Why has phosphate been removed from fertilizer and what are the consequenses?

Phosphate was added to help flowers and vegetable plants bloom. They really don't need it plus it gets into the groundwater and ends up in brooks, streams and lakes. There it helps algae type plants grow fast. oil is one such plant. If you add phosphate it takes over the waterway and uses up the oxygen in the water fast as it grows.Will eventually oxygen starve fish and other marine life. plus if you pick up any on say your boat you transport it to another lake. Up here in maine you can't launch a boat in many lakes without a oil inspection. In other words it does alot of harm and very little if any good.