Where should ballast water exchange take place?

The appropriate location for ballast water exchange is at sea outside the Exclusive Economic Zone (EEZ) in depths greater than 200 meters. This practice is essential for minimizing the introduction of invasive species into new marine environments. Performing ballast water exchange at this depth and location significantly reduces the likelihood of these invasive organisms surviving and establishing themselves.

Exchanging ballast water in deeper ocean waters helps ensure that the organisms present in the ballast water are less likely to be able to thrive because of factors such as lower nutrient availability and environmental conditions that are drastically different from those in coastal or estuarine waters. This is crucial for biodiversity conservation as well as maintaining the ecological balance in the receiving waters.

The other locations mentioned, such as river estuaries, near the shore, and in restricted harbors, can foster conditions that are conducive to invasive species establishment. These areas typically harbor a diverse range of marine life and provide easier access for organisms taken onboard during previous port operations, which increases the risk of unwanted species spreading to sensitive ecosystems.