For ESM, I learned about freshwater eels, called tuna. Female eels travel all the way to the ocean near Tonga to breed, and the baby eels hatch there. Then the young eels swim back to Aotearoa and move into our rivers, lakes, and streams. Native eels can live in freshwater for many years, sometimes even for decades, before they change into silver eels and migrate back to the ocean to breed.
Tuna also have an important relationship with freshwater mussels. Freshwater mussels start life as tiny larvae that attach to native fish, including eels. The fish carry them through the river, which helps the mussels spread to new places and survive in different parts of the river system. Freshwater mussels also filter the water, removing dirt and tiny particles. This helps keep the water cleaner and the habitat healthier for tuna and other native species.









