Inva­sive species can wreak havoc on ecosys­tems, like the Atlantic Ocean off the South­eastern U.S. and the Caribbean. Researchers have strug­gled in recent years to combat the pres­ence of lion­fish — which are native to the Indo-​​Pacific waters. Annette Govin­darajan, an instructor in North­eastern University’s Depart­ment of Earth and Envi­ron­mental Sci­ences, explores the dan­gers that this fish and other inva­sive species present.

Why are lion­fish a threat in the Atlantic Ocean, and what are some solu­tions to curbing their impact?

They are vora­cious preda­tors, and they eat a lot of native fish, many of which are impor­tant to com­mer­cial fishing and the health of coral reefs. The pop­u­la­tion of lion­fish is exploding, but few other fish eat them because of their ven­omous spines. They are a warm water species and will con­tinue to expand in the trop­ical Atlantic waters. One solu­tion being heavily pro­moted is for more people to eat them. The ven­omous parts are the spines, so if removed, the flesh is fine to eat.

Sci­en­tists have also used genetics to dis­cover there are actu­ally two dif­ferent lion­fish species that have come to the Atlantic, though one species is in a clear majority.

What are other exam­ples of inva­sive species taking hold out­side their nat­ural aquatic habitats?

One example is zebra mus­sels, which were dis­cov­ered in the Great Lakes for the first time in 1988, and prob­ably got there through the ship­ping industry in bal­last water — water taken from ports to main­tain a ship’s sta­bility and released at the des­ti­na­tion. If species in bal­last water sur­vive the trip and get estab­lished, they can pro­lif­erate. In the case of the zebra mussel, they grow quickly, and can dis­place native species and clog up water intake pipes for power plants. Another example is comb jel­ly­fish, which are native to the Atlantic but have taken off in the Black Sea.

Your research focuses pri­marily on jel­ly­fish. What is one area you hope to explore next?

A big con­cern out there involves an increasing number of large jel­ly­fish blooms, and one cause is over­fishing. Jel­ly­fish can also inter­fere with fish­eries by feeding on fish eggs and larvae, which could slow the growth of fish pop­u­la­tions. Some areas of con­cern with blooms are the Black Sea, the Gulf of Mexico, the Namibian coast of Africa and the Bering Sea. They also live in degraded habi­tats where oxygen levels are too low for other species.