What is the primary ecological concern for Lake Ontario?

While water pollution is indeed a significant concern for Lake Ontario, the most pressing ecological issue affecting the lake is the presence of invasive species. Invasive species have dramatically altered the ecosystem's balance, impacting native flora and fauna and leading to biodiversity loss. Species such as the zebra mussel and the round goby have outcompeted native organisms for resources, disrupted food webs, and caused long-term ecological damage.

Eutrophication, while an issue associated with nutrient loading and water quality, often stems from pollutants entering the water system. It is a result of excess nutrients leading to algal blooms, which can also be linked back to water pollution. Overfishing is a concern in specific areas but does not represent the overarching ecological challenge that invasive species do given their widespread impact on the lake's ecosystem.

Understanding the role of invasive species in Lake Ontario highlights the importance of ecological management and restoration efforts aimed at preserving the lake's biodiversity and integrity.