if you want to really write about the impact of global warming on marine life, there is tons of information available on the web and your local library. I definitely cannot lend any support to any project by anyone that will intentionally involve hurting animal life, not when there is so much information and research findings already there. Plus, remember you cannot simulate global warming in a few minutes when this is a long term phenomenon. If you want to do an aquarium project, what about
A description of the maturation cycle of a SW
tank (Demonstrate the testing of and you can illustrate varios phases of Ammonia, Nitrite and Nitrate). Talk about the bacteria, the chemistry etc
Maintaining healthy fish in an aquarium: talk about the things that need to be considered - water, salt, food, LR
, waste and handling it, filtration, lighting, salinity etc.