Here is some stuff i found in the scientific community about the effects of Cockle dredging in the Dutch Weddell sea.
here is the gist of there conclusions:
Title: Long-term indirect effects of mechanical cockle-dredging on intertidal bivalve stocks in the Wadden Sea
1. There is world-wide concern about the effects of bottom-dredging on benthic communities in soft sediments. In autumn 1988, almost a third of the 50-km intertidal system around the island of Griend in the western Dutch Wadden Sea was suction-dredged for edible cockles and this study assessed subsequent effects. An adjacent area not directly touched by this fishery and an area from which the mussel beds were removed, served as reference areas.
2. Sediment characteristics, together with the total stock size and settlement densities of
Cockles, Baltic telling and soft-shelled clam were documented during 11 successive autumns before (August–September 1988 ) and after (August–September 1989–98 ) the suction-dredging event in fished and unfished areas. Four other areas in the Dutch Wadden Sea, where changes in densities of juvenile bivalves from 1992 to 1998 were measured, served as additional reference locations.
3. Between 1988 and 1994, median sediment grain size increased while silt was lost from sediments near Griend that were dredged for cockles. The initial sediment character -characteristics were re-attained by 1996.
4. After the removal of all mussels and most cockles, the abundance of Baltic telin declined for 8 years. From 1989 to 1998, stocks of cockle, Baltic telin and mussel did not recover to the 1988 levels, with the loss of cockles and Baltic telin being most pronounced in the area dredged for cockles. Declines of bivalve stocks were caused by particularly low rates of settlement in fished areas until 1996, i.e. 8 years after the dredging.
5. A comparison of settlement in the short (1992–94 ) and medium term (1996–98 ) after
cockle-dredging in several fished and unfished areas spread over the entire Dutch Wadden Sea, showed a significant negative effect of dredging on subsequent settlement of cockles and Baltic telin also declined, but not significantly.
6. We conclude that suction-dredging of cockles had long-lasting negative effects on recruitment of bivalves, particularly the target species, in sandy parts of the Wadden Sea basin. Initially, sediment reworking by suction-dredging (especially during autumn storms) probably caused losses of fine silts. Negative feedback processes appeared to follow that prevented the accumulation of fine-grained sediments conducive to bivalve settlement.
Our conclusion, that cockle-dredging leads to a significant long-term reduction in settlement and stocks of the target species
The attached doc. is a government order for the Solent banning this fishing
technique as the solent is a SAC (Special order of conservation). its its considered that destructive.. why is it allowed anywhere else?
for my two sense..
using this technique supply's a large volume of cockles to the market. (possibly harvested in an unsustainable and non-environmentally friendly manner) would it not be better to collect in a more environmentally friendly manner (hand picking, land based mechanical methods), less cockles to the market = better price (supply and demand).
but.... chances of the government taking a proactive step in the fishing industry.. nil. prob ban the technique when there are no cockle beds left and the habitat has been destroyed past self repair.
Sure there free until someone catches them...
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