“Mékong” or the mother of all the rivers
The Mékong a Southeast Asian river originating in the Himalayas. It is the 11th-longest river in the world, and the 12th-largest by volume .Its estimated length is about 4800 km square and it drains area is 810 000 km2.
Taking its source in Qinghai (on the heights of the Himalayas Tibetan Plateau) the Mekong irrigates successively China (in the province of Yunnan), Myanmar, Thailand, Laos, Cambodia and Vietnam (Vietnam where it is traditionally called the “river of the nine dragons” or Sông Cửu Long.
The Mekong River Basin hosts one of the most diverse freshwater faunas in the world. There are 1,400 recorded fish species and the number will increase as new species are discovered and classified, possibly 1700 species live in the Mekong basin. A short list of these species are illustrate in this photo.
About 70 million people live near the Mekong .They use it for irrigation, fishing, hydroelectricity, production, transport and others.For fishing the most concentrate fish farm are near the Mekong river.
But also people use the Mekong for home and floating market. A wide range of fishing methods is used and most of the fishing gear and boats are of traditional design and manufactured with extensive use of local material.
The Mékong différent Dry an monsoon season
Typical floodplain river dominated by the monsoon climate, it’s a dynamic river system alternating between a dry season from November to April and a flood season from May to October.
The flood season drives the system and creating vast land of floodplains adjacent to the river channels every year. These floodplains are highly productive for fish and other aquatic animals.
Features along its course: variation in depth, rocks, shallow fast and sometimes deep pits.
The Mekong River is a river with special environmental characteristics along its path. Some stretches have little variation in depth, and others have rocks and boulders and vary between shallow rapids and deep pools.
The deep pools play a crucial role in the Mekong river ecosystem because they are important habitats for many fishes during the dry season. When the dry season sets in, water levels in the Mekong reduce and the seasonal fish habitats on the floodplain disappear.
As a result, fishes, go to deeper sections of the river and live there until the next flood sets in.
Also fishes are mainly produced in floodplain habitat. Deep pool are equally important for maintaining the integrity and productivity of the system (there are a lot of deep pool at the border of Laos and Cambodia) 58 deep pools have been identified in the north of Cambodia.Also deep pool are the habitat of some dolphins
Lower Mekong basin an estimated of 2 million tons of fish and other aquatic animals are consumed annually in the Lower Mekong Basin. Of this, 1.5 million originates from catches in natural water-bodies and 240,000 tons from catches in reservoirs
Different fishing techniques for locals along the Mekong
This Large tropical river ecosystems have immense value both in terms of high biodiversity and the numbers of people that depend upon that biodiversity for their live hoods.
But this biodiversity suffers from multiple demands.
- Fast growing population recent improvements in roads, storage transport, fishing gear and communications, mobile phone became accessible to many traders are boosting transboundary fish trade.
- The seasonal peaks in the Mekong catches have stimulated the development of a large industry. Before fishing was use for subsidence, people are now increase fishing to generate incomes.
Which speeds up cross-border exchanges
Some fishers especially particulary in commercial sector use a wide range of gear and technic according of the season and also because the resource are complex (huge variety of species and a huge of habitats at a different time of the year).
Now the catch of this area (Sipandhone fishery) is trades over fast distances (reaching some market to Pakse (2 hours from Sipandhone), in Vientiane (10 hours) and even some market in Thailand. Lao, Cambodia invest in some cooler allowing them to transport fresh fish over long distances.
All this leads to new fishing techniques and large-scale dams completely blocking fish migration along the Mekong River
A ‘dai‘ is a stationary trawl gear fixed by stakes in the river to capture migratory fish, a single gear can land up to 0.5 tons of fish per haul in 15 to 20 minutes during peak periods of the lunar cycle. There are presently 15 rows of dais (more in the past), with one to eight dais in each row
The blocking of entire streams. Dams on the Theun and Ngum Rivers in Lao PDR, the Mun River in Thailand, and the Se San River in Cambodia and Vietnam (large barrage systems).
Large-scale fishing operations are often based on exclusive access to sites obtained through purchase of government licenses.
The majority of large-scale operations include barrages fences, traps, nets in the branches of the upper Tonle Sap, extended lake fences (60 km or more) around demarcated fishing lots in the lake and the largest set bag nets in the system.
The large-scale fisheries in the Tonle Sap Great Lake, fences as long as a kilometre and arrowshaped enclosures direct fish into traps.
In the Tonle Sap River delta, in Kampong Chnang, fish are caught by extensive barrages. In the lower part of the Tonle Sap River, just before it joins the Mekong near Phnom Penh, fisherman use enormous bag, nets to trap fish.
The use of large-mesh gill nets up to 200 m long.
In the dry season, illegal fishing with chemical poisons and explosives, and other illegal method takes place in the deep pools, and channels of the Mekong River
Electroshocking (e.g., in Boeung Thom Lake, Cambodia).
Some other problem are fishing and dynamite blasting in spawning areas.
Illegal expansion of fishing lot boundaries, illegal fishing for juveniles
Illegal fishing includes unauthorized fishing in controlled areas
Most of this Illegal fishing are at the border of Lao and Cambodia, cause managing trans-boundary fisheries is challenge facing government authority and Mekong river fishing communities along the border.
To enrich oneself or simply to feed oneself
We must be proposed something in exchange for a controlled and sustainable fishing. The alternative is Aquaculture and its where our association comes into play, aquaculture will be a subject with many post in our Blog :-)…