Lake trout, ciscos, and sculpins were the dominant species until the early 20th century, when many invasive fish were introduced into the water. In the 1930s, the invasive sea lamprey, alewife, and rainbow smelt numbers increased significantly, posing a threat to the natural ecosystem. Many cisco species were wiped out by both
sea lamprey and overfishing. The only cisco still found at Lake Huron is the bloater.
Invertebrates may also contribute to the damage of the lake's natural system, as species such as zebra and quagga mussels and the spiny water flea have appeared in Lake Huron's waters in recent decades and may have negative impacts on the condition and quantity of plankton.
