Over the next 100 years, factors causing climate change have the potential to increase sea surface temperatures by up to 5 degrees Celsius. However, even a small increase could have drastic effects on tropical areas due to the historical thermal stability of places such as the Caribbean. Recently, the Cape Eleuthera Institute has been focusing efforts on investigating how climate change may affect tropical fish species and the marine communities with which they interact. One specific project is using a swim tunnel to measure the aerobic scope of Great Barracuda (Sphyraena barracuda) and Schoolmaster Snapper (Lutjanus apodus). A swim tunnel is a cylindrical tank in which a fish swims against a current and its oxygen consumption can be measured. Data obtained from the swim tunnel such as swimming velocity and respiration rate can then be used to calculate the fish's aerobic scope. Aerobic scope, or the capacity for oxygendriven metabolism, is a good overall indicator for performance and can estimate how much energy a fish has to devote to essential behaviors such as foraging, predator evasion and reproduction. The water that flows through the swim tunnel can be slightly warmed to simulate future ocean conditions, and the fish's response can be quantified. Through this study, CEI and the Flats Ecology and Conservation Program hope to gain insight on how different coral reef and mangrove fish species will react under the thermal stressors that climate change may present.