How to approach ballast water management in European seas

Estuarine, Coastal and Shelf Science xxx (2016) 1e8

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How to approach ballast water management in European seas Matej David a, *, Stephan Gollasch b a b

Dr. Matej David Consult, Korte 13e, SI 6310, Izola, Slovenia GoConsult, Grosse Brunnenstr. 61, DE 22763, Hamburg, Germany

a r t i c l e i n f o

a b s t r a c t

Article history: Received 22 March 2015 Received in revised form 27 January 2016 Accepted 14 October 2016 Available online xxx

The latest research continues to show that the ballast water issue is very complex, which makes it very challenging to manage. In 2004, the International Convention for the Control and Management of Ships' Ballast Water and Sediments (BWM Convention) was adopted to globally harmonize action against the transfer of harmful aquatic organisms and pathogens via ships’ ballast water and related sediments. Analyses of the BWM Convention requirements, conducted through different research projects mainly aiming to provide support for the implementation of the BWM Convention, have shown that there are different steps countries need to take and that there are still some open issues which need to be solved. This paper presents some of the main issues identified and the core theoretical and applied measures required to solve these issues, with the aim to support more efficient and coordinated implementation of the BWM Convention requirements in EU seas. The approaches recommended here for the EU may be universally interesting for similar application in other areas of the world. © 2016 Elsevier Ltd. All rights reserved.

Keywords: Ballast water management Harbours Risks Introduced species Decision support

Regional index terms European seas, Baltic sea, North sea, North-eastern Atlantic, Western Mediterranean sea. 1. Introduction Commercial vessels are built to transport cargo or passengers. In case a vessel is not fully laden with cargo, additional weight is needed to ensure the vessel's seaworthiness, for example, to compensate for (a) increased buoyancy which can result in a lack of propeller immersion, (b) inadequate transversal and longitudinal inclination or (c) other stresses on the vessel's hull and structure. The material used as additional weight on a vessel is referred to as ballast. In former times ballast material was solid, but, once iron was used as basic vessel construction material in the middle of the 19th century, water was used in cargo holds or tanks as ballast. The loading of water was much easier and more time efficient. Even when a vessel is fully laden with cargo, ballast water operations may be needed due to (a) an unequal distribution of cargo on the vessel, (b) adverse weather and sea conditions, (c) an approach to shallower waters, and (d) to compensate for fuel consumption during the voyage. As a result, vessels fundamentally rely on ballast

* Corresponding author. E-mail address: [email protected] (M. David).

water for safe navigation and operations as a function of their design and construction (David et al., 2012; David, 2015). Aquatic organism transfers occur unintentionally (e.g., with vessels) or intentionally (e.g., for aquaculture purposes). When considering the shipping vector globally, aquatic organisms are predominantly transferred with ballast water and related sediments (Carlton, 1985; Hallegraeff and Bolch, 1991; Gollasch, 1996; Ruiz et al., 2000; Hamer et al., 2000; David, 2007; McCollin et al., 2008), but are also found attached to the vessels' hull or sea chests (Gollasch and Riemann-Zürneck, 1996; Gollasch et al., 2002; Fofonoff et al., 2003; Hewitt et al., 2004a,b; Otani, 2006; Coutts and Dodgshun. 2007). In Europe, a total of slightly more than 1000 marine and brackish water non-indigenous and cryptogenic species, which are species with unknown status as native or introduced, were known when the situation was summarized in 2006 (Gollasch, 2006). At that time it was concluded that shipping was the most important species introduction mechanism, with ballast water being the dominant vector. Subsequently, a total of 1369 marine alien and cryptogenic species have been reported in European seas (Katsanevakis et al., 2013a); more than half arrived with shipping (Nunes et al., 2014). In a more recent overview, the number of coastal non-indigenous species increased to more than 1400, documenting a rising trend of new species findings (Reker et al., 2015). Biofouling was identified as a more important introduction vector until the 1980s, when ballast water-mediated species introductions prevailed (Katsanevakis et al., 2013b). The importance of ballast

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Please cite this article in press as: David, M., Gollasch, S., How to approach ballast water management in European seas, Estuarine, Coastal and Shelf Science (2016), http://dx.doi.org/10.1016/j.ecss.2016.10.018

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water as a species introduction vector is also highlighted by the fact that severely harmful species, such as toxin producing phytoplankton and gelatinous zooplankton, have arrived with ballast water. In general, the transfer of harmful aquatic organisms and pathogens (HAOP) with vessels has resulted in unwanted negative impacts on natural environments and human health, and has also caused drastic economic losses (Gollasch et al., 2002; Casale, 2002; Kettunen et al., 2009; Vila et al., 2010). By IMO1 definition “Harmful Aquatic Organisms and Pathogens” are aquatic organisms or pathogens which, if introduced into the sea including estuaries, or into fresh water courses, may create hazards to the environment, human health, property or resources, impair biological diversity or interfere with other legitimate uses of such areas (IMO, 2004). It is important to note that HAOP in this context are not limited to non-indigenous species, but include all potentially harmful species irrespective of their origin, i.e., non-indigenous, cryptogenic or harmful native species (David et al., 2013). Noting the problems caused by introduced species, IMO started developing instruments to address the issue in 1973 (IMO, 1973). After some ballast water management (BWM) related guidelines were agreed at IMO initially, the work continued and eventually, in 2004, the International Convention for the Control and Management of Ships' Ballast Water and Sediments (BWM Convention) was adopted. It's aim is to prevent, minimize and ultimately eliminate the risks to the environment, human health, property and resources which arise from the transfer of HAOP via ships’ ballast waters and related sediments (IMO, 2004). Among the key principles of the BWM Convention are Ballast Water Exchange (BWE) and the Ballast Water Performance Standard (Regulation D-2, or D-2 standard) as protective measures. The rationale behind BWE is that coastal organisms pumped on board during ballast water uptake are unlikely to survive when they are discharged at sea because of, for example, salinity issues and the absence of hard substrates to complete their life cycles. Further, high sea organisms pumped on board during BWE at sea will be unlikely to survive when they are released in coastal waters due to possible salinity changes and the lack of suitable habitats. Another reasoning for BWE as a species introduction risk-reducing measure is that organism concentrations are much lower in high seas compared to coastal waters. Studies have shown, however, that BWE will not deliver complete protection from species introductions and also that BWE sometimes may be impossible due to safety reasons and other limitations; as a result, the D-2 standard was developed. The D-2 standard specifies a limited number of viable organisms that may be contained in discharged ballast water. The D-2 standard may be achieved by the use of ballast water management systems (BWMS) installed on board vessels. Knowledge about the quantity of ballast water to be discharged in a port is of multiple uses for port authorities and enhances the management process by enabling appropriate management measures. For example, this knowledge will enable assessment of the suitability and dimensions of (land-based) ballast water reception facilities. In addition, ballast water discharge estimates enable an environmental impact assessment for ballast water which was treated with active substances, e.g., chemical treatment, also considering a worst-case scenario and possible long-term accumulation of such substances in the recipient port. Ballast water discharge assessments may also support management measures based on the level of the risk assessed: for higher risk ballast water, more stringent BWM requirements may be imposed, or risk level may be used as a trigger for inspections to verify compliance with

1 International Maritime Organization, the United Nations body to deal with shipping.

ballast water requirements. In cases when a low (or acceptable) risk is identified, the authorities may allow some relaxation of requirements so that unnecessary costs and burden on vessels is avoided. For port States which require ballast water reporting from vessels, a ballast water discharge assessment (BWDA) model can be used to verify the reported data. Lastly, historical ballast water discharge data may be helpful to study vessel and ballast water patterns through time. These data, when related to known introduced species, may be used to calculate the relative importance of ballast water releases as a species introduction vector (David et al., 2012). Knowledge of the aquatic organism transfer process (i.e., entering ballast tanks, voyage survival and unmanaged ballast water discharge) is a critical component of effective ballast water management (BWM) (Hewitt and Hayes, 2002). A crucial element of BWM is risk assessment (RA), as it enables the identification of appropriate management measures according to the risk level identified, e.g., in high risk cases additional control requirements may be implemented, while for low risk situations ballast water management may not be needed (Hewitt and Hayes, 2002; €koski, 2007; David, 2007; Hewitt and Gollasch and Leppa Campbell, 2007; David et al., 2015). There are two very different RA approaches under the BWM Convention: the selective and the blanket approach. In a blanket approach, all ships intending to discharge ballast water in a port are required to conduct BWM measures. The selective approach means that different BWM measures are required depending on different risk levels posed by the ballast water intended for discharge. Consequently, ships may be exempted from BWM requirements provided the risk level of the ballast water intended for discharge is acceptable according to the IMO G7 Guidelines (IMO, 2007a). On the other hand, if the risk of the ballast water to be discharged is identified as (very) high or extreme, these ships may be required to take additional measures based on the IMO G13 Guidelines (IMO, 2007b). Decision Support Systems (DSS) are supporting tools enhancing a (complex) decision-making process. The DSS approach was introduced in BWM to facilitate decisions under a selective BWM approach. Decision-makers are faced with the difficulty of making timely decisions especially on very complex issues, which usually require input of large data sets. DSSs are multi-facetted tools that provide decision makers with an instrument to (a) reduce uncertainties, (b) simplify and speed-up the decision process, (c) avoid subjectivism induced by the decision-maker and (d) guarantee transparency of the entire decision-making process. More precisely, it was quickly recognised that a supporting tool is needed to provide transparency and consistency on BWM requirement-related decisions with the aim to improve environmental protection and to lessen the BWM burden on vessels (David and Gollasch, 2015a,b). In this paper we summarise ballast water discharge profiles of two EU ports, introduce key principles of RA under the BWM Convention including a RA model flowchart, and we introduce the importance of DSSs to support complex decision making in ballast water management. We conclude with recommendations on how to approach the BWM issue in Europe which may also be considered for application in other areas of the world. 2. Materials and methods BWM information was gathered by participating in different national and international projects, expert, scientific and/or governmental working groups or organisations (e.g., IMO, MEPC2,

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Marine Environment Protection Committee (of IMO).

Please cite this article in press as: David, M., Gollasch, S., How to approach ballast water management in European seas, Estuarine, Coastal and Shelf Science (2016), http://dx.doi.org/10.1016/j.ecss.2016.10.018

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BWWG3, EMSA4, HELCOM5, OSPAR6, WGBOSV7, BWMSC8) where a wide array of different BWM aspects (i.e., technical, biological, organisational, administrative, economic, legal and policy issues) were addressed. The authors recognised that the BWM issue has been addressed in Europe at different national, regional and global levels but has not yet been approached at an overarching EU level, although the first European countries have ratified the BWM Convention (see below) and some regional, voluntary BWM requirements are already implemented in Europe. A generic BWDA model was prepared based on vessel cargo operations and dimensions. This model was tested considering real shipping traffic and ballast water discharge data for the Port of Koper, Slovenia (David et al., 2012). The results show high confidence that the model correctly predicts whether or not a vessel will discharge ballast water, as well as the quantity of ballast water to be discharged. The BWDA model was in this study applied to traffic in the Port of Hamburg, Germany, and Port of Tallinn, Muuga Harbour, Estonia for the year 2012 because. Despite best efforts, only these two ports provided the data required to run the model in a sufficient level of detail. Consequently, these two ports were chosen to identify detailed ballast water discharge profiles for risk assessment and management purposes. Running the model resulted in the identification of ballast water volumes discharged per month and per type of vessel, minimum and maximum quantities of discharges per vessel, the frequency of ballast water discharges, and ballast water donor ports (David et al., 2016). Finally, the BWDA model principles were used to assess ballast water discharges globally in 2013. BWM activities were reviewed at regional levels considering the framework and requirements of the BWM Convention and this led to the need for a BWM approach at the EU level in a concerted manner. The geographical coverage of this paper includes the Baltic Sea, the north-eastern Atlantic Ocean (including the North Sea) and the western Mediterranean Sea. Three different RA methods are considered for RA in BWM: “environmental matching”, “species' biogeographical” and “species-specific”. Firstly, in the environmental matching RA, nonbiological parameters are considered as surrogates for organism survival potential between the areas of ballast water origin and discharge. Secondly, the species’ biogeographical RA identifies species which show overlapping distributions in the ballast water donor and recipient ports and biogeographic regions. Species overlap is taken as a direct indication of similar environmental conditions and hence it indicates potential for organism survival in the new environment. Thirdly, the species-specific RA is focused on life history information and physiological tolerances of species to identify their physiological limits with the aim to estimate their potential to survive or complete their life cycles in the new environment (IMO, 2007a). This approach considers target species, i.e., species of special concern whose introduction should be avoided (David et al., 2013; David and Gollasch, 2014). In order to conduct RA for BWM, for each selected ballast water donor port, information on several parameters was gathered, including environment (salinity), occurrence of HAOP, harmful

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Ballast Water Working Group (of IMO). European Maritime Safety Agency. 5 Baltic Marine Environment Protection Commission - Helsinki Commission. 6 OSPAR Commission (“OS00 for Oslo and ”PAR00 for Paris) is based on the Convention for the Protection of the Marine Environment of the North-East Atlantic, and it replaces the original Oslo and Paris Conventions. 7 Working Group on Ballast and Other Ship Vectors (WGBOSV) of the International Council for the Exploration of the Sea, Intergovernmental Oceanographic Commission and International Maritime Organization (ICES/IOC/IMO). 8 Ballast Water Management Sub-Commission for the Adriatic.

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algae, indicator microbes, target species, species under a control programme, and outbreak forming species. This information was gathered by a comprehensive search of publications in consultation with relevant working groups (David and Gollasch, 2014). In the environmental matching RA, the key parameter is water salinity. We considered the minimum salinity difference to estimate the risk of a species being transferred in a two-step approach. A low risk is assumed when ballast water is moved between freshwater (<0.5 PSU) and fully marine conditions (>30 PSU). However, since such conditions are not applicable in all European shipping patterns, other possibilities were considered. What might be acceptable, but at a slightly higher risk, is when ballast water is moved between freshwater ports and brackish ports with salinities higher than 18 PSU. Under these circumstances an additional species-specific method would be required, taking into account known salinity tolerance - especially considering species with broad salinity tolerance <0.5 PSU and >18 PSU (David et al., 2013). The salinity limit of 18 PSU was chosen according to the work of Remane (1934) and Remane and Schlieper (1958) who compared the diversity of freshwater, brackish and marine species along salinity gradients. They showed that for many species groups, the lowest species diversity was found at low salinity conditions and the division identified in their studies is at approximately 18 PSU. Further, the Venice salinity system (Venice System, 1959) draws the line between polyhaline and mesohaline at 18 PSU and it has been found that this division also relates to a change in species diversity (den Hartog, 1964). More recently, this same trend was shown for native as well as non-indigenous species by Paavola et al. (2005) where, in European brackish seas, most non-indigenous species are well adapted to the salinities holding the lowest native species diversity, and the non-indigenous species diversity maximum occurs in the salinity intervals of native species diversity minimum. As a further example, Bleich (2006) compared macrozoobenthos diversity according to salinity at different Baltic Sea sampling stations. He found that species diversity changed by more than 80% at ca. 18 PSU level and concluded that this may be a salinity-related distribution limit. In summary, 18 PSU is well supported as a riskqualifying factor (David et al., 2013). DSS approaches for BWM were reviewed and a complex BWM DSS was prepared to support EU-wide BWM (David and Gollasch, 2015a). The BWM DSS was further validated using one year real ballast water discharge data from the Port of Koper, Slovenia (David and Gollasch, 2015b), including comprehensive data on vessel voyages (collected or assessed), vessel movements, their main routes, navigational constraints and ballast water patterns. Ballast water patterns include the amount of ballast water to be managed per vessel and vessel type, ballast water exchange (BWE) capacity rates per vessel type and further the donor ports relevant for RA. The data were analysed to assess (a) the number of vessels which would have been able to conduct BWE on their intended routes according to the BWM Convention, and (b) the quantity of ballast water intended for discharge (managed versus unmanaged). The RA results from the ballast water donor ports were related to each arriving vessel in order to assign a vessel-specific risk level for each ballast water discharge. 3. Results

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3.1. Ballast water discharges Approximately 10,000 vessels arrive annually to the Port of Hamburg with a diverse set of cargoes, mainly in containers. In contrast, Muuga Harbour received approximately 1500 vessels per year and various liquid cargos in bulk prevail. In Hamburg, on average, ca. 300 vessels per month discharge ballast water, whereas

Please cite this article in press as: David, M., Gollasch, S., How to approach ballast water management in European seas, Estuarine, Coastal and Shelf Science (2016), http://dx.doi.org/10.1016/j.ecss.2016.10.018

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in Muuga harbour the number is much lower, ca. 80 vessels per month. In the Port of Hamburg, more than 4 million tons, and in Muuga harbour, more than 5 million tons, of ballast water were discharged in 2012. In Hamburg, the highest number of ballast water discharges occurred in summer, with ca. 20,000 m3 being the maximum amount of ballast water discharged from a single vessel. The maximum ballast water volume discharged from a single vessel in Muuga Harbour was ca. 45,000 m3 and most discharge events occur in spring. For both ports, most ballast water donor ports were located in Europe, and donor ports outside Europe amounted to less than 5% of all ballast water discharged. Most of the few overseas donor ports were located in North and South America. The global ballast water discharge from vessels engaged in international seaborne trade was estimated as 3.1 billion tons in 2013 (David, 2015). 3.2. Risk assessment in ballast water management The detailed risk assessment (RA) developed strictly follows the BWM Convention and is the most recently prepared global BWMrelated RA (David and Gollasch, 2014). It enables a selective BWM approach according to the BWM Convention (IMO, 2004) and the IMO G7 Guidelines (IMO, 2007a) so that only those vessels carrying critical ballast water are required to conduct BWM. The risk level is a case-by-case RA result and the reliability of the RA input data is of key importance. We developed a detailed RA model for exemptions from BWM requirements and for selective BWM measures, which is ready to be used by administrations. RA can also be used to exempt vessels from BWM requirements (David and Gollasch, 2014) and Fig. 1 shows a summary of the RA. Interest in exemptions is increasing as the BWM Convention is nearing entry into force. As a case study, the RA model for exemptions was applied to intra-Baltic shipping considering the different RA methods, i.e., environmental matching, the species specific method including target species and species biogeographical aspects (see above). However, as reliable species data in the Baltic ports considered were unavailable, following the precautionary principle, no exemptions should be granted. To ensure data reliability, port baseline surveys and regular monitoring programs should be conducted during the BWM exemption period as new species introductions may influence the RA result and the exemption given may have to be revoked. The detailed RA model prepared for European Seas is considered to be of value also to other areas world-wide (David et al., 2013,2015; David and Gollasch, 2014; David et al., 2015). 3.3. Ballast water management decision support system The complex DSS process has several steps and starts with communication and data input, continues with RA, BWM decision, vessel's action(s) and ends with a monitoring and review process. During the entire decision process, information needs to be exchanged with sources from the outside (e.g., vessel, other ports) and inner sources (e.g., vessel's particulars, compliance history), making adequate communication processes and data management essential. When the required BWM measures were not conducted to the satisfaction of the port-of-call, the BWM DSS endpoints range from discharging unmanaged ballast water to cases where vessels may be turned away. The detailed step-by-step BWM DSS model (David and Gollasch, 2015a) is ready to be used by administrations and other authorities involved in BWM related decision making processes (Fig. 2). In the case of the Port of Koper, it is most likely that only vessels from outside the Adriatic Sea are enabled to conduct BWE before they call for the port and this is because a certain water depth and

distance to nearest land are required to conduct BWE, which cannot be met by intra-Adriatic shipping. The designation of a ballast water exchange area in the Adriatic Sea would open more options to conduct BWE. However, Adriatic Sea countries did not agree on the designation of a ballast water exchange area. When RA results from the ballast water donor ports were related to each vessel in order to assign a vessel-specific risk level for each ballast water discharge, a critical situation arose in cases when ballast water is assessed to pose an extreme risk. In such cases, the BWM DSS would conclude that these vessels would not be allowed to discharge unmanaged ballast water. This end point would hinder shipping when a vessel needs to discharge that extreme risk ballast water (i.e., vessel could not continue cargo operations whilst keeping ballast water on board, including a tankto-tank transfer of ballast), so this may only be achieved by using ballast water reception facilities or by applying “emergency” ballast water treatment such as the addition of chemicals. In the latter case, it needs to be shown that the discharge of chemically-treated ballast is environmentally acceptable. 4. Discussion Vessels fundamentally depend on ballast water for safe navigation and operations as a result of their design and construction. At the same time it is well known that species are transferred with ballast water and thereby become introduced into new regions. Some of these species become invasive, i.e., have substantial impacts on the ecology, economy and/or human health in the recipient region. One of the critical issues in invasion ecology is to understand and evaluate the dimensions and processes of aquatic organism transfers with vessels' ballast water. This especially refers to the number of organisms released with ballast water (propagule pressure) and the number of species introduction events (colonization pressure) (Colautti et al., 2006; Lockwood et al., 2009; Carlton et al., 2011; Briski et al., 2012a; Ruiz et al., 2013; Chan et al., 2015). An assessment of the quantity of ballast water discharged as the medium of transfer is one of the basic elements of the decision-making process in ballast water risk assessment and management. Therefore, different studies around the world estimated the quantity of ballast water discharged in selected ports (e.g., Kerr, 1994; Carlton et al., 1995; Gollasch, 1996; Perkovic et al., 2004; van Niekerk, 2008), but none of these studies were as detailed as the BWDA developed here. The possibility to assess ballast water discharges in advance of a vessel's arrival to a port enhances the management process and gives port authorities a decision supporting tool to respond quickly with adequate measures. The BWM Convention has not yet entered into force. This will happen twelve months after the date on which more than 30 States, with combined merchant fleets not less than 35% of the gross tonnage of the world's merchant shipping, have signed this Convention. As of December 2015, 47 States ratified the BWM Convention, representing 34.56% of the world merchant shipping gross tonnage, so that the BWM Convention nears its entry-intoforce limits. Until now there is no common EU ballast water policy and no legally binding BWM requirement in place in Europe. Different BWM approaches have been developed at regional levels and are of voluntary nature (HELCOM/OSPAR/REMPEC BWM approaches). However, a common and mandatory EU wide BWM approach has not yet emerged. The BWM Convention has been ratified by countries bordering the seas considered in VECTORS, i.e., Denmark, Faroe Islands, France, Germany, Morocco, the Netherlands, Norway, Russian Federation, Spain and Sweden (as of December 2015), while several other EU countries have announced

Please cite this article in press as: David, M., Gollasch, S., How to approach ballast water management in European seas, Estuarine, Coastal and Shelf Science (2016), http://dx.doi.org/10.1016/j.ecss.2016.10.018

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Fig. 1. The risk assessment (RA) approaches, showing data quality, environmental matching RA, species-specific RA, the combined RA and the decision on ballast water management (BWM) based on the risk level assessed.

that they are aiming to ratify the BWM Convention in the near future. This risk assessment (RA) developed according to the BWM Convention is the most recently agreed global RA for bioinvasions. It should be noted that even in cases where best efforts are applied and reliable data are used for RA, zero risk with a 100% confidence level is unattainable. One of the reasons is that organisms accumulate in the bottom of ballast water tanks. We found up to 50 cm deep layers of sediment in ballast water tanks in which a rich flora and fauna occurred (see also Duggan et al., 2005; Bailey et al., 2007; Briski et al., 2012b). Noting this, through time, vessels accumulate a species assemblage from all ports where the vessel called and all places where ballast water operations were undertaken. As a consequence, when a RA result is based upon the origin of the

ballast water currently on board, this may underestimate the risk as the biology in the tank sediment cannot be included in such an assessment, which complicates decision making. Here we described in detail BWM-related RA aspects. One RA, ballast water RA, is used to support different BWM actions, and the second RA is for exemptions from BWM requirements (David et al., 2015). Three RA models were prepared, one for ballast water RA, and two for RA for exemptions - one for intra-large marine ecosystems (LME) traffic exemptions and the second for extra-LME traffic BWM exemptions. The RA models were prepared according to BWM Convention and the IMO G7 and G13 Guidelines (IMO, 2004; IMO, 2007a; IMO, 2007b; David and Gollasch, 2014). Salinity was identified as a key risk-quantifier in the environmental matching RA approach. However, less environmentally-similar

Please cite this article in press as: David, M., Gollasch, S., How to approach ballast water management in European seas, Estuarine, Coastal and Shelf Science (2016), http://dx.doi.org/10.1016/j.ecss.2016.10.018

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Fig. 2. Ballast Water Management (BWM) Decision Support System (DSS) model process. BW ¼ Ballast Water, BWDA ¼ Ballast Water Discharge Assessment, PSA ¼ Port State Authority, PSC ¼ Port State Control, RA ¼ Risk Assessment. The yellow box is Situation (1) e the vessel is on the way to a port of call, BWM enabled; the orange box is Situation (2) e the vessel is on the way to a port of call or even entered the port, no BWM is enabled and the port entry permit is not yet issued; the light blue box is Situation (3) e the vessel is in the port, the port entry permit is issued; and the grey box is Situation (4) - the vessel has left port of call. (For interpretation of the references to colour in this figure legend, the reader is referred to the web version of this article.)

ports may also pose a risk should species with broad environmental tolerances be released. Species survival during a voyage, as well as the quantity and frequency of ballast water discharges which may affect the propagule pressure, were excluded in the RA model as risk factors because these elements are species-specific, and there is not enough knowledge available to quantify these. In addition, Ruiz et al. (2013) concluded that there was no relationship between the quantity and frequency of ballast water discharges of foreign vessels with the number of introduced ballast water mediated species in 16 large bays in the United States. Therefore, knowledge about the quantity and frequency of ballast water alone does not allow for a proper RA, but the origin of the ballast water becomes a key feature for examining the environmental similarity of the ballast water donor and recipient regions. The BWDA model we developed addresses this issue. Data reliability was found to be crucial to conduct a RA, which is in line with the precautionary approach when RA relates to environmental and human health

protection. For the RA for exemptions case studies, the intra-LME RA model was applied to different shipping routes of which three are in intraBaltic shipping. In addition the extra-LME RA model was applied to a route that connects Baltic ports with one port in the North Sea (David and Gollasch, 2014). The intra-LME approach has a more complex salinity regime. Both models further consider human pathogens, the abundance of species, whether or not organisms can naturally spread from the ballast water donor to the recipient port, and presence of species under a control or eradication program in the ballast water recipient port. To compare the presence, absence and overlap of target species, harmful algae, and outbreak forming species in the selected ports, the HELCOM/HOLAS lists of nonindigenous and cryptogenic species (HELCOM, 2009) were considered and updated with AquaNIS data. The HELCOM/HOLAS list of non-indigenous species provides data on a regional basis, i.e., it is not port specific. These data are not reliable enough as they do not show the true species diversity in the selected ports. Thus the results presented are hypothetical and we therefore could not recommend granting any exemption from BWM requirements for any of these routes. However, without the HELCOM/HOLAS and AquaNIS species lists, not even a hypothetical RA would have been possible. This highlights the need for fine-scale knowledge about species in ports. To ensure availability of reliable data, port baseline surveys should be undertaken, and monitoring programs need to be established. When undertaking port baselines surveys, a harmonized approach for sampling and standard protocols are needed so that all studies generate reliable and comparable results, e.g., comparable data for Baltic and Adriatic Seas. In this harmonisation process the frequency of studies, the habitats to be included, i.e., plankton, benthos, fouling, the number of sampling stations, and the availability of taxonomic expertise would need to be considered. As additional species may be introduced over time that may influence a RA result, a regular monitoring program needs to be established. As recommended by the BWM Convention, international and/or regional cooperation is essential in RA-based BWM requirements. This is to ensure that a harmonized approach is implemented; this is of particular importance in regional seas with many jurisdictions bordering the coastline of one sea. The RA models developed here may be of value in many other areas worldwide, and if needed, they may be adapted to address different local specifics. The DSS approach has been introduced in the BWM field and the need primarily arose with the introduction of the selective BWM approach. More precisely, it was recognised that a supporting tool was needed to aid transparency and consistency when deciding on BWM requirements to achieve better environmental protection and to lessen the burden on vessels. The RA and BWM DSS approaches presented here have incorporated the main principles of the EU instruments regarding alien species (EU, 2007,2014) and BWM to implement the BWM Convention requirements with EU specifics. BWM by default calls for a concerted regional approach because no country would like to disadvantage its ports economically by introducing mandatory BWM requirements of ships unilaterally. Furthermore, from a biological perspective, it makes no sense if one country implements BWM measures to avoid species introductions when a neighbouring State does not, since after the introduction, species tend to migrate by natural means and eventually also reach neighbouring jurisdictions. As the BWM Convention has not entered into force yet, different BWM approaches have developed world-wide. All jurisdictions along the European seas are engaged in the development of regional BWM approaches and requirements. The first European regional, voluntary requirement of BWE on certain shipping routes

Please cite this article in press as: David, M., Gollasch, S., How to approach ballast water management in European seas, Estuarine, Coastal and Shelf Science (2016), http://dx.doi.org/10.1016/j.ecss.2016.10.018

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is the HELCOM/OSPAR approach, which has been in force since April 1st, 2008 (HELCOM, 2008). Shortly thereafter, REMPEC developed a BWE approach for vessels entering the Mediterranean Sea (REMPEC, 2010). Legally binding, national BWM requirements in or near Europe were developed in Croatia, Bulgaria, Georgia, the Russian Federation, Turkey and Ukraine (Lloyd’s Register, 2011; David and Gollasch, 2014). In other European countries BWM requirements are currently developing. Many of these BWM requirements are focussed on BWE as a BWM tool. However, this is seen as an interim solution only because scientific studies have shown its limited effectiveness. In addition, the water depth and distance from shore requirements for BWE as set forth in the BWM Convention cannot be met in many European seas at all or only in areas too small to enable a complete BWE (David and Gollasch, 2008). Therefore, some countries started to designate BWE areas only to prohibit vessels from “doing nothing”. Problems may also occur when planning to identify appropriate ballast water exchange areas because the BWE requirement may expose adjacent seas or jurisdictions to additional ballast water discharges. This conflict of interest between countries may only be solved by the development of a pan-European BWM approach. As outlined above this was in part realised by the cooperation of OSPAR and HELCOM and in the Mediterranean Sea by REMPEC activities regarding BWM. The shortcomings of BWE highlight the need for use of ballast water management systems (BWMS). Shipowners should be encouraged to adopt a proactive approach and to install and operate BWMS routinely, even before the BWM Convention enters into force. However, recent developments at IMO do not appear to be stimulating this process. The timeline for requiring ships to meet the D-2 standard, which basically forms the grounds for using BWMS, has been postponed, and now some vessels may continue with BWE until 2021 (IMO, 2014).

5. Conclusions All measures reducing the risks of species transfers, including BWE, are seen as essential tools to protect the seas, oceans and coastal waters world-wide from new harmful species introductions. The implementation of mandatory BWE requirements may trigger additional countries to ratify the BWM Convention, and with this, support the timely implementation of the D-2 standard. In principle, this will eventually result in a phasing out of BWE to achieve better protection from new harmful species introductions. The following final recommendations to approach the BWM issue in Europe may also be applicable world-wide:  EU countries should ratify the BWM Convention, which would result in meeting the entry-into-force criteria of the BWM Convention;  Routine operation of BWMS, even before the BWM Convention enters into force;  The ballast water issue should be addressed on a pan-European scale to avoid different BWM requirements in different European seas because regionally varying BWM approaches would complicate shipping;  For regional seas (or wider geographic coverage), a common cross-border BWM RA and DSS approach should be established to lessen the burden on vessels and to maximise the efficiency of required BWM measures;  The BWM DSS would need to be applied as an electronic system to allow fast and accurate reporting from vessels, exchange of information among countries' authorities and vessels, and provide fast and accurate decisions on BWM requirements;

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 EMSA as the responsible EU body may support and coordinate the implementation of a EU-wide BWM approach;  It is recommended to use the BWM RA and DSS presented here, which strictly follow the provisions of the BWM Convention and its supporting guidelines, considering also the EU specifics;  Non-EU countries which are bordering European seas should be encouraged to become engaged in the implementation of common EU BWM requirements, i.e., as a pan-European application. Acknowledgements The research leading to these results has received funding from the European Union's Seventh Framework Programme for research, technological development and demonstration (FP7/2007-2013) within the Ocean of Tomorrow call under Grant Agreement No.266445 for the project Vectors of Change in Oceans and Seas Marine Life, Impact on Economic Sectors (VECTORS). We like to thank Sarah Bailey (Fisheries and Oceans Canada, Great Lakes Laboratory for Fisheries and Aquatic Sciences, Burlington, Canada) for language editing and constructive comments on this manuscript. References Bailey, S.A., Duggan, I.C., Nandakumar, K., MacIsaac, H.J., 2007. Sediments in ships: biota as biological contaminants. Aquat. Ecosyst. Health Manag. 10, 93e100. Bleich, S., 2006. Messung der b-Diversit€ at entlang eines Salzgehaltsgradienten €nosen der Ostsee. Master of Science Thesis. anhand von Makrozoobenthoszo Universit€ at Rostock, Rotock. Briski, E., Bailey, S.A., Casas-Monroy, O., DiBacco, C., Kaczmarska, I., Levings, C., MacGillivary, M.L., McKindsey, C.W., Nasmith, L.E., Parenteau, M., Piercey, G.E., Rochon, A., Roy, S., Simard, N., Villac, M.C., Weise, A.M., MacIsaac, H.J., 2012a. Relationship between propagule pressure and colonization pressure in invasion ecology: a test with ships' ballast. Proc. R. Soc. B e Biol. Sci. 279, 2990e2997. http://dx.doi.org/10.1098/rspb.2011.2671. Briski, E., Ghabooli, S., Bailey, S.A., MacIsaac, H.J., 2012b. Invasion risk posed by macroinvertebrates transported in ships' ballast tanks. Biol. Invasions 14, 1843e1850. Carlton, J.T., 1985. Transoceanic and interoceanic dispersal of coastal marine organisms: the biology of ballast water. Ann. Rev. Oceanogr. Mar. Biol. 23, 313e374. Carlton, J.T., Reid, D.M., van Leeuwen, H., 1995. Shipping study: the role of shipping in the introduction of non-indigenous aquatic organisms to the coastal waters of the United States (others than the Great Lakes) and an analysis of control options. Natl. Sea Grant Coll. Programme/CT Sea Grant Proj. R/ES 6. Carlton, J.T., Ruiz, G.M., Byers, J.E., Cangelosi, A., Dobbs, F.C., Grosholz, E.D., Leung, B., MacIsaac, H., Wonham, M.J., 2011. Assessing the relationship between propagule pressure and invasion risk in ballast water. Committee on assessing numeric limits for living organisms in ballast water, water science and technology board, division on earth and life studies. National Research Council. The National Academies Press, Washington, 123 pp. Casale, G.A., 2002. Ballast Water e a Public Health Issue? GloBallast Programme. IMO, London. Ballast Water News. Issue 8. Chan, F.T., Bradie, J., Briski, E., Bailey, S.A., Simard, N., MacIsaac, H.J., 2015. Assessing introduction risk using species' rank-abundance distributions. Proc. R. Soc. B 282 (20141517). http://dx.doi.org/10.1098/rspb.2014.1517. Colautti, R.I., Grigorovich, I.A., MacIsaac, H.J., 2006. Propagule pressure: a null model for biological invasions. Biol. Inv. 8, 1023e1037. http://dx.doi.org/10.1007/ s10530-005-3735-y. Coutts, A.D.M., Dodgshun, T.J., 2007. The nature and extent of organisms in vessel sea-chests: a protected mechanism for bioinvasions. Mar. Pollut. Bull. 54 (7), 875e886. http://dx.doi.org/10.1016/j.marpolbul.2007.03.011. David, D., Gollasch, S., Penko, L., 2016. Identification of Port Ballast Water Discharges Profiles to Support Effective Ballast Water Management submitted for publication. David, M., 2007. A Decision Support System Model for Ballast Water Management of Vessels. Dissertation. University of Ljubljana, Ljubljana, Slovenia, 271 pp. David, M., 2015. Vessels and Ballast Water. pp. 13-34. In: David, M., Gollasch, S. (Eds.), Global Maritime Transport and Ballast Water Management e Issues and Solutions. Invading Nature. Springer Series in Invasion Ecology 8, Springer ScienceþBusiness Media, Dordrecht, The Netherlands, p. 306. http://dx.doi.org/ 10.1007/978-94-017-9367-4_2. David, M., Gollasch, S., 2008. EU shipping in the dawn of managing the ballast water issue. Mar. Pollut. Bull. 56 (12), 1966e1972. David, M., Gollasch, S., 2014. Review of Ballast Water Discharge Risk Assessment Tools, and New Decision Support Systems for EU Ports to Avoid Aquatic Species

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Please cite this article in press as: David, M., Gollasch, S., How to approach ballast water management in European seas, Estuarine, Coastal and Shelf Science (2016), http://dx.doi.org/10.1016/j.ecss.2016.10.018