An unusually aggressive, novel species of algae is carpeting the Mediterranean seafloor in an invasion that crossed the borders of five countries in just a decade. The algae, Caulerpa taxifolia, is equally adept at colonizing rock, mud, and sand in a virtually continuous swath that can extend from the beach out to a depth of about 150 feet. A single square yard of seafloor can be matted with 700 feet of runners from which emerge thousands of shaggy, thick leaves. This expansive growth suffocates most living things.
Introduced species can wreak havoc on an ecosystem. Look at what the sea lamprey did to the Great Lakes, the mongoose to the Hawaiian Islands, and camels to the outback of Australia. The Caulerpa taxifolia introduction in the Mediterranean is just the latest episode in a long history of tragic human errors.
What makes this introduction especially tragic, as Alexandre Meinesz explains in Killer Algae, is that it was made by the esteemed Oceanographic Museum in Monaco, founded by Jacques-Yves Cousteau, a popular advocate for the protection of marine ecosystems.
Meinesz details the unheeded warning cries when the escaped algae was first discovered offshore near the museum, and the long succession of denials, misinformation, thwarted control efforts and petty squabbles that allowed the algae to continue its destructive growth into the Adriatic Sea.
After all that's been learned from introductions of the past, it is disheartening to see how ineffective science and politics can be at preventing new environmental catastrophes.
