Jun 08 2015

Shrimp trawling in the Negombo Lagoon, SriLanka

Photo credit: Tim Huntington (UK – Poseidon)

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

 

Non-motorized shrimp trawler in SriLanka

 

 

The Negombo Lagoon which is a large estuarine lagoon is situated in the Gampaha district at around 20 km north of Colombo. The lagoon covers an area of approximately 3,200ha. The source of freshwater lagoon is that is the rivers Dandugam Oya and Ja-ela. The lagoon is connected to the sea through a single narrow opening at its northern end. Other than the lagoon entrance, the water depth within the lagoon is less than 2 m.

The lagoon is characterized its brackish water flora (seaweeds) and some mangrove forests in the northern part with its ecological role in providing spawning, nursing, feeding grounds and shelter for a variety of economically important fish and shrimp species.  The lagoon with its high fish productivity (150 kg/ha/year) supplies the community with a good source of protein as well as employment. Shrimps, crabs, food fish and ornamental fish are the most important organisms to the lagoon fishery.

Several fishing gears are used in the lagoon including trammel nets, cast nets, stake nets, and fyke.

Outside the lagoon, there are the non-mechanized shrimp trawlers (as the one shown in the inserted photo) and the mechanized shrimp trawlers which operate 5–10 km to the south.

The non-mechanized trawlers are operated to a distance up to 5 km north of the lagoon entrance, where the sea depth is less than 12 m. They are operated during day-time where four fishermen go in each boat and the trawl is towed manually.

The main species in the trawl catches are  dobsoni and Parapenaeopsis coromandelica while P. indicus and P. semisulcatus were relatively scarce.

 

 

Permanent link to this article: https://fishconsult.org/?p=12685

Jun 06 2015

Boat building along the coast of Volta Lake (Ghana)

Photo credit:David Elliott (Mac Alister Elliott & Pts.) – UK

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

Boat building in Ghana

The inserted picture shows the boat building of a typical boat to be operated in Volta Lake (Ghana). Such boats can be in fishing as well as in carrying feed to cages in Volta Lake.

The wooden boats are built by professional carpenters (boat builders) whereas there are common timber species used in boat building in Ghana:

Wawa (Obeche), Triplochiton sclerozylon (lightweight timber, non-durable)

It has a high strength to weight ratio. The wood can tolerate salt water and dries out well, popular in boat building.

Odum (Iroko), Chlorophora excelsa (hard, medium weight, durable)

Used in boat and ship building, used in the interior in harbor based boats

Kusia (Opepe), Nauclea diderrichii (Very durable)

Used in boat building (except bent work)

 

 

Permanent link to this article: https://fishconsult.org/?p=12682

Jun 05 2015

Bering Sea and the discovery of a new sponge species

Photo credit: Greenpeace

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

Bering Sea (new sponge species)

The Bering Sea, Alaska which is in the northernmost part of the Pacific Ocean, has been named after Vitus Bering, a Danish-born Russian explorer who sailed the Sea in 1728. The sea is considered one of the wildest regions in the world and similarly is one of the most important commercial fishing grounds in the world; of over half of the seafood caught in the USA comes from the Bering Sea. Additionally, the Bering Sea has some of the largest submarine deep enough canyons in the world which provide refuges for fish species from industrial fishing operations

The 2-million annual fish catch from the Bering Sea, has been accompanied by significant reduction offood supply for marine mammals and birds and great changes in the ecosystem of the sea.

Of particular importance, the fragile coral and sponge habitat have been damaged by bottom-contactfishing gear. The ecological concerns regarding the threats to the sea encouraged stakeholders of publicagencies, tribal groups, governments, and seafood businesses to work together and campaign towardsthe protection of Bering Sea.

During the conservation activities carried out by Greenpeace in the Bering sea and while investigating the deep sea canyons, a new species of sponge (shown in the inserted image) was discovered in the summer of 2007 while Greenpeaceannounced the discovery was on April 28, 2008.  The new sponge species was named Aaptos kanuux, the word “kanuux” being the Aleut word for “heart,” to express how the canyons act as the heart of the Bering Sea as felt by the natives.

 

 

Permanent link to this article: https://fishconsult.org/?p=12678

May 30 2015

Introducing reef ball technology into Racha Island, Phuket, (Thailand)

Credit for photos: Reef Ball Foundation (http://www.reefball.org)

Review: Reef Ball Foundation and Abdel Rahman El Gamal (Founder of the website)

Reef balls in Racha Island (Thailand) 01 Reef balls in Racha Island (Thailand) 02

 

 

The December 26 Tsunami struck, negatively affected a significant portion of the coral reef populations in the coastal belt in Thailand.  Accordingly, the tourism activity in Racha Island (Phuket) has been seriously affected especially for the visitors who go snorkeling or diving. The environmental damage as well as the economic loss caused by Tsunami necessitated the immediate introduction of the “reef ball technology” into Racha Island especially this technology has been already in practice in Thailand before the Tsunami. The team of the Racha Island reef ball included the experts of Reef Ball Foundation, over 30 volunteers from around the world together with selected support staff and divers from local resorts.

The reef balls are usually built on the beach before being taken to the selected sites. The design of such reef balls allows them to withstand even heavy storms. The success of reef balls such as this one depends on key factors starting with the design and construction of the balls which are mainly made of concrete which contains silica, with their height of about one meter. The transplantation of fragmented coral pieces on to the reef ball, give it a head start for coral growth.

The choice of the site is another factor for a successful project whereas selected sites are often among the most visited diving sites. Finally, the periodic monitoring by experts is another component in determining the success of a given reef ball project. We will cover some of these issues in specific projects in future posts. More information on reef balls is available on the foundation website:  http://www.reefball.org.

 

 

 

Permanent link to this article: https://fishconsult.org/?p=12670

May 30 2015

Sturgeon farming and caviar production in France – Video

Credit: Laurent DeverLanges (France – Caviar de Neuvic)

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

 

The video tours a facility dedicated for the production of caviar. The sturgeon farm has been established in November 2011. The 19-hectar farm is located in the town of Neuvic, along the banks of the River Isle. The farm is made up of four tanks fed by water drawn directly from the Isle River.

The demand on caviar in the light of the decrease of wild caviar has been the driving force for establishing this farm.

The sturgeons are bred in the farm from birth to the age of 7 years old or more, at which point the eggs can be extracted which takes place in a special laboratory.

The video addresses the standard issues of farm management such as water quality, food quality and the well-being of the sturgeons as well as the quality of their eggs.

Even though French is the language of the video, the English text translation enabled almost a full follow-up all of the contents. I have been told that the initiative of “No Kill Project – NKP” is just an idea under consideration and is not in the practice at the moment.

 

Permanent link to this article: https://fishconsult.org/?p=12656

May 23 2015

Culture of Indian carp (Rohu) in Pakistan

Credit: Muhammad Shahid Iqbal (Tawakkal) – Pakistan

Rohu culture in Pakistan

 

 

 

 

The inserted photo shows a typical earthen pond in which an Indian carp (Rohu; Labeo rohita) is being cultured.  The required fingerlings of rohu are obtained from a hatchery on the facility. This species is popular among consumers in Pakistan. In fact, the rohu farming is traditional farming in Pakistan where about 80% of total farming area is devoted to rohu culture. The production ranges from 3-4 tons/ha. Fish produced is locally marketed.

 

 

 

Permanent link to this article: https://fishconsult.org/?p=12666

May 22 2015

Use of specialized incubators in controlling the hatching of rainbow trout larvae

Credit: Troutlodge (USA)

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

 

Individually temperature incubators for rainbow Trout

 

 

 

The photo shows a row of individually-controlled incubators for rainbow trout (Oncorhynchus mykiss). This unique incubator’s establishment enables the control on egg development and so the hatching time in each individual incubator bearing in mind that fish and so embryos are cold blooded animals whereas warmer temperature would speed the rate of development and hatching while lower temperature would delay it.  Doing so would enable the matching of hatchery production and market demand.

 

 

Permanent link to this article: https://fishconsult.org/?p=12662

May 21 2015

Prior stocking stress tests for the whiteleg shrimp (Litopenaeus vannamei)

This 2-slide bite addresses a quality control procedures which are commonly used prior to the stocking of whiteleg shrimp post larvae in grow-out ponds. The rationality of the tests as well as the common ones are included.

http://fishconsult.org/wp-content/uploads/2015/05/Stress-tests-for-the-postlarvae-of-whiteleg-shrimp.pdf

Permanent link to this article: https://fishconsult.org/?p=12644

May 19 2015

Passing by a penguin community in the SeaWorld (San Diego), California – Video

Source: www.fishconsult.org

This video was filmed from a moving walkway in the penguin counter (Sea World – San Diego) on 26 December, 2014. This encounter was first opened in 1983. The walkway allowed watching and filming with no crowd at the glass.

The encounter hosts some hundreds of birds which belong to several penguin species. Out of which, the “Emperor Penguin”; the species of particular importance as it is believed that this species is kept in captivity in very few places in the world. Also, the penguin chicks including those for the “Emperor penguin” demonstrate the successful captive breeding program of the “Emperor penguin” whereas the first hatched emperor was in 1982. Since then, more of emperor penguins have been hatched and raised at SeaWorld San Diego.

You can watch birds standing, walking and swimming and close to the end of this video, one can observe a penguin bird while shooting through the water of the deep pool. The video shows the encounter staff while caring about the birds.

 

 

Permanent link to this article: https://fishconsult.org/?p=12652

May 19 2015

Freshwater crab entangled in a gillnet in Kyafukuma River (Zambia)

Photos’ credit: Alick Grunnie Mbewe (Zambia)

Review: Alick Grunnie Mbewe and Abdel Rahman El Gamal (Founder of the website)

Freshwater crab in Zambia (01) Freshwater crab in Zambia (02)

 

 

 

 

 

The inserted photos show a freshwater crab, (Potamonautes sp) captured by a gill net in Kyafukuma River, Solwezi District. These crabs can forage over considerable distance by night and they may get entangled in the nets while approaching for feeding on the fishes that could be captured in the nets. This foraging activity may destroy fishermen nets.

While these crabs will feed readily on fishes entangled in gill nets, they may feed –out of water- on algal materials, as well as fragments of terrestrial plants.

Permanent link to this article: https://fishconsult.org/?p=12647

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