A delicacy of the Chesapeake has become the scourge of the Mediterranean.

In a matter of about seven years, the Chesapeake’s native blue crab has invaded and swiftly taken over the ecosystem of the Ebro Delta on Spain’s Mediterranean coast, the Guardian reported last week. If a newly-introduced species has no natural predators in its adopted ecosystem, it is capable of interrupting the food chain by eating up the native species that call the region home.


Invasive species are a global problem caused, in part, by international trade and weakened ecosystems, said Doug Myers, Maryland Senior Scientist for the Chesapeake Bay Foundation.

As cargo ships travel across the globe, they take in and expel water — and sometimes local native species — from the portion of a ship called a ballast while goods are loaded and unloaded at each port.

“I think a lot of people don't realize that keeping [invasive species] out is only half the issue,” he said. “Maintaining your ecosystem in healthy conditions is as important.”

Regions already under ecological distress, either from over-fishing or other human activity, are the most susceptible places for a hitchhiking species to thrive and overrun, Myers said.

The Trump administration is making an additional 30,000 visas available so that businesses – including Maryland crab houses – will have enough migrant laborers.

“Over-fishing creates a blank slate for hearty species to come in and take over,” he said.

Though some might argue that Spanish fisheries can take advantage of the beloved staple of Chesapeake cuisine, Myers says that creating any economic dependence on an invasive species creates economic pressure, but barely puts a dent in overpopulation.

Some local, federal and international leaders have made efforts to tighten regulation on the shipping industry’s role in introducing invasive species. Meanwhile, the Chesapeake Bay Foundation reports more than 170 invasive species now live and reproduce in the region’s watershed.