Cyanobacteria, also known as blue-green algae, are a kind of bacteria found in many lakes. These organisms make their own food through photosynthesis. Small animals, including mayfly larvae, eat the cyanobacteria. Small fish, such as yellow perch, eat the mayfiy larvae. The small fish provide food for larger fish, such as walleye. Describe a model you could use to show the transfer of energy within the lake ecosystem