The Fish Under The River Kwai

Story/Images by: Nonn Panitvong

My dad said, it was a famous movie “The Bridge Over the River Kwai”.  A story of those prisoners of war during the World War II who was captured by the Japanese Soldiers in Thailand and forced to build the bridge – a rail way bridge- to cross the river Kwai which was heading from the west of Thailand to Myanmar.  They said many lives were lost during the construction probably in the region of 80,000 to 100,000, the Japanese never keep that exact record and we will never know the actual number*.  I remembered watching it long time ago, so long that the detail had escaped from my memory.  Anyway, in the real life, the war ended before the rail way reached Myanmar and now the bridge became a famous tourist attraction.  However, it is not the bridge, but the fish and the river Kwai herself that I will introduce to you in this article.   

Where is the River Kwai?

River Kwai -locals pronounce it more like Khwae- is in Thailand, a medium size country with approximately 500,000 square kilometers of land in the heart of South East Asia.  Formerly known as Siam, her 63 millions inhabitants are mainly Buddhist and they are one of the nicest people you would find on the planet earth.  I’m proud to be one of those people.  Have you ever heard of the phase “The Land of Smiles”.   It is a good phase to summarize our country in to 4 short words. 

River Kwai and hers tributaries lie in the west of Thailand.  She starts in Kanchanaburi Province which is about 170 kilometers from Bangkok –the capital city of Thailand, flow a few hundreds kilometers down south through a few more provinces and drain into the Gulf of Thailand.  Near the center of the province is where the Bridge over the River Kwai situated, while the river Kwai herself starts almost 300 Kilometers west in Thailand’s biggest piece of forest near the Border of Myanmar. 

They didn’t tell you in the movie but actually there are 2 river Kwais, we call one “Kwai Yai” meaning “Big River Kwai” and the other one “Kwai Noi” which translate to, you guess, “Small River Kwai”.  The bridge situated over the Kwai Yai just before she merges with Kwai Noi at Kanchanaburi City and became a bigger river with totally different name “Mae Klong”.  Mae Klong is a big river “once” famous for her faunas’ diversity, the Julien’s Brook carp (Probarbus jullieni),now on Appendix I of CITES,  was once a local delicacy for people along the Mae Klong, but it  had severely reduced in number in recent year. River Kwai and Mae Klong have changed over the past 3 decades. 

Click here to see the map of Thailand's river drainage system.  Mae Klong drainage is marked as Mkl.

As tropical fish keepers, I’m sure you must have come across one of these names in your local fish store, Bala Shark (Balantiocheilos melanopterus), Red fin Shark (Epalzeorhynchos frenatus), and Dwarf Chain Loach (Botia sidthimunki).  These fish were once numerous in the Kwais and Mae Klong.  However, there are very few confirmed catching or sighting report of them in this area nowadays.  Those fish now available in the pet trade are being artificially bred –Hormone induced- in captivity and it has been like this for many years already. 

What had happened to the River Kwai?

It started simple; the country was under development, we sell whatever we can find.  Thailand was blessed by Mother Nature for her land and her river is so fertile.  There is an old saying “…in Thailand there are fish in the water and rice in the field”.  In the past the people would grow their own rice and catch their own fish to fill their own stomach, what left is share in the community.  Then come what we called “Export”.  We need more cultivate land and we need to catch more fish.  The big fish would be eaten and the small pretty one would be export as lowly prized ornamental fish.  There was more need for the water as the export market was on the rise.  The Kwais and Mae Klong tributaries could not hold enough water for our need, after all she is seasonal.  We need the water during the dry season, and we don’t want her to flood the agricultural land during the rainy season.  Dam was the answer, but one was not enough so we built 3, one on the upper reach of Kwai Yai, another on the upper reach of the Kwai Noi and the other on the Mae Klong.  It was a disaster recipe for the local fish.  First of all the breeding ground, some fish needs flooded land, some large fish need to get to the upper reach of the river to breed, the giant soft shell turtle –Chitra chitra, the largest soft shell turtle that will grow up to 100 kilograms- need sandy beach during the dry season to lay their eggs, they have all effected by the dams.  Most of the fish hold their ground sparingly but some like what I mentioned lost it all together.  Reduced in number due to the demand from the pet trade, after their habitat has been destroyed they never recovered.  The giant soft shell turtle reduced to a few captive specimens in captivity.  I once asked an old fisherman who live on Kwai Noi for all his life about them.  He said when he was a young man; he would reframe from going out fishing on the sand beach along the river during the hatching season, afraid of stepping on newly hatchling giant soft shell turtle.  They were that numerous.  No more sand beach, no more giant soft shell.  Luckily, we finally can breed them in captivity. 

On the upper reach of the Kwai Noi near Thai-Myanmar border is Koh Lam Dam or officially known as Vajiralongkorn Dam, name after her royal princess.  When they built the dam in 1979, some 3,720 square kilometers of pristine forest and a few villages were flooded, all of the tree were dead but one palm tree miraculously survive.  It is still standing until today, flooded most the time only in the dry season of the driest year would it trunk meet the air.  The scientist can't explain it but the local said that a family of tree angel is protecting this palm. 

One of the village that was forced to move up the hill was Sangklaburi.  This is the place where Thais, Burmeses, Karens, Loas and Mons living together peacefully.  Back in the 60s when my dad was a young man, and there was no dam, he came here in search for valuable ore.  He failed in that project, having found no substantial amount of ore, but he did made a lot of friends during those years spent in the jungle.  When the dam was built, and the condition of the road get better, a friend called and invited him to visit the large lake behind the dam.  He tugged me along and we both failed in love with the natural beauty of the area.  Since our first time that we visited this place 20 years ago, we have been a regular visitor to this area.  We even have a house floating in the lake. 

Almost 20 years has passed and I grew up knowing and loving all the natural beauties in the area.  Over the year, she has changed, getting tired from the activities of us human.  With better road and all, a lot more people moved into the area.  They catch more fish and cut down more trees.  There are less fish in the water now.   Fortunately, the government has –finally- step up to protect some breeding ground of the fish and we have seen some improvement in the past few years. 

There are 3 major rivers that merge to form Kwai Noi, being Runtee, Bekee, and Songgaria.  The government now totally bans any fishing activity on the largest of the 3, the Bekee, this result in fish refugee and also breeding ground for fish of the whole lake.  With plenty of fish, large water birds like Painted Stalk (Mycleria leucocephala) also come to live in the area. 

Of all the 3, Runtee seems to be the one most affected, especially the part near to the lake.  When the dam was built, the forest on the lower Runtee was flooded; all the trees were dead and left the ground bare.  This result in soil corrosion during the rainy season which shallower the river, the still standing tree also coming down every year from the same reason.  There are also a lot of villages upstream of the Runtee.  The government has done very poorly on controlling the new opening of forest area for agricultural, which result in more soil corrosion on the upper part of the river.   The water in the river is extremely murky during the rainy season, and the shallower river mouth makes Runtee no longer suitable as breeding ground for large fish.  I remember, fishing for Hampala from Rantee was very easy when I was young, but nowadays we would be very lucky to catch a fish in a day fishing.     

Bekee, the largest of the tree has been a reminiscence of what the 3 rivers might have been in the past.  Virtually, no human is allows to catch fish in the river.  During fish breeding season, I was fortunate to get permission to visit the area and it was amazing.  There were so many fishes that the wake from our boat push them up on the sandy beach, silvery glittering tried to find their way back into the water.   On the flood plain, small Rasbora and Puntius pushing their way up into a shallow stream to breed.  On the flooded grassy area, the Pristolepis fasciatus were lying all over the place, having spawned in the night before and while pushing our way into a small stream, a giant size Channa micropeltes was startled and jumped into our boat!  While young Osphromenus gorami can be seen foraging along the river bank, there were signs of large fishes everywhere, very often we would see the surface of the water exploded by the large fish coming up for air, probably Wallago attu or Chitala ornata.  The ranger said you can even here the fish calling each other in the rainy night. 

Click here for VDO clip of the fish in the stream. 

Songgaria, is probably the smallest of the 3 but she is my favorite.  Variety of fishes that you can find here are absolutely amazing, from cyprinids to loaches to puffer to catfishes to many others groups of fishes, the famous aquatic plant Dow noi or  Pogostemon helferi that I introduced to the hobby also come from this river.  I spent countless hours diving into Songaria every dry season when her water is calm and clear.  It is absolutely amazing down there.  Here you will see Microrasbora kubotai** swimming in small group in the calmer area, a school of Crossocheilus siamensis –world famous Siamese Algae Eater- doing about their business –eating algae- in the deeper part of the stream, the virtual effect of their black lined body moving together in the same angle and direction really is stunning.  Apart from that, there are many more species of fish you will be able to say Hi to, many neat, newly described or even unknown to science, like the Batasio tigrinus, Badis khwae, Amblyceps variegatum, Poropuntius melanogrammus undescribed Rhinogobius, Rasbora and many Schistura.   Near Songaria is Tree Pagodas Pass, border pass between Thailand and Myanmar this is where most of the popular Myanmar fishes from Ataran river came in, including the very famous Botia kubotai. For your information, here a good size specimen cost US$0.50 a fish.    

In the upper reach of the 2 Kwais is also homes to 3 species of cave fishes. 2 species of loaches, Schistura jarutaninii and Nemacheilus troglocateractus both endemic to only one system of underground water and the other species a Siluridae, Pterocryptis buccata, live in the same cave with N. troglocateractus and report to eat its cavemate.  There are very few caves in the world with 2 cave fish species living together, this shows how rich in diversity this area is. 

Apart from fishes, the other species worth mentioned in this area is what probably the most beautiful land crab in the world, the Queen Crab, Thaiphusa sirikit. First discovered in 1983 and named after our Royal Highness Queen Sirikit, the crab grows to about 5 Cm. wide and 7 Cm. across. Their unique coloration makes them one of the most beautiful crab species in the world. Normally, their legs color is red but when I visited their habitat, the legs were white, probably the color is seasonal adjustable.

20 years has passed by, I still visit the area regularly and every time, there are still more things to learn and more waiting to be discovered.  I hope that I will be able to learn more about this place and be able to save her for the future generation to learn more about her natural beauty. 

Although the river Kwai has changed a lot in the recent year, I still love every single bit of her.  Just like when you really love someone, you just love her no matter what.    

The Beginning

* more detail about the history can be found here http://www.cofepow.org.uk/pages/asia_thailand1.html

** A note on Microrasbora kubotai:  This species has never been report from Mae Klong river drainage until early 2004 when I found a few of them swimming happily in Songgaria River.  I later found out that it was probably introduced by the family of local ornamental fish dealer who imported this fish from Ataran River of Myanmar.  The story was that, he unexpectedly passed away in his sleep and his family didn’t no what to do with the fish, so they released them into Songgaria –the closest river way to their home.  Unfortunately or fortunately, I’m not so sure, this nice little species adapted to its new environment very well and now firmly established in its new home.  So far no native species seems to be effected by them but long term impact on introduction of them into the river is very interesting.  I will keep monitoring and keep updating on this unexpected Grand experiment with mother nature. 

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