Nature's Pride at Risk: River Barak's Pristine Ox-Bow Lakes Threatened by Urea Pollution

The River Barak snakes its way from its point of origin before its bifurcation into Surma and Kushiyara. While traversing initially through the hills of Nagaland-Manipur borders, and then through medium to low hilly tracts of Manipur, it has entered the flat landscape of the valley. Here, the river has taken a series of ‘U’-turns. Such meanderings have enhanced its length to 524 kilometers. Had it traversed in a roughly straight line, the length would have been approximately 90 kilometers, roughly 1/6th of the present length. Such serpentine movement has added a unique beauty to the river, which the locals call ‘Anua’. The word ‘Anua’ is not known to many, better to call it ‘Ox-bow’. These ox-bow lakes are called ‘billabongs’ in Australia and ‘Resacas’ in the Texas Coast of America. Our fishermen are not expected to be well versed with those terms, they are more acquainted with the word Anua, and thus they say ‘Ramnagar anua’, Salchapra anua’ and the like.

Sometimes it takes ten to fifteen years, or even several decades for an ‘Ox-bow’ lake to form. This is the normal process of any river that forms such lakes. As you can see from the adjacent picture (Fig.-1) that the river, which was running in a roughly straight line, first curves slightly, then curves further into a ‘C’ shape, then into a ‘U’ shape, and then constricts altogether and thus finally detaches from the main river. In certain cases, a thin connection is maintained with the main river.

It is amazing to note that in the Manipur portion of River Barak, not a single ‘Anua’ exists. All these are found only in the plains of the Barak valley. This is a usual phenomenon because, when the river flows down along any steep hill, it makes its way with high velocity through less curvy paths to reach the downstream. For that reason, the chances of Anua formation are not there in those hilly terrains. It is in this plain and flat land, where these horse-shoe-shaped curves are witnessed. And if a river follows a less curvy path, then there is no possibility of creating such Anuas.

Except for one or two small examples, the meandering of rivers to form ox-bow lakes is also a rare phenomenon seldom witnessed in the rest of the country. Yeah, one more example is Kabar-Taal or Kanwar-Taal Lake at Begusarai (Bihar) on the Gandak River, a small tributary of the Ganges. Also, there is another small lake named ‘Vynthala Lake’ in the Chalakudy River of Kerala. The above two rivers do not have multiple ox-bow lakes. Here the River Barak is the exception. This is the lone example from the aqua-zone in India, where, in a row, as many as seven Ox-bow lakes are found! This unique nature’s gift to our own River Barak has, hitherto, elsewhere not been mentioned or referred to in any literature!

Speaking about scenarios abroad, someone may argue that there are 1500 odd ox-bow lakes in the lower portion of the Mississippi River. Here it needs to be mentioned that, at the point of origin of River Barak (Tipaimukh) the altitude is about 200 meters above sea level. On the contrary, the Mississippi River originates from Lake Itasca, which is 450 meters above sea level. From that point onward, the river flows about 6275 kilometers to reach the Mexican coast, where it opens into the Gulf of Mexico at the Caribbean Sea. It is known to one and all that Mississippi is the world’s 4th longest River. As compared to the lengthy path Missisippi traverses, Barak passes through only 524 km, (555 km, including Surma & Kushiyara), which is roughly 1/12th of the length of Missisippi.

Shouldn’t we take pride in it? Certainly, we must take pride in our seven ‘Anua’s. We must boast of such nature’s gift. Starting from the upstream, the ox-bow lakes are ‘Chiri’ anua, ‘Rupaibali’ anua, ‘Banskandi’ anua, ‘Kaptanpur’ anua, ‘Gobindpur’ anua, ‘Ramnagar’ anua and lastly the ‘Shalchapra’ anua (Please see Fig.-2 a & b). In addition, few such eutrophied water bodies can no longer be placed under the same category.

But how is the health of our Nature’s Pride? How many of the Barak-izens are eager to keep track of the rare resource bestowed on us by nature? Here is the pathetic story of one of them. The longest and largest ox-bow lake of Barak Valley, the ‘Rupaibali anua’ in the Rupaibali village near Singirband in Lakhipur subdivision of Cachar, Assam.

In the last five to seven years, Rupaibali Lake has completely been covered by water hyacinth. According to locals, this was not the situation even a decade ago. From their childhood experiences, the elders also opined that during the monsoons, when the lake was full to the brim, Barak usually could absorb the excess water. Now the situation is different. The problem they pointed out is an artificial dam, ‘man-made artificial dams’ created exclusively for extensive fishing.

An awareness type of program was organized in the fringe area as a part of the ongoing pilot project of IUCN-India (International Union for Conservation of Nature). Villagers complained that they have been experiencing itching after bathing in the lake water for the last few months. One of the locals came up with the plea that, if the physico-chemical parameters of the water sample are tested, something might be revealed! At their request, samples were brought to the Assam University Laboratory. On testing, it was found that the water had lost its usual qualities. Dissolved oxygen levels are low, biological oxygen demand is high, and nitrates, phosphates, etc. are all higher than the normal range.

Research has reported that the addition of urea to water can have harmful effects on all aquatic life and aquatic ecosystems, such as eutrophication, (i.e., excessive growth of aquatic plants) due to increased phosphorus, nitrogen, etc., thereby, water is bound to lose its natural characteristics. Urea stimulates the growth of toxic phytoplankton in lakes. If such water is used, allergies, itching, skin redness, blisters etc. develop in humans. If the level of urea increases further, there is a possibility of some additional symptoms like shortness of breath, chest pain, swelling of the face, lips, tongue and throat.

Excessive growth of water hyacinth has been witnessed in the Rupaibali ox-bow lake. In many places, more than half of the area has now been covered with this freshwater weed. Deep down the story, the same fact is revealed. ‘Excessive greed’! As per government rules, a lease for the ox-bow lakes is earmarked for a certain community. This is admitted, but what about the Dos and Don’ts regarding the use of all such lake water? Why is SoP lacking in this case? What about the knowledge on ‘aqua-health’ and ‘aqua-environment’ related matters for the persons belonging to that specific community(ies)? This is the Grey area. Fishermen who are officially given the lease, have just one agenda. Grow more and more fish, catch them, sell them in the market, and earn more and more money. Hence, the catalyst, ‘Urea’.

Urea is not just mixed in the water of a particular ox-bow lake. Wherever there are fisheries in the valley, this type of misuse of urea is taking place in almost 9 out of 10 instances. The obvious question that arises is, here what is the ‘thumb-rule’? For the larger benefit of society, will the officials of the concerned department(s) shed some light on this important aspect that directly concerns human health?

We all are looking forward to hearing straightaway from the horse’s mouth! Don’t know, how long we shall have to wait. Or, whether, at all, we’ll hear from the yellow, brown, golden or dark horses..?