Fish Farming Technology Nov | Dec 2015

8/20/2019 Fish Farming Technology Nov | Dec 2015

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SUPPLEMENT

FISH FARMING TECHNOLOGY

AQUACULTURE

S U P P L E M E N T

URBAN AQUAPONICS

sustainability and tourism


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Bibury trout farm is one of Britain’s oldest and most attrac-

tive trout farms, originally founded in 1902 by naturalistArthur 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 hatcheryUpon 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 practiceshave 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 multipleatmosphere 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 roomThe 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 triploidsTriploiding 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 iswhen 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 BrownTrout it now covers 15 acres in one of the most beautiful valleys in the Cotswolds, the Coln Valley. The crystal clearwaters of the Bibury Spring provide the essential pure water required to run the hatchery which spawns up to 6 milliontrout ova every year.

The village of Bibury itself has been referred to as the ‘most beautiful village in England’ by William Morris and is wellworth 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 wellsee grading in progress when the fish are selected for size and quality before being transported to new homes inoxygenated water in specially made fibre glass tanks. Feeding is done daily by staff and the water comes to life asthe 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 toanswer any question you may have.For more information: www.biburytroutfarm.co.uk

002 | INTERNATIONAL AQUAFEED | Fish Farming Technology



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been observed in the wild. It has been suggested that temperature

shock is likely the cause in most instances. Interestingly heat was usedon 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 roomThe 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 willdevelop 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 roomThe 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 roomhad 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



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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 theircaught trout away with them, (there are also onsite barbeque facilities

available for those wanting to consume immediately).

Final thoughtsAs 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 MalachiStone, Darren Parris, Olivia Holden and Tom Blacker from theInternational Aquafeed team around




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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 toproduce 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 aweek 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 wasteor 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 AQUAPONICSby Pete Whiting, Grow Bristol

006 | INTERNATIONAL AQUAFEED | Fish Farming Technology



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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 horticultureand 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 largeraquaponics 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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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 thatmay 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.

InternationalAquafeedhad theopportunity tospeak to PeteWhiting aboutGrow Bristol

IAF: What limita-

tions do you have

regarding the typesof 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 ofintegrating 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 usedby 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 therelarger 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.

GrowBristolbusiness partnersPete Whiting(near) and DermotO’Reagan (far) atwork with urbanaquaponics


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Fish Farming Technology Nov | Dec 2015

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