easily moved. Given the known hazards and escalating environmental costs of dredging projects (including the heavily promoted beach nourishment programs), it would seem such supposed environmental organizations as English Nature (incredibly, an advocate of retreat and its loss of coastal habitat) and local governmental agencies impacted by such counter-productive projects would oppose these. More importantly, advocacy in desperately needed for more fiscally and physically sustainable alternatives to mitigate the damage such project have already done.
