From Live Science
Becky Oskin, OurAmazingPlanet Staff Writer
Date: 06 May 2013 Time: 03:42 PM ET
The world port at highest risk of invasive species is Singapore, according to a new study.
The Suez Canal and Hong Kong follow Singapore, according to the study,
which reveals the 20 ports most likely to be attacked by
invasive species.
The highest ranking U.S. locale is the port of New York and New Jersey, which comes in at No. 13.
Global shipping has carried exotic animals and plants such as lionfish,
zebra mussels and killer algae around the world on ship's hulls or in
their ballast water, which ships add and dump for balance. Recently,
cargo ships started carrying automatic identification systems that track
their movements, giving researchers new insight into the vessels'
journeys.
Marine invaders need more than just a ride on a ship to infest a new
ecosystem, however — conditions at their next port of call must be just
right. So scientists combined data about ports'
environmental
conditions, marine biogeography and ballast water release protocols
with data from nearly 3 million ship voyages. They used this combined
information to estimate the
invasive species risk from ballast water at different ports.
The new model thus accounts for the fact that bioinvasion is a
multistage process, the researchers said. "Our model combines
information such as shipping routes, ship sizes, temperatures and
biogeography to come up with local forecasts of invasion probabilities,"
study author Bernd Blasius, a professor at the University of Oldenburg
in Denmark, said in a statement. The results were published April 24 in
the journal Ecology Letters.
The good news is that most ports are unlikely to receive invaders via
ballast water.
For example, ports in the North Sea (between Great Brittan and mainland
Europe) fall outside of the top 20 endangered ports despite their
enormous shipping traffic, the researchers said.
Some invaders from the U.S. East Coast have established a toehold in North Sea ports, but overall, the region's cold
climate has made it tough for exotics to survive there, the researchers said.
The ports with the highest risk are in Southeast Asia, the Middle East and the United States.
After Hong Kong, the rest of the ports at highest risk are, in descending order:
-
Panama Canal
-
Kaohsiung
-
Suez
-
Port Said
-
Busan
-
Jebel Ali
-
Kawasaki
-
Durban
-
Yokohama
-
New York & New Jersey
-
Long Beach
-
Xiamen
-
Fujairah
-
Los Angeles
-
La Plata
-
Qingdao
-
Santos
The research also revealed that for marine life hitching a ride inside
ships, there is a "sweet spot" distance between the organism's home and a
new habitat: 5,000 to 6,200 miles (8,000 to 10,000 kilometers).
In what could be called a Goldilocks effect, the researchers conclude
that, at short distances, it's unlikely an introduced species will be
non-native. At long distances, the chance to survive transport is small
and there's not much shipping, resulting in low invasion risk.
In another positive result, the shipping model shows the benefits from
ballast water treatment. Scientists and regulators have been trying to
come up with better ways to prevent the spread of invasive species, but
no one has settled on the best method. (Global standards from the
International Maritime Organization could be implemented as soon as
2020.) [
Image Gallery: Invasive Species]
The study suggests that even moderate efforts are helpful, because the
cumulative effect of treating ballast water at each port stop multiplies
during a trip.
Email Becky Oskin or follow her @beckyoskin. Follow us @OAPlanet, Facebook & Google+. Original article on LiveScience's OurAmazingPlanet.
