Exe Shell Fishing Impact Survey
Work will commence during the autumn of 2008 to study the impacts of commercial harvesting of cockles from the eastern side of the Exe Estuary. The study will be jointly undertaken between Devon Sea Fisheries Committee, Natural England, Plymouth University and Exmouth Mussels.
The study will undertake a base line survey of sediment and benthic(the animal and plane life found on the sea floor) communities within a trial area north of the Cockle Sands. Following on from this initial work a limited commercial fishery will be allowed under strict monitoring for 12 months.
During this time sampling will continue of the sediment and benthic communities as well as the size and age of the cockles and damage to juvenile cockles that are returned following grading of the catch.
Monitoring of damage and catch rates of other species taken during the fishing process will also be carried out.
The area will be mapped and any eel grass beds (which are a protected habitat under European law) will be marked so as to avoid damage during the fishing operation. The area around the fishing tracks will also be checked for damaged or dead cockles afther the fishing operation on the low water. The rate at which the tracks are covered over again will also be monitored.
Fishing will be by a low impact "eco-harvester" system used by Exmouth Mussels which involves using a suspended fluidising frame pushed by an aluminium barge. The frame hovers over the surface and uses jets of water to uncover the cockles which are then lifted to the surface on an elevator. The elevator is set to release all cockles below a certain size and only those that are of little interest to the birds and with a high commercial value are kept. All shellfish are harvested in small quantities to match demand then landed into the purification plant on the pier where further value is added.
Fishing will be for about an hour a day, three days a week and will be restricted to the high water window.
Tim Robbins of DFSC said, "We fully support this trial and hope it will pioneer sustainable cockle fishing in other estuaries around the UK."
At the same time work will be undertaken to establish whether the fishery and the effects of the removal of the cockles are impacting on the birds over wintering on the Exe. Following the trials and collation of all the data a decision will be made whether to allow the fishery to continue on a permanent basis. This will be allowed if it can be concluded that the operation will not have a significant effect on the integrity of the Exe Estuary SPA.
Exmouth Mussels have been seeding, farming and fishing the Exe for 7 years and have recently secured the lease on the entire southern shore. Working closely with the Devon Sea Fisheries Committee (DSFC) and Natural England has ensured that their activities are not only in harmony with the estuary but do a great deal to enrich the entire esturine eco-system, sustaining and enhancing the bio-diversity of this unique habitat.
Old beds of mussel which have limited benefit to the wildlife are being removed and replaced with new seed which bursts into life providing a massive surface area and vastly increased feeding opportunites.
Tim Robbins of DSFC said, "Exmouth Mussels continue to work in a responsible manner and we are pleased to work alongside them and Natural England for the sustainable future of the estuary. The health of shellfish is a key indicator of the overall health of the estuary and with Exmouth Mussels recently winning 4 gold medals the the "Taste of the West" it is clear to see that we have a very healthy shellfish population."
From EXE-Press magazine