Imagine you are rushing home and need to breathe harder and harder, but there is less oxygen in the air around you. This is the situation most marine fish are facing with warmer ocean temperatures due to climate change. They breathe the same oxygen we do, except that they have to get it out of the water, which is a much harder task. Warmer water holds less oxygen than cold water. To make matters worse, fish also need more oxygen in warmer waters. So with the higher demand and the lower supply of oxygen, the growth of the fish’ gills (their breathing organs), cannot keep up. This is causing ocean fish species to grow to smaller sizes! We created a model that can predict by how much fish are shrinking, and also developed a theory called GOLT that explains what is going on.