Fish

- The fish market

On average around the world, around 19.7 kg of fish is consumed per person per year. Annual per capita consumption in Oceania is approximately 24.8 kg, in North America 21.4 kg and in Europe 22.2 kg (Source: State of world fisheries and aquaculture, FAO, 2016). ⁽¹

Germany

In 2020, a total of 1.14 million tons of fish and seafood were consumed in Germany. This corresponds to a per capita consumption of 14.1 kg. ⁽² The market shares of fish and fishery products in Germany were broken down as follows in 2018: ⁽³

61.9% sea fish
26.5% freshwater fish
11.6% crustaceans and molluscs

Per capita consumption is distributed across the following product groups:

29% preserves and marinades
25% frozen fish
14% crustaceans and molluscs (fresh, frozen, prepared)
12% fresh fish
11% smoked fish
6% other fish products
3% fish salads

Market shares of the most important fish, crustaceans and mollusks in percent

	2010	2011	2012	2013	2014	2015	2016	2017	2018	2019	2020
Pacific pollack ( Alaska pollack )	20.8	22.1	26.0	22.0	21.4	18.3	14.9	16.5	17.3	17.7	15.2
Salmon	13.0	13.7	15.0	20.0	22.0	20.5	18.2	16.7	16.4	18.8	17.6
Tuna, bonites	10.1	11.3	10.9	13.2	12.4	14.1	9.8	12.9	13.3	11.4	16.4
herring	20.0	19.1	18.1	16.8	14.7	15.9	15.7	13.9	14.1	10.0	10.1
shrimp	–	–	–	–	–	–	5.9	7.0	7.2	7.4	8.1
Trout	4.9	4.2	3.4	5.5	5.9	6.2	5.4	5.8	6.2	6.8	6.9
Köhler (trade name: Pollock )	3.4	2.8	1.6	2.2	1.5	1.5	2.6	2.3	2.7	2.3	1.6
Squids	–	–	–	–	–	–	2.0	2.4	2.5	2.7	2.3
cod	1.6	2.2	2.2	0.3	2.7	2.4	3.2	2.1	1.8	2.1	2.1
Pangasius, catfish	5.8	5.0	3.5	3.5	2.9	2.5	1.9	1.7	1.6	1.7	1.3
Zander	0.8	0.6	0.7	1.0	1.0	0.9	1.0	1.1	1.0	0.9	1.0
Shellfish	–	–	–	–	–	–	1.0	1.1	1.3	0.4	1.7
Redfish	2.5	1.5	1.0	1.6	1.4	1.7	1.3	0.7	1.1	1.5	1.1
sardine	0.6	0.7	0.9	0.6	0.7	1.2	1.1	0.6	0.7	1.0	0.8
hake	2.3	1.7	0.5	0.4	0.3	0.1	0.4	0.5	0.8	1.1	0.3
mackerel	1.2	1.9	1.9	1.7	2.0	2.3	1.5	0.9	0.7	1.8	2.0
plaice	0.8	1.0	0.8	1.1	1.2	0.8	0.9	0.8	0.7	0.6	0.4
carp	1.2	0.8	0.6	0.8	0.8	0.6	0.8	0.8	0.6	0.6	0.5
Dorade	–	–	–	–	–	–	0.5	0.5	0.5	0.5	0.5
Hoki	–	–	–	–	–	–	0.3	0.7	0.3	0.5	0.1
Halibut	–	–	–	–	–	–	0.4	0.5	0.3	–	–
Haddock	0.6	0.6	1.0	0.7	0.7	0.5	–	–	–	–	–
Tilapia	0.5	0.5	0.5	0.6	0.5	0.5	–	0.4	0.4	0.4	0.4
monkfish	0.6	0.6	0.5	0.6	0.3	0.1	–	–	–	–	–
Other	6.1	8.4	9.0	7.4	7.4	9.6	11.2	10.6	8.8	9.8	8.8

86% of edible fish and fishery products are imported.

The most important supplying countries are: ⁽⁴

Poland (19.2%)
Netherlands (11.9%)
Denmark (9.1%)
Norway (10.7%)
China (7.3%)

Sources:

FOEN (ed.): Fish import and fish consumption. In: fischereistatistics.ch. Retrieved April 18, 2021.
Fish Information Center (August 13, 2021): New consumption figures for fish and seafood .
Fishing industry - data and facts 2019. (PDF) Accessed on September 4, 2019.
https://de.wikipedia.org/wiki/Speisefisch

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ID: 550

. Fish in Aquaponics

Fish Quay North Shields unknown c.1890 s — 001835:Fish Quay North Shields unknown ca.1890

by Newcastle Libraries, Public Domain Mark 1.0.

In order to find the right fish for your own aquaponics system, you can already fall back on a large selection of suitable food fish. There are small fish for small systems and large ones for larger ones. However, they all have to fulfil some basic requirements. As a rule, fish are used that can withstand the high, almost tropical temperatures in a plant. So they have to be heat-resistant. Furthermore, they have to get along with many conspecifics in a small space. This requires a certain stress resistance of the fish, which enables the breeders to keep, manipulate and care for the fish conscientiously and without hesitation.

One of the greatest dangers resulting from rearing in open aquacultures is the transmission of diseases and the transfer of genetic material from farmed fish to wild fish. This happens when fish escape from aquaculture and come into contact with wild animals. Since in aquaponics the facilities form a closed circuit and are located far away from the wild fish areas, there is no genetic crossing of the farmed fish with wild fish. This is another factor that has a strong positive effect on the use of aquaponics. So which species are suitable for aquaponics?

In the following we have listed all the relevant key data of a wide variety of fish species, which can narrow down your selection for your purposes by growth, breeding duration, temperature range and many other factors.

Please understand that we only share this information with our customers.

Therefore, only the first entry in our database is displayed publicly. If you have any questions, please do not hesitate to contact us.

Kontext:

ID: 414

. Stocking density

The amount of fish you can safely and legally keep in your system (fish welfare) depends on many factors. There would be, among other things:

Feed rate / quantity / feed type
Pump performance and reservoir size/circulation speed
Amount of water or nutrient solution
Water temperature
water flow
Oxygen content
Nitrite and nitrate content
Number of plants in the bed or in the hydroponic system
Volume of the plant bed or amount of nutrient solution
Fish species or species
Aquarium size

Not all the decisive factors are mentioned here!

In smaller systems but beyond your own needs , you can expect around 10-12 fish in a 1000 liter aquarium = 1m ³ = 1 IBC container (open at the top).

Be sure to consult with an official veterinarian about the legal regulations before building the fish farm. These change regularly!

Here are the regulations, some of which come from breeding in ponds because the legislature has not yet derived all the regulations for aquaponics:

Stocking densities according to EU organic aquaculture regulations:

15 kg/m³ brook trout (Salvelinus fontinalis)

15 kg/m³ Coregonen (Whitefish Coregonus)

15 kg/m³ trout (Oncorhynchus, Trutta)

20 kg/m³ Arctic char (Salvelinus alpinus)

25 kg/m³ brown and rainbow trout

20 kg/m³ salmon: brown trout (Salmo trutta fario), lake trout (Salmo trutta lacustris), sea trout (Salmo trutta trutta), rainbow trout (Oncorhynchus mykiss)

10 kg/m³ milkfish (Chanos chanos)

10 kg/m³ tilapia (Oreochromis sp.)

10 kg/m³ Mekong catfish (Pangasius sp.)

Quote : The prerequisites are compliance with the ban on deterioration in water quality (2) (in accordance with Directive 2000/60/EC European Water Framework Directives), as well as an oxygen saturation of at least 7 mg/L and a minimum inflow rate of 3 seconds liters per ton of fish. Under no circumstances should the animals show injuries (e.g. to the fins) that indicate that the stocking density is too high. Tropical freshwater fish (e.g. milkfish Chanos chanos, tilapia Oreochromis sp., Mekong catfish Pangasius sp.): the stocking density in ponds and net enclosures (pens, enclosures) must not exceed 10 kg/m3 as an upper limit.

COMMISSION REGULATION (EC) No 710/2009 of 5 August 2009

https://eur-lex.europa.eu/LexUriServ/LexUriServ.do?uri=OJ:L:2009:204:0015:0034:DE:PDF

Salmonids in freshwater:
Trout (Salmo trutta) - Rainbow trout (Oncorhynchus mykiss) - Brown trout (Salvelinus fontinalis) - Salmon (Salmo salar)
- Arctic char (Salvelinus alpinus) - Grayling (Thymallus thymallus) - American arctic char (Salvelinus namaycush) -
Huchen (Hucho hoo)

Production system: Production must take place in open systems. The water change rate must ensure an oxygen saturation of at least 60%, be tailored to the needs of the animals and ensure sufficient drainage of the water in the holding area.

Maximum stocking density

Salmonids other than those listed below: less than 15 kg/m ³
Salmon: 20 kg/m ³
Brown trout and rainbow trout: 25 kg/m ³
Arctic char: 20 kg/m ³

Sturgeon (Acipenseridae) in freshwater
production system: The water flow in each housing unit must meet the physiological needs of the animals.
The outgoing water must be of equivalent quality to the incoming water.

Maximum stocking density 30 kg/ ^m3

Carp fish (Cyprinidae) and other associated species in polyculture, including perch, pike, catfish, pike, sturgeon.

In fish ponds, which are completely drained at regular intervals, and in lakes. Lakes must be used exclusively for organic production, including agriculture in their dry areas. The fishing area must have an inflow of fresh water and be large enough so that the animals' well-being is not impaired. After harvesting, the fish are kept in fresh water.

Flag shrimp (Penaeidae) and freshwater shrimp (Macrobrachium spp)

Establishment of production units: Settlement in areas with infertile clay soils to minimize the environmental impact of pond construction. Pond construction with the existing clay. The destruction of mangrove stands is not permitted.

Transition time Six months per pond, corresponding to the usual lifespan of shrimp in aquaculture
Origin of the parents: At least half of the parents must come from offspring after three years of operation of the facility. The remaining parent stock must come from pathogen-free wild stocks from sustainable fishing. The first and second generations must be screened before being introduced into the systems.
Removal of eyestalks is prohibited
Maximum stocking densities and production quantities

Cultivation: maximum 22 postlarvae/m ²
Maximum density: 240 g/m ²

Milkfish (Chanos chanos), cichlids (Oreochromis sp.), shark catfish (Pangasius sp.)
Production systems Ponds and net cages
Maximum stocking density

Shark catfish: 10 kg/m ³
Cichlids: 20 kg/m ³

Sources include: https://eur-lex.europa.eu/LexUriServ/LexUriServ.do?uri=OJ:L:2009:204:0015:0034:DE:PDF

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. Stress in Fish

Fish are much more susceptible to disease than they are stressed. The most important are infectious diseases including parasitoses, water-related damage and stress factors in the housing conditions. Injuries, hereditary diseases, malformations and tumors also occur in fish.

Some infectious diseases can lead to mass loss in fish farming. They are then referred to as fish diseases and are subject to legal measures in accordance with the Animal Health Act, special legal regulations or EU legal provisions.

In Germany, four fish diseases are currently classified as notifiable animal diseases: contagious anemia of the salmon, infectious haematopoietic necrosis and viral hemorrhagic septicemia of the trout as well as the koi herpes virus infection of the carp. The infectious pancreatic necrosis of the salmonids (IPN) is subject to notification.

There is a complex interdependency between the defense capabilities, the pathogens and the living conditions, which ultimately decides on the outbreak of infectious diseases. Different factors can trigger stress. This includes everything that makes fish restless and disturbs their rhythm of life, such as constant handling in the water, but also constant changing of the light-dark phases. Worsened water parameters, such as a lack or excess supply of oxygen, excessive ammonium, nitrite or CO content, are also considered a stress factor2nd, as well as unfavorable pH values, incorrect water temperature, lack of hiding places, wrong choice of species, or excessive flow.

Stress weakens the animal's ability to defend itself. As a result, they cannot maintain an immune imbalance with the most ubiquitous pathogens. Only then does an infection become a breaking „disease“.

Stress triggers:

High ammonia values
Increased nitrate levels
Wrong pH of the water
Fluctuating temperature
Unsuitable salinity
Low oxygen content
Harassment by other fish
Inadequate pool size
Too many fish in the pool
Excessive use of medication
Poor diet
Sudden changes in water chemistry
Improper use of water treatment agents

Stress indicators:

Loss of appetite
Increased gill movements

Diseases and unicellular parasites can cause a variety of symptoms in infected fish:

Some fish have difficulty swimming and lose their balance and buoyancy.
Sick fish often hold their fins flat against the body.
You may see your fish lying on the side of the tank or pond floor.
Some conditions can lead to higher mucus production, which leads to cloudy spots on the flanks of the fish.

Another symptom is an inflated stomach of the fish. Outstanding or damaged scales.
A fish with a weakened immune system is more likely to develop a fungal infection that can form gray growths that look like cotton on the scales.
Harmful bacteria can cause the gills to look red and irritated. The gills may remain open when the fish has gill mites.

Fin rot and bacterial infections can cause the tail and fins of a fish to look frayed.
Stressed fish cannot defend themselves against parasites such as anchor worms or lice.
Aquatic addiction, which occurs in fish with a fluid accumulation under the scales, can also indicate the presence of bacteria.

Stress-related illnesses:

Because the causative agent of ichthyophthiriosis is a weak parasite and the puncture disease actually breaks out mainly when the fish is stressed, the stress for the animals in the aquarium should be reduced as much as possible. This includes stocking density, temperature, lighting, etc.

This article includes. Excerpts from the Wikipedi contribution fish disease: https://de.wikipedia.org/wiki/Fischkrankheit

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ID: 406

. Typicall fish diseases

In aquaponics systems, fish can be susceptible to various diseases, just like in traditional aquaculture setups.

Some common fish diseases that may occur in aquaponics include:

Columnaris Disease (Flexibacteriosis):
- Caused by the bacterium Flavobacterium columnare.
- Symptoms include white or grayish patches on the skin, frayed fins, and lethargy.

Aeromonas Infections:
- Caused by bacteria of the genus Aeromonas.
- Symptoms may include ulcers, fin rot, hemorrhages, and abdominal swelling.

Dropsy:
- A symptom rather than a specific disease, dropsy is characterized by fluid retention and swelling of the abdomen or body cavity.
- Can be caused by various bacterial, viral, or parasitic infections.

Ichthyophthirius (Ich):
- A protozoan parasite commonly known as "white spot disease."
- Symptoms include white spots on the skin, rapid breathing, and rubbing against objects.

Dactylogyrus (Gill Flukes) and Gyrodactylus (Skin Flukes):
- Parasitic flatworms that infect fish gills or skin.
- Symptoms include increased mucus production, respiratory distress, and skin irritation.

Koi Herpesvirus (KHV):
- A highly contagious virus affecting common carp and koi.
- Symptoms include lethargy, loss of appetite, skin lesions, and respiratory distress.

Viral Hemorrhagic Septicemia (VHS):
- Caused by a rhabdovirus, VHS primarily affects salmonids but can also impact other fish species.
- Symptoms include hemorrhages, abdominal distension, and lethargy.

Cyprinid Herpesvirus 3 (CyHV-3):
- Also known as koi herpesvirus (KHV), this virus primarily affects koi and common carp.
- Symptoms include skin lesions, lethargy, and respiratory distress.

Fin Rot:
- Often caused by bacterial infections, fin rot leads to the deterioration of fins.
- Symptoms include frayed or eroded fin edges and reddening or inflammation of the fin base.

Bacterial Septicemia:
- General term for bacterial infections that spread throughout the bloodstream.
- Symptoms may include lethargy, loss of appetite, skin discoloration, and hemorrhages.

Preventive measures such as maintaining optimal water quality, practicing good hygiene, quarantining new fish, and providing balanced nutrition can help minimize the risk of disease outbreaks in aquaponics systems. Additionally, early detection and prompt treatment of sick fish are crucial for preventing the spread of diseases and minimizing losses.

How to avoid them

Preventing fish diseases in aquaponics systems involves implementing various management practices to maintain optimal water quality, minimize stress on fish, and prevent the introduction and spread of pathogens. Here are some key preventive measures:

Maintain Optimal Water Quality:
- Regularly monitor and maintain water parameters such as temperature, pH, ammonia, nitrite, nitrate, and dissolved oxygen levels within recommended ranges.
- Ensure proper filtration and aeration to remove waste products, maintain oxygen levels, and promote a healthy aquatic environment.
- Perform routine water changes to dilute accumulated toxins and replenish essential nutrients.

Practice Good Hygiene:
- Keep the aquaponics system and equipment clean and free of debris, algae, and biofilm buildup.
- Regularly clean and disinfect equipment, such as pumps, filters, and grow beds, to prevent the buildup of pathogens.
- Practice proper hand hygiene and use separate tools and equipment for different aquaponic components to prevent cross-contamination.

Quarantine New Fish:
- Quarantine newly acquired fish in a separate tank or system for a period of time (usually 2-4 weeks) to monitor for signs of illness before introducing them to the main aquaponics system.
- Observe quarantined fish for symptoms of disease such as abnormal behavior, appetite loss, lesions, or fin damage.

Provide Proper Nutrition:
- Offer a balanced diet appropriate for the species of fish being cultured, ensuring they receive essential nutrients and vitamins to support immune function and overall health.
- Avoid overfeeding, as excess uneaten food can decompose and degrade water quality, leading to increased disease risk.

Monitor Fish Health:
- Regularly observe fish behavior, appetite, and appearance for signs of illness or distress.
- Conduct routine health checks and screenings, including visual inspections, netting and handling fish for closer examination, and observing water quality parameters.

Avoid Stress:
- Minimize stress on fish by providing adequate space, shelter, and hiding places within the aquaponics system.
- Avoid sudden changes in environmental conditions, such as rapid temperature fluctuations or water chemistry swings, which can stress fish and weaken their immune systems.

Practice Biosecurity:
- Limit the introduction of potential pathogens by purchasing fish from reputable sources with known health histories.
- Restrict access to the aquaponics system to authorized personnel only, and implement biosecurity protocols to prevent contamination from outside sources.

By implementing these preventive measures and maintaining a proactive approach to fish health management, aquaponics practitioners can minimize the risk of disease outbreaks and maintain a healthy and productive system for both fish and plants. Regular observation, monitoring, and timely intervention are key to identifying and addressing potential issues before they escalate.

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Acipenser baerii / Siberian sturgeon

Siberian sturgeon (Acipenser baerii)

The Siberian sturgeon comes from the rivers of Siberia and Lake Baikal. It is divided into three subspecies; The Acipenser baerii baerii from the Ob River (Western Siberia), the Acipenser baerii baicalensis, which comes from Lake Baikal and the Acipenser baerii stenorhynchus, which is native to the eastern rivers of Siberia.

The sturgeon is not only a tasty food fish, but is also best known for producing caviar. The original Kavier comes from him. The production of the most valuable caviar, Almas, can take up to 30 years from rearing to harvesting.

Each female can then carry 5 to 20 kg of caviar. Cavier is now mainly produced in Russia and Iran. The sturgeon can live for over 60 years, reach a maximum length of 250 cm and weigh up to 210 kg. The sturgeon, like the salmon, is one of the so-called other fish ( potamodromes ). During their spawning period between the ages of 11 and 19, the females lay their eggs in the main current of the water, where the water flows at a speed of 1 to 4 meters per second.

Characteristics	Siberian sturgeon
Latin. Surname	Acipenser baerii
Okay, family	Acipenseriformes, Acipenseridae
Happen	Siberia, Lake Baikal
Habitat	Flowing water and lakes
Height Weight	200 - 250 cm / max. 210 kg
Life expectancy	> 60 years
Stocking density	maximum 30 kg / m ^{3 (1 (vol}
temperatures	16 - 24 ⁰ Celsius
pH range	6.5 - 8.0 (show suitable plants)
oxygen	at least 6.0 mg/l
Water hardness	2 - 25° dGH ^(dGH
NO₂ (nitrite)	max. 1 mg/l
NO₃ (nitrate)	max. 100 mg/l
growth	1-2 g / day at 25⁰ Celsius
FCR	0.7 - 1.5
Fishing	After the first spawning period, caviar can be harvested again in a cycle of 3 - 4 years using the Aquatir technology, in which the females survive and do not have to be slaughtered. Depending on your preference, the animals can also be slaughtered for meat depending on their size.
food type	Omnivore/Omnivore
Preferred	Small crustaceans, insect larvae, mollusks, small fish
Certification	no EU certification. However, there are a number of regulations and certificates for the production and quality of cavier.
ASC/organic seal	unavailable
ASC requirements	unavailable
Feed	High quality dry mix feed from the Coppens International brand in pelleted form 3 - 10 mm in size. It contains 42% proteins, 18% fat, 1.8% crude fiber, 6% crude ash and 0.9% phosphorus. 1% of the fish's live weight is recommended for the daily food ration.

Context:

Sources:
https://www.laprensalatina.com/the-sturgeon-caviar-farm-harvesting-roe-willing-fish/
https://www.researchgate/279581_Growth_food_conion_Siberian_Siberian _Acipenser_baeri_brandt_at_different_daily_feeding_rates https: //www.dehner .at/ratgeber/zoo-tipps/ratgeber-stoere/
http://www.sturgeon-web.co.uk/water-quality
https://www.aquafuture.de/pdf/fischer_teichwirt_1_2010.pdf
https://www .fischlexikon.eu/fischlexikon/fische-suche.php?fisch_id=0000000089

bd) Stocking densities according to regulations for organic aquaculture in the EU:

15 kg/m³ brook trout (Salvelinus fontinalis)

15 kg/m³ Coregonen (Whitefish Coregonus)

15 kg/m³ trout (Oncorhynchus, Trutta)

20 kg/m³ Arctic char (Salvelinus alpinus)

25 kg/m³ brown and rainbow trout

20 kg/m³ salmon: brown trout (Salmo trutta fario), lake trout (Salmo trutta lacustris), sea trout (Salmo trutta trutta), rainbow trout (Oncorhynchus mykiss)

10 kg/m³ milkfish (Chanos chanos)

10 kg/m³ tilapia (Oreochromis sp.)

10 kg/m³ Mekong catfish (Pangasius sp.)

Quote : The prerequisites are compliance with the ban on deterioration of water quality (2) (in accordance with
Directive 2000/60/EC European Water Framework Directives), as well as an oxygen saturation of at least 7 mg/L
and a minimum inflow rate of 3 seconds liters per t of fish. Under no circumstances should the animals show injuries (e.g. to the fins) that indicate that the stocking density is too high. Tropical freshwater fish (e.g. milkfish Chanos chanos, tilapia Oreochromis sp., Mekong catfish Pangasius sp.): the stocking density in ponds and net enclosures (pens, enclosures) must not exceed 10 kg/m3 as an upper limit.

Stocking density regulation EU: REGULATION (EC) No. 710/2009 OF THE COMMISSION of August 5, 2009

https://eur-lex.europa.eu/LexUriServ/LexUriServ.do?uri=OJ :L:2009:204:0015:0034:DE:PDF

dGH values ) https://www.aquarium-guide.de

1) Naturland guidelines: https://www.naturland.de/images/01_naturland/documents/Naturland-guidelines_Aquakultur.pdf

ID: 576

Foreword to fish farming in aquaponics systems

Fish farming plays a central role in aquaponics systems and represents a symbiotic complement to plant production. The combination of fish farming and hydroponics creates sustainable circular systems that make optimal use of and support both components. The fish provide valuable nutrients for the plants through their excretions, while the plants in turn purify the water and provide the fish with a healthy living environment.

The integration of fish farming into aquaponics systems offers numerous advantages. Firstly, it enables the production of fish as an additional source of protein, which increases the economic viability of the systems. Secondly, it promotes environmental sustainability by using natural resources efficiently and reducing the need for chemical fertilizers. The closed loop minimizes water consumption and avoids pollution of the environment through wastewater.

However, fish farming in aquaponic systems requires specific know-how and careful management to maintain the balance of the system. Factors such as fish species selection, feed quality, water parameters and disease control must be constantly monitored and adjusted. However, with growing experience and technological advances, fish farming in aquaponic systems is becoming more accessible and efficient, making it a valuable contribution to sustainable food production.

Image: https://www.flickr.com/photos/105390931@N02/52478994709 Public Domain

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ID: 584

Borgmann Aquaponik & Hydroponik

Fish

- The fish market

Germany

. Fish in Aquaponics

. Stocking density

. Stress in Fish

. Typicall fish diseases

How to avoid them

Acipenser baerii / Siberian sturgeon

Foreword to fish farming in aquaponics systems

Technology