Water hyacinth (water weed) is a menace in Bangladesh which restricts water flow and blocks sunlight in rivers and ponds contributing to contamination and killing of fish. Instead of spending much in removing or eradicating them they can be used for a good cause. Kristin Boekhoff at Panigram blog informs about an innovation in Jessore, Bangladesh which will be the first commercially operating biogas reactor running off of water hyacinth in the world.
Great stuff! Hope to see much more.