Sewage fungus is a clear sign a river is sick. It grows when the pollution in the river is bad enough to see bacteria grow so much that it forms long grey feathery strands and clumps.
"Rivers in Haringey are so polluted they do not contain enough oxygen to support fish, a study by a charity has found."
See things differently
What is Sustainability? ... meeting the needs of the present without compromising the ability of future generations to meet theirs.
What is Sustainable Haringey? ... an independent informal...