The Mekong River is one of the largest river in the world and is home to a wealth of biodiversity and aquatic life. Fisheries is a crucial contributor to socio-economic development in the Mekong and a vital source of livelihood and food security for people living along the Mekong River banks. On the flip side, increasing infrastructural development, population growth, and economic development have changed the fisheries trends over the past few decades. The Mekong countries, thus, have put fisheries monitoring central to understand its status and trend in light of development pressures in the Basin. 

“We recognise the value of fisheries that is crucial to riverine communities, and that’s why the MRC has supported fisheries monitoring program, and now continues to be part of our technical work” said CEO Dr Pham Tuan Phan.

Since 1994 to date, the Mekong River Commission (MRC) have supported four major monitoring programs to track the status and trends of fisheries in the Lower Mekong Basin (LMB)—deploying different methods.

The Fish Abundance and Diversity Monitoring Program implemented in Cambodia, Lao PDR, Thailand, and Vietnam is a routine artisanal fisheries monitoring to determine status and trends of fish abundance and diversity in the LMB through temporal and spatial variation.

The Fish Larvae Density Monitoring Program implemented in Cambodia and Vietnam is an effective means to assess fish larvae quantity and density, and assess the likely fish spawning grounds.  

The Dai Fishery Monitoring Program implemented in Cambodia is the only inland industrial fishery established for more than 140 years, and used to determine the trend of key fishery indicators such as abundance, length frequencies and fish prices at landing sites of migratory fish species that migrate from the Tonle Sap Great Lake to the Mekong.

The Lee Trap Fishery Monitoring Program implemented in Lao PDR at the Khone Falls (Khong District, Champasack Province) tracks the abundance and diversity of migratory white fish in the Lower Mekong River, and supports a valuable information on fisheries resources for fisheries management and impact assessment purposes.

In July 2016, the Governor of Khong district ordered that Lee trap fisheries in Khong District, Champasack province be stopped,  which applies also to Lee trap fisheries monitoring for the year 2017. This guidance follows commitment of the Khong District and Champasack Provincial Office to curb illegal fishing activities (including illegal fishing gears) under the Lao Fisheries Law and Supplement Order by Governor of Khong District (14 December 2016) that prohibits the use of illegal fishing gears and operation. To date, more than 340 lee traps have been removed.

The suspension of lee trap fisheries is an effort to legally control all operations of lee traps as a first step. Lee traps are used for monitoring purposes but if allowed, will serve as a bad example and send different messages to fishers who use illegal lee traps.

 Together with its Member Countries, the MRC strives to manage fisheries by improving and sharing technical know-how on fisheries management and raising awareness on the sector’s significance for the Mekong’s environment and its people. Its Basin-wide Fisheries Management and Development Strategies 2018-2022 has been endorsed by the MRC Joint Committee (the management body of the MRC) in August 2017 and for approval by the MRC Council in November 2017.

This strategy is driven by national strategies in the four Member Countries and focus on capture fisheries including impact and mitigation of hydropower and irrigation dams; transboundary movement of aquatic organisms; transboundary fisheries management; and other cross cutting issues like gender and climate change. 

For more information and research on fisheries, go to: www.mrcmekong.org/topics/fisheries/

 

MRC fisheries monitoring program (1994 – 2010)

The Fish Abundance and Diversity Monitoring Program implemented in Cambodia, Lao PDR, Thailand, and Vietnam is a routine small-scale artisanal fishery monitoring to determine status and trends of fish abundance and diversity in the LMB through temporal and spatial variation. Fishers at each monitoring sites record their daily fish catch by species into their logbook (including weight, number of fish, and maximum fish length) and efforts put in (hours fished, by gear type and size). Around twelve fishing gears are commonly used like gill nets catching gear for its effectiveness followed by big horizontal cylinder traps.
The Fish Larvae Density Monitoring Program implemented in Cambodia and Vietnam is an effective means to assess fish larvae quantity and density, and assess the likely fish spawning grounds. A standardized methodology is employed to monitor relative larvae density by collecting samples repeatedly for thirty minutes every six hours, using a 1 meter bongo-net with a 1 millimeter mesh size, set 2 meters from the surface of the river and 20 to 20 meters from the river bank.
The Dai Fishery Monitoring Program implemented in Cambodia is the only inland industrial fishery established for longer than 140 years, and used to determine the trend of key fishery indicators: abundance, length frequencies and fish prices at landing sites of migratory fish species that migrate from the Tonle Sap Great Lake to the Mekong. The Dai fishery is located in the lower part of the Tonle Sap River spanning more than 30km across the municipality of Phnom Penh and Kandal Province. Dai nets are arranged in up to 15 separate rows of between one and seven nets anchored perpendicularly to the channel, with the net mouth facing upstream. These positions have remained largely unchanged for longer than a century and may have been chosen to maximise catch rates determined by river morphology and hydrology.
The Lee Trap Monitoring Program implemented in Lao PDR at the Khone Falls tracks the abundance and diversity of migratory white fish in the Lower Mekong River, and supports a valuable information on fisheries resources for fisheries management and impact assessment purposes. The Lee Trap fisheries monitoring uses one kind of gear common in Lao PDR, especially in southern Lao PDR locally known as ‘lee’ traps, made from bamboo. Unlike other fishing gears, locations where the lee traps are set are owned by fishers who inherits from generation to generation. Other users who wish to use the lee traps would need permission from its owners by renting or buying it. Compared to ten years ago, the lee traps are now constructed more durable.
The lee traps are mainly used in the rainy season, set into specific location where water level is shallow and rapid to target upstream spawning migration of fish, mainly catfish. Swimming against the rapids, fish eventually tire and are swept back into the trap. Fish are mostly caught at night and the fishers harvest fishes from the trap in the morning. Fishers use more than 40 different types of gears, including the semi-submerged lee traps.
The Khone falls is an important fishing ground supporting the livelihood of more than 60,000 people (2013). There, the mainstream of the Mekong braids into 18 major channels before it flows over the Great Fault Line—a geological fault that causes the river to drop 20m over a distant of around 10km.