On the 6th of August 2015, the enlargement of the Suez Channel was inaugurated. The Suez Canal is one of the most important waterways in the world: 17483 ships transited in 2015. It is also the most potent corridor for invasions by marine species known in the world.
Red Sea species live in one of the most stressful marine environments with water salinity reaching 39ppt, compared to the Mediterranean’s 30ppt, and the water is warming faster than anywhere on the planet, according to a 2011 KAUST study .
The individual and cumulative impacts of these invasions adversely affect the conservation status of particular species and critical habitats, as well as the structure and function of ecosystems and the availability of natural resources.
Some species are noxious, poisonous, or venomous and pose clear threats to human health. While global trade and shipping are vital to society, the existing international environmental agreements also recognize the urgent need for sustainable practices that minimize unwanted impacts and long term consequences.
Marine biologist Bella Galil told CNN that these species they came through the Suez Canal — just one of a number of invasive species now making their home in the Mediterranean.“We have this corridor pushing in all the alien species, who just push them out and replace them with a fauna, which is not the native one,” says Galil, a marine biologist with Israel’s National Institute of Oceanography.The newly-enlarged Suez Canal is forming a superhighway for invasive species, Galil says: “It’s becoming a corridor for invasion. A one-way corridor of invasion.”Each invasive species disrupts the food-chain and changes the underwater environment.The canal used to have its own natural hurdle to help prevent “invasions” — a series of saltwater areas called the Bitter Lakes; far saltier than the surrounding water, the lakes prevented most marine life from passing through the Suez Canal.But Galil says recent expansion works did away with this natural barrier, making it much easier for marine life to travel from the Red Sea to the Mediterranean, carried on the current which flows north for most of the year.
Oceana, an international organisation focussing on oceans, estimated last year around 450 Indo-Pacific invasive marine species have entered through the canal since its opening. This year however the number increased at 750 approximately.
Devote-project writes that of the 720 multicellular non-indigenous species (NIS) currently recognized from the Mediterranean Sea, fully half were introduced through the Suez Canal. Many of the NIS introduced via the Suez Canal have established thriving populations along the Levant, from Libya to Greece, whereas some species spread further, such as the toxic pufferfish, Lagocephalus sceleratus, occurring from Sevastopol in the Black Sea to Italy, Tunisia and Spain : its internal organs contain tetrodotoxin, a strong paralytic neurotoxin, inducing symptoms ranging from vomiting to respiratory arrest, seizures, coma and death.
These Indo-Pacific species are not as accommodating as their new home and are often noxious, poisonous, or venomous, posing threats to both the Mediterranean marine ecosystems and human health.
Between 2005 and 2008, 13 persons were treated for poisoning in Israel alone according to reports . A scyphozoan jellyfish (Rhopilema nomadica), has formed huge swarms annually along the Levantine coast since the mid 1980s, but recently spread westwards to Tunisia and Pantelleria in the Strait of Sicily. Its painful stings adversely affect tourism, fishers complain of net clogging and inability to sort yield, and jellyfish-blocked water intake pipes interfere with the operation of desalination plants and power plants.
- The impacts of these planktivorous swarms on the local food web must be considerable.
Two herbivorous rabbit fish (Siganus luridus and S. rivulatus) are responsible for an extraordinary shift in the Levantine rocky infralittoral from well-developed native algal meadows to ‘barrens’, bringing about a dramatic decline in biogenic habitat complexity, biodiversity and biomass.
Lionfish invading the Mediterranean Sea: Rising temperatures, Suez Canal widening open the door to invasive species https://t.co/rHw58X6oMe
— Neil Tulloch (@ntulloch123) 29 juin 2016
Significant and often sudden decline of native species, including local population extirpations, have occurred and are occurring concurrent with proliferation of Canal-introduced NIS. Among many examples, the introduced goldband goatfish (Upeneus moluccensis) has replaced the native red mullet in the Levantine fisheries, and introduced prawns, though considered a boon by local fishers, have been displacing the native prawn in commercial fisheries.
Local population losses and niche contraction of native species may not induce immediate extirpation, but they augur reduction of genetic diversity, loss of functions, processes, and habitat structure, increase the risk of decline and extinction, and lead to increased biotic homogenization.
Most NIS spread after long residency period, so we may well expect species introduced in the 1980s or earlier to expand their range and spread – the so called invasion debt. The recent enlargement of the Suez Canal is likely to increase the number of prospective NIS swept through.
— Geographical (@GeographicalMag) 30 mai 2016
The individual and cumulative impacts of these species will affect the conservation status of native species and critical habitats, as well as the structure and function of ecosystems and the availability of natural resources. As the sea is warming the spread of tropical species introduced through the Suez Canal may accelerate.
New Letter: The Enlargement of the Suez Canal and Introduction of NonIndigenous Species to the Mediterranean Sea. https://t.co/QhfP1I4AYa
— ICMB (@ICMB2016) 17 novembre 2015
- All images are from Wikipedia/Wikimedia