Transition Water is how we manage our ponds and lakes to include harvesting. Without harvesting – whether it be fish, weeds or other lifeforms – nutrients will stay in the system. A healthy food web is essential to cycling nutrients and removing them permanently. Floating islands were a novelty ten years ago, but now they’re established, well-researched systems that have proved their value in fixing damaged ponds and lakes. It’s all about restoring food webs, says Bruce Kania — and learning to grow fish instead of mats of algae.