May 10 2018

Climate change in Sri Lanka (2017)

A permission from the report owners has been granted for publishing the report on this site.

 

 

 

 

 

 

 

 

 

 

 

Climate Change in Sri Lanka

 

 

 

Permanent link to this article: http://fishconsult.org/?p=14418

May 10 2018

Aquaculture development in Chad

Photo credit: Aliadoumadji Rimadoum (Chad)

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

 

The introduction of fish farming in Chad dates back to the 1970s. Since then, several types of farming have been introduced and tested whereas some positive results have been achieved in earthen pond systems especially when the cost of fish feed is not high and can be tolerated by farmers.

The promotion of aquaculture has been found necessary with a view to food security and the fight against poverty. The Aquaculture Development Directorate that was created in 2009 has taken into consideration some approaches towards the development of aquaculture activity including public/private partnership. It may worth noting that several international agencies, as well as cooperatives, have been engaged in the aquaculture development initiatives.

The inserted pictures have been taken during the practical training on the manufacturing on fish feed highlighting the possibility of the incorporation of locally available ingredients.

According to FAO statistics, the production from aquaculture in Chad first appeared in 2008 with 30 tons reaching its peak with 154 tons in 2015 before declining to 94 tons in 2016.

 

 

Permanent link to this article: http://fishconsult.org/?p=14414

May 09 2018

Temperatures during egg incubation determine the sex of baby turtles  

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

 

 

In most animals, the sex is determined by biological sex determination mechanisms (e.g. sex chromosomes). However, in sea turtles, the matter is different where the sex is determined by temperature during egg incubation.

Typically, turtle female leaves the water and comes to the shore where she lays and buries her clutch of eggs in a sandy nest which she digs.

Depending on the turtle species, when the temperature within the sandy nest is about 28-29 degrees Celsius, the embryos of sea turtle embryos develop into almost equal number of male and female baby turtle. On the other hand,  the baby turtles produced upon warmer incubation temperatures are skewed to females while the incubation at lower temperature results in turtle offspring predominated by male hatchlings. It may worth mentioning that the difference between the influencing hotter and cooler temperature is only a few degrees.

The influence of temperature goes beyond the speed of hatching as well as the sex ratio creating more concern regarding the global warming. In fact, many scientists expressed their concern regarding the expected predominance of baby turtles by females as a result of rising global temperatures and warmer sand. This concern is supported by reports on the born sea turtles in northern Australia that has been very much dominated by females. The same is true in regard to the findings of a study where as much as 99 percent of baby green sea turtles in warm equatorial regions are females.

 

 

Permanent link to this article: http://fishconsult.org/?p=14409

May 08 2018

Accidental occurrence of Bagrus bayad in a fish pond in Egypt

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

 

Bayad (Bagrus bayad) is an important food fish that enjoys a high consumer preference. Almost all produced bayad is captured from natural waters in Egypt. The species occurs naturally freshwater water bodies such as rivers, lakes, and swamps.

The inserted picture was taken in a fish farm in Egypt in which the shown specimen of bayad was caught. The size of the bayad indicates the high growth rate the species enjoy.

Since the species was not intentionally stocked in the fish pond, it may be possible that small fry of bayad found their way to the pond whether mixed with stocked fish or sneaky entering the pond through whatever space around the pond screen.

Bayad feeds near the bottom whereas adults are piscivorous feeding mainly on small fish, insects, crustaceans, and mollusks. The fry of bayad feeds on copepods while small-size bayad feeds on detritus, small crustaceans, insects, and fish. Their feeding habits imply that if the bayad which could occur accidentally in a fish pond is of larger size than stocked fish, this may pose a threat on stocked fish through predation otherwise no threats to stocked fish is expected.

Permanent link to this article: http://fishconsult.org/?p=14406

May 01 2018

Oven fish grilling in a fish market in Egypt (Video)

Video ownership and description: Abdel Rahman El Gamal (Founder of the video channel)

 

 

I filmed this video on January 4, 2018, during my visit to a relatively large fish market in Cairo (Zaton market). The facility shown is typical oven similar to the ones which have been used in bread making in rural areas. This grilling facility serves many of fish displays in the market. Usually, the instructions on the way of grilling are provided by fish buyers including spicing, stuffing, use of oil or coating with wheat bran and others.

Handling many trays of fish in the oven –as expected- requires close monitoring in the light of different species, different sizes, and various grilling types. All these factors are considered upon placing fish trays within the oven as well as the grilling time.
I should thank Mr. Ramy who gave me the opportunity to stay with him in front of his oven and answering my questions. Mr. Ramy claims that the quality of grilled fish is the best compared to the surface grill especially fish receives heat from all directions.

https://youtu.be/-PoAqYbUJ3M

Permanent link to this article: http://fishconsult.org/?p=14403

Apr 10 2018

Nile perch meat stays in Egypt – the bladder goes to China – Video

Ownership of the video and the review: Abdel Rahman El Gamal (Founder of the video channel)

I filmed this video on 1st April 2018 during my visit to a relatively large fish market in Cairo (Zaton). I was lucky to be in the market during the processing of this specimen of Nile perch (Lates niloticus) of about 2.5 kg weight. Nile perch in Egypt comes from two main fishery resources; Lake Nasser (Aswan) and Rayaan Depression (Fayoum). In general, Nile perch is considered a luxury freshwater fish that enjoys higher market price than tilapia. The species is appreciated by a category of consumers who are interested in large-size fish with high-quality meat such as Nile perch.

In regard to the swim bladder to fills most of the body cavity, it is frozen and temporarily stored until sold to the trader who visits the fish market periodically and collects the swim bladders from various fish displays in this market and other markets to be shipped to China. This type of business is new and may go back to around five years. The sale price for a weight unit of the bladder is much higher than that for the Nile perch fillets and hence providing additional revenue to fish traders at no additional effort.

The bladders enjoy a high demand in China, where traditional medicine is advanced, whereas the swim bladder is used in the pharmaceutical industry. According to some published articles, the gas bladders may be used in the making of bio-degradable stitches for surgery. Moreover, swim bladders are an ingredient in nutritious soups in China. It may worth mentioning that the trade in Nile perch swim bladders has developed especially in countries sharing Lake Victoria where the Nile perch fishery is significant.

 

Permanent link to this article: http://fishconsult.org/?p=14397

Apr 10 2018

Collecting Nile tilapia broodstock from Lake Victoria (Kenya)

Photo credit: Gideon Gicheru (Kenya)

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

According to FAO statistics, the contribution of tilapia in total aquaculture is almost consistent with a very narrow range from 72.8% to 74.7% during the period from 2010 to 2016, whereas in tonnage tilapia aquaculture produced 9115, 166602, 16115, 17626, 18072, 13991 and 11180 tons over seven years from 2010 to 2016 bearing in mind that Nile tilapia (Oreochromis niloticus) is the only tilapia species cultured in Kenya.

Such development in aquaculture and in particular in tilapia aquaculture necessitated a high demand of quality fish seed for Nile tilapia in sufficient numbers produced in a large number of hatcheries located in various parts of Kenya.

Typically, operating hatcheries in Kenya keep the broodfish for three years before replacing it with a new stock. The broodfish are usually obtained either from other hatcheries or collected from the wild. The inserted picture was taken at the shore of Lake Victoria, (Obaria Beach) Homabay County whereas the staff from Kisii County fish hatchery are ready to collect Nile Tilapia broodfish.

 

 

Permanent link to this article: http://fishconsult.org/?p=14393

Mar 31 2018

Climate change in Zambia

A permission has been granted from the report owners to publish the report on this site

 

 

 

 

 

 

 

 

 

Climate change in Zambia

Permanent link to this article: http://fishconsult.org/?p=14375

Mar 31 2018

Cage culture of striped catfish in An Giang Province (Vietnam)

Photo credit: Han Huong (Vietnam)

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

 

 

Viet Nam is by far the world’s largest producer of Pangasius with a production that exceeded 1.2 million tons in 2013 and with an annual export turnover of at least US$ 2 billion.  The striped catfish (Pangasius hypophthalmus) which is locally known as “Tra” is the leading Pangasius species that is farmed in commercial aquaculture in Vietnam.

The cage culture of catfish in Vietnam has a relatively long history that started in the 1960s whereas cages are usually sited on major river tributaries of the Mekong River delta. The An Giang province has witnessed a significant development in regard to cage aquaculture reaching about 3000 cages in An Giang province with about 40,000 tons in the year 2000. During the early farming of pangasius, the collection of fingerlings from nature was the only source to stock the cages. However, after the successful artificial reproduction of the species, the collection of the wild fry and fingerlings has been banned and hence the hatchery-produced seeds became the only source for cage stocking. In brief, the farming of “tra catfish” is the most important aquatic farming sector in Vietnam from both a social and an economic point of view.

The stocking density of fish ranges typically from 100-150 specimens/m3. With the scaling-up of cage farming, the use of commercial pellets became essential. Usually, the entire cage is harvested at a single harvest in order to meet the large volume requirements of the processing plants.

It may worth mentioning that the cage culture of pangasius showed a considerable decrease between 2003 and 2007. The decrease has been attributed to farming economics as well as disease outbreaks.

 

 

Permanent link to this article: http://fishconsult.org/?p=14371

Mar 26 2018

Fishing activities by a Somono fisherman’s family along Niger River in Mali

Credit: Elisabeth den Otter (Bozo and Somono fishermen of Mali)

 

 

The inserted photos show some activities of a Somono migrant family in Mali. Typically,  from October until January every year, Bozo/Somono migrants camp on the shore of the Niger river. Their stay coincides with the arrival of large shoals of ‘ntinenin’, a type of sardine.

These particular pictures belong to the Kané family that is an extended family consisting of the fisherman with his wife and a number of children.

As shown in the pictures, men are fishing in their fishing boats, while women sell the fish and take care of the household (cooking and the children). Their makeshift dwellings are made of straw mats and pieces of cloth.

 

 

Permanent link to this article: http://fishconsult.org/?p=14351

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