If you’re trying to study tidepool fishes, two words: good luck. These tiny and cryptic fishes like to hunker down in the rocks, making them very hard to spot. To get a closer look, the MLML Ichthyology class bubbles a little carbon dioxide into the pool to temporarily stun the fishes and coax them to the surface. In this case, the fishes were still playing hard to get – guess they don’t go for sparkling water.