Introduction - Global Maritime Transport and Ballast Water Management: Issues and Solutions - page 3

safety. Nowadays vessels fundamentally rely on ballast water for safe operations.
A model for the assessment of ballast water discharges has been developed and
tested. It is estimated that global ballast water discharges from vessels engaged in
the international seaborne trade in 2013 would be approximately 3.1 billion tonnes
(see chapter “ Vessels and Ballast Water ”).
Water loaded as ballast from a vessel's surrounding environment contains
suspended matter and organisms. Ballast water sampling studies have shown that
various bacteria, plant and animal species can survive in the ballast water and ballast
tank sediment (e.g., Medcof 1975 ; Carlton 1985 ; Williams et al. 1988 ; Locke et al.
1991 ; Hallegraeff and Bolch 1991 ; Carlton and Geller 1993 ; Gollasch 1996 ; Gollasch
et al 2000 , 2002 ; Hamer et al. 2001 ; Murphy et al. 2002 ; David et al. 2007 ; McCollin
et al. 2008 ; Briski et al. 2010 , 2011 ). Some organisms stay viable in ballast tanks for
several months duration (e.g., Gollasch 1996 ; Gollasch et al. 2000 ) or longer
(Hallegraeff and Bolch 1991 ). Estimates indicate that 3,000-4,000 (Carlton and
Geller 1993 ; Gollasch 1996 ) and possibly even 7,000 (Carlton 2001 ) different spe-
cies are transferred daily via ballast water. Species types found range from unicellu-
lar algae to fi sh (e.g., Gollasch et al. 2002 ; David et al. 2007 ). Of those, more than
850 are known as successfully introduced and established into new regions (Hayes
and Sliwa 2003 ). It was concluded that each vessel has the potential to introduce a
species and that any single introduced species has the potential to cause a signifi cant
negative impact to the recipient environment (e.g., Gollasch 1996 ). Therefore, load-
ing ballast water and sediment in one port and discharging in another represents a
potential risk to transfer HAOP into new environments (see chapter “ The Transfer of
Harmful Aquatic Organisms and Pathogens with Ballast Water and Their Impacts ”).
The United Nations also recognised the transfer of HAOP as one of the four
greatest anthropogenic pressures to the world's oceans and seas, causing global
environmental changes, and posing a threat also to human health, property and
resources. Ballast water is one of the prime vectors of this global issue (e.g., Carlton
1985 , 1989 , 1992 , 1996a , b ; Wiley 1997 ; Gollasch et al. 2002 ; Bax et al. 2003 ;
Bailey et al. 2005 ; Davidson and Simkanin 2012 ). The unwanted impacts caused by
introduced species are manifold and include changes of species biogeography, bio-
diversity modifi cations, introduction of predators, bloom-forming harmful algae,
ecosystem engineers, parasites and disease agents resulting in economic problems
of marine resource users, such as loss in fi sheries, fouling of industrial water pipes
and on fi shing or aquaculture gear. Even negative impacts on human health are
reported because, e.g., harmful algae causing amnesic, diarrhetic or paralytic shell-
fish poisoning and Vibrio cholerae as well as other disease agents were found
in ballast water (e.g., Hallegraeff 1993 , 1998 ; Rigby and Hallegraeff 1994 ; Carlton
1996a , b ; Ruiz et al. 2000 ; van den Bergh et al. 2002 ; Hayes and Sliwa 2003 ; Bauer
2006 ; Gollasch et al. 2009 ; Romero et al. 2011 ). In total more than 1,000 aquatic
non-indigenous and cryptogenic 1 species are known from Europe (Gollasch
2006 ; Vila et al. 2010 ), and Hewitt and Campbell ( 2010 ), Hayes and Gollasch
1 Cryptogenic species are species which cannot reliable be assigned as being non-indigenous or
native because their origin is uncertain (Carlton 1996a , b ).