The Transfer of Harmful Aquatic Organisms and Pathogens with Ballast Water and Their Impacts - Global Maritime Transport and Ballast Water Management: Issues and Solutions - page 35

Introduction
The first possible occurrence of a non-indigenous species attributed to being
introduced in ships' ballast water was by Ostenfeld ( 1908 ) who reported the
Asian phytoplankton species Odontella ( Biddulphia ) sinensis following its mass
occurrence in the North Sea in 1903. It was not until 70 years later that the fi rst
biological ballast water sampling (BWS) study was undertaken by Medcof
( 1975 ). This was then followed by several others (e.g., Carlton 1986 ; Williams
et al. 1988 ; Locke et al. 1991 ; Hallegraeff and Bolch 1992 ; Gollasch 1996 , 2002 ;
Hamer et al. 2000 ; Gollasch et al. 2000a , b , 2002 ; Murphy et al. 2002 ; David
et al. 2007 ; McCollin et al. 2008 ; Briski et al 2010 , 2011 ) working in different
world regions.
The annual number of new species records world-wide since 1850 has paral-
leled trade, both by shipping and also aquaculture developments. Improvements to
ship design allowing for the construction of faster and bigger vessels has led to
shorter voyage durations which almost certainly provide for a higher survival of
organisms in ballast tanks, and more frequent discharges of bigger quantities of
ballast water.
For example, in ICES member countries these shipping species introduction vec-
tors together with others result in a new introduction forming a new population
beyond its natural range approximately every 9 weeks (Minchin et al. 2005 ).
Biodiversity and environmental health has been on the agenda of aquatic ecolo-
gists for several decades and of great concern is the potential of “loss of biodiver-
sity” due to increased anthropogenic pressures. However, already in the early
biodiversity debate, few scientists highlighted that we are not only facing a “loss of
biodiversity” but also a “change” or “increase” of species diversity due to human
intervention. These changes may also be considered as threats to ecosystem health
and services (Rosenthal pers. comm.).
Species movements with ships ballast water are in the focus of this chapter,
resulting in (a) transport of native species, i.e., movements within their natural
region of occurrence, (b) introduction of non-indigenous (also named non-native,
alien, exotic, immigrant) species, i.e., species movements to areas where they were
previously unknown and (c) movement of cryptogenic species, i.e., those species
where it is not known if they are native to a region or whether they have been intro-
duced (Carlton 1996 ). In each of these three categories some species arrivals are
simply an addition to the biological diversity of a region without causing negative
impacts, whereas a smaller number of species are considered harmful, e.g., human
pathogens, and some can cause drastic changes to the receiving environments with
a capability of modifying economies and with consequences for human health (e.g.
Gollasch et al. 2009 ).
Here we describe the extent of species movements with ships ballast water
worldwide and also provide some examples of the species that have been transferred
and have resulted in different impacts following their arrival.