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Wooden tanks for tilapia aquaculture in El Salvador

Photo credit: Armando Romero (El Salvador) Description: Armando Romero and Abdel Rahman El Gamal (Founder of the website)

As shown in the photos, the tanks are above ground and constructed using locally available materials especially the wooden materials. The tanks are lined with plastic materials. These aquaculture structures are used to grow tilapia and act to train families on aquaculture. There is a governmental program supporting this initiative.

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Permanent link to this article: http://fishconsult.org/?p=14709

Cage culture of Nile tilapia in Togo

Photo credit: Asma Sabi (Togo) Description: Asma Sabi and Abdel Rahman El Gamal (Founder of the website)

The inserted photo shows a cage farming operation in Lake Nangbeto in Togo. The lake is a man-made lake for hydro-electric power generation with a size of 18,000 ha.

Cage farming was introduced in Lake Nangbeto by private investors. It is believed that cage aquaculture in lakes such as Lake Nangbeto can contribute to aquaculture production in Togo once found economically feasible especially in regard to the high cost of fish feed.  

Even though aquaculture in Togo is still in its infancy stage with a production of about 25, 58 and 98 tons in 2014, 2015 and 2016, Nile tilapia (Oreochromis niloticus) is the leading species representing 76, 69 and 54% of total aquaculture in the three mentioned years.

In the cage operation shown in the picture, the fingerlings of tilapia are either produced in Togo or imported from Ghana. The feed used is imported extruded pelleted feed. The cages in this farm are square with 5 meters for length and width while the depth is also 5 meters.

Permanent link to this article: http://fishconsult.org/?p=14705

Aquatic life in the British Thistlegorm shipwreck in Egypt – Video

Video credit: Patricia Martin Cabrera (United Arab Emirates)

Review: Abdel Rahman El Gamal (Founder of the video channel)

The video was filmed is the premise of the British navy shipwreck “Thistlegorm” located on the west coast of the Sinai Peninsula and 40 km from Sharm El Sheikh. This 125-meter steamship was built in 1940 and was launched in June 1940 and got sunk by two German bombers on 6 October 1941 during the World War II.  

Being well-preserved, the wreck is considered the most popular wreck in the world.  It is estimated that more than one million people have dived the Thistlegorm that acts as a giant underwater museum whereas divers enjoy watching the amazing sea life especially this wreck is in a good visibility. Even though, the focus has been placed more on Crocodile fish, many fish species are present on and around the wreck including barracuda, scorpionfish, moray eels, lionfish, turtles and other aquatic life. In addition to the living organisms, the wreck hosts variety of its original shipment of motorbikes, automobiles, trucks, trailers, armored cars and others. Because the Thistlegorm was classified as an armed freighter, it is considered as a war grave that must be treated with diver’s respect.

Permanent link to this article: http://fishconsult.org/?p=14700

Fish cages in Magat Dam Project in the Philippines

Photo credit: Marx Perfecto C. Garcia (Philippines)

Description: Marx Perfecto C. Garcia and Abdel Rahman El Gamal (Founder of the website)

These fish cage modules are a part of the Magat Dam Aqua-Park Project of the Bureau Resources of & Aquatic Fisheries/ Cordillera Administrative Region (BFAR-CAR). The project is composed of the cage modules and a floating house. Out of the 10 cage modules, nine have been established to provide areas for the fisherfolk to conduct their aquaculture activities towards improving their nutritional status as well as increasing their income. It is used for grow-out of tilapia and carp species. The fish cage modules are located within the Baligatan area of the reservoir. The fish cages are also designed to withstand typhoons.

Each of the nine modules has four cages, plus mooring system, and service boats. Each cage has been stocked with 2,500 fish fingerlings. The tenth module has six cages intended to be used as technology demonstration project of BFAR.

In order to ensure the friendly nature of the operation, the alternate-day feeding strategy has been recommended (skip feeding) which implies less feed provided and hence reduced possible pollution. In addition to the environmental safety of such approach, its economic feasibility has been reported. Note: Magat Dam, which was completed in 1982, is one of the largest dams in the Philippines located in Ifugao. The Magat Dam and reservoir has a total water area of 4,500 hectares. By law, about 10% of the area can be used for aquaculture.

Permanent link to this article: http://fishconsult.org/?p=14696

In-pond raceway aquaculture technology (Description and applications) – Video

Video credit: Marx Perfecto C. Garcia (Philippines)

Description: Abdel Rahman El Gamal (Founder of the video channel)

Historic information: As reported, the “In-pond raceway technology – IPR” was first developed in 2007 on a channel catfish farm in West Alabama, USA. Afterwards, the technology was transferred to China in 2013 and then after to more Asian countries including Vietnam, and India). Currently, the technology has been introduced to more countries around the global.  

System description: The system relies on the creation of water circulation within the raceway units located in earthen ponds as well as on the removal of the organic wastes. The water circulation is done using paddlewheel aerators and/or air blowers. The use of low speed paddlewheels provides a constant water current through the raceways. The aerators should be of capacity sufficient to create water flow of enough volume with particular velocity in the raceway cells which ultimately determines the frequency of water renewal within the raceway that in turn is a function of several parameters including the species, stocking density, and fish biomass.

This video was filmed in the Freshwater Fisheries Research Center (FFRC), Wuxi, China.

In regard to the waste removal, the water and sludge are moved from the raceways into a waste-settling zone in the open pond from where the water is filtered before re-circulation, while the organic wastes are periodically collected using mechanical collectors. The organic waste products in the open pond are carried into the open pond area where they are processed naturally and in the same time stimulate the growth of natural organisms that in-turn become a good food for other fish species especially in the open pond.

Typically,the raceways are constructed in parallel in a chosen corner of a traditional earthen pond with a center baffle to provide for a continuous circulation pattern around the pond and through the raceways. 

Applications: The application of the IPR technology has been promoted as a means to enhance aquaculture production of good quality fish and in the same time achieve a best utilization of water resources. That is why the technology has been encouraged in situations of water scarcity or high cost of natural resources such as land and water especially when the intensification of farming practices is targeted.

Several species have been grown in the IPR systems including and not limited to carps, channel catfish, paddlefish and others. Because of the cost involved in the establishment and operation of this system, high market value fish are often targeted.

Advantages: The IPR as mentioned ultimately targets higher production of high quality fishery products that result from healthy environment that ensures higher growth rate and survival, efficient feed conversion ratio and other productive traits.

Depending on the overall conditions and practices, the increase of the system productivity has varied significantly and ranged from as low as low as 50% to as high as 300%. Moreover, the environmentally nature of the system, the no water discharge from production ponds to outside eliminates the possible negative impacts to the environment. The sustainable utilization of water resources is considered a key advantage for the IPR system especially when compared to the traditional raceway system depends on high-flow rate of incoming water with no reuse of discharged water.   The choice of the raceway fish and the co-cultured species would vary depending on the production target. An example for that is culture of channel catfish (Ictalurus punctatus) in the raceway facility, while the paddlefish (Polyodon spathula) is grown as a co-cultured species in the open pond. In a production arrangement as such, the main cultured species which is channel catfish enjoys the best water quality in the raceway. Also, the open pond system provides a safe and stress-free environment to the paddlefish (co-cultured species).

Permanent link to this article: http://fishconsult.org/?p=14687

Saving and not killing the African catfish males through the ablation of testes

Photos’ credit: Mouhamed Hosni Kouotou (Cameroon)

Description: Abdel Rahman El Gamal (Founder of the website/FB page)

Because the testes of the males of African catfish (Clarias gariepinus) are situated in the dorsal part of the abdominal cavity, and because of the anatomy of the species and the presence of the seminal vesicle and internal organs block the flow of milt and prevent its release under abdominal massage from live males in captivity. Thus, in order to obtain milt for artificially fertilizing eggs, males are generally sacrificed before testes are removed and squeezed to release the milt.

Losing a male catfish after another could limit their numbers along with the possible production problems. Added to that, sacrificing catfish males hinder particular genetic applications that require the repeated use of the same male especially in the absence of cryopreservation facilities.

In order to avoid sacrificing the catfish males, surgical operations have been successfully practiced. The operation begins with the selection of sexually mature males based on their genital papilla. Afterwards, the chosen fish is anesthetized usually in bath treatment to the level that allows the surgical operation.  Even though severalanesthetics have been used, the Tranquil (Tricaine) MS-222 is the only anesthetic approved by FDA for use in food fish.

Once the fish are totally anesthetized, the ventral side of fish abdomen should be disinfected using a proper substance such as methylated spirit (40% alcohol). Immediately after, an incision is made on the ventral side of the abdomen using surgical scissors and the testes are exposed for ablation whereas about three quarter of the testes were removed for the use in the fertilization of catfish eggs.

The incisions are typically sutured in a way similar to surgical operations. On the average, the surgical operation lasts about 10-15 min. An antiseptic medicine is used to treat the wound and skin infection. Afterwards, fish are to be placed in anesthetic-free, aerated water for recovery which is expected to take place within few minutes.

For a relatively long-term treatment, operated fish may be placed in a tank containing water with antibiotics such as Oxtetracycline at proper dosage for recommended period of time; 50mg/L for 5 days. Operated fish should be fed high quality feed as required for speeding the regeneration process of ablated testes which is usually reached after a period ranging from as short as 30 days to as long as 120 days from post the ablation. On the average, the operated male may be used again after about 90 days and so on.

Permanent link to this article: http://fishconsult.org/?p=14683

Cage culture of tilapia in Gabon

Photo credit: Franck Aristide (Gabon) – Description: Abdel Rahman El Gamal (Founder of the video channel)

The inserted picture shows floating cages located in Lake Mbolet in Gabon where Nile tilapia (Oreochromis niloticus) is the species cultured in these cages. The authorities in Gabon are encouraging the development of cage fish farming. It is believed that the new fish station that was inaugurated in July, 2013 and located few miles away from Lake Mbolet would support the development of cage fish farming in the lake. The station with its hatchery, food storage room, research laboratory and others has been constructed as a result of a partnership with the government of Japan.

Permanent link to this article: http://fishconsult.org/?p=14678

Drying of Lake Tanganyika sardines in Zambia

Photo credit: Nathan Chama (Zambia)

Description: Nathan Chama and Abdel Rahman El Gamal (Founder of the website)

The inserted picture shows a woman while drying some Tanganyika sardine Stolothrissa miodon which is known in Zambia as “kapenta”. The sardine drying takes place on the beaches of Lake Tanganyika in Nsumbu area (Zambia). Dried kapenta fetches a good market price in the mentioned area.

These sardines are freshwater species that belong to the family Clupeidae. They are planktivorous,pelagic and characterized by their small size with average length of about 7cm. The species experienced high level of overfishing in the last two decades.The dried kapenta being made from whole fish was found to be a good source for minerals and trace elements such as calcium, iron and zinc. Added to that, the dried kapenta is rich in vitamin B12 and other bioactive substances. The overall nutritive merit of the dried sardines makes it a recommended supplement for the improvement of maize-based diets.

Permanent link to this article: http://fishconsult.org/?p=14671

Aquaculture in Kenya (Status – Challenges – Outlook)

This introductory lecture was delivered in the opening of the “Aquaculture training workshop” which was conducted during the period 24 to 28 September, 2018 and held at Kenya Forestry Research Institute (Nairobi).

I tried in this lecture to bring in the information on fishery/aquaculture sector in Kenya but also to highlight other related sectors such as particular agricultural crops which could be used in fish feed. In order to emphasize the rationality of aquaculture development in Kenya, the key human nutrition parameters have been addressed such as the daily per capita protein intake and identifying all sources for such intake. The lecture ended by the challenges facing the development of aquaculture in Kenya. A brief introduction on world and African aquaculture was included in the first part of the lecture. Asplanned, this lecture served as a platform for subsequent components of this training workshop.

Permanent link to this article: http://fishconsult.org/?p=14662

Small-scale aquaculture training course – Africa (Egypt – EICA, 2018)

 

The inserted photos were taken on December 02, during the first technical day of the “Small-scale aquaculture” training course. This 12-day course is organized by the Egyptian International Centre for Agriculture (EICA). The course hosts 28 participants from 20 African countries. The photos show Dr. Abdel Rahman El Gamal, Mrs. Mona and Mrs. Sohair the course organizers. The course participants are:

Adja Nana Dama and Patindbeme Ily (Burkina Faso), Majambere Gustave and Niyitunga Marcien (Burundi), Djakba Akero (Cameroon), Abdoulkadre Mahamat and Saleh Abakar Oumar (Chad), Mbongo Nzita Lievin and Tusanga Mukanga (DR Congo), Houssein waiss amoud (Djibouti), Santiago Ochaga Edu (Equatorial Guinea), Frank Aristide (Gabon), Mamadou Oulare (Guinea), Judith Auma Okinda (Kenya), Mhango Arthur and Sifo Mofolo (Malawi), Bakary Sidibe and Mahamane Baby (Mali), Abdoola Bye Ibrahim (Mauritius), Kaulo Salushando (Namibia), Moussa Haoua Amadou (Niger), Hassan Shettima Modu and Timothy Fayemi (Nigeria), Chernor Abass Bundu (Sierra Leon), Zakaria Mohamed Hagi (Somalia), Asma Sabi (Togo), Mildred Nabbika and Stella Mbabazi (Uganda)

Permanent link to this article: http://fishconsult.org/?p=14653

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