Changing Planet

Cleaning Up the World’s Ballast Water

Ships travel through the Suez Canal. Photo by Thomas Abercrombie.

According to the International Maritime Organization (IMO), the United Nations agency responsible for the prevention of marine pollution by ships, water carried in ships’ ballasts is a top threat to global biodiversity and marine ecosystems. How? By transporting thousands of species out of their native environments and depositing them elsewhere around the world, where they can wreak havoc on their new host environments, devastate local ecologies, contaminate food sources, and cost millions or even billions of dollars in control measures.

Ballast water has been blamed for bringing the European zebra mussel to North America’s Great Lakes region, where it has nearly wiped out native mussel species. Likewise the jellyfish Mnemiopsis leidyi, which took up residence in the Black Sea three decades ago and has since helped devastate local fisheries.

A potential solution to the problem, International Convention for the Control and Management of Ships Ballast Water & Sediments, has been on the table since 2004. But so far, it hasn’t been ratified by enough nations to come into force.

This opinion piece in New Scientist argues against continued complacence.




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