At a lavish ceremony, Egypt yesterday unveiled what the government is calling its “gift to the world.” A new $8.5 billion expansion of the Suez Canal will allow more ships to make the passage through the 193-kilometer-long waterway, and cut up to 8 hours off each voyage between the Red Sea and the Mediterranean. Suez Canal authorities hope the canal will increase annual revenue from $5.3 billion in 2015 to $13.2 billion by 2023.

Some marine biologists, however, aren’t applauding the expansion. They note the Egyptian government pushed ahead with the project despite the lack of a thorough environmental risk assessment. And the increased ship traffic and 35 kilometers of new, deeper channels could make it easier for invasive species to move between the two water bodies, a group of 18 scientists warned last year in the journal Biological Invasions.

Already, researchers estimate that some half of the 700 nonindigenous organisms found in the Mediterranean Sea got there via the canal. Some have created extensive problems. Less desirable goldband goatfish have replaced economically valuable native red mullet, for example, while invasive jellyfish have clogged water intake pipes.

“I am not aware of any marine biologist who thinks opening the canal without implementing [measures to prevent the spread of invasive species] is a good idea,” Yoni Belmaker, an ecologist at Tel Aviv University in Israel, tells ScienceInsider. For example, scientists say engineers could have created one kind of barrier by creating areas with very salty water, which is inhospitable to many species.

Another researcher watching with concern is biologist James Carlton, a specialist in marine bioinvasions with Williams College’s Williams-Mystic program in Mystic, Connecticut. He recently spoke with ScienceInsider about the expansion’s potential impacts—and possible solutions. The interview has been edited for clarity and brevity.

Q: What are the potential ecological impacts of expanding the canal?

A: The problem with expanding the corridor is it opens this conveyor belt … [it’s like] playing ecological roulette with the Mediterranean. There are literally hundreds of species that are in the Red Sea and the Indian Ocean, and not if, but when they get into the Mediterranean, the impact could be economically devastating. You have to weigh that against the economic benefits of the new canal. What we don’t want to see is another flood of new invasions.

Q: What is being done to prevent that?

A: Nothing that we know of, and that’s the issue. But all is not lost. We need [an] environmental impact statement and a willingness by the canal authorities to sink their teeth into this. We need an effective monitoring early detection, rapid response program, to figure out when and where these invasions occur, but it requires funding. If we don’t have that in place, then we wake up and realize something new has come in—and by that time it’s usually too late.

Q: What could be done?

A: Some early detection techniques [use] genetics. They take plankton samples and run them through multigenomic next-generation sequencing. We can see if the species of concern are in the plankton. This is especially helpful because one adult could be producing thousands of larvae or eggs, and it’s easier to check the [DNA] for species too rare for us to see. It’s been used in the Great Lakes to detect whether the Asian carp was already there without having to try and find the adult. It’s a technique that is becoming more widespread and it’s not expensive, compared to the millions of dollars of impact that these species could have in the Mediterranean.

Q: Could these species leave the Mediterranean and move elsewhere?

A: Every time a new species gets into a major port system in the Mediterranean, it’s going to interface with a whole new world of global shipping. Those ships can pick up new species and begin to disperse them to other parts of the world, back through the Suez Canal or the Strait of Gibraltar. It’s not the endgame, but only the beginning for new invasions.

We’ve got the two greatest canals in the world—Suez and Panama—and both are expanding. That’s a clear eyebrow raiser at almost any level. It’s economic, ecological, environmental Russian roulette—we start spinning that wheel and there is an assumption we can predict what those impacts will be, but we can’t.

Q. How does climate change fit into the equation?

A: It’s intricately interwoven; there is no question that climate change and invasive species are a deeply related issue. The Mediterranean is much more susceptible to invasions now as it’s warming up because of global climate change. It’s the tropicalization of the Mediterranean. The Red Sea is south of the Mediterranean, and so it’s warmer. And those warmer water [Red Sea] species [are] now entering a warming Mediterranean.

(ScienceInsider has contacted Suez Canal authorities for comment, but has received no reply.)