PROFITS by and large, don't stay in Scotland. The vast majority of the fish farms in Scotland are foreign owned, Norwegian in the main, so the environmental damage caused benefits not the Scots, but the vikings who stole all the pretty ones and left Aberdeen the desperate place it is of a weekend night when you're out on the lash.
There are actually more scottish owned fish farms than foreign owned you only here of largest ones which are owned by companies in Norway.
The fish farm food is actually mostly anchovies. Yes there are additives in the food. Sea lice is not a problem for a couple of reasons, one the treatment they get also the use of wrasse for eating them from the salmon when at sea. the left over food feeds a variety of fish if there is any left over.
Fish health is very important, besides the fish health visitors coming around, there are vets who are here weekly constantly checking on health ensuring there well being as well as amounts for food etc. Liver tests are performed frequently on fish as well.
There are varying amounts of testing from sepa to make sure the water going through is as clean if not cleaner than when it came in if the levels are high they get shut down after 3 non conformities in a row. amongst some of the things they have to do is also look for wildlife count any other species etc to see what environmental impact they are having etc.
This is the smallest site this company has and it employes in total 8 full time. However if you think of the amount of people it also provides part of their full time job, well you have lorry drivers for transfers, divers for net checks, vaccinators, vets, health visitors, environment groups, sepa, people who work at the net stations for repairs, then you have other things such as pest control, security etc etc I don't think you realise how much is actually invovled, nor the amount of care nor the amount of people and it actually counts for a lot in small places if you think of 200 people in an area and they are employing 8 full time staff plus part time staff etc. it's not quite as bad as you seem to think.