Apr 02 2015

Cage farming in Kulekhani reservoir, Nepal

Credit: Bishnu khanal (Nepal)

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

Cage farming in Kulekhani reservoir, Nepal

 

 

 

 

Kulekhani resenvoir is one of the reservoir in the middle of Nepal in which cage farming takes place to produce table fish in rural areas. The inserted photo shows some of cage farmers while transporting fish seeds by boat from one corner of the reservoir to another.

As this cage fish farming was successful, it was thought that cage fish farming could also provide an alternative livelihood for displaced fishermen’s families by the Kulekhani Reservoir when a 114m-damwas constructed for hydro-power.

The adoption of plankton-based cage culture using plankton-feeding fish such as bighead carp and silver carp seem to fit more appropriately into the needs of the farmers living around Kulekhani, and offer an increased potential for long-term sustainability for this environmental friendly system. In this “no feed” system, fish advanced fingerlings or juveniles are stocked in 25-50 mm mesh cages at a density that ranges from 10-15 fish/m3. Among 500 families displaced in 1982 due to impoundment, about 81% adopted cage fish farming in the reservoir.

 

 

Permanent link to this article: https://fishconsult.org/?p=12519

Mar 31 2015

What frogs like to eat more, feed pellets or live tilapia?- Video

Note: This short video is a piece of the original 31-min which exists on this site and video channel

This short video shows clearly the preference of frogs towards live tilapia compared to the dry pellets. It is interesting to see an individual from while staying over pellets, chawing one before spitting it out. On the other hand and as the video shows how each of several frogs was able to spot, jump and grab a specimen of tilapia. Frogs insist to swallow their tilapia prey from head. The two front legs helped to guide swallowed tilapia while move in and disappear in frog’s mouth.

 

 

Permanent link to this article: https://fishconsult.org/?p=12517

Mar 30 2015

Beach seining in Sierra Leone

Photo credit: David Elliot (UK – MacAlister Elliott & Ptrs)

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

 

Beach seining in Sierra Leone

 

 

The use of beach seine net –although highly destructive- is popular and widely used in many African countries whereas the practice takes place along the coast in lagoons, estuaries and rivers in areas which are classified as nursery grounds. Based on that, the beach net has been confirmed to catch a higher proportion of juvenile and immature fish than adult fish especially nets used to construct these seines are deliberately of small meshes. The beach seining is commonly known as haul fishing. A survey reportshowed that 85% of beach seine in the western area of Sierra Leone are illegal. The banning enforcement of beach seining in Sierra Leone has been emphasized as documented in The European Union’s 9th EDF programme for Sierra Leone (2009).

 

The seine is deployed off shore with a team of people on the beach who pull in the net by ropes tied to the sides. The net and warp are laid out from, and back to the shore and retrieved by hauling on to the shore.

According to FAO survey study that covered nine countries in Africa (not including Sierra Leone), Asia and Latin America, the beach seines have been banned in several countries due to its perceived negative impact on fishery resources and the coastal environment. However, it is obvious that in order to enforce the banning of beach seining, or at least to mitigate its negative impacts, some social issues have to be considered.

Beach seining is the backbone of employment for some of the poorest and the most vulnerable groups of people including older people and women, who depend on beach seine catches for their processing, nutrition and trade. To other groups of people, the beach seining while it can be a source of subsistence, it is not a sophisticated technology.

The threat to fishery resources caused by beach seining versus the social dimension of the practice to the poorest communities represent a real challenge facing policy makers anywhere who are often try to balance people’s needs with the need to ensure a healthy and functioning fisheries productivity for generations. Based on case studies, it has concluded the managing or banning the beach seining can be only accomplished if the livelihood challenges and opportunities faced by local fishing communities are taken into through participatory approach.

 

 

 

Permanent link to this article: https://fishconsult.org/?p=12513

Mar 29 2015

Culture of Peruvian scallop (Argopecten purpuratus) in Peru – Video

Video credit: Juan Martin Canturin Garcia (Peru)

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

This video shows the harvest of farmed Peruvian scallop, Argopecten purpuratus (fan shell) in Peru. The culture of fan shell (sea scallop) in Peru was developed as small projects in the 1980s; then progressing to much larger number of bigger projects during the 2000s.

The suspended method of scallop culture is favored –compared to bottom culture- due to its easiness in management and de-attachment upon harvest, higher production, better survival, and satisfactory growth rates.

The scallop culture in Peru is an export oriented activity as most of scallop produced in Peru is shipped to international markets as frozen products.

The overall conditions in Peru are in favor of the culture of scallops especially in regard to the availability of aquaculture experience, high natural sea productivity and oceanographic conditions (primarily temperature), availability of labor, and the less production costs compared to other farmed species. The overall conditions allow the organisms to reach commercial sizes or 5 to 8 cm in a brief period of time.  Moreover, the demand on scallop in the international market is much higher than the production of wild scallop.

Permanent link to this article: https://fishconsult.org/?p=12510

Mar 28 2015

Recirculated tunnel tilapia culture in Grahamstown, South Africa

Credit: Nick James (Rivendell Hatchery – South Africa)

Tunnel culture of tilapia in South Africa (01) Tunnel culture of tilapia in South Africa (02)

 

 

 

 

This tunnel grow-out tilapia farm is located in Grahamstown, South Africa. Red tilapia (O. mossambicus is the fish grown in this farm). Each greenhouse measures 46×8 meters. There are 20 tanks under the greenhouse of 7000 l each; water depth in the tanks is 60 cm.

The plastic cover of the greenhouse is a single layer of 200 micron. The plastic stays on all year, when inside temperature turns hot, the ventilation is sufficient to maintain the optimum temperature. This tunnel system raises water temp by 7C over ambient. During the coldest two winter months, an 18kw 3-phase heat pump is used and raises the whole system by additional 4 degrees Celsius.

The system is equipped with 1.5 kw air blower, sufficient mechanical and biological filtration, UV sterilization and 2×1.1 kw pumps capable to carry out changes of water every 2.5 hours.

Each 7000-l tank is initially stocked with 800 tilapia fingerlings of 1g, which is later thinned down as they grow to 400 of 500g harvest sized.  Commercial locally manufactured floating tilapia pellets is used with diameters of 1, 2, and 3-mm. The production of a single tunnel as this one is more than 5 tons of market size tilapia per year (35.7 kg/m3) which seems economically feasible under the overall situation in South Africa.

 

 

Permanent link to this article: https://fishconsult.org/?p=12504

Mar 26 2015

Small-scale production system for duckweed in Vietnam

Credit: Louis Landesman (USA)

Duckweed in Vietnam (02) Duckweed in Vietnam (01) Duckweed in Vietnam (03)

 

 

 

The inserted pictures show a small unit for duckweed production which is located near Hanoi, Vietnam. The unit consists of two small wading pools filled with drinking water and one scoop of biodigester slurry. The water in the two pools have been fertilized with lemna duckweed collected from a local village pond. The visit report tells that after four days, the mass duckweed were harvested and used to feed pigs and chickens living on site.

 

Permanent link to this article: https://fishconsult.org/?p=12497

Mar 26 2015

Shark fishery and marketing in Yemen

Photo credit: Tim Huntington (UK – Poseidon)

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

 

Shark fishery and marketing in Yemen

 

 

 

The inserted picture shows a pile of sharks displayed in a fish market in Hadramout, Yemen.

According to relatively recent statistics (2000s), the overall fish landing in Hadramout is about 78,000 tons total annually; out of which about 4,500 tons of sharks. Sharks are exploited by artisanal fishery whether cooperative or private fishery using gillnets and longlines. Although the shark fishery in Hadramout Governorate witnessed some fluctuations, its production was on the increase trend from 2001 onward.

In regard to shark fins, its trade showed a remarkable and rapid increase resulting in a significant fishing pressure on shark stocks during the last two decades. The high price of dry shark fins in the markets of East Asian Countries has been behind the heavy fishing on sharks in Yemen. In addition to shark fins, the dry shark meat and also the fresh shark as shown in the inserted picture have some demands in local markets particularly in the East Governorates. However, discarding finless shark may also in practice. There is a growing concern about the possible collapse of shark populations in the near future as long as the demand on shark fins remain that strong bearing in mind the long recovery times of sharks in response to overfishing.

 

 

Permanent link to this article: https://fishconsult.org/?p=12494

Mar 24 2015

Jellyfish processing and export in SriLanka

Photo credit:Tim Huntington (UK)

Technical review: Abdel Rahman El Gamal (Founder of the website)

Processing and export of jellyfish in Srilanka

 

 

 

 

 

This jellyfish resource remains un-utilized for many years until an emerging demand on jellyfish showed up and led to a significant activity in SriLanka within a relatively short time.

In order to meet the increasing demand, the harvesting of jellyfish processed in SriLanka seas in several districts especially the seas of Panama and Komariya, in the Ampara district, and in the Kirinda area in Hambantota district. The jellyfish species for export is caught bulk by fishermen and sent for processing where the preparation for export takes place. It is estimated that more than 100 to 150 tons of jellyfish are processed daily and about 20,000 fishermen make a living from the harvesting of jellyfish. Out of the several species of jellyfish, only two species are suitable for export. The two mentioned are characterized by their seasonal catch that lasts for several weeks every year before being drifted away either to India or the Maldives. This causes putting more fishing pressure on these species in SriLanka at this particular time.

The processing is done by immersing the jellyfish in a mixture of alum and salt to extract their water content resulting in a significant shrinking of processed animals whereas 20 kilograms of raw material will be required to obtain 1 kilogram of processed jelly fish. The processed jellyfish is exported primarily to China as well as some other Asian countries where it is considered a delicacy, as well as an aphrodisiac.

There are different opinions related to the catch of jelly fish for export. The fishery authority finds that this activity provides a work opportunity to about 20,000 men who make living of it and is also essential for increasing the inflow of foreign exchange. Moreover, they see –and after a brief stock assessment- that the jellyfish populations are high and so are not threatened by the jellyfish trade, and claim that the ocean’s jellyfish resources were being over-exploited and hence there is no urgency for imposing controls on the harvesting of jellyfish.

On the other hand, the environmentalists find that the mass harvesting of jellyfish is harmful to the marine environment especially in regard to the survival of certain other marine species that feed on jellyfish.  They expressed their concerns about the current exploitation level of this resource without a proper resource assessment of jellyfish within SriLanka waters.

Currently, matters relating to jellyfish are covered by the Fauna and Flora Protection Ordinance that comes under the Director General of the Department of Wildlife Conservation.

 

 

Permanent link to this article: https://fishconsult.org/?p=12490

Mar 22 2015

Supply chain of aquaculture produce in Ghana

Credit: Patrick Appenteng (Ghana)

Supply chain of aquaculture produce in Ghana

 

 

 

A break in the supply chain of aquaculture produce will mean a gradual collapse of the industry since its repercussions cannot be desired to look upon. As it is known worldwide, the demand for fish, especially tilapia is very high, hence middle women waste no time in getting their share when there is ready fish for harvesting.

The picture here shows middle women in a farm in the Asuogyaman District of Ghana, preparing to take their harvested fish away to the ultimate consumers. Some had come along with their iced cubes for icing.

Permanent link to this article: https://fishconsult.org/?p=12488

Mar 22 2015

African catfish from a Dutch hatchery to Nigerian farms (Video)

Video credit: Ahmed Zaki (Egypt)

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

This video was filmed in one of African catfish hatcheries in the Netherlands where the fingerlings of African catch, (Clarias gariepinus) are produced. According to the scattered advertisements, the average size of produced fingerlings is of bout 8-10 g when sold to catfish farms within the Netherlands while much smaller and younger fingerlings of about 0.5 grams are produced when the target is African farms, especially in Nigeria; the largest producer of North African catfish. The Dutch hatcheries claim their use of specially designed transport boxes, which allow shipping to destinations 24 hours away.

The selective breeding programs carried out on African catfish in the Netherlands have justified the reproduction of the species in Dutch hatcheries to be shipped and sold in Africa. The additional cost related to air shipping seems covered by the premium prices of these fingerlings which are promoted as superior fish in regard to key productive traits such as growth, survival and dressing percentage.

 

 

 

Permanent link to this article: https://fishconsult.org/?p=12481

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