Do brine shrimp prefer warm water or cold water? These tiny creatures (Artemia) survive in many salty environments. This project tests which conditions they choose. You fill clear plastic tubes with water and brine shrimp. Each tube gets a gradient (a smooth range from weak to strong) of one variable. One tube varies in temperature. Another varies in pH (how acidic the water is). A third varies in light level. A control tube stays at room conditions. After the shrimp settle you clamp each tube into four equal sections. You count the shrimp in each section and graph where they gather.