Viewpoint

Challenges in global ballast water management

Øyvind Endresen *, Hanna Lee Behrens, Sigrid Brynestad, Aage Bjørn Andersen,

Rolf Skjong

Det Norske Veritas, Veritasveien 1, N-1322 Høvik, Norway

Abstract

Ballast water management is a complex issue raising the challenge of merging international regulations, ship’s specific configurations along with ecological conservation. This complexity is illustrated in this paper by considering ballast water volume, discharge frequency, ship safety and operational issues aligned with regional characteristics to address ecological risk for selected

routes. A re-estimation of ballast water volumes gives a global annual level of 3500 Mton. Global ballast water volume discharged

into open sea originating from ballast water exchange operations is estimated to approximately 2800 Mton. Risk based decision

support systems coupled to databases for different ports and invasive species characteristics and distributions can allow for differentiated treatment levels while maintaining low risk levels. On certain routes, the risk is estimated to be unacceptable and some

kind of ballast water treatment or management should be applied.

 2004 Elsevier Ltd. All rights reserved.

Keywords: Ballast water; Risk assessment; Norway; Water exchange; Ship safety

1. Introduction

A wide variety of organisms that are transported in

ballast water in ocean trade vessels may establish

themselves in new environments when discharged from

the ship and alter or impact the receiving ecosystems

(Hayes and Sliwa, 2003). The rate of introductions has

been increasing exponentially since the 1800s (Carlton,

2001) and invasive marine species are one of the greatest

threats to the world’s oceans (GloBallast, 2002a). The

economical impacts of these invasions is considerable,

the zebra mussel alone accounts for over $500 million a

year (Ruiz et al., 2001).

Ballast water management is a complex issue raising

the challenge of merging international regulations, ship

technical solutions and ecological conservation. International regulations by nature take a relatively long time

to enter into force, hence regional and national regulations tend to be developed to meet with more local demands. Such developments are of major concern to the

shipping industry, which must operate across different

jurisdictions. Ecological awareness that forms the public

opinion now demands that measures to reduce the risk

of invasive species introductions.

The current recommended method for controlling the

introduction of non-indigenous species is open ocean

exchange of ballast water (IMO, 2003). It is expected

that the International Maritime Organisation (IMO)

member countries will adopt a convention (IMO, 2003)

regulating ballast water issues in the Spring of 2004.

Open ocean exchange of ballast water involves replacing

coastal water with open ocean water during a voyage,

either by emptying and refilling ballast tanks (sequential

exchange) or by flow-through dilution (three times tank

volume).

It is important to recognise that open ocean exchange

is not always biologically effective and is not always

possible to perform due to ship safety and operational

issues involved (as access to open ocean water). These

operational considerations and safety aspects indicate

that a portion of the ballast water transported annually

will have to be treated by other methods, or discharged

as untreated ballast water. To determine where most

effort should be expended on mitigation and control

strategies, a risk based approach that ensures focus on

trades posing unacceptable risk should be considered for

ballast management. This again raises the challenges of

data input and quality, methodology and understanding

* Corresponding author. Fax: +47-67-57-75-20.

E-mail address: oyvind.endresen@dnv.com (Ø. Endresen).

0025-326X/$ - see front matter  2004 Elsevier Ltd. All rights reserved.

doi:10.1016/j.marpolbul.2004.01.016

www.elsevier.com/locate/marpolbul

Marine Pollution Bulletin 48 (2004) 615–623
of ecological systems that forms the basis for a risk based

approach. This is further complicated by the presence of

other transfer vectors, as for example hull fouling.

The complexity in the situation is shown in this paper

by going through some of the elements needed for the

understanding of ballast water management. We consider the steps of ballast water volume, frequency, safety

and operational issues aligned with regional characteristics to address ecological risk for selected routes.

2. Ballast water volume

Ballast water capacity varies as a function of cargo

carrying capacity and ship type as discussed in Endresen

et al. (2003c). The annual ballast water amounts transported can be estimated as a function of the total cargo

transported annually. The cargo amounts transported

are less than capacity, which may be measured by the

dead weight tonnage (Dwt). For large tankers, a rule of

thumb is that at least 2.5% of the total carrying capacity

is reserved for stores, provisions and bunkers. The

maximum cargo load factor is hence 0.975, but can also

be lower (0.65) due to partial loading and multi-porting

(Wijnolst and Wergeland, 1997). The converting factor

from Dwt to tonnes of cargo is typically 0.87 for tankers

and 0.91 for Dry bulk (Fearnleys, 2002b), and 0.89 is

assumed to be a representative figure in our calculations.

The ballast capacity is based in these assumptions calculated to about 40% of the cargo transported (36%

ballast capacity per Dwt divided by 0.89 tonnage cargo

per Dwt).

Shipping is the dominant mode of transport,

accounting for almost two thirds of world trade, in

metric tonnes (Hoffmann and Kumar, 2002). Domestic

transport of cargo by ships amounts to some 3300 million tonnes (Mton) while merchant ships in international

trade transport about 5434 Mton of cargo annually

(Fearnleys, 2002a). The major bulk cargoes are fuel, raw

materials for industry, and food. By commodity, crude

oil represents the biggest share (30%), followed by coal

(9.6%), iron ore (8.4%), oil products (7.7%) and grain

(4.2%) (Fearnleys Review, 2001). The global ballast

water required for this cargo transport is estimated to be

approximately 3500 Mton. This is shared between

international (2174 Mton) and national (1300 Mton)

trade. Internationally, oil tankers account for some 37%

of the ballast water annually transported, while Dry

bulk cargo carriers account for 39% (coal, iron ore,

grains and other bulk commodities). The remaining 24%

includes General Cargo, Container vessels, Ro-Ro,

Chemical tankers and LNG tankers. The contribution

of the latter group may be lower since General Cargo

and Container vessels rarely operate return voyages in

ballast condition and mainly use ballast for adjusting

trim and heel.

3. Ballast water movement

Most of the maritime traffic (85%) takes place in the

northern hemisphere, specifically the North Atlantic/

Northern Europe and the northern Pacific (Corbett

et al., 1999; Endresen et al., 2003a). This is supported by

international cargo statistics (Fearnleys, 2000) and port

surveys (ISL, 2001). The major bulk cargoes are mainly

transported in large vessels within a fairly well defined

system of international sea routes. Fig. 1 presents

international sea routes for some of these vessels types

(Endresen et al., 2003b). The international sea borne

cargo statistics indicate that the US, Europe and Japan

are the main export regions of ballast water by crude oil

carriers. The main importing regions are the Middle

East, the Caribbean and Africa (Fig. 3). The pattern is

different for bulk vessels where the most important export areas of ballast water is Asia and Europe while the

importing regions are North and South America, Australia and Asia (Fearnleys, 2000). Table 1 presents cargo

trade per region indicating export and import regions of

ballast water.

4. Volume exchanged in open ocean

Ballast water volume uptake in port and volume exchanged in open sea are not necessarily equal. This

section evaluates safety and operational issues involved,

and estimate the potential ballast water volume that can

be exchanged in the open ocean.

4.1. Safety factors

The hazards associated with the sequential method

are presented in two studies performed by the International Association of Classification Societies (Skjong

and Dahle, 1997; Skjong and Spouge, 2000). One hazard

is that permissible bending moments and the shear forces on the ship’s hull may be exceeded (Rigby and

Hallegraeff, 1994; Transport Canada, 1995; Karaminas,

2000). Obviously, the problem may be solved by

designing new ships. This would, however, add costs.

Other criteria most frequently found difficult to maintain during all stages of the exchange sequence are

bridge visibility, propeller immersion and minimum

forward draft (Skjong and Dahle, 1997; Skjong and

Spouge, 2000; Karaminas, 2000; Japan, 2001). From

these studies it is apparent that a vessel carrying out

sequential exchange while exposed to wave loads might

experience excessive bending moments and shear stresses representing a threat to structural integrity. Slamming and tank sloshing increase the risk of causing

structural damage to the vessel. Sequential exchange is

the option chosen by most ships that exchange ballast

water, including 75% of the ships coming into California

616 Ø. Endresen et al. / Marine Pollution Bulletin 48 (2004) 615–623
and Texas ports, but there are some variations between

vessel types (National Ballast Information Clearinghouse, 2002).

The continuous flushing method avoids the problem

of exceeding safe bending moments and shears forces,

since the fresh ocean water is pumped via the ballast

pumps into the ballast tanks and allowed to overflow in

a safe manner. However, the IMO guidelines (IMO,

1997) require that three times the tank volume must be

pumped through the tank, which increases the exchange

time and cost significantly compared to the sequential

method. One of the major concerns with this process is

over-pressurization of the ballast tank(s) or ballast

piping system, which could cause damage to the ship’s

structure. Other safety issues are interference with the

watertight integrity of the main deck during removal of

the main deck manhole covers and icing on deck during

sub-zero temperature conditions. For new ships all these

hazards could be removed at a cost.

4.2. Modelling ofballast water exchange

Ships on ballast voyages will have to exchange ballast

water mid-ocean. Based on the above studies, we have

assumed that the safety critical significant wave height is

3 m, and that this applies to all vessels executing open

sea exchange. This is clearly a simplification since the

critical limits will depend on actual sea-state (direction,

periods, spectrum, etc.) and ship specifics (arrangements, design, ballast condition, etc.). Ballast voyages

are normally shorter in distance compared to cargo

voyages. A study that followed 1580 cargo vessels,

demonstrated significant variations in operational

Fig. 1. Vessel traffic densities for year 2000 based on the AMVERdata (AMVER, 2001). Upper left: all cargo and passenger ships in the merchant

fleet, upper right: oil tankers, lower left: bulk carriers, lower right: container vessels (from Endresen et al., 2003b).

Table 1

World seaborne cargo trade per region in 2000 (in Mton) (Hoffmann

and Kumar, 2002)

Region Exports Imports Total

Asia Pacific 1395.0 2106.1 3501.2

Europe 673.4 1421.8 2095.2

North America 536.2 910.7 1446.9

Latin America

and the Caribbean

948.3 313.0 1261.3

Persian Gulf 832.3 76.2 908.5

Other 829.2 386.6 1215.8

Total 5214.5 5214.5

Ø. Endresen et al. / Marine Pollution Bulletin 48 (2004) 615–623 617
profile of different vessel types/sizes and type of trade

(United Kingdom, 2002). They reported a mean total

time at sea for all vessel types involved in all trades of

5.8 days and up to 13–14 days for larger vessels. Taking

this into account we assume that on average a ballast

voyage by vessels in international trade takes 7 days. Of

these 2 days are spent within the 200 nm zones leaving 5

days for open ocean exchange. The probability of performing ballast water exchange under these criteria (5

days and 3 m critical wave height) is estimated by Monte

Carlo simulation using hind cast wind data (The Norwegian Meteorological Institute, 1955) from the period

1955–1999 for a representative sector for the Norwegian

Sea (for details see Endresen et al., 2002). These calculations show that 7% of the ships will not be able to

exchange ballast water by open ocean exchange if 1 day

is needed, and 30% of the ships will not be capable of

performing exchange if 2 days are needed. Note that the

necessary ballast water exchange period varies, but larger ships may use up to 2 days for ballast water exchange.

Seasonal variations in traffic, geographical variations

and weather conditions may influence the results. As an

example, for vessels operating on routes north of the

25th latitude during winter the possibility of performing

ballast water exchange will be significantly reduced

(Young and Holland, 1996; Gulev and Hasse, 1998;

Bitner-Gregersen et al., 1995).

5. Operational issues

Medium and small vessels operating in shallow

coastal routes (such as the North Sea) will not necessarily comply with the IMO Guideline for ballast water

exchange (Spain, 2000; Endresen et al., 2002). Such

routes exist between the North Sea and other European

countries, in the Mediterranean Sea and between the

Caribbean Sea and North/South seas of America. These

and other shallow and near coastline sea routes represent a large portion of the traffic. The global traffic data

from AMVERshows that about 60% of the traffic in the

North Atlantic operates within 200 nautical miles (nm)

from shore at any given time (Fig. 2). The AMVER

system is used to track about 30% by number of the

world cargo and passenger fleet greater than 2000 Dwt

(more than 7300 vessels) that daily report to AMVER

during voyage (AMVER, 2002). These findings correspond with those of Corbett et al. (1999) and Oftedal

(1996), who reported that 74–83% of the ships are within

200 nm of land at all times (Liberia, 1996; Norway,

1994). A large fraction will also be employed in regional

or coastal trade. For example, Whall et al. (2002)

claimed that some 60–65% of the traffic in European

waters was regional.

Table 2 summarizes the results of our analyses, and

presents cargo and ballast water inventories (uptake and

discharge). Based on the above analyses we assume the

Fig. 2. Shows ship traffic density and bottom topography (GEBCO, 1997; AMVER, 2001), which illustrates that a significant portion of the ship

traffic occurs in costal and shallow waters. When compared with the reported ballast water exchange locations for individual ballast tanks (Ruiz

et al., 2001) it is apparent that much of the ballast water exchange is not performed in deep ocean water.

618 Ø. Endresen et al. / Marine Pollution Bulletin 48 (2004) 615–623
national part of the ballast water, i.e. about 1300 Mton,

will not be handled through open sea exchange. Taking

into account the practical and operational aspects it is

expected that about 10% of the loaded international

ballast water or 200 Mton will not be exchanged in open

sea. It is assumed that 25% of the international vessels

will use the three times dilution of flow through exchange, and the rest sequential exchange (75%). The

total ballast water volume exchanged in open waters will

then be 2788 Mton (Table 2). The estimated volume

exchanged in open ocean might be too low, when the

considering location reported for completion of ballast

exchange (see above). The cost of an open ocean exchange of 2788 Mton of ballast water is estimated to be

USD 40–60 million, assuming 1.6–2.4 cents/m3, converted from Australian cents, i.e. 2.5–3.7 cents/m3 and

assumed 1 m3  1.025 ton based on Rigby and Taylor

(2001).

5.1. Ecological risk assessments

Ballast water exchange is not always possible to

perform due to safety issues as well as to geographical

constraints (see above). In addition, it is not always

biologically efficient, thus providing motivation for the

development of technologies to reduce the risk of unwanted invasions via ballast water and risk based approaches that determine what type of treatment is called

for. Risk based decision support systems are currently

being used by the Australian government (AQIS, 2002),

and being developed for developing countries by GloBallast (GloBallast, 2002b, 2003), and have been

developed by Det Norske Veritas (Behrens et al., 2002).

Risk based systems must be able to couple data bases

that include the potentially invasive species present in

each port, port characteristics and animals characteristics and distribution spatially and seasonally. The

development of good data bases and systems for utilising data can allow for differentiated treatment levels of

ballast water while maintaining low risk levels. If a ship

on a route can be shown to represent an acceptable risk

in of introducing unwanted organisms, the level of

treatment required could be different compared to

routes posing an unacceptable risk of transfer. Present

efforts are still focusing on developing risk based evaluation methodologies able to assess the need for ballast

water treatment. It is important to recognise that

current knowledge does not allow for predictive modelling of ecological systems. In addition, the data collection is difficult and needs to be organised so that

the data can be used in ecological models. The development of empirical ecological modelling approaches

and associated risk evaluation systems will enhance the

understanding of data needs and the development of a

common framework to assess this information.

This section presents a general risk assessment for

transport of ballast water with Crude oil carriers from

different donor areas into Europe (recipient area)

applying the risk evaluation approach using the DNV

EMBLA concept, which is outlined in Fig. 4.

5.2. Risk assessment for ballast transport into the western

coast ofNorway

The origin of ballast water discharged in ports by

large vessels is normally well defined according to vessels

types and/or cargo. Thus it is possible to undertake risk

assessments for transport of ballast water from one area

to another area. The risk assessment approach allows

differentiation on the use of treatment (exchange or any

other type of treatment) based upon the risk posed by

the ballast water transported.

A crude oil transport model has been developed by

means of a Geographical Information System (GIS).

Fig. 3 illustrates the relations between loading and

unloading locations for Crude oil carriers greater than

50,000 Dwt (Endresen et al., 2003a). Based on the GIS

model input data, the amount of ballast water, discharge

frequency and voyage duration are calculated. Combining these results with ecological information it is

possible to estimate the overall risk for this fleet segment by applying the risk evaluation methodology in

Table 2

National and international cargo and ballast water inventories, separated on ballast water uptake and ballast water exchanged (Mton)

Inventory International National Comments

Cargo 5434 3300 Year 2000

Ballast uptake 2174 1300 40% of cargo

Ballast uptake oil tanker 804 – 37% of ballast uptake

Ballast uptake bulk ships 848 – 39% of ballast uptake

Ballast uptake other ships 522 – 24% of ballast uptake

Ballast uptake not exchanged 217 – 10% of total uptake

Ballast uptake and exchanged 1956 – 90% of total uptake

Flow through exchanged 1467 – 25% of exchanged, three times diluted

Sequential exchanged 1320 – 75% of exchanged

Sum exchanged at sea 2788 –

Ø. Endresen et al. / Marine Pollution Bulletin 48 (2004) 615–623 619
EMBLA. To illustrate this method, risk is estimated for

selected sea routes into the western coast of Norway

(Table 3).

The overall risk evaluation indicates that ballast water from the northeast coast of the US poses a high risk

irrespective of season. This is due to the high biogeographical compatibility level between the east coast of

the US and western coast of Norway, 1994, and the

overlap in physical conditions as temperature and

salinity. Water from Piraeus, Greece is estimated to have

a high risk level during spring and a medium risk level

for the rest of the year. A more detailed risk analysis on

species and ship level can be undertaken when more

data is available.

5.3. Risk reduction

For the high and medium risk routes, assessment of

the ballast management onboard is recommended for

the purpose of minimising the risk potential through

improved internal ballast water management. For further reduction of the environmental risk, ballast water

exchange or treatment by an approved technology

should be used. Ideally, for high risk routes, open ocean

exchange should only be accepted if it can be documented that the exchange is biologically efficient,

otherwise other technology should be applied. Currently

no ‘‘silver bullet’’ technology is available, but the new

opportunities for good technological solutions are

driving research, and a number of technologies are

Fig. 3. Export (loading) and import (discharge) areas of ballast water by large crude oil carriers in 1996.

Fig. 4. EMBLA risk assessment structure (Behrens et al., 2002).

620 Ø. Endresen et al. / Marine Pollution Bulletin 48 (2004) 615–623
under development (Hallegraeff, 1997; Buchholz et al.,

1998; Oemcke, 1999; GloBallast, 2002a; Ruiz et al., 2001;

AQIS, 2002; Brynestad, 2002, Cangelosi et al., 2001,

Rigby et al., 1999; Tamburri et al., 2002, URS/Dames

and Moore, 2000).

As physical methods cannot practically remove all

organisms and most of the chemical/ionisation methods

require an initial ‘‘clean-up’’ step before the desired effect can be assured, the use of combinations of methods

is often considered. There is a need for the development

of internationally agreed and approved performance

standards and evaluation procedures for the formal

acceptance of any new techniques that are developed to

ensure compliance with defined ballast water standards

(i.e. the IMO ballast water standard to be outlined in the

forthcoming convention). Such performance standards

must also take into account the occupational safety and

health issues. Several institutions are at present working

on developing such standards (Andersen et al., 2003;

Stevens et al., 2003) that are expected to be finalised

during 2004.

6. Discussion

The total amount of ballast water unloaded from

ships in international trade is estimated to be 2200 Mton

in 2000. Tankers and bulk carriers account for about

76% (37% oil tankers + 39% bulk carriers) of the total

ballast water volumes. These vessels mainly operate

within a fairly well defined set of international trade

routes. General Cargo and Container vessels, often

sailing with a mix of ballast and cargo comprise a major

part of the remaining 24%. Untreated ballast water

discharged by ships in national trade is estimated to be

1300 Mton, resulting in global annual amount of 3500

Mton. This figure is significantly lower than previous

reported estimates.

The global ballast water amount discharged into

open sea is estimated to be around 2788 Mton taking

into account the use of flow through method and

practical and operational issues. A mid-ocean exchange

of 2788 Mton of ballast water represents an annual

treatment cost of USD 40–60 millions. Using alternative

treatment methods is expected to introduce higher costs

to the industry. The ballast treatment methods used will

vary according to ship type and requirements set by the

authorities, but developing methods for large volumes of

water is a challenge that has not yet been adequately

met.

Risk based decision support systems coupled to data

bases for different ports and invasive species characteristics and distributions can allow for differentiated

treatment levels while maintaining low risk levels.

Within certain routes as from the northern US to western coast of Norway, the risk is estimated to be unacceptable and some kind of ballast water treatment or

management should be applied.

Another challenge is the documentation of potentially invasive species in the water taken on board. An

international harbour monitoring network and database

regime is necessary to make risk assessment a viable

alternative. As the presence of organisms can vary

greatly by season, monitoring would have to be on a

regular basis. Advances in rapid genetic detection

methods may enable the development of simple diagnostic tests that can detect the presence of selected

indicator species.

Although this paper focuses on the ballast water

transfer the authors acknowledge that other vectors may

be equally important and must be considered for any

ecological system.

References

AMVER, 2001. Daily vessel observations for 2000/2001 provided by

Carroll, E., US Coast Guard, autumn 2001.

AMVER, 2002. The AMVER fleet, provided by Carroll, E. US Coast

Guard, 2002.

Andersen, A.B., Dragsund, E., Johannessen, B.O., 2003. Tentative

rules for Approval of Onboard Installations of Ballast Water

Treatment Systems. Paper presented at Imarest 2003.

Australian Quarantine and Inspection Service (AQIS), 2002. Available

from <http://www.affa.gov.au/>.

Buchholz, K., Tanis, D., Macomber, S., Farris, E., 1998. Battelle

Duxbury Operations Ballast Water Secondary Treatment Technology Review. Northeast-Midwest Institute, Washington DC,

USA. Available from <http://www.nemw.org/Balsurv_Contents.htm>.

Behrens, H.L., Haugom, G.P., Mordal Bakke, S., 2002. EMBLA

Concept; Risk assessment Methodology and Impact and Consequence Methodology Scheme. DNV Rep. No. 2002–1269. Available from <http://www.projects.dnv.com/embla>.

Table 3

Biogeographical evaluation of transport of ballast water from selected regions to the western coast of Norway (Eastern Atlantic Boreal region)

Donor area Recipient area Compatibilitya Compatibility level

USA, Chesapeake bay area Western coast of Norway Compatible High

Canada, Vancouver area Western coast of Norway Compatible High

Greece Western coast of Norway Compatible Medium

Spain, Atlantic coast Western coast of Norway Compatible Medium

a Compatibility evaluation is based on the work of Ekman (1953) and Briggs (1974, 1995).

Ø. Endresen et al. / Marine Pollution Bulletin 48 (2004) 615–623 621
Bitner-Gregersen, E.M., Cramer, E.H., Løseth, R., 1995. Uncertainties

of load characteristics and fatigue damage of ship structures. Mar.

Struct. 8, 97–117.

Briggs, J.C., 1974. Marine Zoogeography. McGraw-Hill, New York.

Briggs, J.C., 1995. Global biogeography. Developments in Palaeontology and Stratigraphy. Elsevier science, Amsterdam.

Brynestad, S., 2002. Ballast water treatment methods. DNV Technical

Report No. 2002-1230.

Cangelosi, A., Knight, T., Balcer, M., Wright, D., Dawson, R.,

Blatchley, C., Reid, D., Mays, N., Taverna, J., 2001. Evaluating

bioeffectiveness of flow-through mechanical ballast water treatment

systems (cyclonic separation + UV and filtration + UV) at the pilotand full-scale. Presented at the Second International Conference on

Marine Bioinvasions, New Orleans, LA, April 9–11, 2001.

Carlton, J.T., 2001. Introduced Species in US Coastal Waters:

Environmental Impacts and Management priorities. Pew Oceans

Commission, Arlington, VA.

Corbett, J.J., Fischbeck, P.S., Pandis, S.N., 1999. Global nitrogen and

sulfur emissions inventories for oceangoing ships. J. Geophys. Res.

104 (D3), 3457–3470.

Ekman, S., 1953. Zoogeography of the Sea. Sidgwick and Jackson,

London.

Endresen, Ø., Sørgard, E., Andersen, A.B., Gravir, G., BitnerGregersen, E., 2002. Implications of open ocean ballast water

exchange. Marine Science and Technology for Environmental

Sustainability, ENSUS 2002.

Endresen, Ø., Berglen, T.F., Sundt, J., Isaksen, I.S., 2003b. Impacts of

ship SOx emissions, in preparation.

Endresen, Ø., Sørgard, E., Sundet, J.K., Dalsøren, S.B., Isaksen,

I.S.A., Berglen, T.F., Gravir, G., 2003a. Emission from international sea transportation and environmental impact. J. Geophys.

Res. 108, 4560.

Endresen, Ø., Sørgard, E., Behrens, H.L., Andersen, A.B., 2003c. How

Much Ballast? Ballast Water News, Issue 14. Available from

<http://globallast.imo.org/BallastWaterNews14.pdf>.

Fearnleys, 2000. World Bulk Trades 2000. An analyse of 1999 with

2000 update, Compiled, prepared and published by Fearnresearch,

Norway. Available from <http://www.fearnleys.com/fearnleys/

fearnresearch.htm>.

Fearnleys Review, 2001. (the tanker and bulk markets and fleets),

Compiled, prepared and published by Fearnresearch, Norway.

Available from <http://www.fearnleys.com/fearnleys/fearnresearch.htm>.

Fearnleys, 2002a. Total Seaborne cargo transport figures, (provided by

Hammer, J.).

Fearnleys, 2002b. Typical converting factors between tonnes of cargo

and Dwt, (provided by Hammer, J.).

GEBCO, 1997. (General Bathymetric Chart of the Oceans) Digital

Atlas. British Oceanographic Data Centre, web site <http://

www.ngdc.noaa.gov/mgg/gebco/gebco.html>.

GloBallast, 2002a. The GEF/UNDP/IMO Global Ballast Water

Management Programme (GloBallast). Available from <http://

www.globallast.imo.org>.

GloBallast, 2002b. Risk Assessments Underway, Ballast water News,

Issue 8.

GloBallast, 2003. Risk Assessment released for I.R. Iran. Ballast

Water News, Issue 14.

Gulev, S.K., Hasse, L., 1998. North Atlantic Wind Waves and Wind

Stress Fields from Voluntary Observing Ship Data, JPO, June pp.

1107–1130. Data sets on <http://dss.ucar.edu/datasets/ds541.3/>.

Hallegraeff, G.M., 1997. Transport of toxic dinoflagellates via ships’

ballast water: bioeconomic risk assessment and efficacy of possible

ballast water management strategies. Mar. Ecol. Prog. Ser. 168,

297–309.

Hayes, K.R., Sliwa, C., 2003. Identifying potential marine pests––a

deductive approach applied to Australia. Mar. Pollut. Bull. 46, 91–

98.

Hoffmann, J., Kumar, S., 2002. Globalization: the maritime nexus. In:

Grammenos, C. (Ed.), Handbook of Maritime Economics and

Business. LLP, London, pp. 35–62. Available from <http://

bell.mma.edu/~skumar/IAMEBook.pdf>.

Institute of Shipping Economics and Logistics (ISL), 2001. In:

Zachcial, M., Heideloff, C. (Eds.), Shipping Statistics Yearbook.

Bremen, Germany.

International Maritime Organisation (IMO), 1997. Ballast water

Guidelines A 868 (20). Available from <http://globallast.imo.org/>.

International Maritime Organisation (IMO), 2003. Marine Environmental Protection Committee (MEPC), Draft International convention for the control of management of ships’ ballast water and

sediments. MEPC 49/2/3, 24 March.

Japan, 2001. Marine Environmental Protection Committee (MEPC),

Harmful Aquatic Organisms in ballast water, Safety of Ballast

Water Exchange at Sea, submitted by Japan, MEPC 47/2/7.

Karaminas, L., 2000. An investigation of ballast water management

methods with particular emphasis on the risks of the sequential

method. Lloyd’s Register of Shipping, June.

Liberia, 1996. Prevention of air pollution from ships, submitted by

Liberia, 17 April, MEPC 38/INF.12.

National Ballast Information Clearinghouse (NBIC), 2002. Data from

National Ballast Information Clearinghouse, an online database with ballast water reporting forms from ships arriving at US

ports. Available from <http://invasions.si.edu/NBIC/nbic_database.

htm>.

Norway, 1994. Prevention of air pollution from ships including fuel oil

quality, submitted by Norway, 29 July 1994, BCH 24/INF.28.

Oemcke, D., 1999. The treatment of Ships’ Ballast Water. Ecoports

Monograph Series No. 18, Ports Corperation of Queensland,

Brisbane.

Oftedal, S., 1996. Air pollution from sea vessels. European Federation

for Transport and Environment, Secretariat: Rue de la Victoire 26,

1060 Brussels, Belgium.

Rigby, G.R., Hallegraeff, G.M., 1994. The transfer and control of

harmful marine organisms in shipping ballast water: behaviour of

marine plankton and ballast water exchange on the MV ‘‘Iron

Whyalla’’. J. Mar. Environ. Eng. 1, 91–110.

Rigby, G., Taylor, A.H., 2001. Ballast water treatment to minimise the

risks of introducing nonindigenous marine organisms into Australian Ports. Fisheries and Aquaculture, Department of Agriculture, Fisheries and Forestry––Australia, Invasive Marine Species

Program, report nr. 13. Available from <http://www.affa.gov.au/

content/output.cfm?ObjectID 1⁄4 8859A2EE-ECC0-45C8-A5EA9-

EB0FE19CB8A#3_2_1>.

Rigby, G.R., Hallegraeff, G.M., Sutton, C., 1999. Novel ballast water

heating technique offers cost-effective treatment to reduce the risk

of global transport of harmful marine organisms. Mar. Ecol. Prog.

Ser. 191, 289–293.

Ruiz, G.M., Miller, A.W., Lion, K., Steves, B., Arnwine, A.,

Collinetti, E., Wells, E., 2001. Status and trends of ballast water

management in the United States. First biennial report of the

National Ballast Information Clearinghouse: submitted to United

States Coast Guard, 2001. Available from <http://invasions.si.edu/

NBIC/nbic_news.htm>.

Skjong, R., Dahle, E., 1997. Hazard identification, Ballast Water

Exchange at Sea. IMO MEPC 41/9/2.

Skjong, R., Spouge, J., 2000. Hazid of ballast water exchange at sea for

bulk carriers by SWIFT. London, IACS, 2000, International

Association of Classification Societies (IACS), International Maritime Organisation, Document, MEPC 45/2/1.

Spain, 2000. Marine Environmental Protection Committee (MEPC),

Harmful Aquatic Organisms in ballast water, Influence of the

operating conditions on board ship on the change of ballast during

sailing, submitted by Spain, MEPC 45/2/4.

Stevens, T., Frederick, R., Everett, R., Hurley, J., Hunt, C., Tanis, D.,

2003. Performance Verification of Ballast Water Treatment Tech622 Ø. Endresen et al. / Marine Pollution Bulletin 48 (2004) 615–623
nologies by USEPS/NSF Environmental Technology Verification

Programme. Paper presented at Imarest 2003.

Tamburri, M.N., Wasson, K., Matsuda, M., 2002. Ballast water

deoxygenation can prevent aquatic introductions while reducing

ship corrosion. Biol. Conservat. 103, 331–341.

The Norwegian Meteorological Institute, data hindcast for wind and

wave parameters each 6 h for the Norwegian Sea, time period 1955

to 1999.

Transport Canada, Ballast Water Exchange Study, Phase I. Ottawa,

Canada: Melville Shipping for Transport Canada Marine Regulatory Directorate, 1995.

United Kingdom, 2002. Rep. MSC 76/INF.6. submitted to the

International Maritime Organisation (IMO), Bulk Carrier Safety,

International Collaborative FSA Study––Crew Performance and

Voyage Cycles, 30 August.

URS/Dames and Moore, 2000. Feasibility of Onshore Ballast Water

Treatment at California Ports. Available from <http://www.epa.

gov/owow/mts/capareport/>.

Whall, C., Cooper, D., Archer, K., et al., 2002. Quantification of

emissions from ships associated with ship movements between

ports in the European Community, Report to the European

Commission, Entec, Northwich, UK.

Wijnolst, N., Wergeland, T., 1997. Shipping. Delft University Press,

Netherlands.

Young, Holland, 1996. Atlas of the Oceans: Wind and Wave Climate.

Elsevier Science, Pergamon, Oxford, UK.

Ø. Endresen et al. / Marine Pollution Bulletin 48 (2004) 615–623 623