Mar 22 2015

Pole and Line tuna fishing in the Maldives

 

Pole and Line tuna fishing in the Maldives

 

 

 

 

 

Photo credit: David Elliott (UK); http://www.macalister-elliott.com/index.php

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

 

Introduction:The Maldives that consists of a very large of islands in the middle of the Indian Ocean is a nation that comprises of 99% sea. That is why more than 70% of people are fishermen who Maldives sees fishing not just a job but as a way of life. This mater is even more pronounced when we know that Maldives is the home to one of most renowned tuna fisheries in the world. The high value of tuna in the international markets brings the export of tuna second to tourism which is the primary source of income.

Tuna fishery in the Maldives:In terms of fish exports, the most important tuna species is the skipjack tuna while the yellowfin tuna comes next. The catch of tuna in the Maldives is done in a special way which is namely “Pole and line” which is usually described as catching tuna one by one. This traditional contributes with about 90% of total tuna catch in The Maldives.

 

Description and operation: As its name indicates, the gear is composed of a 3-4 m rigid pole made of bamboo or fiberglass capable of handling a fish weighing of about 20-25 kg.  At the extremity of the pole, a strong short hooked line is attached. Thus the “Pole and line” requires just one pole, one line and one barbless hook used by one fisherman to catch one tuna at a time. In exceptional cases, a special line can be attached to 2 poles held by 2 fishermen allowing the catch of much larger fish. Bait fish is an integral part of the pole and line tuna fishery where anchovies, small scads, silver side and sardine are the most common bait fish that are kept alive using sea water circulation; 1 kg of baitfish can deliver 10kg of tuna.

The fishing operation takes place on a medium size fishing vessels of about 40-meters. About 10-20 fishermen position themselves almost all around the boat.

Different methods are followed to locate the schools of tuna which could range from the visual spotting,watching sea birds till the use of fish aggregating devices and/or acoustic instruments.

Once the school of tuna is located, small amounts of live bait are regularly scooped up and tossed overboard to mix with water sprays agitating the water, giving the illusion that the water surface is alive with small fish and hence attracting and concentrate the tuna school in the trail of the fishing vessel. At this point, skillful fishermen will use their fishing gears to catch a tuna after another and place the catch on the deck to be chilled as soon as possible whereas  ice slurry is the most efficient cooling medium which is in use. Often, the fishing crew work six days per week.

Advantages: The pole and line tuna fishing has several advantages whether economically, socially as well as the sustainability of tuna as well as other fish species stocks. The “Pole and Line” eliminates indiscriminate harvesting fish species other than tuna and hence brings the bycatch to almost zero.

This method also safeguards some endangered species which could be caught in purse (e.g. sharks, rays, pilot whales, whale sharks, turtles, dolphins, and seabirds).

In regard to the employment, the “Pole and line” fishing requires more fishermen per ton of catch compared to other fishing methods. This leads to more jobs, higher standard of living across coastal communities especially tuna fishermen are well paid. Finally, enhancing the nutrition status of households should not be overlooked.

 

 

 

Permanent link to this article: https://fishconsult.org/?p=12479

Mar 19 2015

Fish consumption and marketing in Azerbaijan

Photo credit: Luis Landesman (USA)

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

Fish marketing in Azerbaijan (02) Fish marketing in Azerbaijan (01)

 

 

 

 

 

 

The inserted photos were taken during April 2013 in a typical market in Azerbaijan. Even though our focus remains on fish, it is obvious that there are no specific markets for fish or fish products in Azerbaijan. Instead, fish are sold in reserved sections in public markets whereas other products are sold.

In the fish display shown in the photos, customers can find fresh fish from the Caspian Sea as well as frozen fish products, as well as smoked fish which are imported from the Baltic States, Kazakhstan and the Russian Federation.There are no specific markets for the sale of fish or fish products in Azerbaijan. However, in public markets and supermarkets, sections are reserved for the sale of fish.

 

Displayed fish as shown in the photos are headed and gutted. Also, there are no price labels. This could be attributed to either possible bargaining by the buyers and/or possible price changes throughout the day; especially there is no ice is seen on the display. We need to remember that the visit took place during the month of April where the temperature is not usually high with its average highest of 14 C and average lowest of 9.

 

In a recent study done in 2013, the price of fish and fish products in Azerbaijan  market vary significantly

Fish/fishery product US$/kg
Fresh sturgeon meat 30
Smoked sturgeon meat 50
Fresh and fresh-frozen fish 4
Large fresh fish 7
Small fresh fish 3.5
Smoked fish 7
Salted fish 4.8 – 6.0

 

According to FAO statistics, the per capita fish consumption in Azerbaijan in 2010 is very low and stays just below one kg/year. However, in the coastal regions of the Caspian and in the regions adjacent to the main inland waters, fish consumption is much higher than the country average compared to the rest of the country. Also, fish is consumed in the cooler months is much higher than the year average.  The same is true for the consumption during the lunar New Year celebration (Novruz Bayram), during which a traditional meal of fish is usually prepared.

Reference: Salmanov, Z., Qasimov, A., Fersoy, H. & van Anrooy, R. 2013. Fisheries and aquaculture in the Republic of Azerbaijan: a review. FAO Fisheries and Aquaculture Circular No. 1030/4. Ankara, FAO. 42 pp.

 

 

 

Permanent link to this article: https://fishconsult.org/?p=12473

Mar 15 2015

Promoting small-scale cage culture in oxbow lakes in Bangladesh

Photo credit:Abu Sayed Talukder and  Zahangir Alam (Bangladesh)

Review:Abu Sayed Talukder & Zahangir Alam (Bangladesh) and Abdel Rahman El Gamal (Founder of the website)

 

Bangladesh cages (01) Bangladesh cages (02)

 

 

 

The inserted pictures were taken in a training session conducted at a fish farmer’s village in Gaibandha Sadar Upazila, District “Gaibandha”. Most of the course participants are small-scale fish farmers along with some fishermen.

Cage culture in Bangladesh is practiced in water bodies with proper water current which are not subject to drying-up in dry season. Cage farming practices take place in oxbow lake, baor, haor and bills. In river- Chandpur and Faridpur districts are mentioned.

The history of cage culture in Bangladesh is a very recent and started from early 80’s only on trial basis. The utilization of the oxbow lakes to its full potential has considered cage culture especially by resource-poor fishing communities.

Based on earlier findings, cage culture has been promoted through different projects such as the one carried out in Oxbow Lakes which is titled as “Small Scale Fishermen Project (OLP-II)” which has been implemented in in two baors (Konnadah and Bahadurpur). Moreover, CARE Bangladesh CARE, initiated a project at the end of 1995 until 2000, supported by the Department for International Development (DFID) named Cage Aquaculture for Greater Economic Security (CAGES). The species of fish which have been tried and produced include Asian catfish, Clarias batrachus, Thai pangas, Pangasius sutchi, common cap (Cyprinus carpio) and silver barb (Puntius gonionotus).

 

 

Permanent link to this article: https://fishconsult.org/?p=12468

Mar 11 2015

Peaceful angelfish may fight sometimes – Video

This video has been filmed during December 2014 in the Sea World, San Diego, California, USA. Before going over the biological information, I was surprised to see how these peaceful fish –as their name tells- can fight. In fact, angelfish are generally peaceful especially when not mating but they under certain conditions such as overcrowding, they exhibit their territorial behavior and turn aggressive.

Introduction: The freshwater angelfish that belongs to the family “Cichlidae” is native to South America. The species is prized for their unique shape and color making them one of the most popular freshwater aquarium fish. These fish can live ten years or longer.

Feeding habits: Even though, freshwater angelfish prefer meat-based diet, they are omnivorous and they feed in nature primarily on smaller fish, crustaceans and invertebrates in addition to food particles which could be found in the water.

In home aquarium, angelfish feeds on a wide variety of foods including feed pellets or flakes, frozen foods, bloodworms and other small insects and crustaceans.

On the other hand, the freshwater angelfish is preyed upon by larger fish species, birds and marine mammals.

Reproduction and life history: Freshwater angelfish usually pair for life and it is often found that if one of the parents dies, then the remaining spouse loses its interest in breeding.

It is very difficult to determine the sex of angelfish especially when outside the breeding season. However, male angelfish have smaller, more pointed genital papillae than females. Also, males exhibit more aggression or territorial behavior.

When the angelfish pair is ready to mate, they choose an appropriate spawning substrate upon which female lays the eggs. Depending on the size and general fitness of the female, she deposits between 100 and 1000 eggs in organized lines. The male follows and fertilizes the eggs. During incubation, the parents take turns in circulating water around the eggs through swimming and fan the eggs using their pectoral fins until eggs hatch in about two days.

The hatchlings of angelfish remain attached to the spawning substrate for about a week. During this period, hatchlings feed on the remaining yolk in the egg sack. When they are a week old, the angelfish fry detach and become free swimming and feed on the appropriate nutrients in the water and on plants.

Under aquarium condition, when fertilized eggs are removed from the aquarium immediately after spawning and fertilization, the pair is capable of spawning every seven to 10 days. At 3-year old, the spawning frequency decreases before eventually ceases.

Body shape, color and camouflage: The angelfish has a triangular shape with laterally thin, compressed, with round bodies and elongated triangular dorsal and anal fins. The body shape as well as the distinctive dark stripes that run vertically down their bodies provide camouflage and allow angelfish to blend in its surroundings and hide among the aquatic plants.

Permanent link to this article: https://fishconsult.org/?p=12464

Mar 08 2015

Integrated Agriculture-aquaculture Project in Solwezi District (Zambia)

This project has been developed by a group of trainees who participated during 2014 in the  “Fish Culture Development” training course” which is annually hosted by the Egyptian International Centre for Agriculture (EICA). The proposed location of this project is Solwezi District, Zambia. The proposed project covers the integration between aquaculture with two agricultural systems that are namely plant agriculture and poultry.

The rationality of this project in regard to chosen place has been covered. The technical component considered the nature of each integrated component. The same is true for the economic analysis including the key economic parameters including the IRR, NPV, Pay-back period and benefit-cost ratio. The three integrated components of the project are considered when judging the feasibility of the project.

This project is one of more group projects which have been supervised by Dr. Abdel Rahman El Gamal.

http://fishconsult.org/wp-content/uploads/2014/07/Integrated-agriculture-aquaculture-project-in-Tanzania.pdf

Permanent link to this article: https://fishconsult.org/?p=12460

Mar 05 2015

Small-scale cage culture of red tilapia in Perak River, Malaysia

This project has been developed by a group of trainees who participated during 2014 in the “Fish Culture Development” training course” which is hosted by the Egyptian International Centre for Agriculture (EICA). The proposed location of this project is Perak River, Malaysia. The proposed project covers the small-scale cage culture. The rationality of the project type as well as the chosen species (red tilapia) has been covered in the attached document. The technical component of the project has been adequately addressed. The same is true for the the economic analysis including the the economic parameters. The itemized budget is included in the attached document. The project include an economic sensitivity analysis as a mean to evaluate the feasibility of the project under different circumstances.

This project is one of more group projects which have been supervised by Dr. Abdel Rahman El Gamal.

http://fishconsult.org/wp-content/uploads/2015/03/Small-scale-cage-culture-of-red-tilapia-in-Malaysia.pdf

Permanent link to this article: https://fishconsult.org/?p=12456

Mar 05 2015

Sea stars feeding on scallop jingles (Monterey, California, USA)

Credit: Michelle Kaiser (Monterey, USA)

 

Sea stars while feeding on scallop jingles

 

 

 

 

The inserted picture was taken at the commercial Wharf Piling and shows Sea stars such as Pisaster ochraceus whilefeeding on scallop jingles that are very plentiful within the harbor. This star is joined by a purple urchin, Strongylocentrotus purpuratus, and a decorator crab, Loxorynchus spp.

 

 

Permanent link to this article: https://fishconsult.org/?p=12453

Mar 04 2015

Field analysis of ammonia in fish ponds using color disk kits – Video

Video credit: Carolyn Madalo Chinguo (Malawi)
Description: Abdel Rahman El Gamal (Founder of the video channel)

This video was filmed in the WorldFish Center-Egypt during a regional training course.

This 9-min video demonstrates the field testing of total ammonia in water using the color disk kits. The video starts with water sampling emphasizing how to obtain a sample without air bubbles from a designated depth which was 30-cm in this video.

The demonstrated method can produce fast and reasonably accurate results especially when the individual color perception is high (individual sensitivity), especially this method depends on color comparison.

The analysis proceeds as follows:

Place the ammonia color disk on the center pin of the color comparator with the lettering facing out

Rinse the 2 viewing test tubes using the sample water before testing

Insert the blank test tube (only sampled water) into the left opening of the color comparator

Insert the ammonia-nitrogen test tube into the right opening of the color comparator. Add three drops of Nessler Reagent to the water sample and swirl to mix. A yellow color will develop if ammonia-nitrogen is present. Allow samples to sit for a maximum of 10 minutes.

Hold the color comparator up to sunlight or a lamp and view the openings in front. Rotate the color disk until a color match is reached then read and record the value of ammonium-nitrogen in mg/l as seen through the scale window.

The temperature and pH of sampled water should be measured in the same time of ammonia sampling. In order to obtain the toxic (unionized) component of total ammonia (NH3),  consult a specialized table that considers the pH and temperature values. As a rule of thumb, the NH3 increases (and so the toxicity) as the pH rises.

 

Permanent link to this article: https://fishconsult.org/?p=12450

Mar 03 2015

Napping Sea Lion in the territory of an abalone farm (Monterey, USA)

 

Napping sea lion

 

 

 

 

During my visit to the abalone farm in Monterey, California, I took this picture for this napping sea lion. The abalone grow-out cages are located in the water several meters under the napping animal who reached the farm along with the morning high tide leaving the animal behind in the low tide. There is no worries about the abalone for having sea lions who are not abalone eaters in contrast with the sea otters; the abalone lovers. Surprisingly, nether our existence and talk nor the camera flash were disturbing sleeping animal who can either wait for the afternoon hide tide to leave or simply jump in the water at any time.

 

Permanent link to this article: https://fishconsult.org/?p=12445

Mar 02 2015

Nursed red abalone while grazing on sea lettuce (Ulva sp.)

Credit: Peter Hain (Monterey, USA)

Grazing abalone

Red abalone, Haliotis rufescensis an important fishery resource in California, where several hatcheries are producing juveniles of this species. This picture has been taken in a nursing tank in one of those hatcheries located in Monterey region, California.

Diatom is the starting feed for baby abalone. As abalones grow on the corrugated sheets, diatoms can be supplemented with the addition of dried diatom powder, artificial abalone feed wafers and with wild Ulva sp. that grows in the tanks as shown in the picture. About two months before harvest the abalone for grow-out, abalone juveniles are introduced to macroalgae which may include Ulva, Palmaria, or Gracilaria sp.

 

 

Permanent link to this article: https://fishconsult.org/?p=12442

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