900 Species Invade the Mediterranean, Alter Entire Food Chain


The puffer fish is just one invasive species that now dominates in the Mediterranean. Photo credit: notsogoodphotography/Creative Commons

Over the last several decades, more than 900 invasive species have moved into the Mediterranean Sea, many of which have become established—and even dominant—in the region. As a result, coastal communities of plants and animals are experiencing major shifts and, in some cases, entire food chains have been altered.SLIDESHOW: The World's Most Lovable Invasive Species

"The Mediterranean is the world's most invaded sea," said Stefan Kalogirou, a researcher at the Department of Marine Ecology at the University of Gothenburg, adding that "once species have become established in the Mediterranean it is almost impossible to eradicate them."

The problem, he believes, stems from the 1869 construction of the Suez Canal, which created a corridor linking the Mediterranean to the Red Sea and, eventually, the Indian Ocean. Ship traffic through the region continues to be a major vector for the introduction of alien species.

Though the conduit has been open for more than 150 years, surprisingly little is known about how many species are introduced to the Mediterranean or what happens once they are there. Kalogiru's research, part of a four-year study of Mediterranean coastal ecology, found a clear impact on native species.

He explains:

The results show...[that] when alien species either become dominant, like pufferfish, or are piscivores, like barracuda and cornetfish. It is evident that the food chain is being restructured, but the lack of previous studies limited our conclusions.

Kalogiru concludes that a better monitoring methodology and detailed risk assessments are essential to protecting Mediterranean ecosystems.

Read more about the Mediterranean:
6 Mediterranean Biodiversity 'Hotspots' Identified by New International Conservation Plan
Gray Whale, Extinct for Centuries, Sighted in Mediterranean
Overfishing Means 40 Species of Mediterranean Fish May Be Extinct in Next Few Years

Tags: Animals | Conservation | Oceans