How villagers use citizen science to test river pollution

24Apr 2017
Edward Qorro
Ifakara
The Guardian
How villagers use citizen science to test river pollution

Down the slopes of Udzungwa Mountains, Alvinus Linus Ngwale, and his colleagues are wading through a river, perhaps looking for something.

Juwamange Group members wade through Mchombe River as they begin assessing the river’s water quality.

Each wearing gumboots, the enthusiastic group look focused; fishing out small aquatic invertebrates from Mchombe River in Kilombero District.

These are men and women of Mngeta Village, Mchombe Ward, Kilombero District in Morogoro Region, who have embarked on a mission; a mission of saving the river using mini SASS (Stream Assessment Scoring System), a simple tool which can be used by anyone to monitor the health of a river.

Through their group locally known as Juwamange which comprises of water users in Mngeta village, the group treasures the source of water so much, that they have dedicated this particular day to ascertain how contaminated the river is.

“We are here to asses the destruction dealt in our river,” says the chairperson of Juwamange, a 30 member group that was established in 2016.

According to Ngwale, some dishonest villagers wash their clothes inside the river while others have decided to cultivate crops near the river banks, leaving the only source of water to peril.

“We have allowed drawing water from the river, but this doesn’t mean that they have to do laundry in here,” Ngwale explains.

Even when the group has enacted laws to keep the dishonest villagers at bay where anyone found washing in the river will be slapped a Sh50, 000 penalty, the river is still fast becoming polluted.

Reliable indicators of water quality and river health are often difficult and expensive to derive. To address this need, the SASS river health biomonitoring method was first developed in the mid 1990's as a low technology, scientifically reliable and robust technique to monitor water quality in rivers and streams.

Mini SASS is the development of a simplified method of biomonitoring based on the tried and tested SASS technique. This involved reducing the taxonomic complexity of SASS to a few aquatic invertebrate groupings which would act as surrogates for the complete suite of SASS taxa.

The method is considered easy to learn river health biomonitoring tool which is ideal as an environmental education tool for learners, but can even be used by non-technical, private persons to monitor the health of rivers in their communities.

As a result the miniSASS method is also ideal for use by community based NGO's and environmental conservation clubs or conservancies to monitor and create education and awareness of river health in their community.

Dr Lulu Tunu Kaaya, a lecturer in fresh water ecology from the University of Dar es Salaam, who was instrumental in tutoring Juwamange on miniSASS says the method can only be done in rivers and streams. Unfortunately, it cannot be done on stagnant water like ponds, dams and wetlands.

“It is very important to check whether the sample area has flowing water, if no then miniSASS cannot be done there. The best sites for miniSASS are those sections with sand, vegetation and stones available for sampling,” she explains.

“The villagers have exhibited utmost passionate as they use waders and wellingtons that help them to protect their feet from the sharp rocks, insects and other animals, nets, life jackets, white trays as they assess the river’s health status.”

According to Dr Kaaya, nothing goes to waste in the exercise.

Every insect drawn out of the water source is microscopically studied to check if they have been affected by the contamination in the water.
“We use the macro invertebrates (small animals) depending on which groups are found, and then we have a measure of the general river health and water quality in that river,” she explains.

Detailing how the Mini SASS is done, Dr Kaaya says the villages have to wade in through the river for at least 100meters to establish its biotope.
This would entail at establishing the biological habitat type of the area where they look at three types in the miniSASS.

Usually the common types would include vegetation areas, rocky places and rivers with a lot of sand.

“Normally, a group will get inside the river and kick the rocks with a view of making the bugs to emerge from the river bed,” she says.

“They would then be placed on trays to be studied to check on how they’ve been affected by assigning them into their ecological categories.”
Some of the species that are put test include Mollusca, Worms, Flies, Caddisflies and Stoneflies.

Others are Damsflies, Mayflies, Dragonflies and Crabs.

According to Dr Kaaya, the method, Mini SASS is an easy and cheap method of ascertaining the disturbance on water systems.

“Anyone can learn how to collect a miniSASS sample on a river. Once you have collected a sample you look for the different bug groups and score whether they were found. The score then tells you the health class of the river, ranging across five categories from natural to very poor.”

Much has it has been scientifically proven, Dr Kaaya says the the method lays bare the pollution in the water sources.

Reasons for the changes in river health over space and time can be explored based on the land uses and other activities that can be observed on the interactive satellite map, supplemented by knowledge of their community, according to Dr Kaaya.

The water expert from the UDSM adds that the miniSASS method provides spontaneous results on how the river has been affected without requiring any complicated technology.

According to Dr Kaaya, though the method took long to arrive in Tanzania, it is still implemented in some countries in Europe and America.
Back at the river, Ngwale and his colleagues have established the magnitude of the problem.

“Having studied the bugs and their endurance to have the chemicals and other effects, our outright conclusion is that River Mchombe has been greatly affected by human activities,” observes the chairperson.

According to Ngwale, river was given an E category, was a clear evidence of how the source of water was badly polluted.

This was attributed by the disappearance of many species in the river and its change in its change in color.

“The water in Mchombe is usually clear, but today it became a bit brownish

Sharing similar sentiments is Salome Mayenga, an environmental officer in Kilombero District who goes further leveling the whole blame on administrative leaders in the area for politicizing the issue.

Mayenga alleges some local leaders use the river as a bait o win over support from the villagers.

“They allow them to farm near the river so that they can be voted into office come next polls,” she says.

A Hydrologist with the Rufiji Basin Water Office (RBWO), Sebastian Kulinga says the results speak volume of how the water source has been tampered with.

He urges water users in the area to plant more trees and enact more punitive measures that will help protect the water source, a call that is heeded by both, the village and ward executive officers in the area.

“We are deeply concerned by the outcome of the test, if this continues then this source of our life will vanish from our sight,” opines Hongera Hageni, Mngeta Village Executive Officer.

Though he denies they have been responsible in polluting the River Mchombe, Hageni assures his village Ngwale and his colleagues that they will become more vigilant in protecting and conserving the water sources.

On his part, Damas Patrick Mbaga, a hydrologist with the African Wildlife Foundation (AWF), an organization which facilitated the training of the communities on mini SASS is happy to see how Mngeta villagers have embraced the method of assessing the quality of water in Mchombe River.

He says that AWF implements the project as part of the Sustainability and Inclusion Strategy for Growth Corridors in Africa (SUSTAIN-Africa) project implemented by the African Wildlife Foundation (AWF) in partnership with the International Union for Conservation of Nature (IUCN).

According the AWF official, the collection of miniSASS data during the walk is a perfect illustration of citizen science, where a group of volunteers with no formal training in the aquatic sciences undertook a source-to-sea assessment of the river health condition of the River.

“The follow up of this exercise will help us determine the need of scaling up the project,” says Mbaga.

As for Dr Kaaya, she is happy to return to the lecture theaters a contented academician having attested how well Mngeta villagers have understood the method.