Environmental Assessment (Scotland) Act 2005 Aquaculture and Fisheries Bill Consultation Document Environmental Report February 2012

This Environmental Report sets out the results of the assessment of the possible environmental effects of provisions in the Aquaculture and Fisheries Bill.


Current Situation

9.1 The harvesting of farm-produced salmon in Scottish waters is typically conducted in a number of ways. Live salmon are either transported via wellboat to a killing station, before being sent onwards for processing at a dedicated processing plant, or are transported by wellboat directly to a fish processing plant for killing and processing. A more recent method has been introduced involving transferring farmed salmon directly from the cage to a dead-boat for killing at site, followed by transportation for processing at a designated processing plant [42] .

9.2 The fish processing is undertaken in two stages. The primary process is undertaken at a designated processing plant and involves the evisceration of the killed salmon [43] ; the removed solid offal fish waste is ensiled and disposed of in accordance with the Animal By-Products (Scotland) Regulations 2003. The secondary production process involves the preparation of the salmon product for sale (by smoking, deboning, packaging, etc). While some plants are limited to the primary or secondary processing, most fish processing in Scotland is undertaken in mixed facilities undertaking both stages at the one location [44] . The primary production process in Scotland is undertaken separately for wild salmon and farmed salmon, although the secondary processes can be undertaken at the same plant.

9.3 Waste discharges from processing plants are authorised under permit or licence, i.e. CAR licence for plants processing less than 75 tonnes/day of carcass, or Pollution Prevention and Control ( PPC) permit [45] for plants processing more than 75 tonnes/day. (Salmon factories receiving and processing live fish from wellboats are generally considered to be slaughterhouses, and a lower threshold of greater than 50 tonnes/day applies for licensing in these cases.)

9.4 Solid wastes from plants are disposed of to land. Waste water is typically treated onsite (via filtering and chemical treatment) prior to discharge into "controlled waters", under the conditions detailed in the facility permit or licence specifying allowable limits for discharge volumes and environmental parameters (such as biological oxygen demand and chemical concentrations).

9.5 International studies have found high concentrations of sea-lice in marine waters in the vicinity of fish processing plants [46] , but there is little evidence to confirm that the source of the sea-lice was the processing plant. Anecdotal evidence suggests that, in Scotland, sea-lice and their eggs are often present in waste water at processing plants, and can survive the waste water treatment process.

9.6 Some concerns have been raised about the possibility of the spread of sea-lice or pathogens through discharges associated with farmed fish processing plants, for example sea-lice and/or eggs that have survived the waste water treatment process. Where fish may have been brought in from outside the local area for processing, this could undermine otherwise effective local Farm Management Agreement/Management Area practices and controls.


9.7 The proposed provisions include additional powers for Scottish Ministers to place controls on discharges from plants processing farmed fish.

Potential Effects

9.8 The proposals are intended to control the discharge of sea-lice and pathogens in treated waste water from farmed fish processing plants. Improved control of discharges has the potential for significant environmental benefit, particularly for wild salmonid populations


9.9 As no significant negative effects from these provisions have been identified, no mitigation measures are required. Given the high-level nature of the provisions, enhancement measures have not been proposed at this stage of the Bill's development.

Effects of Continuing the Status Quo

9.10 Continuing the current situation would result in the continuing risk that sea-lice may be discharged from farmed fish processing plants, which would have adverse implications for wild salmonid populations.


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