How can improper ballast water discharge impact local ecosystems?

Improper ballast water discharge can significantly disrupt local ecosystems primarily by introducing harmful organisms that threaten native species. When ships take on ballast water in one ecological region and discharge it in another, they often bring along a variety of aquatic organisms, including invasive species, pathogens, and parasites that did not previously exist in the local waters.

These introduced organisms can outcompete native species for resources, leading to declines in native populations and altering the natural balance of the ecosystem. Additionally, some invasive species can carry diseases that affect local wildlife, further exacerbating the impact on native species and biodiversity. This phenomenon can lead to a cascade of ecological changes, negatively affecting not only the species involved but also the overall health and functionality of the local ecosystem.

In contrast, options like improving biodiversity or enhancing water quality do not accurately reflect the consequences of introducing non-native species, as these changes often lead to a decrease in biodiversity and can deteriorate water quality due to the overpopulation of invasive species. Providing nutrients for local species may also be misleading, as the introduction of non-native organisms does not necessarily equate to an overall benefit for the ecosystem.