help me with this paragarph, grammar problem and flow?

First of all herbicide contains two specific ingredients are glyphosate or 2,4D. These two chemicals are very common use in farm, park and golf course, farmer and gardener would like use these chemicals to kill unwanted plants, but they don’t know the trouble is it doesn’t stay on plants. It’s getting into our water, rivers and even into the rain. If herbicide is able to get into the streams, it could kill a lot of aquatic species such as fishes, beavers, frogs and birds. I found some researches had proven weed killer is toxic to the environment, according to John Struger has analyzed urban streams and detected nine kinds of different herbicides in there a Scientist of the Canadian Centre for Inland Waters.
Another resource is form Tyrone Hayes the developmental endocrinologist of University of California at Berkeley, he said the over use of herbicide is directly effect male tadpoles in the laboratory, he tested the level used to in the environment, he found out this chemical will remove the testicles of a male tadpoles and preventing male characteristics from fully forming. The important thing is herbicide exposure turns the tadpoles into hermaphrodites (creatures with both male and female sexual characteristics). If there is no more male, then frog will be decrease and bugs will be increase because there are no enough frogs to eat bugs.