Aug 14 2014

Tunnel freezing of tilapia in China

Credit: Kevin Fitzsimmons (USA)

Review: Abdel Rahman El Gamal (Founder of the website)

The photos show the tunnel freezing of tilapia fillets or as a whole that is carried out in a processing establishment in China.

Tilapia is an emerging species in China’s processing industry whereas tilapia fillet is the major output from tilapia processing. The export of processed tilapia has been supported by the Simple basic fish handling and processing technologies are being progressively replaced by the latest modern processing technologies.

According to the U.S. Commerce Dept., about 80 percent of the frozen tilapia in the U.S. is imported from China.

China - Tunnel freezing of tilapia fillets China - Freezing of whole tilapia

 

Permanent link to this article: https://fishconsult.org/?p=11520

Aug 12 2014

Developing and disseminating the YY technology of tilapia super male in the Philippines

Photo credit: Kevin Fitzsimmons (USA)

Review: Abdel Rahman El Gamal (Founder of the website)

The “YY super tilapia male technology is considered an effective breeding protocol towards the production of all-male progeny for farming which has a special importance in tilapia farming.

The YY technology is a form of a breeding program which combines feminization and progeny testing resulting what is known by “super tilapia male” with two male sex chromosomes “YY” instead of the usual XY male. These YY males when mating with regular females, the progeny are only males.

In the Philippines, the dissemination of YY technology is being done through accredited hatcheries. There have been funded projects in Philippines on the production and dissemination of YY super tilapia male technology whereas the Bureau of Fisheries and Aquatic Resources (BFAR), and some Pilipino universities collaborated in these projects.

Philippines - YY Hatchery complex

 

 

 

Permanent link to this article: https://fishconsult.org/?p=11516

Aug 12 2014

A typical fishing boat and gears in the Blue Nile (Sudan)

Credit: Mamoun Obeida (Sudan)

The photo shows from a distance a traditional boat which is locally named “Bongolu” that operates in Blue Nile River (Roseires Reservoir-Blue Nile State). The boat is used for collecting fish from fishing camps and could be used for transportation during flood seasons. This boat is equipped with 40-hp out-board engine. The fishing gears which are commonly used in these boats are gill nets with different mesh sizes, long line, traps and seine nets.

Fishing boat (Blue Nile - Sudan)

 

Permanent link to this article: https://fishconsult.org/?p=11511

Aug 12 2014

Experimental polyculture of tilapia in shrimp ponds in Thailand

Credit: Kevin Fitzsimmons (USA)

The photo shows an earthen shrimp pond in which tilapia cages are installed. The aerators in the pond indicate the intensification level of pond management. This experimental operation is carried out at Asian Institute of Technology (AIT), Thailand. The key outcomes of this operation show > 90% as survival rates. The yield of shrimp amounted around 3000 kg/ha while tilapia yield amounted 1500 kg/ha. The average size of tilapia is about 10 g upon stocking and reaches about 300 g upon harvesting after 10 weeks.

Source: Remedios Bolivar, Yang Yi Wilfrido Contreras, and Kevin Fitzsimmons, 2003. International cooperation in evaluation of environmental & economic impacts of tilapia-shrimp polycultures.

Shrimp tilapia polyculture in Thailand

Permanent link to this article: https://fishconsult.org/?p=11508

Aug 12 2014

Cage culture of meagre in Spain – Video

Video credit: Ahmed Shaheen (Egypt)

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

The farming of meagre, Argyrosomus regius in Spain started in 2004 peaking in 2010 whereas its production amounted 3250 tons before declining in 2011 and further declining in 2012 whereas the meagre production amounted 1640 tons. Although meagre is well known by wholesalers, retailers and large outlets, a large proportion of the Spanish consumers are not aware about meagre that has been seen as a new species to the majority of consumers.

Meagre is mainly farmed in marine floating cages of 500–1 000 m³, and more recently submerged cages have been used in the culture of meagre whereas cages are submerged at 10–20 m.

The stocking density is often low and could range between 10–15/m³. Target produced size varies according to the market chain and could range from 1-2 kg for consumers to 2-3 kg for restaurants.

The incorporation of meagre in the Spanish aquaculture will be of great value in diversifying the production basket that mainly focuses on gilthead seabream and European seabass especially when considering the high quality of meagre flesh that are summarized in its low fat, high levels of Omega-3 fatty acids and has a long shelf life. Promoting meagre aquaculture should start from consumers who need to be aware of this species and its advantages, and supply must be adjusted to meet potential demand.

 

 

Permanent link to this article: https://fishconsult.org/?p=11505

Aug 11 2014

Fish smoking and commonly used smoker “Chorkor” in Ghana

Credit: Patrick Appenteng (Ghana)

In Ghana most harvested fish from aquaculture are usually processed and enjoyed by grilling; which usually go well with a local dish called “banku and hot pepper sauce”.

This is however not the case with most fishes from the various inland and marine water bodies: Fishes from these sources are usually smoked on locally accepted smoking plants called the “chorkor” smoker.

The insert shows a “chorkor” smoker which is used by fish processors at the Kpong landing site in the Lower Manya Krobo District, although it is almost used in the whole country of Ghana for processing fish from the various water bodies.

The “chorkor” smoker is made from mud either in a rectangular or square shape, with a single or double stoke hole. The insert however has a single stoke hole. Fishes are arranged on wooden trays which are placed on each other (sometimes up to 15 trays on a single smoker). The “chorkor” is most preferred for smoking fish in Ghana because of added advantages of easy smoking, gives well smoked fish, ability to smoke many fishes at a time among many others.

Ghana - Fish smoking and smokers

 

 

Permanent link to this article: https://fishconsult.org/?p=11502

Aug 11 2014

Stock enhancement of Giant clam in Thailand (Demand – threats – conservation)

Photo credit: Kevin Fitzsimmons (USA)

Review: Abdel Rahman El Gamal (Founder of the website)

Introduction: Giant clams are marine bivalve molluscs in the family Cardiidae and sub-family Tridacnidae that are considered the largest bivalves in the world. Their large size, delicious taste and attractive shell colors have made them target animals for consumption and decorative purposes.

Threats: The strong demand on giant clam and their overfishing along with the degradation of their natural habitats have been responsible for stock depletion throughout much of their geographic range.

The desire to get quick and big harvests of the giant clams have been achieved through the use of special fishing boats with dredging techniques.

The danger of the over-fishing was even more dangerous when the clam hunting targeted the bigger and sexually mature animals. The late sexual maturity of the giant clams makes them highly vulnerable to stock depletion.

 

Conservation measures

Governing regulations: Due to the slow recovery from overfishing, giant clams are listed under Annex II of CITES (1983), and are considered vulnerable under the IUCN red list of threatened species (1996). Therefore, their collection, property, sale and export is prohibited. However, Because of the high price for clam-meat, the enforcement of such regulation is not as hoped and hence the violators continue their illegal fishing and trade.

Stock enhancement: The restocking programs of giant clams target to reinforce its stocks especially in the overfished places with the aim of re-establishing its populations.

The restocking activity usually begins at aquaculture facility in which the breeding takes place. Fortunately, Giant clams are not difficult to reproduce and culture. There are a number of hatcheries and grow-out operations have been established in the Indo-Pacific region. While such hatcheries can provide the giant clams juveniles for human consumption and/or aquarium trade, the hatchery produced juveniles could be utilized in the stock enhancement programs.

The photos are taken in a giant clam facility in Thailand. The first photo shows specimens of giant clams while the second photo shows the growing of giant clams as required for a stock enhancement program.

Thailand - Growing giant clams in raceways with paddlewheels Thailand - close-up of giant clams being grown for stock enhancement

 

 

Permanent link to this article: https://fishconsult.org/?p=11497

Aug 09 2014

Growing Gracilaria to feed abalone in Thailand

Photo credit: Kevin Fitzsimmons (USA)

Review: Abdel Rahman El Gamal (Founder of the website)

In Asia including Thailand, several red seaweeds such as Gracilaria have been identified along with their natural habitats. Gracilaria are harvested in large quantity as a commercial source of agar. The increasing demand on agar encouraged the Gracilaria farming to meet the growing demand from the agar processing industry; several species of Gracilaria were found qualified candidates for farming.

The use of Gracilaria in polyculture with finfish and shellfish has been practiced in several Asian countries. Because of the high market price of abalone in world markets and their herbivorous feeding habits, Gracilaria has been used in the culture of abalone.

In Thailand, the culture of abalone began in the early 1990s at experimental scale in which Gracilaria has been used as a principal or sole source of fresh food to farmed abalone juveniles until they reach a marketable size (40- 50 mm in shell length). The two photos which were taken in Thailand show a specimen of abalone and the seaweed Gracilaria.

Thailand - Gracilaria grown to feed abalone Thailand - abalone

 

 

Permanent link to this article: https://fishconsult.org/?p=11495

Aug 08 2014

Growing tilapia in raceways originally designed for catfish in Mexico

Credit: Kevin Fitzsimmons (USA)

It should be noted that the series of raceways shown in this photo were original designed for catfish studies but later and for economic reasons, the operations were stocked with tilapia.

The following descriptions were developed by the author and found in the reference below. The first facility is located near Abasolo, Tamaulipas. The raceways were built in a series of stair steps with 17 reuses of the water. The design was based loosely on a system developed for catfish by Leo Ray of Idaho. The vertical drops are sufficient to replace oxygen in the raceways, but there is no mechanism to remove ammonia from the water. That metabolite accumulates in the water and reduces growth of the tilapia.

The managers of the demonstration farm leave sections of raceways open to allow for solids settling and some natural dissipation of ammonia which allows some production in the lower raceways, but much of the facility is underutilized. When stocked heavily, the raceways were found to be effective for controlling unwanted reproduction and for ease of feeding and harvesting. One of the problems encountered was that the fish had a tendency to congregate near the head of the raceway where the oxygen levels were highest. Any uneaten feed would then be pushed to the opposite end and begin to decay. Another problem was jumping. The tilapia would jump from one raceway to the adjoining raceway, thereby mixing up the inventory. They would also expend considerable time and energy attempting to jump up the waterfall to the higher raceway. A final problem with the raceways was that the sides were convenient for fish eating birds to perch.

This operation –like similar others- was redirected towards tilapia when US prices for catfish fell and tilapia prices in Mexico and the US stayed relatively constant.

Reference: Fitzsimmons K. 2000. Tilapia aquaculture in Mexico. Pages 171–183 in B.A. Costa-Pierce and J.E. Rakocy, eds. Tilapia Aquaculture in the Americas, Vol. 2. The World Aquaculture Society, Baton Rouge, Louisiana, United States.

Mexico - culture of tilapia in raceways

 

 

 

 

Permanent link to this article: https://fishconsult.org/?p=11485

Aug 07 2014

Cage culture of red tilapia in Brazil

Photo credit: Kevin Fitzsimmons (USA)

The photos have been taken in the aquaculture component of this multi-discipline farm which is located in the State of Rio de Janeiro, County of Paraíba do Sul, District of Werneck.

The farm consists of 100 floating cages located in running water dams controlled by biological filters and aerators for oxygenation purposes. Red tilapia is cultured species in the farm. The 120,000 tilapia fingerlings stocked in the cages are produced in the reproduction section of the farm (not shown here). The annual production of the cage farm is 60 tons of market size fish with about 500-g average size.

Source: Brochure Fazenda farm.

Brazil (Tilapia cages) 02 Brazil (Tilapia cages) 01

 

Permanent link to this article: https://fishconsult.org/?p=11479

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