Study/Research Paper Help! Ocean Life/Importance Paper?

Ok so I have a paper due in three weeks that has to be around 7 pages long. My topic is the importance of aquatic life and how we need to take care of are ocean. How should I set up my paragraphs. I need a intro, 3 bodys with 2-4 concrete details, and a conclusion. I was thinking Intro and then my three main points would be Why the ocean is important to our planet, negative things that have effected the ocean and I dont know about the third one.? My rough draft is due Friday and I'm trying to finish it before than. Any info and/or ideas would be helpful. Thanks