What is the minimal information you need to decide if the tuna will float in the water?

To determine if the tuna will float in water, you need to know its density compared to that of water. If the density of the tuna is less than that of water (approximately 1 g/cm³), it will float; if it is greater, it will sink. Additionally, knowing the temperature of the water can be relevant, as water density slightly varies with temperature.