VOA慢速英语--通过苏伊士运河到达地中海的入侵动物（在线收听）

Invasive Animals Passing Through Suez Canal to Mediterranean Sea

Not long ago, Egypt marked the 150th anniversary of the opening of the Suez Canal.

The canal connects the Mediterranean Sea to the Red Sea and the Indian Ocean. It helped speed world trade between the East and the West.

But the man-made waterway has also helped speed the rise of other things, such as invasive non-native species.

Scientists say the invasive creatures have damaged the Mediterranean's environment and caused native species to disappear.

The number of non-native creatures has risen since the Suez Canal was widened in 2015. The "New Suez Canal" has raised concerns in Europe and brought criticism from many Mediterranean countries.

The main critic has been Israel, Egypt's neighbor.

Bella Galil is an Israeli biologist who has studied the Mediterranean for over 30 years. She says much of the environmental damage cannot be repaired. She said urgent action is needed to ease the effects of the invasive fish and other sea life.

Galil works at Tel Aviv University's Steinhardt Museum of Natural History.

She noted that the widening and deepening of the Suez Canal has created a "moving aquarium" of species. These creatures could make coastal waters almost unusable for human beings.

Galil believes the number of invasive species has reached 400. That is two times the number from 30 years ago. She said this is a "historic example of the dangers of unintended consequences."

Affecting the whole Mediterranean

Israel is now dealing with huge numbers of poisonous jellyfish that affect coastal power centers and keep people from visiting the seashore.

Other poisonous species, such as the lionfish and silver-cheeked toadfish, are also appearing.

The invasion of new species has reached as far as Spain in the west. Many European countries on the Mediterranean are paying attention. The issue is expected to be discussed later this month at the United Nations meeting on ocean science in Venice, Italy.

Galil said the problems of invasive species can be compared to those of climate change, pollution and over-fishing. She argues that the new species have caused a major "restructuring" of the environment. This has endangered native species like mussels, prawns and red mullet.

Israel's Environmental Protection Ministry said it is concerned because its coast is the "first stop" for invasive species in the Mediterranean. But it noted that Israel cannot fight the problem alone.

Lebanese scientists at the American University in Beirut have written about threats to the environment linked to the canal's expansion. The Associated Press reports that scientists in eastern Mediterranean countries from Turkey to Tunisia share these concerns.

A possible way to fix the problem

Some experts have suggested that increasing salt levels in the canal itself could create a barrier that would keep invasive species out.

Desalination centers are currently being built, with money from Qatar, near the canal. They will make fresh water out of seawater. The first such plant is expected to open later this year.

Bella Galil said that if salt from the desalination centers could be put in the canal, it could create a "salinity barrier" to protect the Mediterranean. The Great and Litter Bitter Lakes, which are linked to the canal, once provided a salty barrier to animals that might pass through. But the lakes have become less salty because of the widening of the Suez Canal and agricultural wastewater.

Egypt does not consider the environmental concerns as urgent. The country has been at peace with Israel since 1979 and recently signed a huge agreement to supply Israel with natural gas.

Some Egyptians do not think the invasive species are a problem at all. Moustafa Fouda is an advisor to Egypt's environment minister. He said invasive species can be helpful by "replacing species that are overfished." He said only five percent of the invaders are a problem.

Some Egyptian experts also deny that the widening of the canal is responsible for the increase in invasive species. They say that rising water temperatures and wastewater from ships are to blame.

The Suez Canal Authority is the government agency that operates the canal. It says the environmental concerns are overstated. The agency said the widening of the canal has increased water flow into the Mediterranean by only four percent.

Canal officials say they are closely watching the movements of sea creatures. They say they are requiring ships to take measures to avoid carrying species from one side of the canal to the other. And they are trying to keep salt levels high in the Bitter Lakes as a barrier.

Galil, however, questions whether these measures will be enough to serve as a barrier against invasive species.

"One day we will wake up to a complete and irreversible change and know that there was something we could have done about it, if only it had been done on time," she said.

Words in This Story

species – n. a group of animals or plants that can produce young and are closely linked

aquarium – n. a container to keep fish

unintended – adj. not planned as a purpose or goal

consequences – n. the result of some action or decision

irreversible – n. something that cannot be changed back