For the past 120 years, Bisphenol-A (BPA) has been used in plastic products, such as water bottles, due to its strength. BPA, which contaminates 93% of the human population (Houlihan, et. al, 2011), has started to be replaced by other materials that leach antimony, a harmful contaminant commonly found in polyethylene terephthalate (PET) water bottles. Additionally, as global and ocean temperature start to rise, antimony leaching levels have been predicted to increase as studies by Fan, et. al and Westerhoff, et. al observed a directly proportional relationship between water temperature and the leaching of antimony. This investigation examined the effect of varying saltwater temperatures on the leaching of antimony from PET plastic water bottles, and the subsequent impacts on brine shrimp hatch rates. Six buckets of saltwater were heated to appropriate temperatures (two of each temperature - 17 degree C, 22.5 degree C, and 28.1 degree C - one control and one experimental). Antimony, ammonia, pH, phosphate, and nitrate levels were measured over the three weeks. Then, brine shrimp hatching began, using the experimental and control water. The brine shrimp were allowed to hatch for 48 hours, after which a net was used to separate and count the hatched eggs. The results showed an increase in antimony in the plastic bottle groups; however, the measurement was not quantifiable. Additionally, results showed an increase in phosphate, ammonia, and pH levels for buckets with the water bottles. This investigation has shown that as the temperature of water increases, antimony levels increase and brine shrimp hatch rates decrease.