Study: Invasive fish species increase after expansion of Panama, Suez canals

The expansion of the Panama and Suez canals has increased the number of invasive, non-native fish species on the waterways, according to a new study from the Smithsonian Tropical Research Institute (STRI) and the Leibnitz Center for Tropical Marine Research (ZMT).

Since the Panama Canal expansion was completed four years ago, 11 new salt water species have been detected at Lake Gatun, which has been a freshwater barrier on the canal since it opened in 1914, the Smithsonian said. The number of salt water fish in the lake has increased from 18 to 29. In some parts of the lake. Jacks, snooks, mojarras and ladyfish have “entirely replaced freshwater fishes,” the Smithsonian said in its press release. 

The salinity of the water in Lake Gatun has increased since the expansion, although research aren’t sure why. 

“These marine fish invasions are an early warning sign of what could happen if no corrective measures are taken,” Gustavo Castellanos-Galindo, a postdoctoral fellow at STRI and guest scientist at ZMT Castellanos-Galindo, said in the press release. “We don’t know what the ecological and socioeconomic consequences of these fishes crossing the canal to either the Pacific or the Atlantic would be.”

On the Suez Canal, the problem is the opposite, researchers said. The Bitter Lakes, were actually saltier than then Mediterranean and Red Seas which the canal connects. The lakes served as a barrier to invasive fish, the Smithsonian said. However, over the last five years since the completion of the canal expansion, eight news species of fish have entered the Mediterranean through the canal, the Smithsonian said.

“It may be possible to use the hypersaline effluent from desalinization plants to make the Bitter Lakes saltier again,” the Smithsonian said in its press release.

Researchers had warned early on while the canal expansions were being planned about the dangers of invasive species.

“This report documents those changes in real time,” Castellanos-Galindo said in the press release.

The study is published in the journal Nature Ecology and Evolution.