Anchor system fails as storm hits Carradale salmon farm
Quick reaction from staff and contractors resulted in fewer fish escaping from a salmon farm off Carradale’s coast than originally feared after 10 cages shifted position during Storm Ellen last Thursday.
While initial reports suggested that as many as 550,000 farmed salmon could have escaped from the Carradale North farm into the Kilbrannan Sound when the circular pens became detached from their seabed anchors, the site’s owner, Mowi Scotland, said on Tuesday that the number of escapees was actually 48,834.
There have been reports of the escaped salmon being predated upon by seals and other wildlife while several Kintyre anglers rushed to East Kintyre in an attempt to catch any fish that came close to shore.
Despite stories circulating about ‘deformities’ in the escaped fish, Mowi insists that the salmon raised at the Carradale North farm are healthy, with some having already been processed for market.
The company’s immediate priority when the incident took place was to secure the fish pens – which contained 550,700 salmon, weighing about 4.2kg each – in place until the storm subsided, and to safeguard staff, contractors
Of the salmon contained within the four compromised pens, 125,900 were harvested, 30,616 died and 48,834 escaped
and fish stock. This was achieved by last Saturday, with teams of trained staff and service contractors and up to 12 vessels at the site during the recovery operation, which was completed without injury or incident.
By Monday, August 25, the farm was secured back in its proper location and all 10 pens were either visually inspected for integrity or inventoried.
A Mowi spokesperson said: ‘Following thorough inspection by dive teams, the root cause of the incident appears to be breakage of mooring ropes that attach to the main system of seabed anchors.
‘The farm was installed five years ago according to the Marine Scotland A Technical Standard for Scottish Finfish Aquaculture, and the infrastructure inspected three months ago.
‘The rope type is marine grade, 4.8cm in diameter, with a break strength of 89.5 tonnes – roughly twice the maximum strength required for its application, ranging from 33 tonnes to 51 tonnes.
‘The rope has been sent to third-party testing facilities in Aberdeen, with further investigation to follow.’
Of the 10 pens, Mowi revealed that six were found to be structurally sound with fish in good condition and are now secured back in their original
position. The remaining four pens were structurally compromised, with two experiencing torn nets.
Of the salmon contained within the four compromised pens, 125,900 were harvested, 30,616 died and 48,834 escaped.
The company informed watchdog Marine Scotland of the incident and the potential for fish escape immediately and key stakeholders were informed within 12 hours.
Environmental campaigners were quick to voice their concerns about escaped farm salmon potentially breeding with wild Scottish salmon.
Mowi is working with Marine Scotland and Fisheries Management Scotland to finalise a monitoring and mitigation plan in an attempt to minimise the number of farmed fisha entering the rivers draining into the Firth of Clyde.
Mowi told the Courier it continues to engage with local and national wild fisheries groups to monitor and assess the presence or absence of salmonid genetic introgression.