Aquaculture, sustainability and tourism / Urban Aquaponics

1. SUPPLEMENT
FISH FARMING
TECHNOLOGY
AQUACULTURE
SUPPLEMENT
URBAN AQUAPONICS
sustainability and tourism

2. B
ibury trout farm is one of Britain’s oldest and most attrac-
tive 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.
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 hatchery
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 neces-
sary as some of the customers of the hatchery supply to supermarkets.
GlobalGAP is a Global Food Safety Initiative (GFSI) recognised stand-
ard 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 tour-
ist 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
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.
Fertilisation room
The place where science and skill play the largest part is the fertilisa-
tion 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 triploid-
ing is a very time specific task.
Producing triploids
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 pro-
cess 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 fertilisa-
tion (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
Aquaculture, sustainability and tourism
by Peter Parker, International Aquafeed Magazine
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
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FISH FARMING TECHNOLOGY

3. been observed in the wild. It has been suggested that temperature
shock is likely the cause in most instances. Interestingly heat was used
on fish farms prior to the use of pressure. The eggs would be brought
up to 60 degrees for a specific amount of time to cause the same
effects, however the results were not as consistent as those obtained
via the pressure method.
Checking that the triploiding process has been successful is of vital
importance. At Bibury 100 fish that have reached five grams per batch
are checked to see if they have developed a reproductive system. “If I
went around saying I was selling triploids, but was actually selling regular
females, a customer could release them into a river and get into a lot
of trouble” says Martin. This is why ensuring accuracy throughout the
process is of paramount importance.
At the time we visited the farm, we were informed that Bristol water
had recently purchased an equal number of rainbow trout eggs from
a large scale egg producer and from Bibury trout farm to make com-
parisons. While there had not yet been any results to share, Martin was
eager to discover the results, even if they were negative – this would be
motivation for him to find out how to further improve his eggs.
Incubation room
The next room we were shown was the incubation room. Restored
a few years ago, there was a wall of sealed glass jars connected by pip-
ing. The vessels were full of bore hole water that had passed through
a de-gassing unit, just like the rest of the water used for all of the
hatchery processes.
When we visited there were no eggs currently being incubated,
this was probably a good thing considering how fragile the eggs are in
this state. Nurturing trout eggs can be very difficult, a lot can go wrong
very quickly. From days two through to 19 the fertilised ova are very
delicate. A small knock on one of the jars is potentially enough to kill
the entire 200,000.
The greatest risk at this stage however is fungus. The issue being
that if an egg dies there is a high probability that Saprolegnia will
develop on the dead egg. Saprolegnia will not directly ‘attack’ a live
egg but as the fungus spreads on the dead egg the water flow to the
live eggs surrounding it will be impaired causing them to die as well.
Once it has become established it can quickly take over an entire jar.
A constant but steady flow of water into the bottom of each tank
functions to keep the eggs only just in a state of suspension so that
the weight of eggs on top does not affect the rest. The flow of water
assists in keeping the water in the tank sustaining good oxygen levels.
During the incubation period around 80 percent of fertilised eggs
make it to hatching, in winter this figure can reach 95 percent.
At the end of the incubation period, all eggs will be subject to a
process referred to as ‘shocking’, this involves moving the eggs about
to rupture the unfertilised ova, at Bibury they do this by pouring them
back and fourth between buckets a few times. This will cause any
unfertilised eggs to turn white, making them easier to identify so they
can be removed. In the past all of the eggs would be laid out in a tray
and the white ones would be removed by hand, a time consuming task
indeed. Now days a machine is implemented, using infrared technology
the machine can detect the white eggs and remove them, a time saving
device appreciated by the hatchery staff.
Hatching room
The hatching room was dark, and contained many fish at various
stages of early development in shelved trays of water. Some of these
trays contained 5000 fingerlings. The majority of fish in this room
had hatched and were now at the swim up stage. Some 21-day-old
eyed ova were still incubating, they were not as fragile as the eggs we
had encountered earlier. Once an egg has visible eyes they are more
resilient to external forces and can then be transported as required.
All fish that reach 5 grams at the hatchery are vaccinated against Enteric
Fish Farming Technology | INTERNATIONAL AQUAFEED | 003
FISH FARMING TECHNOLOGY

4. redmouth, Aquavac Relera is used and administered via submersion method.
When the fish are large enough they are moved to another area of
the hatchery where they are graded. Grading is essential to reduce the
risk of cannibalism but also to ensure the different size fish are getting
the correct feed size for optimal growth.
The hatchery also contains three black poly tunnels used for photo-
period manipulation of brood stock. This process controls the amount
of daylight hours effectively fooling the fish into spawning in the middle
of summer rather than natural winter spawning.
Farm tour
At the end of our hatchery tour, we were kindly shown around the
beautiful outdoor uncovered fish farm that is accessible to visitors of
the public. At the farm visitors are able to purchase food to feed the
fish. This is of course only a small amount of additional feed, the vast
majority is fed to them by staff.
The food conversion rate (FCR) at Bibury ranges from 0.7 – 0.8 for
the fry, meaning that for every 700 – 800 grams of feed given to a fish,
they expect to see one kilogram of growth. The larger fish on the farm
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FISH FARMING TECHNOLOGY

5. convert at a rate of 1.2:1. Sketting feed is used, and a lot of it! A lorry
will deliver a load of feed at least once per month.
There is also a fishing experience available to visitors where in
one specific part of the farm they can catch, purchase, and take their
caught trout away with them, (there are also onsite barbeque facilities
available for those wanting to consume immediately).
Final thoughts
As I walked around the grounds I reflected on what Martin had
shared with us, the farm produces upto 110 tonnes of live Rainbow
Trout per year; an impressive feat considering it is run by just five staff;
including a delivery driver, a maintenance manager, two full-time staff
on the farm, and Martin who runs the hatchery.
We were told that the shop, café, and tourist side of things employs
somewhere around 20 staff in the peak season of summer.
Bibury trout farm is a beautiful place to be on a fine autumn day, I
see it being an excellent day out for families. Behind the scenes hard
work and care goes into nurturing the plenty rainbow trout on display.
Wheat proteins
for aquafeed
• Vital wheat gluten : Amytex® range
• Hydrolysed wheat proteins : Solpro® range
Nutritional benefits
• High protein content
• High digestibility
• Rich in glutamine
Technological benefits
• High binding capacity
• Improved durability
• Improved water stability
Tereos Syral is a leading producer of starch,
starch sweeteners, alcohol and proteins in Europe.
Martin Smith from Bibury Trout Farm showing Malachi
Stone, Darren Parris, Olivia Holden and Tom Blacker from the
International Aquafeed team around
Fish Farming Technology | INTERNATIONAL AQUAFEED | 005
FISH FARMING TECHNOLOGY

6. G
row Bristol is a small social enterprise with big plans
for farming fish and greens using aquaponics. Set up by
myself, with business partner, Dermot O’Reagan, Grow
Bristol is transforming a disused space in the centre
of the city of Bristol, UK, into a farm for the future. Our aim is to
produce great food in the heart of the community where it is eaten,
whilst farming in a more sustainable way. We hope to change the
way we feed our city, using innovative agricultural methods and by
connecting the people of Bristol to their food.
At Grow Bristol, we believe in producing truly local, high quality
food, close to the people who eat it. Currently, there is a need to
explore further ways to grow more quality food, more sustainably, on
less land, with fewer resources. Fisheries and farmland are increasingly
coming under pressure. A recent report by the University of Sheffield
created widespread speculation that there may be only 100 harvests
left in UK soils due to intensive agriculture (we have reached Peak Soil
as well as Peak Oil!) Water scarcity is also becoming a bigger problem
globally and the UK is one of the largest importers of virtual water
(other nations’ water used during the production of our imports). The
food miles and carbon footprint of what we eat is also contributing
significantly to climate change. Clearly, farmers need to continue to
consider alternative methods of producing and transporting their food.
Can one part of the solution be to produce more in the city for grow-
ing urban populations?
At Grow Bristol, we initially began farming using a more conven-
tional approach. We started by growing salad leaves in the soil in two
large polytunnels, but were disillusioned with the vulnerabilities of the
system and lack of suitability to the urban environment. We were
producing on average 60kg (or 600 small bags) of mixed leaf salad a
week for the local market. However, with a short growing season, a
hugely inefficient irrigation system, poor soil and limited effective pest
control, we started to consider the need for more resilient solutions.
That’s when we turned to commercial urban aquaponics.
Having visited Paignton Zoo’s ground breaking Verticrop hydropon-
ics system we were inspired to set up our own urban farm: producing
vegetables vertically, without soil and using much, much less water! In
this type of system, the water and nutrient solution is pumped around
the suspended root zone of the crops on multiple layers, perhaps
ten high. The water is then re-circulated rather than running to waste
or evaporating. With ‘Controlled Environment Agriculture,’ almost
everything can be managed to optimize growing conditions, even the
light. Philips, one of the leading commercial producers of LED grow
lights, are creating “Light Recipes” (with particular parts of the light
spectrum) to manipulate productivity, nutrition, taste, and texture in
crops, in the absence of daylight. It sounds futuristic, but such closed
growing systems could potentially mean food security in the desert, in
our cities, or even the arctic year round.
Add to all this, the possibility of farming fish as well as growing
greens and you have aquaponics. Integrating RAS aquaculture into
URBAN AQUAPONICS
by Pete Whiting, Grow Bristol
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FISH FARMING TECHNOLOGY

7. such a closed loop system provides an alternative source of nitrates
and other nutrients. It is then possible to grow vegetables using 95
percent less water when compared to soil-grown vegetables, whilst
farming fish! Using fish (or aquafeed) to grow vegetables commercially
is on the increase globally and though not new, is still in its infancy.
The technology is already there in both aquaculture and horticulture
and both industries are waking up to its growing commercial potential.
For us, at Grow Bristol, we wanted to start by seeing if we could cre-
ate an aquaponics project that could produce enough green vegetables
to be commercially viable. However, this time achieving it year round
and with all the benefits of soilless growing and farming fish. Currently,
we are building a unit to farm tilapia, herbs and leafy crops. Following
a similar model to the market gardens of the past, we will be supplying
directly to the immediate locality, with fresh produce. However, the big
difference here is that our aquaponics market garden is housed in con-
verted shipping containers on a brownfield site, close to the city’s main
railway station. We believe it is the future of urban farming.
The project involves a small RAS aquaculture system and verti-
cal LED lit hydroponic system that when completed will produce
leafy greens and tilapia for sale to cafes, restaurants and specialist
distributors. This will enable us to test the viability of a much larger
aquaponics farming business for Bristol. We are realising this early stage
project with funding and support from Bristol 2015 Green Capital, and
other organisations such as Innovate UK and The School for Social
Entrepreneurs.
Through Bristol 2015 Green Capital, we have been involved in
many public events where communities have come to learn and get
involved with urban agriculture. People have shown an increasing level
of consumer knowledge, combined with a demand in the market for
high quality, local food, with clear provenance. Consumers also voiced
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FISH FARMING TECHNOLOGY

8. strong concerns about the impact of agriculture on the environment
and the difficulty of buying fish from truly sustainable sources. At a
recent event, promoting tilapia to the ‘uninitiated,’ I was asked, “This
tilapia is amazing, but where does your fish feed come from?” We,
at Grow Bristol, see the issue of true sustainability as one of the big
challenges, not only for ourselves, but also for the aquafeed industry
to answer. Whilst there is already some research taking place that
may help to address this issue, (for example, the report in last month’s
edition about the use of pea protein concentrate), as a business with
social and environmental aims, we are keen to build partnerships
around further research within the industry.
Farmed fish for many consumers has the potential to be the only
truly sustainable protein (apart from insects perhaps!). However, as
smaller producers trading on the sustainability of our methods, we
would like to be able to reassure customers that in the future, our
tilapia won’t just be fed on other fish or industrial monoculture crops.
We hope this is a realistic possibility for the aquaculture and aquapon-
ics industry.
International
Aquafeed
had the
opportunity to
speak to Pete
Whiting about
Grow Bristol
IAF: What limita-
tions do you have
regarding the types
of plants you can
grow using aqua-
ponics? Are you
restricted to the
nutrients from the
waste bi-products
of the fish?
PW: Aquaponics
is most suited to
growing leafy veg-
etable crops. This
is primarily due to
the main nutrient
source being the ammonia from the fish that is converted into nitrates,
which plants use in foliar growth. However, some aquaponic farm-
ers do also grow root and fruit crops. Additional nutrients could be
added to your growing system without harming the fish if the system is
designed with this in mind.
IAF: You say that the technology is already available in aquaculture
and horticulture, what do you think needs to happen for aquaponics
to be more widely adopted?
PW: For aquaponics to be adopted more widely both the hor-
ticulture and aquaculture industries need to be convinced by a
large commercial scale success story in the UK. The benefits of
integrating these two farming methods are plain to see and with a
growing market for farmed fish and locally produced (not just locally
sourced) veg we believe it will happen.
IAF: Why have you selected Tilapia as your species to farm, I
understand that it is not so common in British supermarkets, how
has it been received in the marketplace?
PW: We have chosen to farm Tilapia as it ticks all the boxes for
us. Tilapia has a very good Food Conversion Ratio and is suited
to the conditions of an indoor urban farm. It also has a great taste
when farmed to a high standard of welfare and sustainability. It is
the second most farmed fish globally and is well known amongst the
UK’s ethnic population. Tilapia is already being more widely used
by some large restaurant chains, particularly in Asian cuisine. As a
“new” niche product for UK consumers who value provenance as
much as price it has great potential.
IAF: Why do you see an urban setting as the future for farming?
PW: The future of farming is certainly not just in an urban setting
but thus far we are largely looking to the peri-urban and rural envi-
ronment to help feed our cities. With growing urban populations
planners need to make provision for urban farms. They can help
supply the most perishable products directly from within the city
reducing waste and transport even without soil!
IAF: How do you foresee the future for GrowBristol? Are there
larger scale projects on the way?
PW: Next year Grow Bristol will start to develop plans for a large
indoor aquaponics farm. We aim to create a scaled up version of
our current project in a light industrial unit in the city.
GrowBristol
business partners
Pete Whiting
(near) and Dermot
O’Reagan (far) at
work with urban
aquaponics
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FISH FARMING TECHNOLOGY