iaf1405 fish farming technology supplement

8/11/2019 IAF1405 Fish Farming Technology Supplement

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SUPP L EMENT

FISH FARMINGTECHNOLOGY

SUPPLEMENT

Recirculationaquaculturesystems

All go forAquacultureEurope 2014!

Technical aquacultureconference- focus on the Mediterranean


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Recirculation aquaculture systems (RAS) represent an

exciting, eco-friendly and unique way to farm fish. Instead

of the traditional method of growing fish outdoors in

open ponds, net cages or tanks, this system rears fish at

high densities within an operator controllable rearing environment

inside a building. Recirculation systems filter and clean the water for

recycling back through the fish culture tanks. New water is added

to the tanks only to make up for water loss due to splash out and

evaporation and to replace that used to f lush out fish waste materials

to storage tanks.

RAS designs have several system process technologies, all of whichwork together to ensure minimum loss of water, heat and of course

fish stocks, while constantly cleaning and re-using the fish tank water.

RAS farms can be designed to various levels of complexity, however

all true water recirculation designs involve the use of equipment to

remove and safely store wastes, clean and re-use water and maintain

rearing conditions at or near optimum for the species of fish being

raised.

In contrast, many older style tank farming systems that have been

used to grow fish are termed open or flow through systems

because the water makes only one pass through the tank and then

is discarded. Although several improvements can be added to older

designs to reduce water usage and create hybrid types of operations,

these are not exactly true water recirculation farms.

Benefits of Water RecirculationAquaculture System Designs

Fish farmed in any facility must be supplied with the correct

conditions necessary to remain healthy and grow with a good Feed

Conversion Rate (FCR). Fish need a continuous supply of clean water

at an appropriate temperature and dissolved oxygen content that is

optimum for good growth.

Water recirculation farms accomplish these tasks. A mechanical

and biological system is necessary to purify the water and remove

or detoxify harmful waste products and uneaten feed. The fish must

be fed a nutritionally complete feed on a daily basis to encourage

fast growth and high survival. With that in mind, it is now possible

to review the potential benefits of using a Recirculat ion Aquaculture

Systems.

Low water RequirementsBecause RAS farms recycle most of their water, they consume

considerably less than other types of culture systems and are especially

well suited to areas with limited water supplies. The required quantity

of water needed to successfully grow fish varies with the species of

fish selected, size of the farm system, and the unit process equipment

design. As a general rule, a minimum water volume of one-five gallons

is needed for every pound of fish reared and minimum new water

flows of five-20 gallons per minute are needed to grow 50,000 - 75,000

pounds of fish per year.

A properly designed and operated recirculation system requires

a minimum daily input of water, just enough to clean the waste

from the filters and to replace water lost to evaporation. Thisallows construction of fish farms in areas where ground water

is limited and even opens the possibility of an operation being

located in an urban area to use de-chlorinated municipal water.

Such a production facility could be located close to the market.

By comparison, a recirculation system which produces the same

number of pounds of fish as 1000 acres of ponds (about 4.8

million pounds of fish) would require only about 4000 gallons of

fresh water each day or 1.5 million gallons per year. However, to

fill 1000 acres of ponds averaging just 5 feet in depth, once only,

would require 1.6 billion gallons of water. That is just to fill the

ponds and does not include any water added to maintain levels or

freshen the ponds after the initial filling.

Less Land RequirementsSince fish in a recirculation system are reared in tanks, with oxygen

being supplied and their metabolic wastes removed by constant recir-

culation of water, fish can be safely stocked and grown in high densities.

Currently the goal, which designers are striving to attain, is 1 pound of

fish per gallon of water. However, many people consider 0.5 to 0.75

pounds of fish per gallon of tank water as being acceptable. In pond

aquaculture, the common maximum density is about 0.003 pounds

of fish per gallon of water. Therefore, a recirculation system can be

located in areas where large amounts of level land (to build ponds) are

not available. The low land requirement also permits the facility to be

located in areas where the soil cannot hold water or, again, in urbanareas, or housed in vacant farm or warehouse buildings converted to

fish farming.

Control of Water TemperatureThe low water requirement of recirculation systems opens up

Recirculation aquaculture systems

RAS

002 | INTERNATIONAL AQUAFEED | Fish farming Technology

FISH FARMING TECHNOLOGY


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the possibility of economically controlling temperature which, next

to the lower water amounts need, controlling water temperature

(and the resulting stock growth rates) is one the greatest benefits of

these systems. Control of water temperature allows the aquaculturist

to produce a fish species, which could not normally be raised in a

given geographic area. It also permits the water temperature to be

maintained at the optimum level to maximize food conversion and

provide optimum growth. Growth can also occur throughout the year,

maximising production and allowing rapid turnover of the product. In

theory, marketing of the product is also enhanced, since fish can be

supplied each week.

Protection From The Elementsand Potential Predators

By rearing the fish indoors, the farmer is no longer limited by

weather conditions where a sudden cold spell can wipe out a years

production by killing the larval fish or disrupting the normal spawning of

the brood fish. In addition, pond and cage culturists can lose their crop

to low oxygen during the summer or winter and have greater difficulty

controlling predators. Having the fish indoors also permits harvest at

times when heavy rain, snow or ice would stop the harvest of pondfish or cage, creating a definite market advantage to the indoor farmer.

Indoor RAS farms are designed to prevent stock escapement, meaning

less potential for loss and mitigation of potential conflicts with regula-

tions governing water bodies and fish escapements.

Control of Water QualityWith recirculation systems , the aquacultur ist has the opportu-

nity to control water quality, to the benefit of the live fish stock

and to the final product sold in the supermarkets and to the

environment. By maintaining dissolved oxygen at optimum levels,

the fish have better food convers ion and are less stressed, which

translates into greater disease resistance, less wasted feed and

faster stock growth.

In addition, the fish are isolated from potential environmental

contaminants such as off-flavor caused by algal blooms that can affect

cages and from any potential pollution resulting from soil run-off or

residual pesticides into the water that the fish are held in. This results in

a high quality product. In many cases where the fresh water is supplied

by wells, the likelihood of disease outbreaks are greatly reduced and

medications are not required.

SummaryThere are various designs for recirculation systems and most will

work effectively if they accomplish oxygen and aeration, removal of par-

ticulate matter, biological filtration to remove waste ammonia and nitrite

and buffering of water pH levels. These processes can be achieved by

using the simple units, that use combination filters which are often used

in small farm systems. In the case of larger farms filtration will often be

carried out using several interconnected components and unit processes.

Land based fish farms that use RAS technologies are indeed analternative to pond and cage culture systems. As with any technology

or any other business the operators must have the knowledge and

the inclination to manage the business and undertake the daily tasks

required. In RAS farms the staff must care for and manage both the fish

stocks and the systems. So having the best systems and no knowledge

of good husbandry will not work. Knowledge is king and one should

not attempt operating a farm without having the training and experi-

ence required. Water recirculation farms are also generally more costly

to build and more complex to manage.

Fish farming Technology | INTERNATIONAL AQUAFEED| 003


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RAStechnology overview

WATER proved

WATERproved develops, delivers and installs aquaculture systems

for all kinds of application.

Careful planning, precise calculation and simulation of the set up

make you safe money when it comes to energy efficiency and ease

of maintenance.

Selling state of the art technology, we develop all projects com-

pletely in house - from basic calculation to 3D model farm design.

We know what we are doing-all our staff have practical farming

background in recirculation and flow through systems.

We worked with Trouts, Chars, Salmons, Sturgeons, European

Perch, Pike Perch and Cyprinids.

WATER proved is working together with notable suppliers such

as Hydrotech, Lykkegaard and Ultra Aqua. All individually manu-

factured devices in plastic or steel are made in Germany and from

highest quality.

WATER proved will join Aquaculture Europe in San Sebastian

on booth No. 25. We consider the show an excellent place for

exchanging with international scientists, farmers and business part-

ners. There are already lots of meetings arranged with customers

during the exhibition. From the venue San Sebastian we hope toget into contact with new customers from Europe and especially

France and Spain. Our French representative, Mr. Sylvain Delord

from Smart Aqua, will also join us during this show.

Pentair

DSF Series Drum Screen Filters: Rotary Micro Filters

In demanding aquaculture applications, drum screen filters have

proven to be highly efficient and reliable in removing solids from

volumes of water large and small. Pentair Aquatic Eco-Sytems is

product to offer our DSF Series line of drum screen filters, with a

wide range of models, sizes and micron ratings to meet the specific

needs of nearly any field application. Featuring a field-proven design

and the highest quality materials available, the DSF Series follow

the simple, robust and time-tested principles of drum screen screen

filter operation.Water containing solids enters the rotary drum in the front of

the system. Water passes through the micro-mesh filter, which

filters out solids (for increased durability, stainless steel wedge-wire

filtration material is also available). As the filter mesh or wedge-wire

material becomes increasingly loaded with solids, the water level

within the drum increases to the point that it triggers the cleaning

process. As the drum starts to rotate, the spraybar nozzles scour

the filter mesh or wedge wire with high-pressure water, returning

the screen to its original permeability. This allows the internal water

level to drop and stop the cleaning process. Solids that are cleaned

from the water are collected in a trough and transported away from

the drum screen filter.www.pentair.com/en/solutions/advanced-filtration-and-desalination

AquaBioTech - Filtration Systems

As a result of our own research and development work we have

developed some of the most advanced and cost effective filtration

solutions available on the market today. Filtration modules that can

process two 2000m3 / hour of water are available, as well ascustom-designed solutions that are specific for each client's require-

ments and budget.

www.aquabt.com/filtration-systems

Primzone Ozone

Research shows that water treatment with ozone increases produc-

tivity at RAS aquaculture systems.

Three reasons why ozone in aquaculture improves water quality

and increases aquaculture productivity.

As recirculating aquaculture systems (RAS) operate by reusing

the fish tank water it is essential to control the water quality. Many

studies show that treating RAS systems with ozone increases pro-

ductivity as fish health and survival is increased.

At RAS the organic load tend to be high and the homogene-

ous fish stock leads to a high risk of infections and problems with

bacteria, fungi and viruses. Although ozone is not primarily used for

disinfection at RAS the reduction of solids and DOC often creates

an environment that is less favourable for bacterial growth and thus

creates a reduced need for disinfection.

1. Removal of colloidal solids with ozone micro flocculation

The organic load is a constant concern for RAS systems,

especially when the fish density is high and the water exchange

rate low. Ozone has the ability to cause clumping or micro

flocculation of fine and colloidal solids, which in turn facilitates

removal by filtration and sedimentation.

2. Removal of dissolved organic compounds Ozone changes the characteristics of the dissolved organic

compounds (DOC) by oxidation and precipitation that makes

it easier to remove the DOC by bio filtration and sedimenta-

tion.

3. Turn lethal nitrite into harmless nitrate with ozone treatment

A high organic load is a favorable environment for nitrite

growth. When reducing the organic load with ozone treat-

ment the risk of nitrite growth is also reduced. Ozone also has

the ability to oxidize nitrite to nitrate.

Suffer with any of the above problems with water quality at your

RAS plant? Contact our Aquaculture Specialist Dan Johansson.

How Primozone can help you increase productivity with ozone

water treatment

Primozone offers unique solutions for water treatment of recir-

culating aquaculture. We offer ozone generators and ozone water

treatment systems that are especially designed for the aquaculture

market. The Primozone OM-series ozone generators have several

advantages that applies to aquaculture fish farming such as:

compact in size

built in redundancy

easy to operate

low life cycle cost

ozone levels automatically controlled by redox/orp values in

each tank

ozone distribution module that can distribute ozone to several

different tanks with individual ozone dosage




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HydroTech

The highest levels of filtration efficiency

Water is filtered through the periphery of the drum and parti-

cles are carefully separated from the liquid through the special cell

structure of the filter panels. As solids build up on the filter cloth,

the automatic system starts rotating the drum and initiates the back-

wash. Solids are gently rinsed off the filter cloth and collected in the

waste trough and discharged. The filtration continues on clean filter

cloth during the backwash, thus allowing a continuous filtration pro-

cess. The unique design of our filter panels prevents fragmentation

through careful handling of the solids. This high filtration efficiency is

essential in optimizing water quality parameters.

Flexible, modular design

The modular design incorporates 5 different drum diameters ranging

from 0.5 m to 2.0 m with filter areas from 0.35 m2 for the HDF 501

to 22.5m2 for the HDF 2010. In total there are 20 different standard

drum filter sizes depending upon your requirements. We also work

with our knowledgeable clients by providing unique configurations

to meet specific needs.

Variable drive systemsThe Hydrotech Drumfilter is available in two drive system versions:

direct drive and chain transmission. Direct drive: The direct drive

is used on the two smallest drum sizes with 0.5 and 0.8 m drum

diameter. Chain transmission: For larger units, a chain drive provides

optimum performance.

www.hydrotech.se/aquaculture

Faivre Drum Filters

The operating system is simple. The water to be filtered is directed

into a rotating drum. The outer surface of the drum is manufactured

with a number of stainless steel plates covered with stainless steel

(or Nylon) mesh plates. Suspended solids larger than the perfora-

tions are unable to pass through the mesh and thus, are retained

in the drum.

The slowly rotating drum separates the solids from the water

and discharges the solids through a discharge channel located at

the top of the drum as indicated on sketch.

FAIVRE filters are designed to resist to all corrosion, due to their

construction entirely of stainless steel type AISI 304L for fresh

water, and type AISI 316L for salt water.

All parts of the filter have been engineered and calibrated for

their specific duty.

FAIVRE drum filters are manufactured with less moving parts as

possible. The drum is driven by belts so as maintenance is reduced

to a minimum.

The efficiency of the design is contained within the construction

of the stainless filter plates that are integrated into a strong stain-

less steel framework. Replacement of filter plates is operated in a

few minutes due to the exclusive design. The filter plates are easilycleaned and replaced on the drum.

FAIVRE offers a complete range of efficient filters, strongly made

and economic to operate.




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EuroFish, in association with Turkish

Food, Agriculture and Livestock

Ministry delivered an interesting

programme. International Aquafeed,

following the attendance of Tom Blacker

report from three talks given by presenters

at the conference.

At the welcome address it was highlighted

that aquaculture in Turkey has grown to world-

wide proportions with Izmir at its centre.

Izmir acts as an important hub for the Turkish

aquaculture sector said Mr Carak from

the Turkish Food, Agriculture and Livestock

Ministry. Turkish aquaculture is growing rapidly,

partly because of consumer dietary demands

for animal protein and omega 3 as well as

Turkeys noticeably increasing population. It

is encouraging to see how dynamic aquacul-

ture is in this country, with huge trade flows

between Europe and Turkey. Equally, compet-

itors from emerging markets are growing aswell and internal factors relative to Turkey

are also creating new challenges. All industry

organisations, companies and participants

must partake in aquaculture actively, share

experiences and ask questions.

Best Aquaculture practices:BIOSAFETY- The new objective

of modern farmingby Dr Pierpaolo Patarnello Veterinary Fish Pathologist

Dr Pierpaolo Patarnello, an early pioneer from

Mediterranean marine aquaculture who has

been in the industry for twenty years spoke.

He gave an informative presentation on how to

modernise fish farming, stating that, Aquaculture

cannot be reinvented as [in] the past. In order

to achieve this, a new approach must be found.

Following a holistic approach, the welfare of the

workers, the welfare of the animals, the protec-

tion of the environment and food safety are all

vital factors to be considered in reaching this

goal. By improving and regenerating the trade,

Dr Patarnello says that Turkey will be the leader

of aquaculture in the Mediterranean.

The Mediterranean is a diverse ocean for

fish farming from west to east, with dedicated

industry sites spread throughout. However,

Turkey has to take more care than they are

currently doing with regards to environmental

impact. Currently, minority species fish are

being developed at the same level and in the

same way that bass and sea bream were in the

early 2000s. Choice of feed, water control andsanitation must be bettered to see the industry,

as a whole, improve. Sanitary control, in par-

ticular, is critically importantpathology is just

the tip of the iceberg. Diseases easily develop

in water and, in the aquaculture industry it

Technicalaquacultureconference- Focus on the

Mediterranean

by Ruby Bircher

Tom Blacker from

International AquafeedMagazine attended the

recent conference entitled

Tendencies in Aquaculture

Value Chain. The full-day

conference took place at the

FutureFish Eurasia exhibition

in Izmir, Turkey, on Friday

6th June 2014. EuroFish

organised seven separatetalks with questions and

answers.




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is pivotal that they are stopped before mor-

tality rates in fish increase. The speed at which

technology is now allowing industries to work

at is saving both time and, resultantly, money.

Because of this, any technology used needs to

be ensured that it is clean and safe.

Finishing remarks focused on the impor-

tance of the control at the production stage.

Using a Standard Operating Procedure (SOP)

is a good way to achieve this. In the 1990s,

skeletal deformities in fish were a problem

at the production stage. Practices around

improvements at this stage are so vital for

good quality products. Standards in produc-

tion can lead to standards in the end product,

such as certifying and tracing the route to

the consumer. Throughout the stages , Dr

Pierpaolo Patarnello said, feed choice is abso-

lutely essential for success.

On the whole, International Aquafeed

Magazine found the talk very topical and inter-

esting. It raised other wider ranging issues such

as how much longer is it expected to takein order for Turkish aquaculture to develop?

There are currently 4 standards internation-

ally for fish and Turkey must follow one.

Technological Developments inthe Open Seas in Fish Farming- by Darko Lisac of Refa Med Italy

Darko Lisac of Refa Med Italy has been

in aquaculture for thirty-five years. In 1977,

the first trials of marine cage farming in the

Mediterranean began, creating an early-stage

cage. This later developed into steel cages,however, it was found that the strength of

the waves caused the metal to crack. Cages

with flexible structures fit for absorbing the

force of the waves and environmental condi-

tions were soon produced however, a new

challenge arose where, in the open seas, the

waves are even greater. Circular cages were

later manufactured to solve this problem as it

was found that it could withstand the severe

exposure.

New nets are also now being tested,

using high tenacity polyolefin (plastic) to

produce knotless nets. As Tom Blacker from

International Aquafeed saw at an ear lier show

this year-Aquaculture UK, W&J Knox are just

one of the companies who manufacturer

these products. However in Turkey, these nets

are excellent in local conditions because of

the following reasons:

No water absorption

UV protection

The waxy surface reduces the amount

of fouling

Easy to clean in situ in which it is resist-

ant to abrasion High tensile strength- the fibres are

woven together tightly

Mr. Lisac then moved on to talk about other

equipment such as grid mooring farms and

the challenges facing them: big storms, the

domino effect (if one goes wrong so do the

others when the cages are adjoined)as well

as the existence submersible PE cage models,

Bonnar Engineering and Dunlop cages made of

submersible rubber material. Open Sea cage

systems such as the Ocean Spar sea station

(USA) and the Subflex system were discussed

also. The Refa Tension Leg Cage (TLC) was

mentioned. The TLC is another Open Sea

cage system that, during the build-up of waves,

can sink by itself, catching fish easily with very

little maintenance required.

Darko Lisac concluded that, Refa Med works

with farmers to overcome the environmental

and operational constraints in the open seas

and deliver functional technical solutions.

Health Management in MarineFinfish Productionby Dr Pierpaolo Patarnello

Veterinary Fish Pathologist

This was the second presentation Dr

Patarnello gave at the conference in whichthe concern for sanitation in fish farming was

addressed. To an extent there is always some

biological risk in intensive farming where infec-

tious, as well as environmental diseases can

manifest. Stress in cultured fish is also a major

problem that exposes them to disease due

to the metabolic stress condition to which

they are subjected. This refers to the uncom-

fortable habitat in which they live, including:

high density, intense feeding and a small envi-

ronment.

It is important that disease in aquacul-ture is contro lled not only to save the fish

product itself but also the wild species. A

recurring problem of marine farmed fish

is that the cages often attract those from

the wild. The promise of food and shelter

encourages the wild fish to get into the

cages by slipping through available holes

and gaps. Any possible diseases carried by

these fish then infiltr ate the water infect ing

the surrounding farmed fish. Dr Patarnello

describes pathology as the alteration of one

or more physiological aspects in a living

organism which appreciably compromises its

biological functions until the extreme conse-

quences of death. Pathogens are exchanged

between the fish, spreading disease, and,

potentially, inciting an epidemic. However,

the risk is not only limited to fish- in some

cases, diseases are zoonotic, allowing them

to be passed to humans, putting the farmers

in danger of infection as well.

Several diseases that can develop were

mentioned, including:

Vibriosis-results in skin and visceral

haemorrhages. In some cases, strainsof the bacteria have appeared that are

resistant to drugs/chemicals used to

treat the disease.

Lymphocystis-it is found that this viral

disease commonly manifests when fish

are under stress. Small, white growths,

occasionally mistaken for Ich, appear

on the fishs skin, growing until the

fish eventually dies. While there is no

known cure, some recommend surgery

in serious situations.

Pseudotuberculosis- this is an example

of a zoonotic bacteria that is common

in South America. In fish, the disease

causes the spleen, liver and lymph nodes

to inflame as well as cells in tissues to

die.

Streptococcus-this disease, also zoonot-

ic, is prone to appearing in fish that

live in stressful conditions, resulting in

inflammation of the brain. Side effects

can include lethargy, dorsal rigidity, and

erratic swimming behaviour; death fol-

lows in a matter of days. One way

to control the infection is to decrease

the quantity of feed given to the fish;

some antibiotics have also been proven

successful.As has been mentioned, there are some

ways to cure these diseases. But is there

a way to manage the risk so that the

fish dont become infected in the first

place?

Dr Patarnello reveals that control is the key.

It is impor tant, he says, to always keep sanitary

conditions under control, to be vigilant and

willing to increase and adapt the conditions

as and when problems arise. Other advice,

regarding technical and strategic control,

was relayed to the audience. The applica-

tion of health moni tor ing programmes by

fish farm managers can help to assess which

best practices should be enacted. Prevention

was described as a proactive type of treat-

ment:

Increase the control over the manage-

ment level of farms

More attention to sanitary requirements

of new seeds

More attention to prophylactic stand-

ards for infectious diseases

More attention to the feeding and to the

growth of cultured species

The presentation concluded that the con-

tinuous environmenta l mon itoring of fish

farms is vital in controlling the spread of

diseases. To do so requires specialized vet-

erinarians to carry out the surveillance as

well as making a routine of investigating the

fish, water and feed. Dr Patarnello finished

saying, According to 2006/88, all European

aquaculture companies must implement

Sanitary Surveillance programs, aimed not

only to control the epidemiological risk of

disease spread, but also to minimize theuse of disinfectants and chemotherapies

for a future production that is increasingly

healthy and safe for our fish, for our envi-

ronment, and for our children as future

consumers.




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