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FISH FARMING TECHNOLOGY

Aquaculture, sustainability and tourism Bibury Trout Farm is one of Britain’s oldest, and certainly most attractive Trout Farms. Founded in 1902, by the famous naturalist Arthur Severn, to stock the local rivers and streams with the native Brown Trout it now covers 15 acres in one of the most beautiful valleys in the Cotswolds, the Coln Valley. The crystal clear waters of the Bibury Spring provide the essential pure water required to run the hatchery which spawns up to 6 million trout ova every year. The village of Bibury itself has been referred to as the ‘most beautiful village in England’ by William Morris and is well worth a visit, with the historic Arlington Mill, Arlington Row and the beautiful St Mary’s Church. Visitors can learn about the Rainbow and Brown Trout while you wander in the beautiful surroundings. You may well see grading in progress when the fish are selected for size and quality before being transported to new homes in oxygenated water in specially made fibre glass tanks. Feeding is done daily by staff and the water comes to life as the fish vie for the last morsel. Information boards give an insight to what goes on in the hatchery and fryary areas and staff will be delighted to answer any question you may have. For more information: www.biburytroutfarm.co.uk by Peter Parker, International Aquafeed Magazine

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ibury trout farm is one of Britain’s oldest and most attractive trout farms, originally founded in 1902 by naturalist Arthur Severn to stock the local rivers and streams with native Brown Trout. The main focus of the trout farm today remains the same, 90 percent of fish go towards restocking and only a mere 10 percent are sold for direct consumption.

farm certified in the future. The hatchery complex was made up of three buildings and multiple atmosphere control marquees. Each of these components is necessary to produce eggs, and raise them into triploid females of a size where they can safely be introduced to the farm.

Hatchery Manger, Martin Smith provided us with a comprehensive tour of the farm; a very knowledgeable aquaculture practitioner, he is enthusiastic about his role as a fish farmer as well as his many ongoing projects on the farm. There was not a question he could not give us a precise answer to throughout the tour. We all came away feeling privileged to have been shown around the premises and to have been given such an insight into the careful husbandry and precisely measured processes that are undertaken to produce the beautiful rainbow trout of Bibury.

The place where science and skill play the largest part is the fertilisation room. This is where Martin collects the eggs and the sperm from female only fish. These are the requirements to produce a female only population. A female population is preferred for the rainbow trout species as males sexually mature while they are quite small and by time they reach market size the meat is grey and watery. Fertilisation and triploiding is a very time specific task.

The hatchery

Triploiding is a process involving the manipulation of an egg by applying pressure at a specific time during the fertilisation process that causes an extra set of chromosomes to develop. The resulting fish will not grow any reproductive organs, after triploiding these fish could be summarised as female but genetically sterile. This is an important process as it ensures that the farmed fish will not interact with any native fish. Additionally, a nice bi-product of triploiding is that fish will expend no energy into reproduction and instead use that energy for growth. “Triploiding is all about timing”, says Martin. “Everything is recorded, time zero is when I add the sperm to the eggs, and at minute three is when I deem the eggs as fertilised. At exactly 40 minutes after fertilisation (when factoring in machine start up time) I will turn the machine on, that will pressurise up to 10,000 PSI, the eggs will sit inside for five minutes before the pressure is released”. Martin tells us that spontaneous triploidy in certain species has

Upon arrival at the hatchery area of the farm Martin instructed us to dip the soles of our shoes in a disinfectant solution. He went on to explain that this is to prevent unwanted pathogens entering the hatchery area and also to separate the hatchery from the farm as the hatchery is GlobalGAP certified. The GlobalGAP (good agricultural practice) certification is necessary as some of the customers of the hatchery supply to supermarkets. GlobalGAP is a Global Food Safety Initiative (GFSI) recognised standard that assures buyers that basic food safety and sustainability practices have been upheld. The entire farm complex is not yet GlobalGAP certified due to the difficulty of upholding the standards while the farm functions as a tourist attraction – for example it would be difficult if a tourist showed up in a pair of flip flops! However, they do have plans to have the entire

Fertilisation room

Producing triploids

002 | INTERNATIONAL AQUAFEED | Fish Farming Technology

Nov | Dec 2015 International Aquafeed  

The November - December 2015 edition of International Aquafeed magazine