Black Sh...t - thought this was interesting

[Steve]

It turns the lowerland rivers black and can kill your dog or worse... This explains what is going on - link below



It [Phormidium] uses the phosphorus attached to sediment to actually grow, so it doesn't use the phosphorus from the water, it actually traps sediment and uses the phosphorus that is stuck on to the sediment to grow

http://www.radionz.co.nz/news/national/ ... s-and-pets