Because this is just too weird:
The fluorescent green colouring appeared to start about 500 metres on the Victoria side of the entrance to the park and, over the course of an hour, the substance flowed down into the environmentally sensitive estuary.
By 5:30 p.m. the river, known for its dramatic salmon runs, eagles and other wildlife, was back to its normal colour.
You always wonder about stories from the Old Testament where the Nile turns red, and what sort of geological phenomena would have caused that. Green? I really hope this isn’t your garden variety Photoshop hoax.