Linda Kumblad

Physiological effects of diclofenac, ibuprofen and propranolol on Baltic Sea blue mussels

Pharmaceuticals are constantly dispersed into the environment and little is known of the effects on non-target organisms. This is an issue of growing concern. In this study, Baltic Sea blue mussels, Mytilus edulis trossulus, were exposed to diclofenac, ibuprofen and propranolol, three pharmaceuticals that are produced and sold in large quantities and have a widespread occurrence in aquatic environments. The mussels were exposed to pharmaceuticals in concentrations ranging from 1 to 10,000 microg l(-1). The pharmaceuticals were added both separately and in combination. Mussels exposed to high concentrations of pharmaceuticals showed a clear response compared to controls. Firstly, they had a significantly lower scope for growth, which indicates that the organisms had a smaller part of their energy available for normal metabolism, and secondly, they had lower byssus strength and lower abundance of byssus threads, resulting in reduced ability to attach to the underlying substrate. Mussels exposed to lower concentrations showed tendencies of the same results. The concentration of diclofenac and propranolol was quantified in the mussels using both liquid chromatography coupled to mass spectrometry (LC-MS). The measurements showed a significantly higher concentration in the organisms as compared to the water the mussels were exposed to; the uptake reached concentrations two orders of magnitudes higher than found in sewage treatment plant effluents. This study showed that common pharmaceuticals are taken up and negatively affect the physiology of a non-target species at levels of two to three orders of magnitudes higher than found in sewage treatment plant effluents.

An ecosystem model of the environmental transport and fate of carbon-14 in a bay of the Baltic Sea, Sweden

The environmental transport and fate of a hypothetical discharge of radioactive 14C from the Swedish final repository for radioactive operational waste (SFR) was investigated using an ecosystem m ...

Ecological Stoichiometry and Multi-element Transfer in a Coastal Ecosystem

Energy (carbon) flows and element cycling are fundamental, interlinked principles explaining ecosystem processes. The element balance in components, interactions and processes in ecosystems (ecological stoichiometry; ES) has been used to study trophic dynamics and element cycling. This study extends ES beyond its usual limits of C, N, and P and examines the distribution and transfer of 48 elements in 16 components of a coastal ecosystem, using empirical and modeling approaches. Major differences in elemental composition were demonstrated between abiotic and biotic compartments and trophic levels due to differences in taxonomy and ecological function. Mass balance modeling for each element, based on carbon fluxes and element:C ratios, was satisfactory for 92.5% of all element–compartment combinations despite the complexity of the ecosystem model. Model imbalances could mostly be explained by ecological processes, such as increased element uptake during the spring algal bloom. Energy flows in ecosystems can thus realistically estimate element transfer in the environment, as modeled uptake is constrained by metabolic rates and elements available. The dataset also allowed us to examine one of the key concepts of ES, homeostasis, for more elements than is normally possible. The relative concentrations of elements in organisms compared to their resources did not provide support for the theory that autotrophs show weak homeostasis and showed that the strength of homeostasis by consumers depends on the type of element (for example, macroelement, trace element). Large-scale, multi-element ecosystem studies are essential to evaluate and advance the framework of ES and the importance of ecological processes.

A carbon budget for an oligotrophic clearwater lake in mid-Sweden

Abstract.In this study, a whole-lake carbon budget for the oligotrophic, clearwater Lake Eckarfjärden was established both on an annual and seasonal basis. For budget calculations, the lake was divided into three habitats (pelagial, littoral and benthic) and the biota into 19 functional groups. In the lake, major parts of biomass (97%) and primary production (91%) are concentrated in benthic and littoral habitats and to a few functional groups. Respiration on the other hand, is focused on benthic and pelagial habitats where 60% and 39%, respectively, of the respiration took place. Our conceptual model indicates strong interactions between habitats. For instance, the pelagial is fed with carbon fixed by primary producers in the benthic and littoral zones. On an annual basis, total primary production exceeds total respiration and the lake is net autotrophic. However, there are clear differences between habitats and between seasons. For instance, the littoral is net autotrophic during spring, summer and autumn, the benthic habitat is net autotrophic only during summer, and the pelagial is always net heterotrophic. Our results demonstrate clear couplings between habitats and organisms and the importance of a holistic view when studying lake ecosystems.

Effect studies of human pharmaceuticals on Fucus vesiculosus and Gammarus spp

In two experiments, the human pharmaceutical propranolol negatively affected the physiology of two test organisms, Fucus vesiculosus and Gammarus spp. from a Baltic Sea littoral community in a concentration of 1000 μg l⁻¹. Some effects were also observed for the lower, more ecologically relevant concentrations (10 μg l⁻¹ and 100 μg l⁻¹). The effects on F. vesiculosus not only increased with increasing concentration, but also with exposure time; while the effects on Gammarus spp. were more inconsistent over time. No clear effects of the pharmaceuticals diclofenac and ibuprofen were observed for any of the organisms. Physiological parameters measured were GP:R-ratio, chlorophyll fluorescence and release of coloured dissolved organic matter, respiration and ammonium excretion. Pharmaceutical substances are repeatedly detected in the Baltic Sea which is the recipient for STP effluents from more than 85 million people living in the catchment area, but the knowledge of their effects on non-target organisms is still very limited.

Weak governmental institutions impair the management of pesticide import and sales in Zanzibar.

Poor pesticide handling practices and risk-awareness among African farmers puts human health and the environment at risk. To investigate information available to farmers in Zanzibar (Tanzania), an interview study was conducted with retailers, and governmental pesticide importation to Zanzibar was examined. Pesticide retailers in Zanzibar did not have the necessary knowledge to safely handle or to advise farmers on proper use of pesticides. Licensed shop owners were rarely found in the shops; instead, untrained personnel were employed to sell the pesticides. Implementation of the legislation was weak, mainly due to lack of surveillance by governmental institutions. Poor governmental importation practices and unregulated private imports indicate serious weakness in the management of pesticide importation in Zanzibar. The situation calls for increased attention on the monitoring of pesticide importation and sales to protect the health of farmers and retailers, as well as the environment.

Community Interactions Modify the Effects of Pharmaceutical Exposure: A Microcosm Study on Responses to Propranolol in Baltic Sea Coastal Organisms

This study investigated the uptake and effects of a common human pharmaceutical, propranolol, on the structure and function of a coastal Baltic Sea model community consisting of macroalga (Ceramium tenuicorne), mussels (Mytilus edulis trossulus), amphipods (Gammarus spp.), water and sediment. The most sensitive species, the mussel, was affected to the same extent as in previous single species studies, while the effects on the amphipod and alga were smaller or even positive compared to experiments performed in less complex test systems. The observed cascade of beneficial effects was a result of inter-specific species interactions that buffered for more severe effects. The poor condition of the mussel led to a feeding shift from alga to mussel by the amphipods. The better food quality, due to the dietary shift, counteracted the effects of the exposure. Less amphipod grazing, together with increased levels of nutrients in the water was favourable for the alga, despite the negative effects of propranolol. This microcosm study showed effects on organisms on different organizational levels as well as interactions among the different components resulting in indirect exposure effects of both functional and structural nature. The combination of both direct and indirect effects would not have been detected using simpler single- or even two-species study designs. The observed structural changes would in the natural environment have a long-term influence on ecosystem function, especially in a low-biodiversity ecosystem like the Baltic Sea.

Pools and Fluxes of Organic Matter in a Boreal Landscape: Implications for a Safety Assessment of a Repository for Nuclear Waste

Abstract To provide information necessary for a license application for a deep repository for spent nuclear fuel, the Swedish Nuclear Fuel and Waste Management Co is carrying out site investigations, including extensive studies of different parts of the surface ecosystems, at two sites in Sweden. Here we use the output from detailed modeling of the carbon dynamics in the terrestrial, limnic and marine ecosystems to describe and compare major pools and fluxes of organic matter in the Simpevarp area, situated on the southeast coast of Sweden. In this study, organic carbon is used as a proxy for radionuclides incorporated into organic matter. The results show that the largest incorporation of carbon into living tissue occurs in terrestrial catchments. Carbon is accumulated in soil or sediments in all ecosystems, but the carbon pool reaches the highest values in shallow near-land marine basins. The marine basins, especially the outer basins, are dominated by large horizontal water fluxes that transport carbon and any associated contaminants into the Baltic Sea. The results suggest that the near-land shallow marine basins have to be regarded as focal points for accumulation of radionuclides in the Simpevarp area, as they receive a comparatively large amount of carbon as discharge from terrestrial catchments, having a high NPP and a high detrital accumulation in sediments. These focal points may constitute a potential risk for exposure to humans in a future landscape as, due to post-glacial land uplift, previous accumulation bottoms are likely to be used for future agricultural purposes.

Marine Ecosystem Modeling Beyond the Box: Using GIS to Study Carbon Fluxes in a Coastal Ecosystem

Abstract Studies of carbon fluxes in marine ecosystems are often done by using box model approaches with basin size boxes, or highly resolved 3D models, and an emphasis on the pelagic component of the ecosystem. Those approaches work well in the ocean proper, but can give rise to considerable problems when applied to coastal systems, because of the scale of certain ecological niches and the fact that benthic organisms are the dominant functional group of the ecosystem. In addition, 3D models require an extensive modeling effort. In this project, an intermediate approach based on a high resolution (20×20 m) GIS data-grid has been developed for the coastal ecosystem in the Laxemar area (Baltic Sea, Sweden) based on a number of different site investigations. The model has been developed in the context of a safety assessment project for a proposed nuclear waste repository, in which the fate of hypothetically released radionuclides from the planned repository is estimated. The assessment project requires not only a good understanding of the ecosystem dynamics at the site, but also quantification of stocks and flows of matter in the system. The data-grid was then used to set up a carbon budget describing the spatial distribution of biomass, primary production, net ecosystem production and thus where carbon sinks and sources are located in the area. From these results, it was clear that there was a large variation in ecosystem characteristics within the basins and, on a larger scale, that the inner areas are net producing and the outer areas net respiring, even in shallow phytobenthic communities. Benthic processes had a similar or larger influence on carbon fluxes as advective processes in inner areas, whereas the opposite appears to be true in the outer basins. As many radionuclides are expected to follow the pathways of organic matter in the environment, these findings enhance our abilities to realistically describe and predict their fate in the ecosystem.

Effects of land-rise on the development of a coastal ecosystem of the Baltic Sea and its implications for the long-term fate of 14C discharges

Due to the long half-lives of many radionuclides, safety assessments of nuclear waste facilities often need to consider the potential fate of radionuclides discharged to the environment in the future. In this study we explored the environmental fate of a hypothetical 14C release from a nuclear waste repository to a Baltic Sea bay in 2000 years. This was accomplished by connecting spatially linked biomasses and metabolic rates from a carbon flow model of the ecosystem at the site today to predicted changes in geomorphology and water exchange regimes. The employed extrapolation method was selected as shoreline displacement due to land-rise and sea level changes is the main process that affects the development of the coastal ecosystem around the repository in the coming 10 000 years. The modelling results indicate that the ecosystem will go through changes in several ecosystem properties in the coming 2000-year period, e.g. a decreased rate of primary production and changed feeding preferences of the fish community. Also, a decreased total biomass is expected and an ecosystem change altering the balance between producers and consumers towards a dominance of benthic plants. The changes of the ecosystem structure and carbon dynamics will also influence the potential fate of future discharges of 14C. We estimated an up to 1000 times higher 14C concentrations in biota compared to today. However, due to radioactive decay and reduced total biomass in the receiving ecosystem, the proportion of accumulated radionuclides is expected to decrease. Although the modelling approach used in this study is associated with several sources of uncertainty, it provides a way to both qualitatively and quantitatively assess likely effects of future discharges of contaminants.