Monday, 18 March 2013

Farming the Sea - 2

One of the things that most interested The Dairy during the visit to the Marine Harvest fish farm at Camas Glas (see earlier post here) was the facilities available for the crew.  During a visit to Laga Bay a year or two ago, the crew worked out of a portakabin.  Now they are quartered in a new building with rest rooms, toilets, a fridge and microwave, an office, and changing rooms - this is visible, with the slipway, in the right foreground of this picture of Laga Bay. 

The facilities are as good out on the C-Cap.  One of the things they have is a microscope.  Each morning, a sample of water is brought in and checked for algae.  Intensive farming on land pours fertilizer into the sea, and this encourages blooms of algae, which can kill the fish by blocking their gills.

Assistant Manager Calum MacPhail is seen here in the C-Cap's office, at the computer which controls the amount and timing of the food that is delivered to each cage.  As the food is spread automatically, he monitors a CCTV camera which moves up and down, both above and under the surface, to ensure that no food falls right through the cage.

The food leaves the C-Cap through pipes which snake out across the water to the cages where....

....within each cage, there is a central sprinkler which distributes the pellets to the fish.  At present all this is controlled from the C-Cap, but developments are in hand to allow it to be done from the office on land.  Although we haven't had a bad storm recently, conditions can prevent the staff from reaching the C-Cap.  The most extreme case was on Barra, where they couldn't get out to the cages for 25 days.

A million fish are a terrible temptation to the two local seal populations.  In the past, their attempts to get in to the cages resulted in escapes by farmed salmon, which could then breed with the wild salmon which are native to these waters.  These days, the nets are stronger, and the the seals don't approach the cages as they are deterred by machines which let out an electronic noise which resembles the sound of a cricket in the grass - it's the same principle as householders use to deter mice from coming into the home.

The Diary hopes to return to the facility at Camas Glas later in the year, perhaps to watch the fish being graded.

Many thanks to Marine Harvest for the invitation to visit their Camas Glas facility, and to Rosie and Calum for the very enjoyable tour.

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