Macro Invertebrate Flyer

Water insects indicating water quality TEXT BY REACH

MAY 2009

Since 2005 local community organization Regional Environmental Awareness Cameron Highlands has initiated a new community based approach of water management in the Cameron Highlands. By aid of aquatic marco invertebrates and basic chemical testing water quality in the areas major rivers is monitored regularly.

Macro invertebrates

President of REACH: Mr. Ramakrishnan Ramasamy AMN Email: president@ reach.org.my

P LE AS E S U P P O RT R E A CH Contact us at: REACH Office No. 1 Jalan Besar Brinchang, Caneron Highlands

Aquatic macro-invertebrates are tiny creepy crawlies living in the rivers. It is a community of insect (larvae), beetles, worms, snails and other small creatures. Not every aquatic macro-invertebrate can live in every type of water quality: some species need really clean water (water with the quality of drinking water) others can live perfectly well in polluted water with lots of sewage. These little creatures are super-sensitive for changes in their environment. This means that they are very accurate in telling you how clean the water is. But how exactly can you tell from these macroinvertebrates if the water is clean then?

Well first you need to catch them with a net on the bottom or the sides of a river or stream: that is where they live. Then you have to identify which species and in which amount they occur in your collected sample. By filling in the species that you found and their abundance (numbers) in a special table you can classify the stream or river for its water quality. This method is used as a standard tool by many countries around the globe to asses water quality.

Water pollution

Where does this water pollution come from in the first place? The main reason for water pollution in the Cameron Highlands are the big agriculture (farms) that

By looking at which insects are living in the water, you can tell exactly how clean or how polluted the water is.

you see everywhere, they use enor mous amounts of toxic pesticides and fertilisers. Also the domestic sewage from villages that is poured in the river courses, causes severe water pollution. Erosion from far mland additionally causes mud to flow into the rivers; this is called ‘siltation’. You can easily see that most rivers are brown, especially during rain. Tiny particles of clay and sand are washed down. This has resulted in the Ringlet Reservoir being completely clocked by mud. All rivers in the main valley between Brinchang, Tanah Rata and Ringlet are now strongly polluted. The most important pollutants are: faecal bacteria (E. coli), organic pollution (sewage, manure & fertilisers), suspended solids (washed off clay and sand), solid waste and pesticides. Virgin mountain streams in the forest have outstanding water quality and are very important for the ecosystem. These streams also form a vital and reliable supply of good quality drinking water for the people living in the Cameron Highlands. Unfortunately the

intensive agriculture also needs large amounts of water for irrigation. That is why illegal water taping now only leafs 20% of all water in the forests for public drinking water production. Most of this water that is used in agriculture is (illegally) tapped from small mountain streams in the forest containing the best quality water of the Highlands.

Water quality monitoring

Water quality monitoring is important for a better understanding of the reasons for water pollution, also well as to follow changes in water quality of the rivers (is it going better or worse?) and to create awareness among people. Macro invertebrate assessments are perfect for water quality monitoring because there are very precise, and because it is an inexpensive method that does not need complicated equipment. By taking samples on a regular basis (once a month) of different rivers, and identifying the species and then filling in the monitoring forms, groups of students or volunteers can monitor the quality of the rivers themselves.

Sample point B

5%

9% 45%

EPT-taxa 45% Decapoda 0% Gastropada 41% Chironimidae 5% Hirundinae 9%

41% 0%

Invertebrate assessments The aquatic macro invertebrate assessment involves collecting, processing, and analyzing aquatic organisms to determine the health of the biological community in a stream. This in turn tells you about the health of the river in general and the amount of pollution that affects it. Aquatic Macro invertebrates inhabit all types of running waters. They live part or most of their life-cycle attached to submerged rocks and vegetation or hiding in the sand or g ravel. Aquatic macro invertebrates are good indicator s of s tream q u ali ty because: 1) They are affected by the physical, chemical, and biological conditions of the stream; 2) They can't escape pollution and show the effects of shortand long term pollution events; Some are very intolerant of pollution; 3) They are relatively easy to sample and identify.

Water quality monitoring is important to create awareness and to learn about the changing environment.

www.reach.org.my

The pollution tolerances of the various aquatic macro invertebrates are based upon the aquatic macro invertebrates' tolerance to pollution. Organisms are separated into 3 categories of pollution tolerance: Sensitive or intolerant, S o m e - w h a t s e n s i t i ve a n d Tolerant to pollution.    In a river/stream with good water quality aquatic macro invertebrates of both sensitive to pollution and invertebrates tolerant to pollution are found.  No particular group or types of organisms will dominate the aquatic macro invertebrate population of the stream.  The stream has a high diversity; a ‘little bit of everything’ is found. The main organisms found here are Stonefly larvae, Mayfly larvae and Caddisfly larvae. With increased organic pollution (from nutrients found in fertilizers, sewage, and other sources) dissolved oxygen levels within the stream fluctuate more extremely and fewer pollution sensitive organisms will be found.  Aquatic macro invertebrates that can tolerate lower oxygen levels will become more prevalent. As organic pollution continues to increase, some pollution tolerant aquatic macro invertebrates will become dominant and will be able to support large populations within the stream, while pollution sensitive or some-what organisms will be unable to survive. 

In this polluted stream a few species ‘’can take over’’ and thrive by the thousands. Main organisms found here at leeches, snails and blood worms.

REACH Regional Environmental Awareness Cameron Highlands was formed by several residents of the Cameron Highlands who were concerned about environmental problems in the Cameron Highlands. It was officially registered on 6th September 2001. REACH and aims "to conserve Cameron Highlands as an area of natural resources and as a natural heritage, a highland resort surrounded by permanent forest reserve and sustainable agriculture with quality drinking water". REACH tries to increase the awareness of the importance of good river water quality. The community based approach to river quality monitoring is one of the ways of doing so. Also REACH organizes exhibitions, give talks (for instance on World Water Day) and they do their own research.