The hypothesis is that automobile exhaust will have a negative effect on the Hydra.

You will be filling four petri dishes with pond water and placing five Hydra in each dish. You will then place two petri dishes in each of the two environmental chambers. One chamber will be connected to the source of pollution (the automobile exhaust) and the other will be the control chamber containing room atmosphere. After each of four 24 hour periods, you will examine both groups of Hydra using a binocular microscope and compare any morphological changes that may have occurred.

You will need 100 brown Hydra, fresh pond water, 2 environmental chambers, mixed crustaceans including daphnia and artemia (for feeding), auto exhaust, large tire inner tube with delivery tube to the environmental chamber, 10 petri dishes, 6 eye droppers or clean micropipettes, hand lens, one binocular stereo microscope with zoom lens, clock, one microprojector and prepared slides (plain hydra, hydra with spermaries, with ovary, budding and feeding).

After observing the Hydra in both chambers, it was found that the Hydra in the chamber exposed to automobile exhaust had morphological and behavioral changes compared to the Hydra in the control chamber. The most notable change was that the Hydra in the chamber exposed to automobile exhaust had a decreased appetite and were less active.

This science project is interesting and unique because it is a great way to observe the effects of automobile exhaust on a living organism.

Experiment variations to consider include reducing the trial periods to 12 hours over a four day period and observing the effects of different types of automobile exhaust on the Hydra.