Jun 04 2018

Purse seining of bluefin tuna in Libyan waters – Video

Video credit: Abdallah Elmgawshi (Libya) Review: Abdel Rahman El Gamal (Founder of the video channel)

 

The video shows a typical fishing of Bluefin tuna (Thunnus thynnus) in Libyan Mediterranean waters.

In the present, almost all tuna fishery in Libya is carried out by longline and purse seining. This video shows the purse seining of the Bluefin tuna. The fishing season generally starts in the middle of May and extends to the middle of July or reaching the approved quota whether for the whole country and/or for the particular fishing vessel.

Typically, before taking a fishery action, the tuna stocks have been explored using appropriate equipment such as HD Binoculars, sonars, etc. As shown, the frozen sardines are thawed and moved from the mother ship to a boat where sardine is distributed in the target zone to attract and keep the tuna stocks in place.

Immediately after, the seine surrounds the tuna stocks to the tuna stock to keep the fish in place and then the purse seiners act immediately surrounding the tuna fish and crowding them in order to be lifted easily on the mothership. It seems that the fishing crew is pleased with their catch.

https://youtu.be/9IxZSe0spWs

 

 

Permanent link to this article: https://fishconsult.org/?p=14493

May 31 2018

Role of women in the farming and processing of seaweed in Tanzania

Photo credit: Lucka Paschal and Erick Kiiza (Tanzania)

Review: Lucka Paschal – Erick Kiiza (Tanzania) and Abdel Rahman El Gamal (Founder of the website)

So far, the culture of seaweed is limited to soap making. The culture and processing of seaweed are mainly conducted by women who form groups in seaweed culture and soap making. The culture of seaweed is conducted in Zanzibar Island, and recently it has drawn attention for the Coastal community.

 

 

Permanent link to this article: https://fishconsult.org/?p=14489

May 29 2018

Processing of rainbow trout in Colombia

Photo credit: Marleyi Acuna Torres and Sandra Magally Sanchez Trujillo (Colombia)

Review: Marleyi Acuna Torres, Sandra Magally Sanchez and Abdel Rahman El Gamal (Founder of the website)

The inserted picture shows a fish processing facility located in Silvia, Cauca (Colombia). The facility processes rainbow trout (Oncorhynchus mykiss). This processing plant belongs to “Apropesca” -Association of producers and traders of aquaculture and agricultural products of Silvia.

This processing plant -as expected- targets to enhance the quality of marketed trout whether for national and international markets in addition to securing a constant supply of fish in the market.

The main product of the plant is the frozen rainbow trout. However, smoked trout may be produced upon specific requests.

It may worth noting that the annual production of rainbow trout from aquaculture in Colombia slightly exceeds 6000 tons.

 

 

Permanent link to this article: https://fishconsult.org/?p=14483

May 29 2018

Use of lined-earthen ponds in red tilapia culture in a biofloc system in Colombia

Phots’ credit: Marleyi Acuna Torres and Sandra Magally Sanchez Trujillo (Colombia)

Review: Marleyi Acuna Torres, Sandra Magally Sanchez and Abdel Rahman El Gamal (Founder of the website)

The inserted pictures were taken in Antioquia (Colombia) and show an aquaculture facility used in the production of red tilapia in a biofloc system. This particular project is operated in high-density polyethylene (HDPE)-lined earthen ponds.

The use of HDPE geomembranes has been recommended for a variety of applications including aquaculture. This is based on the main features of the HDPE including its low permeability as well as its chemical and ultraviolet resistance and so it is used as landfill liners, municipal waste containment, power plants and aquaculture projects such as the one shown in these photos. Depending on its applications, the thickness of the HDPE liners ranges from 0.1mm to 3.0mm.

 

 

Permanent link to this article: https://fishconsult.org/?p=14480

May 28 2018

Daily life of the Bozo/Somono fishermen in Mali

Photo credit: Elisabeth den Otter

Review: Elisabeth den Otter and Abdel Rahman El Gamal (Founder of the website)

The inserted pictures show a sample of the daily life of the Bozo and Somono fishermen who live in Kirango, a village located on the bank of the Niger river, near the Markala dam, about 35 km north-east of the city of Ségou. The inhabitants are Bamanan (farmers) and Bozo/Somono (fishermen).

These fishing activities shown in the attached photos show the fisherman upon casting his cast net, a part of the catch. The drying of fishnets, as well as the sun-drying of a part of the fish catch, is shown in one of the pictures.

 

 

Permanent link to this article: https://fishconsult.org/?p=14475

May 23 2018

Status of the narrow-clawed crayfish in Turkish fishery

Photo credit: Mykola Fedorenko (Ukraine)

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

The Narrow-clawed crayfish (Astacus leptodactylus) occurs in several freshwater bodies in Turkey. According to FAO, crayfish appeared in the Turkish fishery in 1977 with 3885 tons. The largest crayfish catch occurred in 1985 with 6224 tons before declining to lower catch. In recent years, the catch of crayfish seems somehow stable amounting to 610, 492, 532, 582, 532, and 544 tons during the years from 2011 till 2016 respectively.

The decline in the crayfish catch has been attributed to the crayfish plague (Aphanomyces astaci) which seemed affecting the catch of crayfish since the mid-1980s.

The inserted picture shows the crayfish caught in one of the Turkish lakes whereas some lakes such as Lake Eğirdir represent a rich source of fish and crayfish in Turkey.

In addition to the locally consumed crayfish, a part of the catch is processed and exported especially to Scandinavia, particularly into Sweden.

 

 

Permanent link to this article: https://fishconsult.org/?p=14467

May 20 2018

Moina as a natural food in aquaculture

Photo credit: Luis Landesman (USA)

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

 

Moina is a genus of crustaceans which belongs to the family “Moinidae”. As young moina is less than 400 µm in size, they can serve as the initial food for most freshwater fish species. Monia has been used as the sole food for fry of many ornamental tropical fish species. In order to enhance its nutritional quality, moina should be enriched with algae and yeast before feeding them to fish.

The culture of moina has been easily practiced using horse manure, chicken manure, cow manure, wheat or rice bran, alfalfa pellets or meal, cotton seed meal, spirulina powder, and others.

Moina are characterized by their significant tolerance to adverse water quality parameters. For example, they are able to survive in oxygen-poor environments whereas the amount of dissolved oxygen could be as low as almost zero. Interestingly, the ability of monia to tolerate such very low level of dissolved oxygen is attributed to their ability of the organism to synthesize hemoglobin that greatly enhances the ability of the organism to cope with such poor oxygen situation. Added to that, monia are resistant to withstand an extreme thermal variation that ranges from as low as 5°C to as low as 31°C and above.

 

 

Permanent link to this article: https://fishconsult.org/?p=14464

May 18 2018

Shrimp eye-tagging

Photo credit: Andres Delgado (Colombia)

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

The inserted picture shows the eye-tagging of shrimp broodstock. This type of marking was found tolerable by shrimp especially large adult shrimp and is not lost during molting.

Eye tags are commonly used to mark adult marine shrimp in captive broodstock populations in hatcheries and/or in genetic breeding programs. The tag is made of plastic or metal and is numbered for identifying individual shrimp. The tag ring is placed on the eyestalk behind the bulbous of the eye.

 

Permanent link to this article: https://fishconsult.org/?p=14460

May 14 2018

Fish trapping during the early 1900s in Cook Islands – eel trap

Photo credit: New Zealand Museum (A permission has been granted to use this picture on this site)

This conical trap which has been known as “Inak” has a flat bottom and a narrow opening at the top. The trap is woven from the long thin coconut roots or the aerial roots of Freycinetia. The trap base is cross strengthened by two wooden strips. The construction of the trap allows easy removal of trapped fish. Usually, such traps are baited with small fish in order to effectively attract target fish especially eels and other larger fish species.

Such traps may have different shapes and sizes. According to the museum records, this particular trap dates back to 1907 and was made in Cook Islands with overall dimensions of 45 cm height and 69 cm diameter.

 

Permanent link to this article: https://fishconsult.org/?p=14451

May 13 2018

Cage culture of red tilapia in Vietnam – Video

Credit for the video and the caption: DO Xuan Hai (Vietnam)

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

Tilapia culture in Vietnam usually targeted local markets before being exported to a large number in the USA and the European Union.

Red tilapia (Oreochromis spp.) is mainly cultured in floating cages as practiced in the Mekong Delta are made of wooden frames and nets. As the case with cages elsewhere, the ones shown in the video have the advantages of the relatively low capital investment, low operating costs, and easiness of their management.

Almost all cage farmers live on the site for most of the time. Depending on the farm size, the farmers may hire full-time employees, or use part-time workers.

Based on a recent survey, the average dimensions of a cage is 10 m length × 5 m width × 3.5 m depth.  Each cage is stocked by about 16,000 fingerlings of an average weight of about 4 g ranging from 1 to 10 g. The growing season takes about 5.5 months, allowing the production of two crops/year. Some cage farmers produce their own fingerlings while others depend on external resources. The harvested fish often has an average weight of about 700 g. During that grow-out period, fish are fed on pelleted feed.

In addition to cleaning the cages in-between the production cycles, fingerlings may be treated before stocking using baths of either salt, potassium permanganate (KMnO4), copper sulfate (CuSO4), or iodine.

In linkage with that, resource-poor farms such as the red tilapia cage farms are often at the risk of experiencing disease outbreaks and subsequent losses of production, income, and assets.

https://youtu.be/c_tqJD5vpM8

Permanent link to this article: https://fishconsult.org/?p=14447

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