As global trade increases and ships from all over the world call at Washington’s ports, invasive species can sometimes be accidentally introduced into a harbor through a ship’s ballast water. These species sometimes thrive in the new environment, crowding out the native plants and animals.
Our state is blessed with a bounty of sensitive native aquatic species that live in the Columbia River, along the coast, and in Puget Sound. When an ocean-going vessel arrives at a port, it may discharge ballast water picked up in a faraway port of call, pumped in to counterbalance the weight of cargo and prevent the vessel from rolling or breaking in half. If invasive species are in that water, they can rapidly gain a foothold in the new environment and spread.
To prevent these invasions, vessels calling at Washington ports are advised to perform “open ocean” ballast water exchange. A vessel pumps out ballast water in the open ocean, replacing it with water found at sea. Sometimes, severe weather prevents a ship from performing this kind of exchange – high seas pose too much danger for ships to complete the maneuver. In addition, some ships still operate with outdated technology that prevents it from exchanging water in the open sea.
Port staff members and agency personnel continue to research ways to prevent the introduction of invasive species into our waters.