Development of Tools for Integrated Monitoring and Assessment of Hazardous Substances and Their Biological Effects in the Baltic Sea

The “BonusHAZ” database forms, to date, the most comprehensive data collection on biological effects of hazardous substances in the Baltic Sea region, consist of 60 different parameters for more than 600 single specimens of different fish and invertebrate species in different subregions of the Baltic Sea. As of 2010, BEAST has a formal arrangement with ICES to use their database code lists (RECO), and the “BonusHAZ” is planned to become available in public domain at a later stage.

With the new database and along with information from various national initiatives and monitoring activities in the Baltic Sea countries as well as improved scientific understanding of cause-and-effect relationships, sufficient data are now available and used to develop Baltic Sea-specific assessment criteria for biological effects of contaminants. In fact, this is a prerequisite for including any method in a monitoring program. A set of specific biological effects indicators tailored for the Baltic Sea has now been selected, based on knowledge obtained during scientific research in the area, e.g., within the BEEP, BEAST, and BALCOFISH projects, as well as from the work performed in relevant ICES and OSPAR expert groups.

The chosen core indicators listed below describe either effects caused by mixtures of contaminants or specific contaminants. They also indicate adverse effects at different biological levels, i.e., molecular/biochemical/cellular (“early warning”) or individual/population (health and reproductive impairments) levels. For these indicators, cause–effect relationships have been studied, and assessment criteria have been established. Furthermore, being important for method of harmonization across the sea areas of Europe, these are the established methods recommended by ICES expert groups, and many have already been included in other regional monitoring programs, e.g., under OSPAR and MEDPOL, or in national monitoring programs (Denmark, Sweden, and/or Germany). The recommended core methods are:In addition, two contaminant-specific biological effects indicators, imposex in marine prosobranch gastropods and PAH metabolites in fish, have been included as part of the core indicators for TBT and PAH, respectively. Finally, a few methods have been placed in the candidate list, including intersex or vitellogenin induction in male fish (endocrine disruption), acetylcholinesterase activity (neurotoxicity), and ethoxyresorufin-O-deethylase activity (biotransformation).

The future application of biological effects indicators in a combined monitoring strategy strengthens the assessment of contaminants that are approaching critical concentration levels giving rise to pollution effects in the Baltic Sea. Inclusion of biological effects indicators into the HELCOM Cooperative Monitoring in the Baltic Marine Environment (COMBINE) program in the future also allows for the detection of combined effects of complex mixtures of hazardous substances, which is the norm for most sea areas. In using only contaminant-specific effect methods, such as imposex in prosobranch gastropods or PAH metabolites in fish, a much larger number of indicators would have to be applied to cover the effects of all relevant groups of hazardous substances present in the marine environment. In addition, most of them would still be neglected since some of the process-related chemicals released to the Baltic Sea are presently unidentified. Effect indicators with a wider detection spectrum pinpoint the need for further investigations to identify the chemicals causing the effects observed. Besides fulfilling the requirement of the Baltic Sea Action Plan (BSAP), inclusion of core indicators of biological effects into the HELCOM COMBINE program will be an important step toward harmonization of environmental assessments of different sea areas in Europe; eventually, this will allow for comparisons on larger scales and, thus, implementing important main goals of the MSFD.

At present, various methodologies are either available or under development to monitor and assess pollution effects and ecosystem health in marine and coastal waters. Integrated indices and similar approaches (e.g., multivariate approaches, expert systems, and decision support systems) based on the measurement of a set of biomarkers have recently been developed and applied in the North Sea, the Northeast Atlantic, and the Mediterranean Sea (Cajaraville et al. 2000; Beliaeff and Burgeot 2002; Moore et al. 2004; Broeg and Lehtonen 2006; Dagnino et al. 2007; Viarengo et al. 2007; Hagger et al. 2009; Marigómez et al. 2013). During BEAST, feasibility of application of these approaches for integrated assessment between contaminant levels, different biomarkers, and/or species was explored (Höher et al. 2012; Dabrowska et al. 2012, 2013; Turja et al. in press). These studies showed different patterns in biological responses between the more- and less-contaminated sites, often also with discrimination between effects caused by contaminants and salinity.

One example of the data integration methods was the application of the Integrated Biomarker Assessment Tool (IBAT), developed jointly by BEAST and BALCOFISH, and tested on eelpout (Strand et al. unpublished data). The IBAT tool allows for comparisons of input data for the measured biological effect parameters for which assessment criteria have been developed, and an overall Integrated Biomarker Assessment Score (IBAS) can thus be calculated. IBAS includes weighted score values depending on the biological response level of the respective effects, and therefore, considers the biological significance of the effects observed, i.e., subcellular (Score 1), cellular/tissue (Score 2), or whole organism responses (Score 3). IBAS summarizes all weighted scores by the formula IBAS = (Σ X)/(sqrt n), which follows the principles of the indicator-based integrative assessment tool CHASE, developed during the HELCOM Integrated Thematic Assessment of Hazardous Substances in the Baltic Sea (HELCOM 2010). CHASE has been used to integrate the status of contamination by individual chemicals and biological effects at specific sites or areas into a single status value termed “contamination ratio.” The assessment of the IBAS value follows the “traffic light” assessment scale as applied in the CHASE tool, i.e., <1 (low impact), 1 to <5 (moderate impact), and >5 (high impact). Subsequently, IBAT has the potential to be incorporated as an improvement into the CHASE tool for future assessments. IBAS also has the potential to be used for a single-species health index if enough data for relevant biological effect indicators are available, or for several species as an integrative measure for the all the observed biological effects in a particular area.

An example of the use of IBAT is given in Fig. 1, showing the outcome of a study on eelpout in selected coastal areas in Denmark. The IBAS indicates a relatively high impact of pollution in eelpout at two of the stations investigated, whereas at two others, the impact is moderate. Only at one station, a low impact of pollution is indicated. Considering the available information on contaminant levels at the respective stations, the impact levels of pollution in eelpout defined by IBAT are considered feasible.

The integration of several effect biomarkers measured at different levels of biological organization up to the level of reproduction has been a further challenge with respect to incorporating all information into an integrated assessment and to provide a science-based “traffic light” score. Thus, IBAT has been developed based on data from all biological effects indicators, and it can be used to perform an overall assessment of risk level for pollution effects at a specific location. The application of the integrated pollution–response model and the use of a decision support system for the ranking of responses from the cellular to the reproduction level in amphipods have proven to be promising approaches (Löf et al. in prep.).

Another example of integrated approaches performed under BEAST is given in Fig. 2. Biological effects data obtained from females of herring collected from all the studied subregions were fed into a simple algorithm set-up, the Integrated Biomarker Response (IBR) (Beliaeff and Burgeot 2002; Broeg and Lehtonen 2006). The results of the IBR approach demonstrate the value of integrated methods in describing the combined environmental stress experienced by organisms at different field sites in relation to each other.

The implementation of guidelines and standard operating procedures is a fundamental quality assurance requirement for monitoring and assessment. Although guidelines for many biological effects techniques already exist (largely developed by ICES), they often lack coherence and do not sufficiently address the specific environmental conditions of the Baltic Sea. Therefore, it was necessary to develop specific guidelines and standard operating procedures for those biological effects techniques identified by BEAST as being useful for the Baltic Sea. Guidelines and instructions generated were subsequently transferred to draft standard operating procedures, focusing on the core and candidate indicators identified by HELCOM CORESET (Table 3). These standard operating procedures will be published once the results of the present revision of HELCOM’s monitoring program with regard to indicators for future monitoring and the structure of the monitoring guidelines become available. It is envisaged that standard operating procedures for other techniques applied and assessed in the BEAST project will be developed at a later stage. Further research is needed to integrate the BEAST draft standard operating procedures with those on chemical measurements that are partly existing (e.g., under HELCOM COMBINE) or are currently under development. The preparation of the guidelines and standard operating procedures can be considered as a major milestone for the implementation of a quality-assured integrated monitoring and assessment program for the Baltic Sea that will meet the goals and ecological objectives of HELCOM BSAP and EU MSFD in relation to hazardous substances.

Training of personnel and intercalibration of methodologies applied in research and monitoring are essential for their implementation in joint monitoring and assessment programs. Together with the establishment and use of guidelines and standard operating procedures they form the essential components of quality assurance. The importance of quality assurance, especially in international monitoring programs with contributions from several national institutes/laboratories into a common data pool, has been clearly recognized.

Aspects covered during BEAST intercalibration and training exercises included sampling of biotic and abiotic matrices, processing and conservation of samples, on board examination of the health status of organisms, laboratory-based analysis of samples, and data treatment (Table 4). While intercalibration was mainly meant as an internal process (involving BEAST, and, partly, BALCOFISH partners) to improve the comparability of results, many of the workshops arranged were open to both project partners and external interested colleagues, e.g., the intercalibration of PAH metabolite measurement in fish bile attracted several non-BEAST specialist laboratories from the OSPAR area (Kammann et al. 2013).

Overall, the BEAST training/intercalibration activities contributed to the enhancing of quality assurance, capacity building, and networking in the Baltic Sea region. It is emphasized that internal and external training and intercalibration have to be understood as dynamic processes that need to be carried out on a continuous basis as an important part of marine monitoring and assessment. It is, thus, essential that the revised HELCOM COMBINE program (as well as the future monitoring under the MSFD) encompasses an operative quality assurance component.