You can refer the book "Fish & Fisheries of India" by Jhingran,in which he has pointed out such cases on major rivers of India.

I worked for DfID with WB in Kazakhstan in 1998 developing ToR for a project to rehabilitate the Nura river, polluted with mercury from an aldehyde plant. Most of the year the mercury was locked away in sediments but every spring the snow-melt, carrying all the acid derived from sulphur emissions throughout the previous summer and winter, solubilised and mobilised the mercury, which the floods dsitributed over the 100-500 metes either side of the river bed. Local fishermen continued to catch and consume the fish, which were most dangerous during the spring floods (they weren't "safe" at other times!). The economic consequences were indirect and not measured because nobody cared.

China is the country where river pollution can sometimes sterilise a river but you need to contact WWF in Beijing for information.

Russia has problems with some rivers - the Irtysh rises in China, then passes through the (previously) weapons manufacturing area of Kazakhstan before entering Russia. These problems have diminished as local manufacturing has declined and, outside of the big cities, the sewage works are in terrible condition but the population is migrating to the cities and the sewerage system is falling apart so that much of the waste goes straight into the ground where it does not harm rivers.

I've worked in 20 countries and never found a country, apart from China, where chronic pollution damaged a fishery. The Tisza suffered a severe pollution accident in Romania (one branch of the upper catchment) when a tailings dam from a mine broke in rain and released a lot of cyanide which affected Hungary and Serbia but mobile creatures quickly escape into ditches and tributaries and re-colonised the river, which recovered quite quickly. Pollution incidents are also common in China.

The EU responded to a request to prepare a plan for the Dniester near Odessa, which was alleged to be in "terrible condition". We did some detailed studies, training and using some excellent local specialists, which showed that the river was in very good condition.

One of the things to be wary of is local individuals or small groups, often without much scientific education that launch an NGO and claim that there are bad environmental conditions int he hope that some friendly western government or charity will donate some money to "save the river". The local press like to hear things they can use as sticks to beat the local government with and disputes result. Our reports were attacked before they were published ....... but not afterwards.

This is a rather rambling account of a few of the projects I have been involved in but this sort of stuff never gets published in Journals. I have project reports if you like but nothing appeared in the literature.

In general economic decline is good for river quality and rabid (sic) growth is bad. China's policies on water resources are unsustainable.

Part 1-comments; Part 2: Some references relevant to water pollution and livelihood impacts on fishers

Part 1: Fishing has become an important source of food security and livelihood for many poor rural families including fishers (an estimated 200 million people and their dependents mostly in developing countries live by fishing and aquaculture). However both rivers and coastal pollution (as a consequence of pesticides pollution, metals pollution, nutrients pollution, acid mine drainage, oil pollution, faecal pollution etc.) have caused significant impact on fisheries and thus on fishers livelihood. For example, oil pollution can cause damage to nets and boats, consumer will be reluctant to buy oil contaminated fish; pesticide and metal pollution can cause significant decline in fisheries, there is now a new threats (due to climate change) such as ocean acidification on marine fisheries. In Egypt, many fishermen have either left their jobs altogether or migrated (a 2009 Environment Ministry report said 129 industrial facilities and 300 floating hotels are pumping chemical and other waste into the Nile). The waste from El Alto city in Bolivia (trash and sewage) fills riverbeds that carry contamination downstream to the lake. Rivers in the USA, most of Europe, large portions of Central Asia, the middle East, the Indian subcontinent, and eastern China are currently under severe threat due to pollution and river habitat modification .The Buriganga River in Bangladesh is extremely polluted as evidenced by low dissolved oxygen content (

Thank you Chandravadan

Thank you Stephen for valuable insite

Thank you Golam for references

I should add that fish can themselves be contaminated with microorganisms and/or toxic material such as heavy metals without dying or becoming visibly sick but they may affect the health of those who eat them. Nevertheless a lot of the anxiety about toxic substances is a result of fear of the unknown. Often these fears are misplaced and I prefer to look at evidence on the ground rather than at what might (or might not) be a problem. Everything is toxic if you consume enough of it. It is simply a question of dose. Even if there is a risk to health you have to balance that against necessity. For example in the 1980s an incipient swarm of locusts threatened crops in (I think) a region of N.Africa but the UN forbade the use of DDT, at that time the only truly effective insecticide against locusts. At a subsequent conference, which I attended, the delegates congratulated themselves on a victory against those who wished to use a banned substance. When I asked how many had died of starvation following the inevitable swarm (thousands) compared with the numbers who would have died from DDT poisoning (probably none) there was a disapproving silence. I am not in favour of DDT but I am against mindless adherence to rules rather than objective pragmatism.

We use national and international guidelines to check out whether water quality is within recommended threshold values for beneficial water usage with regard to targeted toxicants in waterways for example.

Kindly more specify on what parameter you want publication.

When the EU published its list of dangerous substances with MACs there were only methods available for measuring 30% of them at the MAC level. The situation is probably better now but the methods are often difficult and expensive. It takes up to 2 years to train analysts and get equipment like GC-MS to the point at which it can produce reliable and consistent results. Many of these standards are aspirational rather than realistic and incorporate very (often overly) large safety margins. A map of water bodies that exceeded one or more of the MACs would give an enormously more pessimistic view than a map of water bodies showing where fisheries had been demonstrably damaged, or the health of the local population impaired, by water pollution.

Experience in trying to apply with the EU Framework Directive on Water Policy shows that it too is aspirational rather than realistic (and much too prescriptive and detailed to be described as a "framework").

thanks Stephen for valuable inputs

thanks meena

Golam I have compared the water parameters results with international as well as with indian standrads.

Prof. M Ramachandra Mohan

Lots of studies have done and are going on water quality, impacts of various pollutants on the aquatic life including fish, crabs, amphibians, etc.

Many inland fishermen were dependent on river fishing for their livelihood. Growing river water pollution is affecting fishes. Many species are extincted. Natural biota has been changed. Pollutant adapting species are surviving. Frequently massive fish kills are occurring. dams. All such activities are affecting the communities who are directly dependent on river and fishes for their livelihood. they are looking for other livelihood resource. hence this is not only affecting the environment but also various communities and creating one kind of new environmentally excluded group or environmental refugees. I want study what are impacts of river water pollution on socio-economic status of fishermen especially those who does fishing in river.

Dear Nilisha Desai,

Do you also monitor dissolved oxygen in rivers where fish kills occurred? This will provide a simple clue about fish kills. Also it may be important to monitor pollutants concentration (such as pesticides and metals) in fish of pollutant adapting species for human health and safety reasons

Be careful with DO. Saturation is 14.63 mg/l at 0 deg, 10.13 at 15 deg and 7.62 at 30 deg. A low moving shallow river will reach 30 deg in summer and even at 80% saturation will barely reach 6 mg/l which is the limit for recommended in the EU. The Dniester near Odessa used to fall below 6 mg to 5 mg/l sometimes without any ill effects. The level was reduced by the bio-oxidation of organic matter (decaying leaves and soil run-off - NOT pollution).

I do not wish to paint a too rosy picture of water quality but you need to understand water quality well to deduce things about the origin and effects of substances in water. I am neither a skeptic nor an environmentalist but a scientist who likes to get to the truth because truth is an attribute of reality and science has become so politicized that we have to be very careful before we accept others' conclusions.

Thank you Stephen. I understand your view but there is no harm of measuring DO as it could help rather than having no measurement of this important WQ parameter. Oxygen levels are often used to indicate the quality of freshwater, health of streams and rivers and the intensity of aquatic pollution. DO limit tastes, odours, discolouration and corrosion in drinking water. The tolerance of DO varies from fish species to species. As a general rule when you measure WQ, you do also measure water temperature as well since there is an inverse relation between DO and temperature. Furthermore, when there is a cyanobacterial blooms/blue green algal blooms, DO can be also be low and fish kills may or may not occur

Dear Stephen

Can only DO will be sufficient for commenting on water quality?

How the other parameters react with saturation points of DO?

Many time fish kills occur in the perennial river in our area. problem of water pollution is severe. frequent outbreaks of Jaundice are noticed in last 2 decades.

Fishermen are facing lot of problem in terms of their livelihood. People avoid to buy fishes from river due to polluted conditions.

the rivers in our region have DO in the range of 5.5 to 7.0 mg/L with BOD levels of 3.0-9.0 mg/l, COD varies between 10 - 45 mg/l. how to describe the water quality?