Rivers in Myanmar: can the ecosystem tell us how things are going?

Towards the end of 2015 I travelled to Myanmar and was struck by the vibrancy and beauty of a country that has gone through long periods of conflict, where the people seem to reflect an optimism and an inspirational enthusiasm for a new way of living.

Rivers are the lifeblood of Burmese society, and yet coming out of years of political and economic isolation it is perhaps not surprising that the rivers are not well researched or understood.  So much of Burmese culture is tied to these big rivers for transport, food and livelihoods.  Many of the people live in close contact with the rivers and have a thriving boat culture, with boats and barges of all shapes and sizes navigating hundreds of kilometers up the river.

With Myanmar opening up and development of its water resources occurring at a fast rate, there is an urgent need to understand the river situation and to ask questions of how best to manage these rivers so that they continue to provide services to a society that appears destined to grow. An issue that is already suggesting that things are not as good as they could be, is that the fish stocks that people are so dependent on, appear to be in serious decline.  Why is this?  Have the fish and the rivers themselves been used too much?  Are the rivers polluted or are they suffering some other form of stress?  What can be done to protect the fish stocks so that they continue to provide for the people of Myanmar?

It is from questions such as these that a project was born looking at the health of the rivers in Myanmar, concentrating on the lower reaches of the Ayeyarwady (Irrawaddy), a “working river” at the heart of Myanmar’s national prosperity; and the Thanlwin (Salween), a near-pristine system with large potential for development, shared with China and Thailand.  Called the Myanmar Healthy Rivers Initiative (MHRI) project, the MRHI aims to answer the questions: what ecosystem services provided by rivers are valued?  Which communities and sectors value them?  Is the health of the river, and the provision of these services, changing over time?  The aim is to develop and test an approach which allows government and communities to monitor the status of the riverine ecosystem services they value, which provides evidence for informed, integrated water resource planning.

The project brings together two international organisations with experience in river health (IWMI and ICEM) and two local partners with experience at implementing community development and environmental management projects in Myanmar (ECCDI and MIID).   We are working closely with the Ministry of Environment, Conservation and Fisheries (MOECAF), and consult with a wide range of stakeholders from national to community level.  There has been a lot of interest shown in this approach by Burmese institutions and donors as well.

Keeping tabs on the rivers

One of the easiest ways of keeping a check on the state and health of a river, that is followed in many countries around the world, is to check with the fish (and the bugs) how they are doing.  Are the populations of fish (and bugs) healthy?  Are they breeding and thriving, or are they under pressure?  If they are under pressure, is it because they are being over-used, or is it because the water has become toxic?  And what about the people?  Are they getting sick from using the water or the fish, and is there enough water all the time for agriculture and for the towns and cities?  One way to check this is called “biomonitoring,” where the animals (and sometimes plants) are checked to see how they are doing.

An added advantage of this type of approach is that it is relatively easy to do and can be done without the need for expensive equipment.  And the most important aspect of this, is that it looks directly at the ecosystem in order to check its state.   Indeed this kind of approach is now recognised to be the foundation of water resource monitoring and management in many regions.  Examples include a requirement to maintain a “good ecological status” in Europe, the River Eco-status Monitoring Programme (REMP) in South Africa, and closer to home, biomonitoring conducted in the Mekong.

Biomonitoring of the bugs in Myanmar's rivers

So, we undertook an assessment of the potential to do biomonitoring in the Ayeyarwady and Thanlwin Rivers. We wanted to know: would this approach work in Myanmar?

Firstly we surveyed the Ayeyarwady river in the middle reaches from upstream of Mandalay to below Bagan in October 2015.  This was at full river flow which made biomonitoring impossible due to the high water.  Even the vegetation in the river which appeared to be ideal habitat for invertebrates, proved to have almost none.  Maybe this was because of the high water level, but the results were very surprising. 

We waited until the dry season and then visited the Lower Salween in Feb 2016 to test out the sampling procedures for biomonitoring using the river bugs (aquatic invertebrates). The trip included sampling at locations above and below Hpa An city, visits to at Hton Aing village (Kayin state), Ka Doe village (Mon state), and sampling at locations downstream from Ka Doe.  We also visited Bagan on the Ayeyarwady.

The sites on the Thanlwin and Ayeyarwady Rivers were all in the middle to lower reaches of the river where the river meanders through a large alluvial plain.  All of the sites on the Thanlwin were also subject to tidal influence (Hpa An is about 65 km from the sea).

River sites subject to tidal influence

Within the delta/estuary

The banks of the river within the delta are in a good condition dominated by mangroves and reeds, but this conclusion was based purely on judgement as the biomonitoring procedures being tested for the rivers were not appropriate for these sites which are very different ecosystems.  If there is a need to pursue this type of investigation within the delta, there are estuary biomonitoring techniques that could be evaluated which are normally based on macroinvertebrates living at a depth in the sediments.

Upstream of the delta/estuary

At all of these sites the riparian ecosystem is highly unstable, the banks are topped by grass and trees but the banks themselves are in a state of continual change.  Bank collapse and erosion is common although probably natural due to the meandering nature of the river, although probably made worse by the wash from boat traffic.  The substrate of the banks is generally fine grained mud, with small patches of coarser sand in some regions.  Only a few patches of reed vegetation were found in the water at low tide, some in backwaters not subject to scour, and other in banks that were eroding.

None of these sites yielded sufficient invertebrates for use in any form of biomonitoring.  The sediments themselves yielded almost nothing, while the riparian vegetation only occasional invertebrates.  These sites were unsuitable for invertebrate monitoring.

River sites upstream of tidal influence

Both in October when the river flow was high and the riparian vegetation inundated, and in February when there were only small patches of wet vegetation but abundant sand substrates, collection of invertebrates yielded almost nothing and certainly not enough to assess the condition of the river using a biotic index. The only exception that provided a valid sample was in Bagan where a rare cobble beach yielded a good result.

Small streams and canals

There are abundant small streams and canals that run adjacent to the rice fields. These streams are relatively stable with good riparian and marginal vegetation, and more importantly they are in close contact with the local people who are clearly having an impact on the stream ecosystem. They also provide important services to those same people, and thus management of their state could be important.  Biomonitoring of these canals thus is a real possibility. 

Preliminary collection of invertebrate samples from these streams yielded good results, confirming that these ecosystems are good for biomonitoring. These canals and streams also have potential to be used as part of a citizen science programme, involving citizens in the monitoring of the ecological health as it directly affects their own wellbeing.  A recommendation for a citizen science program that comes from Africa is the mini Stream Assessment Scoring System, an excellent program that is having a big impact on the awareness of river health at all levels of society: it is possible to upload your results onto a Google Earth map to compare with everybody else’s!

Alternative forms of biomonitoring

The riparian vegetation is to a large extent disconnected from the river especially during the dry season and so does not directly reflect any instream changes.  For this reason the vegetation itself is not suitable for biomonitoring.

Diatoms are tiny algae that grow on river substrates and can reflect with great accuracy any changes to the quality of the water as some of the species are very sensitive to water pollution and thus disappear if the water deteriorates.  They were monitored with some success in the Mekong River where there were cobble sections that yielded good samples.  In the rivers in Myanmar (the lower reaches) there is insufficient stable substrate from which to collect samples so this form of biomonitoring is also not recommended.

Fish are clearly in abundance in the river and have potential for a biomonitoring programme, but certainly not as a small-scale programme as the procedures are expensive and time-consuming. Monitoring of the fish as part of a larger program to assess the state of the fish populations can be considered as extremely urgent and necessary particularly because the fish are already showing signs of being in serous decline (we spoke to villagers who informed us that catching fish today is far more difficult and unsuccessful than in the past).  However this type of monitoring, in rivers of this size, requires a far greater input in terms of equipment and manpower and is not suitable for the present program. 

Conclusion

The opportunities for biomonitoring in the lower reaches of the big rivers in Myanmar seem remote, while monitoring the small canals and streams criss-crossing the country would be good for local management.  This is in contrast to the successes achieved in the Mekong where biomonitoring has proved successful.   

The authors of this blog would really appreciate any inputs to this!  Those with experience in biomonitoring in the rivers of the region would be most welcome.  If you wish to receive more detail on what was done, please contact the author and follow the project.