MICROBIAL SURVIVABILITY
Haruo Mimura
Graduate School of Maritime Sciences, Kobe University,
Kobe, Japan
Synonyms
Adaptability to new habitats; Microbial viability, Potentially survivable marine organisms
Definition
Ballast water. Seawater loaded onto ships as ballast to
maintain hull stability and propulsion efficiency.
Cyst. Highly survived state of phytoplankton from
which plankton cells are reproduced by germination.
Ten of the most unwanted marine organisms. Ten kinds
of marine organisms listed by the International Maritime
Organization as highly survivable, ecological threats.
Introduction
The first iron steamship, Aaron Manby, was built in the
nineteenth century. Thereafter, seawater was commonly
used as ballast on ships. Massive transport of seawater is
still continued by ships, and many marine organisms are
transported across oceanic boundaries in the ballast water
that is loaded on board. Modern developments in
containerizing cargo, the increasing size of hulls, and
high-performing seawater pumps also accelerated the
utilization of seawater as ballast.
The International Maritime Organization (IMO)
adopted the International Convention for the Control and
Management of Ships’ Ballast Water and Sediments in
2004 to determine the minimum viable cell numbers of
pathogenic Vibrio cholerae, Escherichia coli, and intestinal Enterococci as standards for discharged ballast water
(IMO, 2004). The IMO also listed ten of the most
unwanted kinds of marine organisms. These organisms
are V. cholerae, cladoceran water flea, mitten crab, toxic
algae (red/brown/green tides), round goby, European
green crab, Asian kelp, zebra mussel, North Pacific
seastar, and North American comb jelly. Zebra mussel is
one of the most successfully established invasive species
in the Great Lakes, propagating inside seawater intake
pipes and sometimes interrupting seawater uptake of
power plants.
Potentially survivable marine organisms transported
across oceanic boundaries affect the ecosystem of estuaries throughout voyages.
Effectiveness of ballast water exchange on the
high seas for the prevention of nonnative
microorganism invasion into estuaries
Dissolved oxygen and nutrients in seawater stored in
a ballast tank are consumed by surviving marine
organisms contained in the water during a voyage. Zooplankton cells have difficulty surviving in such conditions. Cysts of phytoplankton, however, can survive
a voyage despite the low oxygen and poor nutrients in
the ballast water stored in a dark ballast tank. In order
to prevent dispersal of cysts across ocean boundaries
via ships’ ballast water, the IMO recommends ballast
water exchange on the high seas before arrival at
a foreign port.
Japan imports huge amounts of natural resources, such
as crude oil, liquefied natural gas, iron ore, wood chips,
etc., that arrive on mercantile ships from many countries.
Therefore, Japan is one of the major ballast water export
countries in the world because ballast water is discharged
at the ports of call where the cargoes are loaded. The
effectiveness of ballast water exchange in reducing
plankton populations was examined using a liquefied
natural gas carrier (110,000 gross tons) on the way to
Qatar from Japan. The resulting reduction in the total
number of phytoplankton cells by the exchange of ballast
water on the high seas was confirmed by measuring the
surface color of the ocean with a satellite remote sensor
as well as direct counting of phytoplankton in samples
taken on the ship (Kozai et al., 2006). In addition, the
marine bacterial population can change markedly by
replacing ballast water on the high seas. This process
has been confirmed based on denaturing gradient gel
electrophoresis analysis of samples taken on a coal carrier (58,098 gross tons) bound for Australia from Japan
(Tomaru et al., 2010).
Surviving bacterial populations in sediments taken into
a ballast tank are 10–100 times higher than those in ballast
water (Mimura et al., 2005). Therefore, suspended sediments in ballast water should be controlled prior to the discharge of ballast water on the high seas or at ports of call.
Development of onboard ballast water treatment systems
is in progress (Wright et al., 2010; Nanayakkara et al.,
2011; Abe and Mimura, 2013).
Using toxic dinoflagellates as a model indicator of
microorganisms to trace biological invasion
pathways
Marine organisms must survive several steps to become
established in a new environment: (1) passing through
a seawater pump when ballast water is loaded onto
a ship, (2) remaining in a ballast tank during the voyage,
(3) passing through the seawater pump when discharged
with the ballast water, (4) adapting to a new environment,
(5) reproducing and establishing a population, and (6) creating damage to populations of native species and the local
economy. It has been pointed out that the blooming of toxic
dinoflagellates is an intrinsic threat to coastal areas. An
incidence of paralytic shellfish poisoning, which is closely
related to the consumption of shellfish products that
had accumulated alkaloid toxins, caused human illness.
434
MICROBIAL SURVIVABILITY
Haruo Mimura
Graduate School of Maritime Sciences, Kobe University,
Kobe, Japan
Synonyms
Adaptability to new habitats; Microbial viability, Potentially survivable marine organisms
Definition
Ballast water. Seawater loaded onto ships as ballast to
maintain hull stability and propulsion efficiency.
Cyst. Highly survived state of phytoplankton from
which plankton cells are reproduced by germination.
Ten of the most unwanted marine organisms. Ten kinds
of marine organisms listed by the International Maritime
Organization as highly survivable, ecological threats.
Introduction
The first iron steamship, Aaron Manby, was built in the
nineteenth century. Thereafter, seawater was commonly
used as ballast on ships. Massive transport of seawater is
still continued by ships, and many marine organisms are
transported across oceanic boundaries in the ballast water
that is loaded on board. Modern developments in
containerizing cargo, the increasing size of hulls, and
high-performing seawater pumps also accelerated the
utilization of seawater as ballast.
The International Maritime Organization (IMO)
adopted the International Convention for the Control and
Management of Ships’ Ballast Water and Sediments in
2004 to determine the minimum viable cell numbers of
pathogenic Vibrio cholerae, Escherichia coli, and intestinal Enterococci as standards for discharged ballast water
(IMO, 2004). The IMO also listed ten of the most
unwanted kinds of marine organisms. These organisms
are V. cholerae, cladoceran water flea, mitten crab, toxic
algae (red/brown/green tides), round goby, European
green crab, Asian kelp, zebra mussel, North Pacific
seastar, and North American comb jelly. Zebra mussel is
one of the most successfully established invasive species
in the Great Lakes, propagating inside seawater intake
pipes and sometimes interrupting seawater uptake of
power plants.
Potentially survivable marine organisms transported
across oceanic boundaries affect the ecosystem of estuaries throughout voyages.
Effectiveness of ballast water exchange on the
high seas for the prevention of nonnative
microorganism invasion into estuaries
Dissolved oxygen and nutrients in seawater stored in
a ballast tank are consumed by surviving marine
organisms contained in the water during a voyage. Zooplankton cells have difficulty surviving in such conditions. Cysts of phytoplankton, however, can survive
a voyage despite the low oxygen and poor nutrients in
the ballast water stored in a dark ballast tank. In order
to prevent dispersal of cysts across ocean boundaries
via ships’ ballast water, the IMO recommends ballast
water exchange on the high seas before arrival at
a foreign port.
Japan imports huge amounts of natural resources, such
as crude oil, liquefied natural gas, iron ore, wood chips,
etc., that arrive on mercantile ships from many countries.
Therefore, Japan is one of the major ballast water export
countries in the world because ballast water is discharged
at the ports of call where the cargoes are loaded. The
effectiveness of ballast water exchange in reducing
plankton populations was examined using a liquefied
natural gas carrier (110,000 gross tons) on the way to
Qatar from Japan. The resulting reduction in the total
number of phytoplankton cells by the exchange of ballast
water on the high seas was confirmed by measuring the
surface color of the ocean with a satellite remote sensor
as well as direct counting of phytoplankton in samples
taken on the ship (Kozai et al., 2006). In addition, the
marine bacterial population can change markedly by
replacing ballast water on the high seas. This process
has been confirmed based on denaturing gradient gel
electrophoresis analysis of samples taken on a coal carrier (58,098 gross tons) bound for Australia from Japan
(Tomaru et al., 2010).
Surviving bacterial populations in sediments taken into
a ballast tank are 10–100 times higher than those in ballast
water (Mimura et al., 2005). Therefore, suspended sediments in ballast water should be controlled prior to the discharge of ballast water on the high seas or at ports of call.
Development of onboard ballast water treatment systems
is in progress (Wright et al., 2010; Nanayakkara et al.,
2011; Abe and Mimura, 2013).
Using toxic dinoflagellates as a model indicator of
microorganisms to trace biological invasion
pathways
Marine organisms must survive several steps to become
established in a new environment: (1) passing through
a seawater pump when ballast water is loaded onto
a ship, (2) remaining in a ballast tank during the voyage,
(3) passing through the seawater pump when discharged
with the ballast water, (4) adapting to a new environment,
(5) reproducing and establishing a population, and (6) creating damage to populations of native species and the local
economy. It has been pointed out that the blooming of toxic
dinoflagellates is an intrinsic threat to coastal areas. An
incidence of paralytic shellfish poisoning, which is closely
related to the consumption of shellfish products that
had accumulated alkaloid toxins, caused human illness.
434
MICROBIAL SURVIVABILITY