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A large part of oil spills happen near busy marine fairways. Presently, oil spill detection and monitoring are mostly done with satellite remote sensing algorithms, or with remote sensors or visual surveillance from aerial vehicles or ships. These techniques have their drawbacks and limitations. We evaluated the feasibility of using fluorometric sensors in flow-through systems for real-time detection of oil spills. The sensors were capable of detecting diesel oil for at least 20 days in laboratory conditions, but the presence of CDOM, turbidity and algae-derived substances substantially affected the detection capabilities. Algae extract was observed to have the strongest effect on the fluorescence signal, enhancing the signal in all combinations of sensors and solutions. The sensors were then integrated to a FerryBox system and a moored SmartBuoy. The field tests support the results of the laboratory experiments, namely that the primary source of the measured variation was the presence of interference compounds. The 2 month experiments data did not reveal peaks indicative of oil spills. Both autonomous systems worked well, providing real-time data. The main uncertainty is how the sensors' calibration and specificity to oil, and the measurement depth, affects oil detection. We recommend exploring mathematical approaches and more advanced sensors to correct for natural interferences.

Hydrogen sulfide (H2S) is linked to water quality deterioration in the Baltic Sea, with widespread seafloor hypoxia. We examined the vertical and temporal variability of in situ [H2S], oxygen concentration ([O2]), temperature (T) and pH at weekly, hourly and minute intervals at 13 locations in the western Gulf of Finland in 2013–2014. The main target was the 60–100 m water depth range, containing 3.2–290 μM O2 and 6.3–22.6 μM H2S. Where gas was detected by acoustic surveys, the structure of the H2S layer was more complex compared to stations devoid of gas. Local minima and maxima in pH frequently occurred near the H2S upper boundary (redox transition zone). Except for the homogeneous, tranquil zone above the seafloor at some stations, substantial rapid changes in hydrographic conditions were common. Typically, a layer of marked temporal T variability was present atop or within the topmost H2S layers. The largest temporal changes over a weekly period were − 0.44 °C/− 10.8 μM H2S/− 0.12 pH units (at seafloor level), + 0.18 °C/+7.9 μM H2S between casts (1 h) and + 0.03 °C/− 2.5 μM H2S per minute (high resolution logging). Abrupt [H2S] changes were recorded at two stations with sediments containing free gas. The T and [H2S] changes were synchronous at several layers, reflecting water movement. We conclude that rapid changes occur in hydrographic conditions in the near-bottom H2S layer in the northern Baltic Sea, especially at locations where free gas is present in the underlying sediments.

This article introduces the EU Horizon 2020 research project GRACE (Integrated oil spill response actions and environmental effects), which focuses on a holistic approach towards investigating and understanding the hazardous impact of oil spills and the environmental impacts and benefits of a suite of marine oil spill response technologies in the cold climate and ice-infested areas of the North Atlantic and the Baltic Sea. The response methods considered include mechanical collection in water and below ice, in situ burning, use of chemical dispersants, natural biodegradation, and combinations of these. The impacts of naturally and chemically dispersed oil, residues resulting from in situ burning,and non-collected oil on fish, invertebrates (e.g. mussels, crustaceans) and macro-algae are assessed by using highly sensitive biomarker methods, and specific methods for the rapid detection of the effects of oil pollution on biota are developed. By observing, monitoring and predicting oil movements in the sea through the use of novel online sensors on vessels, fixed platforms including gliders and the so-called SmartBuoys together with real-time data transfer into operational systems that help to improve the information on the location of the oil spill, situational awareness of oil spill response can be improved. Methods and findings of the project are integrated into a strategic net environmental benefit analysis tool (environment and oil spill response, EOS) for oil spill response strategy decision making in cold climates and ice-infested areas. © The Author(s) 2019. This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/)

Active sedimentation is one of the distinguishing characteristics of the Baltic Sea. This has led to the formation of fractally-distributed soft sediment deposits (muds) that can be up to several meters thick. In this study we examined, for the first time, stability of soft sediment deposits within a 3 km 2 -sized sedimentary basin in the northern Baltic Sea (Eastern Archipelago Sea, Finland) using acoustic profiling (28 kHz and 3.5 kHz) and 200 kHz multibeam surveys, on three occasions from 2011 to 2013. Sub-bottom profile data and rasterized deposit thickness data revealed maximal annual thickness changes between − 1.1 m erosion or + 1.1 m deposition along primary survey lines, and skimming of up to 9% of the soft deposit area. The most notable finding was the significant instability of mud. When examined at local scale there was substantial and very localized erosion and deposition (apparent horizontal movement of unconsolidated mud 250–400 m per year) between 2012 and 2013. Maximum relocation of unconsolidated deposits was approximately 0.3 km 3 a − 1 with 94% export to the exterior area (2011–2012), and was likely affected by abnormally high wave action in the northern Baltic Sea during the period of observation. The combination of acoustic and mathematical techniques is shown to be highly suited to examination of temporal variations in sub-bottom level environments.

A saxitoxin (STX) proficiency test (PT) was organized as part of the Establishment of Quality Assurance for the Detection of Biological Toxins of Potential Bioterrorism Risk (EQuATox) project. The aim of this PT was to provide an evaluation of existing methods and the European laboratories' capabilities for the analysis of STX and some of its analogues in real samples. Homogenized mussel material and algal cell materials containing paralytic shellfish poisoning (PSP) toxins were produced as reference sample matrices. The reference material was characterized using various analytical methods. Acidified algal extract samples at two concentration levels were prepared from a bulk culture of PSP toxins producing dinoflagellate Alexandrium ostenfeldii. The homogeneity and stability of the prepared PT samples were studied and found to be fit-for-purpose. Thereafter, eight STX PT samples were sent to ten participating laboratories from eight countries. The PT offered the participating laboratories the possibility to assess their performance regarding the qualitative and quantitative detection of PSP toxins. Various techniques such as official Association of Official Analytical Chemists (AOAC) methods, immunoassays, and liquid chromatography-mass spectrometry were used for sample analyses.

The Gulf of Riga, river Daugava and several interconnected lakes around the City of Riga, Latvia, form a dynamic brackish-freshwater system favouring occurrence of toxic cyanobacteria. We examined bioaccumulation of microcystins and nodularin-R in aquatic organisms in Latvian lakes, the Gulf of Riga and west coast of open Baltic Sea in 2002–2007. The freshwater unionids accumulated toxins efficiently, followed by snails. In contrast, Dreissena polymorpha and most lake fishes (except roach) accumulated much less hepatotoxins. Significant nodularin-R concentrations were detected also in marine clams and flounders. No transfer of nodularin-R and microcystins between lake and brackish water systems took place. Lake mussels can transfer hepatotoxins to higher organisms, and also effectively remove toxins from the water column. Obvious health risks to aquatic organisms and humans are discussed.

Nodularin (NOD) is a cyclic penta-peptide hepatotoxin mainly produced by Nodularia spumigena, reported from the brackish water bodies of various parts of the world. It can accumulate in the food chain and, for safety reasons, levels of NOD not only in water bodies but also in food matrices are of interest. Here, we report on a non-competitive immunoassay for the specific detection of NOD. A phage display technique was utilized to interrogate a synthetic antibody phage library for binders recognizing NOD bound to an anti-ADDA (3-Amino-9-methoxy-2,6,8-trimethyl-10-phenyldeca-4(E),6(E)-dienoic acid) monoclonal antibody (Mab). One of the obtained immunocomplex binders, designated SA32C11, showed very high specificity towards nodularin-R (NOD-R) over to the tested 10 different microcystins (microcystin-LR, -dmLR, -RR, -dmRR, -YR, -LY, -LF, -LW, -LA, -WR). It was expressed in Escherichia coli as a single chain antibody fragment (scFv) fusion protein and used to establish a time-resolved fluorometry-based assay in combination with the anti-ADDA Mab. The detection limit (blank + 3SD) of the immunoassay, with a total assay time of 1 h 10 min, is 0.03 µg/L of NOD-R. This represents the most sensitive immunoassay method for the specific detection of NOD reported so far. The assay was tested for its performance to detect NOD using spiked (0.1 to 3 µg/L of NOD-R) water samples including brackish sea and coastal water and the recovery ranged from 79 to 127%. Furthermore, a panel of environmental samples, including water from different sources, fish and other marine tissue specimens, were analyzed for NOD using the assay. The assay has potential as a rapid screening tool for the analysis of a large number of water samples for the presence of NOD. It can also find applications in the analysis of the bioaccumulation of NOD in marine organisms and in the food chain.

The Baltic Sea suffers from extensive blooms of the toxic cyanobacteria Nodularia spumigena that produces nodularin toxin (NOD). Additionally, intensification of oil transportation and related activities in the area increase the risk of oil spills. The current experiment was designed to mimic a situation where an oil spill occurs during a cyanobacterial bloom by exposing the amphipod Gammarus oceanicus to a NOD-rich cyanobacterial extract and the polycyclic aromatic hydrocarbon compound benzo[a]pyrene (B[a]P), a common constituent of oil. The activity of the antioxidant enzymes glutathione S-transferase (GST), glutathione peroxidase (GPx), catalase (CAT) and superoxide dismutase (SOD) were examined after 48 and 96 h of exposure. Exposure to low and high levels of the NOD-rich extract produced a time-dependent activation of GST, GPx and SOD. CAT levels were elevated only by high NOD treatment. Also the toxicity of B[a]P was indicated by significantly elevated antioxidant response. In the combined exposures treatment-dependent additive increases in the activity of GPx and SOD were observed as well as inhibitory (antagonistic) effects on GST, CAT and GPx. Rapid concentration-dependent accumulation of NOD by G. oceanicus was observed. The addition of B[a]P reduced the accumulation of NOD and resulted in different biomarker response patterns compared to single exposures demonstrating the effects of mixture toxicity.

The concentrations of per- and polyfluoroalkyl substances (PFASs) in the Finnish aquatic environment were measured in riverine waters and in inland, coastal and open sea fish. In addition, the PFAS load to the Baltic Sea from 11 rivers was calculated. Measurements show that PFASs, including restricted perfluorooctane sulfonic acid (PFOS), are widely present in the Finnish aquatic environment. At three out of 45 sampling sites, the concentration of PFOS in fish exceeded the environmental quality standard (EQS) of the Water Framework Directive (WFD). The annual average (AA) &sum, 23PFAS concentration in surface waters ranged from 1.8 to 42 ng L&minus, 1 and the concentration of PFOS exceeded the AA-EQS in three out of 13 water bodies. In European perch (Perca fluviatilis) and Baltic herring (Clupea harengus membras), the &sum, PFAS concentration ranged from 0.98 to 1 &micro, g kg&minus, 1 f.w. (fresh weight) and from 0.2 to 2.4 &micro, 1 f.w., respectively. The highest concentrations in both surface water and fish were found in waters of southern Finland. The riverine export of &sum, 10PFAS to the Baltic Sea from individual rivers ranged from 0.4 kg yr&minus, 1 to 18 kg yr&minus, 1. PFAS concentrations in fish of point-source-polluted sites and coastal sites were higher compared to fish of open sea or diffusely polluted sites. The PFAS profiles in surface waters of background sites were different from other sites. This study shows that PFASs are widely found in the Finnish aquatic environment. Different PFAS profiles in samples from background areas and densely populated areas indicate diverse sources of PFASs. Although atmospheric deposition has a substantial influence on PFAS occurrence in remote areas, it is not the dominant source of all PFASs to the aquatic environment of Finland. Rather, wastewaters and presumably contaminated land areas are major sources of PFASs to this aquatic environment.

Sediment trap material was collected during May-December in the period 1996-2008 in three coastal areas and four open sea stations in the Finnish territory of the Baltic Sea. The highest sedimentation of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) with a typical source-related congener profile from chlorophenol production dominated by highly chlorinated dibenzofurans was found close to a historical source in the Kymijoki estuary. This was an order of magnitude higher than in other river estuaries and two orders of magnitude higher than in the open sea stations. The sedimentation of polychlorinated biphenyls (PCBs) was also higher in river estuaries than in other areas. No significant decrease over a 12 year period of monitoring was found in concentration or in sedimentation in the Kymijoki estuary. In the western Gulf of Finland, the Archipelago Sea and the Gulf of Bothnia, the dominating congeners, calculated as toxic equivalent (TEQ) in sedimentation were 1, 2, 3, 7, 8-PeCDD and 2, 3, 4, 7, 8-PeCDF, often reported as the main congeners in deposition.

A B S T R A C T In the past years, some coastal areas in the central and northern Baltic Sea have experienced recurrent blooms of the potentially toxic dinoflagellate Alexandrium ostenfeldii. The population dynamics and spatial distribution of the species were studied in the Fogloarchipelago, a bloom area in Aland, northern Baltic Sea. During a two-year survey, cell and toxin concentrations of A. ostenfeldii were recorded in summer phytoplankton communities and related to environmental parameters. The studies revealed that A. ostenfeldii blooms were restricted to a small area in a narrow sound, where cells of this species were detected from May to September in 2009 and 2010. A. ostenfeldii proliferated to bloom concentrations (1.7-2.1 � 10 5 cells L � 1 ) only at water temperatures around 20 8C during warm periods in July and August. Abundance of A. ostenfeldii did not significantly correlate with dissolved inorganic nutrient concentrations (p = 0.4-0.6) but was related to high concentrations of resting cysts in the sediment (p < 0.001). The blooms were not monospecific but A. ostenfeldii was a part of a diverse productive phytoplankton community forming 30-60% of the total biomass during the abundance peaks. This study provides the first evidence of paralytic shellfish poisoning (PSP) toxins produced by dinoflagellate blooms in the Baltic Sea: PSP toxin dynamics correlated with the progression of the A. ostenfeldii bloom with toxin peaks mirroring the species abundance peaks. No other potentially toxic species were identified from the phytoplankton community. PSP toxin concentrations of up to 2.3 mg L � 1 measured in the A. ostenfeldii cell fraction suggest that blooms may have toxic effects on co-occurring biota.

Concentrations of the very long-lived fission product 129 I and stable iodine ( 127 I) in the Baltic Sea and lake and rain waters from Finland, were measured as well as their occurrence as iodide (I − ) and iodate (IO 3 − ). The highest concentrations of both 127 I and 129 I occurred in sea water, on average 11.1 ± 4.3 μg/l and 3.9 ± 4.1 × 10 − 9 at/l. In rain and lake waters the concentration of 129 I was more or less identical and almost one order of magnitude lower than in sea water. Based on these observations, and data from the literature, it is assumed that the source of 129 I in lakes is precipitation and the major source in the Baltic Sea is the inflow of sea water from the North Sea through the Danish Straits. The concentration of 129 I in the Baltic Sea has increased by a factor of six during ten years from 1999. In all studied water types the main chemical form of both iodine isotopes was iodide; in sea and lake waters by 92–96% and in rain water by 75–88%. Compared to 127 I the fraction of iodide was slightly higher in case of 129 I in all waters.

The Baltic Sea is a large, shallow, and strongly stratified brackish water basin. It suffers from eutrophication, toxic cyanobacterial blooms, and oxygen depletion, all of which pose a threat to local marine communities. In this study, the diversity and community structure of the northern Baltic Sea bacterial communities in the water column were, for the first time, thoroughly studied by 454 sequencing. The spring and autumn bacterial communities were one order of magnitude less diverse than those in recently studied oceanic habitats. Patchiness and strong stratification were clearly detectable

The phenomenon of cyanobacterial blooms in the Baltic Sea is getting very common during the last few years. These blooms mostly consist of Nodularia species which can be toxic, producing nodularins. As some of these blooms are wind driven to the coastline, an influence of the aquatic flora, especially on the macroalgae is expected. One of these common macroalgae is the red alga Furcellaria lumbricalis, living on hard bottom substrates in the lower part of the phytobenthic zone. Uptake of nodularin into red alga the generation of oxidative stress, respectively the antioxidative response is shown measuring the activity of several antioxidative enzymes. The uptake of nodularins by the red alga is shown. The toxins caused oxidative stress in the algae and induced an antioxidative defence.

In the Baltic Sea regular, intensive cyanobacterial blooms rich in the cyanobacterium Nodularia spumigena occur during the summer season. N. spumigena is known to produce the cyclic pentapeptide nodularin (NOD) in high concentrations. Marine macroalgae, together with sea-grass meadows, are an extremely important habitat for life in the sea. In addition to this, the decaying macroalgae substantially contribute to the substrate for the microbial loop in coastal food webs. Uptake of nodularin into the brown macroalga Fucus vesiculosus was assessed using an ELISA technique resulting in an uptake of up to 45.1 microg kg(-1) fresh weight (fw). Nodularin was also detected in the reproductive part of the algae (receptacle) at 14.1 microg kg(-1) fw. The induction of oxidative stress in F. vesiculosus, after exposure to NOD, was also shown by monitoring cellular damage as changes in lipid peroxidation and the activation of antioxidative defence systems (antioxidative capacity, superoxide dismutase and soluble glutathione S-transferase).

Blue mussels (Mytilus edulis) were exposed to an extract made of natural cyanobacterial mixture containing toxic cyanobacterium Nodularia spumigena (70-110 microg nodularin l(-1), 24-h exposure followed by 144-h depuration period in clean water). Toxin concentration increased from initial 400 to 1100 mg kg(-1) after 24-h exposure, measured by liquid chromatography/mass spectrometry (LC/MS). Acetylcholinesterase activity (AChE), a biomarker of direct neurotoxic effects, showed inhibition after 12 and 24h exposure but returned to control level during the depuration period. Catalase (CAT) activity, an indicator of oxidative stress, showed significantly elevated levels in exposed mussels but only 72 h after the end of the exposure. No change in the activity of glutathione-S-transferase (GST) involved in conjugation reactions could be observed. A gradual yet incomplete elimination of nodularin (from 1100 to 600 mg kg(-1)) was observed during the depuration period, and the tissue levels were 30% lower in clean water after 24 h. The observed increase in oxidative stress indicated by elevated CAT activity is likely connected to detoxification reactions leading to the production of reactive oxygen species, including an apparent time lag in this specific enzymatic defence response. That no change in GST activity was observed suggests that this enzyme is not significantly involved in the detoxification process of nodularin-containing cyanobacterial extract in M. edulis.

Cyanobacterial blooms are a common phenomenon in the Baltic Sea, and the hepatotoxin nodularin has been frequently detected in certain Baltic Sea fishes and mussels. However, there is no knowledge about the naturally occurring concentrations of nodularin in Baltic Sea zooplankton. The aim of this study was to survey the concentrations of nodularin in natural zooplankton assemblages, and to study the depuration of nodularin in one common copepod species, Eurytemora affinis, experimentally. The nodularin concentrations in common zooplankton species were determined from field-collected samples from the northern Baltic Proper in 2001 and 2002, during cyanobacterial blooms, and the samples were analysed by ELISA immunoassay. Nodularin could be detected from the field-collected zooplankton, suggesting that during a natural bloom event toxins accumulate in their tissues. The concentrations were relatively low (0.07±0.01 μg g−1 ww), ranging from below detection limit to 0.62 μg g−1 ww. Some variation occurred in the concentrations between species and years; generally concentrations were higher in 2001 than in 2002. In the depuration experiment E. affinis copepods were fed with toxic Nodularia spumigena for 24 h, and their toxin contents were monitored for 24 h after transferring them to filtered seawater. A rapid decrease in nodularin concentrations occurred during the first 0.5–3 h after the exposure. However, after a 24-h depuration period in filtered seawater, nodularin could be still detected in E. affinis tissues, indicating that part of the accumulated nodularin, or its derivatives, could be transferred to planktivores.

Cyanobacterial bloom samples from the Gulf of Finland (northern Baltic Sea) were collected in July 2003 and analyzed for microcystins and nodularins, cyanobacterial peptide hepatotoxins, by ELISA, HPLC-UV and LC-MS. The blooms consisted mainly of the genera Nodularia, Anabaena and Aphanizomenon. The main hepatotoxin in the samples was nodularin-R (Nod-R), all the samples also contained demethylnodularin-R. The presence of microcystin-LR was confirmed in three locations out of nine by multiple reactant monitoring on the triple quadrupole mass spectrometer. This is the first reported finding of microcystins in the Baltic Sea from the open sea area. Anabaena was the likely producer of microcystin-LR in the samples.

In this laboratory study the effects of the cyanobacterium Nodularia spumigena (strain AV1) that produces hepatotoxic nodularin (NODLN), non-toxic Nodularia sphaerocarpa (strain UP16f) and purified NODLN on the infaunal clam Macoma balthica from the Baltic Sea were examined. N. sphaerocarpa (2.4 and 12.5 mg dw l(-1)), N. spumigena (4 and 20 mg dw l(-1), intracellular NODLN content ca. 4 and 20 microg l(-1)) and purified NODLN (10 and 50 microg l(-1)) were applied in experimental tanks at 24 h intervals for 96 h. Water samples were taken during the experiment for the measurement of soluble NODLN concentrations. The concentrations of total hepatotoxins in the soft tissues were analysed with enzyme-linked immunosorbent assay (ELISA) and NODLN with high-performance liquid chromatography/diode array detection (HPLC/DAD). Acetylcholinesterase (AChE) activity was measured from the foot tissue samples taken at 0, 24 and 96 h. In the water phase, 60-100% of NODLN in the pure-toxin treatments and all the NODLN in N. spumigena treatments appeared as a yet unidentified form with NODLN-like spectral characteristics. The compound was present in similar quantities also in the non-toxic N. sphaerocarpa treatments. In the toxic N. spumigena treatments the tissue concentration of hepatotoxic NODLN-like compounds (measured with ELISA) increased from the control levels of 0.16 to 16.6 microg g(-1) dw (24 h), reaching 30.3 microg g(-1) dw at 96 h. However,5% of the toxin detected by ELISA could be shown to be NODLN in HPLC/DAD analysis. Matrix-assisted laser desorption/ionisation-time of flight mass spectrometry (MALDI-TOF/MS) analyses revealed no NODLN-glutathione (GSH) conjugates in the tissues of M. balthica. Combining the responses in the AChE activity recorded after 24 and 96 h exposure, increases by 46% (N. spumigena) and 36% (soluble NODLN) compared with the control activity were observed in the low-level toxic exposures. Oppositely, decreases by 19% (N. spumigena) and 27% (soluble NODLN) of control activity were observed in the high-level exposures. Only the differences between the increased and decreased AChE activities were statistically significant, with individuals exposed to high levels expressing approximately 55% of the activity of those exposed to low concentrations. The results show that M. balthica readily ingests toxic N. spumigena and that accumulation of peptides takes place rapidly, which has potential food chain effects through toxin enrichment. However, it appears that M. balthica is at least partly able to metabolise NODLN. In addition to hepatotoxicity, NODLN seems to induce concentration-dependent neurotoxic effects; this must be taken into consideration when applying AChE activity as a biomarker of specific anthropogenic contamination (e.g. organophosphate and carbamate pesticides).

Nodularin, a cyclic pentapeptide hepatotoxin closely related to microcystins, is produced by the toxic brackish water cyanobacterium Nodularia spumigena which regularly forms blooms in the Baltic Sea. Baltic herring (Clupea harengus membras L.) and salmon (Salmo salar L.) were caught in the Baltic Sea during 1997 to assess levels of nodularin and microcystins resulting from the blooms. The total toxin content in herring muscle and salmon liver was measured with an enzyme-linked immunosorbent assay. Despite exceptionally heavy blooms of toxic Nodularia in the Baltic Sea during the summer of 1997, Baltic herring and salmon contained very low quantities of nodularin and microcystins (2.5–6.5 ng g–1 dry weight, not corrected for recovery, [30%]). These concentrations do not pose a health threat to humans, based on the World Health Organization value of tolerable daily intake. Moreover, the concentrations we found in salmon and herring were much lower than those reported for livers of European flounder (Platichthys flesus L.) or Atlantic cod (Gadus morhua L.) from the Baltic Sea during 1996–1999. We suspect that cyanobacterial hepatotoxins do not effectively accumulate in herring and salmon.

Nodularin (NODLN) is a cyclic pentapeptide hepatotoxin that is regularly produced in high amounts by the cyanobacterium Nodularia spumigena in the Baltic Sea, and can bioaccumulate in Baltic biota. Baltic sea trout (Salmo trutta m. trutta L.) were exposed orally to a single dose of food containing NODLN (125 mg/kg ww) from N. spumigena (strain AV1, from the Baltic Sea). The level of exposure was 210-620 (average 440) microg NODLN per kg bw. Based on an 8-day survey under laboratory conditions, NODLN-like compounds accumulated in trout liver, with increasing liver concentrations (from 19 microg/kg on day 1 up to 1200 microg/kg on day 8 as measured with the EnviroLogix ELISA kit) during the experiment. Thus, accumulation of NODLN-like compounds in liver increased from 0.05% of the total NODLN dose administered on day 1 to 0.53% on day 8. However, the ELISA test kit is also sensitive to metabolites of algal hepatotoxins. In the HPLC chromatograms, no NODLN peak was detected after 24 h that also suggested NODLN absorbed in trout was metabolized or bound rapidly. According to ELISA, NODLN-like compounds also accumulated in trout muscle in lower quantities (from 125 to 34 microg/kg dw). Histopathology revealed complete loss of liver architecture after 1-2 days of the single oral dose. From day 4 to 8, there was partial recovery of liver cells. NODLN did not affect thiamine levels or water content of trout liver. The results showed that NODLN rapidly induces severe but reversible liver damage. Apparently NODLN accumulated in trout liver from cyanobacteria in the intestine, but was detoxified rapidly. On the basis of discrepancies between the histopathology and ELISA, and on the other hand, between the HPLC and ELISA methods, analysis of NODLN and its metabolites in biological tissue needs to be improved.

Cyanobacterial hepatotoxin accumulation in mussels (Mytilus edulis, Dreissena polymorpha), clam (Macoma balthica), and flounder (Platichthys flesus) tissues was measured. Flounder were caught with gillnets from the western Gulf of Finland on 21 August 1999, 25 July 2000, and 25 August 2000. Blue mussels were collected from: (1) a steel cage at a depth of 3 m on 20 August 1999, (2) an enclosure at depths of 3-5 m, and (3) an artificial reef (wreck at 25-30 m) in the western Gulf of Finland between June and September 2000. Furthermore, blue mussels were collected from two sites between August and October 2000: south of the town of Hanko at depths of 5 and 20 m in the western Gulf of Finland and south of the city of Helsinki at a depth of 7 m in the central Gulf of Finland. M. balthica and D. polymorpha were collected at a depth of 12 m from Russian waters in the eastern Gulf of Finland on 1-4 August 2000. The samples were analyzed for the cyanobacterial hepatotoxins nodularin (NODLN) and microcystins (MCs) using enzyme-linked immunosorbent assay (ELISA), liquid chromatography-mass spectrometry (LC-MS), and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS). ELISA indicated a time-dependent accumulation of hepatotoxins in flounder liver up to 400 +/- 10 (SD) microg/kg on 25 August 2000. No hepatotoxins were detected in flounder muscle samples. In blue mussels, collected from an enclosure 3-5 m deep in the western Gulf of Finland on 23 August 2000, ELISA indicated cyanobacterial hepatotoxins up to 1490 +/- 60 microg/kg dry wt. Blue mussels collected from the other sites contained less cyanobacterial hepatotoxins (40-130 microg/kg dry wt). Clams and mussels from Russian waters contained cyanobacterial hepatotoxin at about 100-130 microg/kg dry wt. Total hepatotoxin levels in mussels from enclosures decreased from August to September, indicating at least partial detoxication/depuration of the toxins. LC-MS verified the presence of NODLN in mussels and flounder. Typical detoxication conjugates were observed by MALDI-TOF-MS in mussel samples collected during August 2000. In deeper-living wreck mussels cyanobacterial hepatotoxin levels continued to increase, from August to September, indicating that portions of cyanobacterial hepatotoxins reach the sea floor. NODLN bioaccumulation is a constant phenomenon in the area.

Dated sediment cores and surface sediments were analyzed from the Gulf of Finland, a part of the Baltic Sea, to study the sources, levels, distribution, and total amounts of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) and polychlorinated biphenyls (PCBs). The gulf was found to be severely polluted, with PCDD/F sum concentrations as high as 101000 ng/kg and 479 ng/kg WHO-TEQ in dry weight. The source of pollution was the former manufacturing and use of a chlorophenol based wood preservative along the Kymijoki River. It was estimated thatthe impacted sedimentary area stretched a distance of 75 km away out from the coast and that the PCDD/F sum load attributed to the wood preservative source was 1770 kg of PCDD/Fs or 12.4 (+/-2.8) kg WHO-TEQ. The surface sediments contained 24-66% of the maximum concentrations present in the 1960-1970s, showing that the river still acts as a significant PCDD/F source and may contribute to the high levels in fish. Moreover, the reduced PCDD/F and PCB concentrations were partly due to the dilution by increased dry matter deposition. PCBs were uniformly distributed over the gulf, and the PCB load in the polluted area was 2020 kg or 0.14 kg WHO-TEG.

High-performance liquid chromatography (HPLC) was applied in the analysis of nodularin (NODLN), a potent, bioaccumulable hepatotoxin. The behaviour of NODLN in biological matrices and possibility to analyse biota samples for NODLN content was examined using a conventional HPLC/diode array detector method that uses C18 solid-phase cartridge clean up. Tissues of European flounder, blue mussel (spiked and naturally contaminated), clam (exposed to NODLN in an aquariuml and mouse (subjected to i. p. administration of NODLN) were analysed. UV detection was 5 times more sensitive than electrochemical detection. Recovery of NODLN from spiked tissues was 59% for mussel, 53% for flounder, and 44–75% for mouse tissues. NODLN was detected in clams exposed with NODLN, but not in naturally contaminated mussels where NODLN conjugation occurs. Through the use of spectral processing, free NODLN was unambiguously identified from tissue samples. The HPLC method showed limits of quantification between 90 and 150 μg NODLN kg−1 dw. The method proved applicable for routine tissue analysis and can be used in the monitoring of acutely toxic NODLN levels.

During 2–12 August 1999, the development of a surface bloom dominated by the cyanobacterium Nodularia spumigena was followed in the western Gulf of Finland, Baltic Sea. Intense surface scums of aggregated N. spumigena existed on calm days. The low-nutrient N. spumigena-dominated water mass was separated by a front from a nutrient-rich water mass dominated by Aphanizomenon cf. flos-aquae (Nostocales, Cyanobacteria). Owing to inadequate mixing of the two water masses, it is likely that N. spumigena growth was based mainly on the use of internal phosphorus stores. Signs of cell decay were observed on 5 August, and the proportion of empty filaments in the community increased towards the end of the survey period. A high number of Nitzschia spp. (Bacillariophyceae) was recorded within the N. spumigena aggregates on 8 August, suggesting nutrient leakage from the N. spumigena filaments. Senescence of N. spumigena and a decrease in the proportion of intact N. spumigena cells in dry material resulted in de...

The brackish water cyanobacterium Nodularia spumigena regularly forms waterblooms in the Baltic Sea. Many N. spumigena strains can produce nodularin, a hepatotoxic penta-peptide, which has caused several animal poisonings in the Baltic Sea area. To improve our understanding of nodularin bioaccumulation in aquatic organisms this study measured nodularin in flounder and cod caught from the Baltic Sea. Flounders were collected from the western Gulf of Finland in July 1996, September 1997, and September 1998, and from the Gulf of Bothnia in August 1997 and September 1998. Flounders were also collected from the coastal areas of Sweden in the Baltic Proper during September 1998. Cod were caught from the southern Baltic Sea in August 1998. Livers and muscles of the 1997 fish were isolated, extracted, and analysed for nodularin using high-performance liquid chromatography (HPLC) and enzyme-linked immunosorbent assay (ELISA) and protein phosphatase 1 (PP1) inhibition assay. Approximately 30–70 ng of nodularin/g dry weight (maximum value 140 ng/g) were found in the liver tissue samples by ELISA and PP1 inhibition. These concentrations were below the detection limit of HPLC. PP1 assay showed inhibition also in muscle samples, but this may due to other compounds present in the muscle extracts rather than NODLN or due to matrix interference. The recovery of nodularin from liver tissue with ELISA and PP1 assays was about 30%. Nodularin concentrations in samples are not corrected for recovery. Although the concentrations of nodularin found in this study are low further studies of nodularin are needed to assess possible bioaccumulation in brackish water food webs. © 2001 John Wiley & Sons, Inc. Environ Toxicol 16: 121–126, 2001

There is only limited information about the accumulation of algal toxins in aquatic organisms in the Baltic Sea. In this study we measured total cyanobacterial hepatotoxin levels in blue mussel (Mytilus edulis) and flounderi (Platichthys flesus) tissues. Flounder were caught with gillnets from the western Gulf of Finland during July and August 1999. Blue mussels were collected from an enclosure at 3 m depth and from an artificial reef (wreck, 25-35 m depth) in the western Gulf of Finland between June and September 1999. Flounder liver and muscle samples and soft tissues of mussels were analyzed for the cyanobacterial hepatotoxins (nodularin, NODLN and/or microcystins, MCs) using an enzyme-linked immunosorbent assay (ELISA). Results showed a time-dependent accumulation of hepatotoxins in flounder and mussels. In flounder, the maximum concentration 399 +/- 5 (sd) ng NODLN or MC/g dry weight (dw) was found in the liver of specimens caught on 21 August 1999. No hepatotoxins were detected in muscle samples. The maximum concentration of 2150 ng +/- 60 (sd) ng hepatotoxin/g dw was found in the mussel soft tissues collected on 20 August 1999. Temporal NODLN or MC trends indicated depuration of cyanobacterial hepatotoxin from mussels at surface level and an increase in NODLN or MC concentrations in those from the sea bed. These studies showed that despite the low cyanobacteria cell numbers the cyanobacterial hepatotoxins can accumulate in flounder and mussels. This may allow the further transfer of cyanobacterial hepatotoxins in the food web.

Okadaic acid (OA) is a relatively stable polyether toxin causing diarrhetic shellfish poisoning, DSP. OA is produced by dinoflagellates such as Dinophysis acuminata and D. norvegica, which are common throughout the Baltic Sea. This protein phosphatase (PP) inhibitor can induce toxic effects such as hepatocyte apoptosis after in vitro exposure. The aim of this study was to analyse the liver and muscle of flounder from the Baltic Sea for okadaic acid. 30–50 flounder (Platichthys flesus) were caught at depths between 6 and 20 meter in different areas of the northern Baltic Sea every 3–4 weeks in June– September 1996–1998. The presence of OA was analysed using HPLC. The flounder caught in August 1996 contained OA (222 ng OA g-1 ww, liver tissue). This was the first observation of OA in fish from the northern Baltic Sea.

Organochlorine compounds present in effluents from the pulp and paper industry are regarded as a potent threat to the environment. Total organohalogen concentrations are commonly measured in sediment as extractable organic halogen (EOX). Spacial and vertical levels of EOX were determined in areas likely to be affected by organochlorine pollution in Lake Saimaa, along the Kymi River, and around the Gulf of Finland. High levels of EOX were found in samples from southern Lake Saimaa and the Kymi River. Spacial EOX distribution indicated that there is transport of organochlorines from the Kymi River to the eastern Gulf of Finland, and EOX results from the Kotka area showed that substantial, widespread, organochlorine pollution persists 30 km off the coast. Sediments from Vyborg Bay (Russia) and from Tallinn Bay and Ihasalu Bay (Estonia) contained low amounts of EOX. Results from 73 stations indicated that pollution from chlorine bleaching and municipal water chlorination remains localized. Vertical EOX distri...

The crustacean Monoporeia affinis Lindstrom was exposed to two different concentrations of bleached kraft mill effluent (BKME) containing, originally, 8.3 mg/g organic chlorine determined as adsorbable organic halogen (AOX). The swimming activity of the animals was recorded by pairs of infra-red sensitive photocells attached to 5.6 1 aquaria having a seawater inflow rate of 12 ml/min. The test sequence included a control phase, an exposure phase and a recovery phase. During the exposure phase the total swimming activity decreased in three of the four test aquaria containing effluent, indicating that the animals had retreated into the sediment. Total activity increased during the recovery phase and, in the case of the lower organic chlorine concentration, activity almost achieved the original control-phase level. Statistical differences in swimming activity changes during experiment were evaluated using ANOVA. Experimental methods are explained in detail.

Surficial sediment samples from nine stations in the Kotka area, Finland, and from ten stations in the Neva Bay, near the city of St. Petersburg, Russia, were analysed for EOX and AOX. In this study levels of total EOX (1.4–60 μg/g dw) and AOX (120–620 μg/g dw) in the Kotka area and EOX (0.1–1.7 μg/g dw) in the Neva Bay were determined. Three open sea stations in the Gulf of Finland (1.7–3.9 μg/g dw) were analysed for EOX. SEC-HPLC fractioned EOX concentrations of seven selected stations were also determined. The results show the total MW and EOX-MW distributions are similar in all samples tested. The high levels of AOX and EOX clearly indicated pulp industry derived organochlorine contamination in the Kotka area. EOX concentrations in the Neva Bay are at background level, which indicated a low organochlorine load or no accumulation in the sediments in that particular area.

Surfical sediment samples from thirteen stations in the offshore areas of Finland, Estonia and Russia in the Gulf of Finland were analysed first time for EOX and AOX. In addition to the total normalised EOX (0.5–2.5 μg/g dw) and AOX (50–180 μg/g dw), SEC-HPLC fractioned EOX concentration was also determined. EOX dependence on molecular weight of the organic material was established. AOX and EOX were tested for correlation with TOC and chloride content. The results show that the total MW and EOX MW distribution is strikingly similar in all samples, suggesting that the EOX levels are of natural origin. This is also the case with AOX. The similarity of the samples was also observed in UV and VIS spectra of the sediment extracts. The sum EOX of the HPLC fractions was in agreement with the total EOX.

Concentrations of the very long-lived fission product (129)I and stable iodine ((127)I) in the Baltic Sea and lake and rain waters from Finland, were measured as well as their occurrence as iodide (I(-)) and iodate (IO(3)(-)). The highest concentrations of both (127)I and (129)I occurred in sea water, on average 11.1 ± 4.3 μg/l and 3.9 ± 4.1 × 10(-9) at/l. In rain and lake waters the concentration of (129)I was more or less identical and almost one order of magnitude lower than in sea water. Based on these observations, and data from the literature, it is assumed that the source of (129)I in lakes is precipitation and the major source in the Baltic Sea is the inflow of sea water from the North Sea through the Danish Straits. The concentration of (129)I in the Baltic Sea has increased by a factor of six during ten years from 1999. In all studied water types the main chemical form of both iodine isotopes was iodide; in sea and lake waters by 92-96% and in rain water by 75-88%. Compared to (127)I the fraction of iodide was slightly higher in case of (129)I in all waters.

The Baltic Sea is a large, shallow, and strongly stratified brackish water basin. It suffers from eutrophication, toxic cyanobacterial blooms, and oxygen depletion, all of which pose a threat to local marine communities. In this study, the diversity and community structure of the northern Baltic Sea bacterial communities in the water column were, for the first time, thoroughly studied by 454 sequencing. The spring and autumn bacterial communities were one order of magnitude less diverse than those in recently studied oceanic habitats. Patchiness and strong stratification were clearly detectable;1% of operational taxonomic units were shared among 11 samples. The community composition was more uniform horizontally (at a fixed depth) between different sites than vertically within one sampling site, implying that the community structure was affected by prevailing physical and hydrochemical conditions. Taxonomic affiliations revealed a total of 23 bacterial classes and 169 genera, while 5% of the sequences remained unclassified. The cyanobacteria accounted for2% of the sequences, and potentially toxic cyanobacterial genera were essentially absent during the sampling seasons.

A procedure for preparing sea sediment samples for AOX analysis is described. Due to the high chloride content in sea sediment, pretreatment with silver nitrate to precipitate halides is suggested, in addition to using the conventional nitrate wash according to the standard DIN 38409 procedure. The sediment samples collected in the vicinity of a bleach-plant, from the Bothnian Bay, which is in the northernmost part of the Baltic Sea gave AOX values of 400–600 μg/g. A trial of using gel column chromatography in separating molecules with a molecular weight of the order of 100–500 daltons from chloride is reported, and proved unsuccessful with either o-chlorobenzoic acid or DDT. Using o-chlorobenzoic acid as a model compound, the possible loss of organic material with the silver halides was tested. No loss was observed at least in the case of high AOX values with this compound. Mean recoveries of 88 to 98% in the AOX value were obtained for o-chlorobenzoic acid when using a sample volume of 10 ml. Salinometric measurements indicate that there is no correlation between chloride concentration and AOX in the samples. The silver that may be carried over in the sample does not interfere in the titration.

Elintarvikkeiden ja talousveden kemialliset vaarat kuvataan nyt uusitussa muodossa. Raportissa käsitellään 40 vierasainetta tai –ryhmää, ja saadaan samalla kertaa kuva koko ongelmakentästä. Kaikki raporttiin valitut kemialliset yhdisteet ovat olleet viime vuosina mukana elintarvikkeiden ja/tai talousveden riskinhallintaa käsittelevissä valmisteluissa tai toimenpiteissä sekä kansallisella että EU-tasolla. Kemiallisista vaaroista oli suurimmasta osasta runsaasti tietoa saatavilla: esiintyminen elintarvikkeissa, tutkimukset ja saantilaskelmat, terveydelliset haittavaikutukset ja valvontaan liittyvät tarpeet ja lopuksi kattavat kirjallisuuskatsaukset. Yhteensä 21 suomalaista kutsuttua vierasaineasiantuntijaa on ollut mukana eri sektoritutkimuslaitoksista tämän raportin sisällön kirjoittamis- ja tarkistamistyössä. Lisäksi suuri joukko muita asiantuntijoita on kommentoinut raporttia. Asiantuntijat ovat eri hallinnonaloilta, ja osa aiheistakin ja niihin liittyvistä vierasaineista, kuten talousveden vierasaineet, kuuluvat hallinnollisesti muihin kuin maa- ja metsätalousministeriön alaisiin asiantuntijalaitoksiin. Tämä raportti on tehty mahdollisimman laajalle käyttäjäkunnalle ottaen huomioon viranomaiset sekä kuluttajat ja opetus- ja tutkimuslaitokset. Raportti on tehty helppokäyttöiseksi ja mahdollisimman selkeäksi ja lyhytsanaiseksi monine taulukkoineen ja kuvineen. Tarkoitus on, että siitä löytyy helposti eri vierasaineiden ominaisuuksia, joita voi tarvittaessa vertailla. Siitä voi etsiä uusimmat tutkimustulokset ja kansainväliset riskinarvioinnit sekä löytää vierasaineiden pitoisuustietoja etenkin kotimaisista elintarvikkeista. Arvioituja vierasainesaantimääriä voi verrata vierasaineille asetettuihin siedettäviin enimmäissaantimääriin tai vaikkapa verrata näitä turvallisuutta kuvaavia suureita eri vierasaineiden kesken. Valvontaviranomaiset voivat löytää lisäksi nopeasti tietoa lainsäädännöstä ja suositelluista valvontatoimenpiteistä. Valvontaan ja muuhun riskinhallintaan liittyvät ehdotukset ovat syntyneet yhteistyössä valvonnasta vastaavien Eviran asiantuntijoiden kanssa. De kemiska kontaminanterna förknippade med livsmedel och dricksvatten beskrivs nu i förnyad form. Rapporten behandlar 40 främmande ämnen eller grupper av främmande ämnen och ger samtidigt en bild av hela problemfältet. Alla kemiska föreningar som valts med i rapporten har på senare år tagits med i beredningar och åtgärder som gällt riskhantering i fråga om livsmedel och/eller dricksvatten såväl på nationell nivå som på EU-nivå. Om största delen av de kemiska farorna fanns tillgång till rikliga mängder information: förekomsten i livsmedel, analyser och intagsberäkningar, skadeverkningarna på hälsan och behov som hänför sig till tillsynen och slutligen också täckande litteraturöversikter. Inalles 21 inkallade finska experter på främmande ämnen från forskningsanstalter i olika sektorer har deltagit i arbetet med att skriva och granska innehållet i denna rapport. En stor mängd andra experter har också kommenterat rapporten. Experterna representerar olika förvaltningsområden och också en del av ämnena som behandlats och de främmande ämnena som hänför sig till dem, såsom främmande ämnen i dricksvattnet, hör förvaltningsmässigt till andra expertinstitut än de som är underställda jord- och skogsbruksministeriet. Denna rapport har utarbetats för en så bred skara läsare som möjligt beaktande såväl myndigheterna och konsumenterna som undervisnings- och forskningsanstalter. Rapporten har gjorts lätt att använda och så tydlig och kortfattad som möjligt med mångahanda tabeller och figurer. Meningen är att rapporten skall ge information om olika främmande ämnens egenskaper som vid behov kan jämföras. Rapporten redogör för de senaste forskningsresultaten och internationella riskvärderingar och den ger också information om halterna främmande ämnen särskilt i inhemska livsmedel. De beräknade intagen främmande ämnen kan jämföras med de tolerabla dagliga intagen som fastställts för främmande ämnen eller också kan dessa storheter som beskriver säkerheten jämföras olika främmande ämnen emellan. Tillsynsmyndigheter kan också snabbt finna information om lagstiftningen och rekommenderade tillsynsåtgärder. Förslagen som hänför sig till tillsynen och annan riskhantering har uppkommit i samarbete med de experter på Evira som svarar för tillsynen. The chemical contaminants of foodstuffs and household water are now described in a revised form. The report addresses 40 contaminants or groups of contaminants and, at the same time, provides an overview of the whole problematic. All the chemical compounds selected for the report have in the recent years been included at both national and EU level in deliberations and measures pertaining to the risk management of foodstuffs and/of household water. An abundance of information is available on the majority of chemical hazards; occurrence in foodstuffs, research and intake calculations, health effects and needs related to control and finally a comprehensive literary review. A total of 21 Finnish experts in contaminants from various sector research institutes were invited to take part in the preparation and review of the content of this report. A large number of other experts have also provided comments on the report. The experts represent different administrative sectors and some of the topics and of the associated contaminants, such as the contaminants of household water, are also administratively managed by other expert institutes, which are not organised under the Ministry of Agriculture and Forestry. This report is designed to an as wide audience as possible, taking into account authorities and consumers as well as educational and research institutes. The report has been drawn up in an easy-to-use form to be as clear and concise in words as possible with a multitude of tables and figures. It is designed to provide easy reference to the properties of various contaminants for comparison purposes, if required. It contains the most recent research results and international risk assessments and lists contaminant level data on particularly domestic foodstuffs. The estimated contaminant intakes can be compared with the tolerable intake levels set for contaminants or different contaminants can be compared with each other in terms of these magnitudes that express the safety of the foodstuff. Control authorities can quickly find information about regulations and recommended control action. The suggestions related to control and other risk management efforts have been drawn up in cooperation with Evira’s experts in charge of control.

Microbiological studies were carried out on chemical weapon dump sites in the Baltic Sea. The effect of mustard gas hydrolysis products (MGHPs) on marine microbiota and the ability of microorganisms to degrade MGHPs were studied. Many stations at the dump sites demonstrated reduced microbial diversity, and increased growth of species able to use mustard gas hydrolysis products as sole source of carbon. Significant amounts of MGHP-degrading bacteria were revealed in the near-bottom water. The MGHP-degrading microorganisms identified as Achromobacter sp., Pseudomonas sp., and Arthrobacter sp. were isolated. These microorganisms were capable of utilizing the major product of hydrolysis, thiodiglycol, as the sole source of carbon and energy. The bacteria were capable of metabolizing MGHPs at a low temperature. The metabolic pathway for thiodiglycol degradation was proposed. The results suggest the potential for MGHPs biodegradation by naturally occurring populations of near-bottom-water and sediment microorganisms.

This seven-year survey was primarily targeted to quantification of production of nodularin-R (NOD-R), a cyclic pentapeptide hepatotoxin, in Baltic Sea cyanobacteria waterblooms. Additionally, NOD-R and microcystin-LR (MC-LR; a cyclic heptapeptide toxin) sedimentation rates and NOD-R sediment storage were estimated. NOD-R production (70-2450 microg m(-3); approximately 1 kg km(-2) per season) and sedimentation rates (particles; 0.03-5.7 microg m(-2)d(-1); approximately 0.3kg km(-2) per season) were highly variable over space and time. Cell numbers of Nodularia spumigena did not correlate with NOD-R quantities. Dissolved NOD-R comprised 57-100% of total NOD-R in the predominantly senescent, low-intensity phytoplankton blooms and seston. Unprecedentedly intensive MC-LR sedimentation (0.56 microg m(-2)d(-1)) occurred in 2004. Hepatotoxin sedimentation rates highly exceeded those of anthropogenic xenobiotics. NOD-R storage in surficial sediments was 0.4-20 microg kg(-1) ( approximately 0.1 kg km(-2)). Loss of NOD-R within the chain consisting of phytoplankton, seston and soft sediments seemed very effective.

Nodularin (NODLN) is a hepatotoxin produced by the cyanobacterium Nodularia spumigena, which occurs regularly in the Baltic Sea. The primary aim of this study was to study the transfer of NODLN to three-spined stickleback (Gasterosteus aculeatus L.), herring (Clupea harengus membras L.), and salmon (Salmo salar L.), which were caught from the northern Baltic Sea between August 2002 and August 2003. Liquid chromatography mass spectrometry (LC-MS) was used for NODLN analysis. NODLN was found in both herring (0-90 microgkg(-1)dw) and three-spined sticklebacks samples (2.8-700 microgkg(-1)dw). The recovery for the spiked stickleback samples in vitro was 28%. Only 1 salmon of a total of 10 contained a small amount of NODLN (10 microgkg(-1)dw). However, the high concentrations in individual stickleback suggest that possible transfer to higher trophic levels deserves more research.

Cyanobacterial toxins have been shown to have a far-reaching impact-from aquatic organisms to human health. Aquatic organisms are typically exposed in their natural environment to toxic cyanobacteria, and exposure can occur via ingestion of cyanobacterial cells or by bioaccumulation of water-borne toxin. The aquaculture and fisheries of crustaceans are among the most important seafood industries. Concomitant with the growth of this industry, the importance of the health of crustaceans increased. The black tiger prawn is the major cultivated prawn in Australia. The aquaculture of these prawns takes place in shallow ponds, where blooms, often of cyanobacteria, develop. Cyanobacterial toxins were hypothesized to contribute to the mortality of prawns. Many aquatic organisms have the possibility of detoxifying cyanobacterial toxins via conjugation to glutathione. The presence of several classes of the cytosolic glutathione S-transferase system in black tiger prawns-mu, pi, theta, alpha, and tau-was shown using different substrates for measurement. Injection experiments with microcystin-LR and feeding experiments with nodularin revealed elevation of GST activity in different types of prawn tissue in parallel with reduction in the GST classes. Correlation analyses of toxin content of the prawns with GST activity showed that low toxin content was correlated with high elevation of enzymes and high toxin content with low elevation of enzymes.

The cyanobacterial hepatotoxin nodularin is abundantly produced by the cyanobacterium Nodularia spumigena in the Baltic Sea during July-August. Nodularin is a potent hepatotoxin and a tumour promoter, distributed in various Baltic Sea environmental compartments, especially food webs involving mussels. Flounders receive nodularin through consumption of blue mussels. In this study nodularin concentrations in individual flounders (liver) were examined between July and September 2002 (six sample sets, four to 10 samples/set), providing information about contribution of sampling on estimates of bioaccumulation intensity. Toxin was determined using liquid chromatography/mass spectrometry (LC/MS) and enzyme-linked immunosorbent assay (ELISA). Additionally, liver histopathology was examined. Observed toxin concentrations were ND-390 microg kg(-1) dw (LC/MS) and 20-2230 microg kg(-1) dw (ELISA), with maximum concentrations in September (ELISA). The ELISA protocol generally resulted in higher, up to approximately 10-fold, toxin concentrations than LC/MS, with increasing difference toward September. This difference may have originated from different extraction solvents in LC/MS and ELISA, ion suppression in LC/MS, and temporal increase in nodularin metabolites detectable with ELISA. The differences in toxin concentrations between individual liver samples were considerable with relative standard deviation values of 20-154% (LC/MS) and 28-106% (ELISA). Since the precision of the ELISA method employed was

Harmful cyanobacteria pose a hazard to aquatic ecosystems due to toxins (hepatotoxic microcystins, nodularins, and cylindrospermopsin) they produce. The microcystins and nodularins are potent toxins, which are also tumor promoters. The microcystins and nodularins may accumulate into aquatic organisms and be transferred to higher trophic levels, and eventually affect vector animals and consumers. Prawn farming is a rapidly growing industry in Australia. Because information regarding effects of cyanobacteria at prawn farms was lacking, we examined diversity of cyanobacteria and toxin production plus bioaccumulation into black tiger prawns (Penaeus monodon) under both field (northern New South Wales, Australia, December 2001-April 2002) and laboratory conditions. Samples were analyzed for hepatotoxins using enzyme-linked immunosorbent assay (ELISA) and high-performance liquid chromatography (HPLC). The maximum density of cyanobacteria (1 x 10{sup 6} to 4 x 10{sup 6} cells/l) was reached in April. Cyanobacteria encountered were Oscillatoria sp. (up to 4 x 10{sup 6} cells/l), Pseudanabaena sp. (up to 1.8 x 10{sup 6} cells/l), Microcystis sp. (up to 3.5 x 10{sup 4} cells/l), and Aphanocapsa sp. (up to 2 x 10{sup 4} cells/l). An uncommon cyanobacterium, Romeria sp. (up to 2.2 x 10{sup 6} cells/l), was also observed. Contrasting earlier indications, toxic Nodularia spumigena was absent.more » Despite that both Oscillatoria sp. and Microcystis sp. are potentially hepatotoxic, hepatotoxin levels in phytoplankton samples remained low (up to 0.5-1.2 mg/kg dw; ELISA) in 2001-2002. ELISA was found suitable not only for phytoplankton but prawn tissues as well. Enzymatic pretreatment improved extractability of hepatotoxin from cyanobacteria (nodularin from N. spumigena as an example), but did not generally increase toxin recovery from prawn hepatopancreas. There were slightly increasing hepatotoxin concentrations in prawn hepatopancreas (from 6-20 to 20-80 {mu}g/kg dw; ELISA) during the study. Hepatotoxin concentrations in surface sediment remained low (

Large benthic accumulations of cyanobacteria occur in sheltered embayments within Myall Lake, New South Wales, Australia. The lake is shallow, with the entire bottom within the euphotic zone, and it is generally considered pristine, having low nutrient concentrations. The accumulations are highly organic and contain a mix of species mainly from the order Chroococcales, with two forms of Aphanothece being dominant. However polymerase chain reaction (PCR) analysis indicates a close similarity to Microcystis flos-aquae. The cells appear to lack aerotopes and form sticky mucilaginous amalgamations, which may enhance their benthic habit. Although Chroococcales also dominate the planktonic cyanobacterial community, the benthic species are seldom, if ever, found entrained within the water column. Some hepatotoxicity was indicated by mouse bioassay, protein phosphatase inhibition assay, enzyme-linked immuno-sorbent assay (ELISA) for microcystins, PCR and by chromatographic evidence for a microcystin. Ecological aspects of the distribution, gross morphology of the organisms and management implications for recreational water-users are discussed.