The OSH way

We do things #theOSHway


Our deep, exposed locations are hand picked to create the best conditions for our fish and protect the environment from harm. The clear, open waters of North East Skye are perfect for the development of our organic salmon. High flow/water exchange rates, stable temperatures, salinity and dissolved oxygen levels all play a vital role. These conditions all help to safeguard the livestock of OSH from unfavourable environmental and biological conditions as the seasons change and our fish develop from smolts through to marketable salmon.

The wide dispersal of nutrient rich discharge (in the form of fish faeces) from our sites aids the environmental assimilation of our inputs. When operated from a balanced perspective, fish farm discharge may actually stimulate the surrounding ecosystems by supporting food chains - directly feeding benthic invertebrate species, through to fish, then marine bird and mammal populations.

OSH periodically employs third parties to carry out benthic surveys, ensuring that our farming operations comply with statutory requirements and that fish production in these locations does not come at the expense of local biodiversity. 

Stocking density

The cages at the OSH sea sites have a maximum stocking density of 10kg per m3 - this equates to 99-99.9% water and only 0.1-1% fish, maximising the animals’ freedom to grow and thrive during the production cycle. Furthermore, these lower stocking densities reduce the transmission rates of salmon lice (and non-specific sea lice) between our livestock. This in turn, reduces the likelihood of needing to treat the fish for parasite infestations.

Fish feed

The feed our fish eat doesn't contain GMO's (Genetically Modified Organisms) or artificial preservatives. Working in close partnership with our dedicated organic fish feed supplier, we prefer to use the highest proportion of marine ingredients available to us. This helps to maintain high levels of omega 3 & 6 that you find naturally in salmon populations, whilst also being of benefit to the health of the consumer.

No chemical anti-fouling

The nets in our salmon pens are constantly submerged, which means they are subject to fouling pressure by marine macroalgaes, bivavle spat, hydroid colonies etc. - all of which can cause direct damage to the net fibres through their various forms of attachment.

To combat this, we use high pressure, rotating water jets to keep our nets clean. This eliminates any potential risk of heavy metal pollutant release into the sea during the cleaning of each net, simply through the non-use of traditional antifouling paints/coatings on our nets.

Natural ways to keep our salmon healthy

As well as salmon, each pen has also previously contained wrasse and lumpfish to help prevent sea lice spreading amongst our fish stock and increasing to unacceptable levels. These wee “cleaner fish” will gently pluck off and eat any lice that settle on the skin of the salmon - providing relief from this natural parasite for one, and a tasty snack for the other! Organic Sea Harvest is now in the process of phasing out the use of cleaner fish on our sites and are moving to using innovative freshwater treatments and technology onboard the new generation of state-of-the-art wellboats, which have the ability to filter and collect sea lice.

A freshwater treatment is a non-medicinal freshwater bath used to remove lice from the salmon. Lice can't survive in freshwater for extended periods of time as they are a marine, salt water species, but salmon on the other hand can readily go between the two (referred to as "anadromous"). If required, we let our fish swim in freshwater for a few hours to shift the balance back in favour of our livestock.