Kerstin Magnusson

The Effect of TBT on the Structure of a Marine Sediment Community - a Boxcosm Study

The effect of tri-n-butyl tin (TBT) on an intact marine sediment community after five months exposure was investigated. Changes in the structure of macro- and meiofauna communities were determined, as well as the functional diversity of the microbial community using BIOLOG microplates for Gram negative bacteria. Development of tolerance in the microbial community was investigated using Pollution Induced Community Tolerance (PICT) experiments with fluxes of nutrients as effect indicators. TBT affected the structure and recruitment of the macro- and meiofauna at nominal additions of 30-137 micromol TBT/m2 sediment. Number of species, diversity, biomass and community similarity was reduced at these concentrations compared to control. Species that molt seemed to be the most tolerant since they were predominant in boxes that had received the highest TBT addition and echinoderms were the most sensitive species. Renewed addition of TBT in PICT experiments with sediment from each boxcosm showed that TBT had an effect on individual nutrient fluxes from all sediments. Analyses of the flux patterns revealed a memory of previous TBT exposure, either due to induced tolerance or other community conditioning.

The importance of uptake from food for the bioaccumulation of PCB and PBDE in the marine planktonic copepod Acartia clausi

The accumulation of (14)C-labelled PCB 31, PCB 101, PCB 153 and PBDE 99 was investigated at the two lowest trophic levels of the pelagic food web. Accumulation was measured in the small phytoplankter Thalassiosira weissflogii (Coscinodiscophyceae: Thalassiosirales) and in the neritic zooplankter Acartia clausi (Copepoda: Calanoida) exposed to the substance either only via water or through ingestion of contaminated T. weissflogii. Bioaccumulation factors (BAFs) for all four compounds were significantly higher in A. clausi feeding on contaminated phytoplankton than in animals exposed only via water. The logBAF for the PCBs increased linearly with the octanol-water partitioning coefficients (logK(OW)) in both the algae and the copepods, but with steeper slopes for feeding than non-feeding animals. Reported values for K(OW) for PBDEs vary by almost an order of magnitude and it was therefore not meaningful to calculate a logBAF-logK(OW) ratio for PBDE 99. It is clear that the nutritional status of the zooplankton affects the uptake of the compounds and that the bioaccumulation cannot be modelled as a passive partitioning between the organisms and the surrounding water. Small copepods are typical of coastal waters and point sources (both temporal and spatial) may be the rule for HOC releases into the sea. Thus, the pathways shown in this study are important and realistic.

Effects of the planktonic flagellate Chrysochromulina polylepis Manton et Park on fertilization and early development of the ascidian Ciona intestinalis (L.) and the blue mussel Mytilus edulis L

In late spring 1988, a bloom of the planktonic green alga Chrysochromulina polylepis Manton et Park along the coasts of the Skagerrak caused mortality of many species of fish and marine invertebrate. C. polylepis was found to be acutely toxic to eggs and larvae of the ascidian Ciona intestinalis (L.) and the bivalveMytilus edulis L. at algal concentrations commonly found in coastal waters. In both species, the fertilization of ova and successful development of embryos was completely inhibited. This is the first time that such toxic effects have been reported for C. polylepis. The results are interpreted as demonstrating the possibility of a severe reduction in larval settlement and recruitment in affected areas.

Distribution and abundance of surface water microlitter in the Baltic Sea: A comparison of two sampling methods.

Two methods for marine microlitter sampling were compared in the Gulf of Finland, northern Baltic Sea: manta trawl (333μm) and a submersible pump (300 or 100μm). Concentrations of microlitter (microplastics, combustion particles, non-synthetic fibres) in the samples collected with both methods and filter sizes remained <10particlesm(-3). The pump with 100μm filter gave higher microlitter concentrations compared to manta trawl or pump with 300μm filter. Manta sampling covers larger areas, but is potentially subjected to contamination during sample processing and does not give precise volumetric values. Using a submerged pump allows method controls, use of different filter sizes and gives exact volumetric measures. Both devices need relatively calm weather for operation. The choice of the method in general depends on the aim of the study. For monitoring environmentally relevant size fractions of microlitter the use of 100μm or smaller mesh size is recommended for the Baltic Sea.

Effects of contaminants in roundnose grenadier (coryphaenoides rupestris) and Norway lobster (nephrops norvegicus) and contaminant levels in mussels (mytilus edulis) in the skagerrak and kattegat compared to the faroe islands

Abstract In situ biomonitoring of roundnose grenadier (Coryphaenoides rupestris) and Norway lobster (Nephrops norvegicus) and measurements of pollutants levels in caged common mussel (Mytilus edulis) were used to assess the environmental impact of contaminants in the Skagerrak and Kattegat and near the Faroe Islands. By comparing the responses of a suite of established and potential biomarkers, i.e. different liver detoxification enzymes and histopathology in roundnose grenadier in the Skagerrak, and at a reference site off the Faroe Islands, evidence was found that the deeper parts of the Skagerrak are affected by anthropogenic contaminants. Levels of polycyclic aromatic hydrocarbons (PAH) and organochlorines in caged mussels were compared with those sediment. The Skagerrak/Kattegat area was found to be more polluted than the Faroe area and the caged mussels bioaccumulated the PAHs to a higher degree than the organochlorines. This seems to indicate that the PAHs in the sediments are more bioavailable than the organochlorines and that the induced ethoxyresorufin-O-deethylase activities observed in Skagerrak roundnouse grenadier may be due to PAH exposure. The Norway lobster accumulated manganese to various degrees in the different parts of the organism. The excretion rate of manganese could not cope with the uptake rate at higher exposure concentrations. Enhanced manganese concentrations, especially in the gills and haemolymph, seem to be a useful indication of increased manganese levels in the water. Hypoxia makes a sediment-bound manganese much more bioavailable. The elevated levels of manganese in Norway lobster from the Skagerrak/Kattegat area therefore seem to reflect the increasing occurrence of hypoxic conditions in the Kattegat and coastal areas of the Skagerrak. Accumulated manganese in Norway lobster may thus serve as a biomarker of hypoxia. In conclusion, the use of a suite of different biomarkers in ecotoxicological and ecophysiological studies and analyses of contaminant levels have provided evidence of a large-scale environmental impact of pollutants and nutrients in the Skagerrak/Kattegat area. This should lead to further efforts to decrease transport into and deposition of waste compounds in the sea.

Molecular investigations into pollutant impact on roundnose grenadier (C. rupestris) and transplanted common mussel (M. edulis) in Skagerrak, the North Sea

The use of a suite of different biochemical markers in the deep sea fish Roundnose grenadier and caged common mussels, and analyses of contaminant levels in the mussels, indicate that Skagerrak are more polluted than waters around the Faroe Islands. In Roundnose, induction of ethoxyresorufin-O-deethylase (EROD) is consistent with increased benzo(a)pyrene hydroxylase (BPH) in mussels and elevated levels of polynuclear aromatic hydrocarbons (PAHs) in mussels and sediment from Skagerrak. This evidence of a large-scale environmental impact of pollutants should lead to further efforts to decrease transport into, and deposition of, waste compounds in the Skagerrak area.

Microlitter in sewage treatment systems

The report presents results from a study on the role municipal sewage treatment plants (STPs) have as entrance routes for microplastics and other microlitter particles to the marine environment. Microlitter concentrations were analysed in waste water before and after treatment in the STPs, and in the recipient waters where the treated waste water is discharged. Municipal waste water was found to contain a substantial amount of microlitter, but in STPs equipped with chemical and biological treatment most of the litter particles were retained in the sewage sludge. This reduces the impact on the recipient water, but if the sludge is used as fertilizer on farm land the microlitter will still reach the environment. Efforts to reduce the microlitter concentrations should therefore preferably be done in households and other locations where the waste water is originally being formed.

Toxicity of treated bilge water: The need for revised regulatory control

Water accumulating in the bottom of ships (bilge water), contains a mixture of oil, detergents and other compounds from on board activities. To evaluate ecological effects of released bilge water the chemical composition and toxicity of treated bilge water from seven passenger ships was analysed. The oil content was below 15mgL-1, the threshold for legal discharge, in all but one ship. Still, significant reductions in feeding and reproduction of Acartia tonsa were found after 48h exposure in dilutions with 2.5-5% of bilge water. Mortality was significant at dilutions of 5-10% in 4 of the 5 bilge water samples. Surfactants were the most significant contributor to the toxicity on copepod vital rates and survival. Toxicity was also tested with Microtox where an EC50 was found at dilutions between 4.3% and 52%. The results show that ecological effects might occur also in diluted suspensions of bilge water.

Risk assessment of bilge water discharges in two Baltic shipping lanes

Environmental concentrations and effects of bilge water contaminants in two Baltic Sea areas were estimated from modelling of discharge rates and analytical data on bilge water from seven ships. Biodegradation of bilge water oil was accounted for and annual water concentrations were estimated to peak in late spring, which coincides with the beginning of a period with extensive biological activities in the sea. Concentrations on bilge water metals were calculated both as water concentrations and as the annual contribution of metals to sediments. The predicted bilge water concentrations of oil and metal in the marine environment were estimated to be 4 to 8 orders of magnitude lower than reported toxic concentrations. However, available toxicity data are based on short term exposure and there is to date limited information on toxic effects of the small but chronically elevated contaminant concentrations derived from bilge water discharge and other operational shipping activities.