Nomad Jellyfish Colonize Mediterranean

Rhopilema nomadica wsah onto beaches in Mediterranean, by Dor Galia Pasternak.

Rhopilema nomadica wash onto Mediterranean beaches. Photo by Dor Galia Pasternak.

SUEZ CANAL – For marine scientists, the stinging jellyfish that have colonized Mediterranean shorelines, ushering bathers from tepid vacation waters and clogging cooling plants in Israel, are more than a passing nuisance. Their arrival, sometimes in swarms up to 110 miles long, sounds an alarm.

The nomad jellyfish – Rhopilema nomadica – are the frontrunners in a wave of invasive species being slowly pumped from the Red Sea through the Suez Canal, depleting native Mediterranean populations, throwing the ecosystem out of balance, and putting fisheries, tourism, and public health at risk. And as Egyptian President Abdel Fattah al-Sisi inaugurates a controversial $8 billion expansion to the canal, promising to add more than 20 miles of new waterways, the scientific community is scrambling to stop them.

Since its construction in 1869, the Suez Canal has become the salt-water super highway of the Middle East, generating $5.5 billion for the Egyptian government in 2014 and facilitating trade between Europe and Asia. The government claims that the upcoming expansion will contribute an additional $13 billion a year to public coffers by 2023, but marine biologists, including Dr. Bella Galil from Israel’s Oceanographic and Limnological Research Institute in Haifa, warn that the environmental and consequent economic costs may be too high.

“Each time that the canal is enlarged, we get a new cohort of invaders,” said Galil. “Biodiversity is a complex web of relationships and in the Mediterranean, this web has been unraveled to a great degree.”

Together with 500 scientists from 40 countries, Galil is spearheading an international campaign to raise public awareness of the impact of invasive species entering the Mediterranean through the Suez Canal. In addition, the group is calling on Egyptian authorities to release an environmental impact assessment of the proposed expansion of marine biota and habitats in the Mediterranean, as required by international and regional agreements.

The canal once included a series of hypersaline pools, known as the Bitter Lakes, to block the migration of species between the two bodies of water. These barriers were removed during repeated expansions to the canal, and no additional measures ­to prevent species migration – such as the locks used on the Panama Canal – were implemented. Today, the Suez Canal Authority boasts the waterway as the longest, free-flowing canal in the world.

“The Suez Canal has been endangering the Mediterranean for almost 150 years,” Dr. Ilaria Vielmini, a marine biologist with Oceana, an international NGO, said in a statement earlier this month. “And although naivety can excuse its previous environmental impacts, we don’t have that excuse this time around.”

To date, 443 non-native species have successfully completed the passage between the Red Sea and the Mediterranean, accounting for two-third of all non-native species in the northern body of water.

While not all migrating species are problematic, those labeled as invasive, such as the jellyfish, have outcompeted native species and wiped out the plankton that would populate the next generation.

“This is one of those cases where protecting the environment can also protect our economy,” said Dr. Piero Genovesi, the chair of the Invasive Species Specialist Group at the International Union for the Conservation of Nature. His group estimates that invasive species cause losses to the European coastal economies to the tune of 12.5 billion Euros per year.

And the fact that it the waters of the Mediterranean is warming has only served to further facilitate the spread of invasive species. The poisonous silver-cheeked toadfish, a native of the Indian and Pacific Oceans, has been caught along the coast of Malta, while tropical rabbitfish, known to deplete algae forest for native species, have devastated large portions of the Mediterranean sea floor.

“Combine the fact that these species come from tropical waters with the warming waters in the north, and you see the expansion of these species throughout all of the Mediterranean, even the most northern part into Italy and France,“ Genovesi added. 

While the imminent expansion of the Suez Canal has the scientific community in Europe scrambling to find solutions, the problem highlights the inherent limitations to coordinating large-scale efforts between the sovereign countries that share the Mediterranean coastline.

Some fingers point to the International Maritime Organization, the United Nations agency tasked with setting international shipping standards. For now, the organization says that it is pushing the adoption of a ballast water convention among its member states as a “direct, large-scale action” that they say would improve the sustainability of shipping while reducing its impact on marine ecosystems. But for others, the real potential for change lies at the point of entry, in the hands of canal authorities.

“The responsibility for action lies with Egypt,” said Trine Christiansen, who leads the Marine Environment Group for the European Environmental Agency (EEA), an agency of the European Union. The EEA has been tasked with compiling information to inform policy, but lacks regulatory power in the matter.

“The species that move through the Suez Canal have an impact everywhere, but the action must be taken by one country,” she added.

The Egyptian embassy in Washington D.C. did not respond to a request for comment.