Testing effects of a mixture of hydrophobic organic contaminants and zinc in Daphnia magna.

Ecotoxicity assessments often struggle with contaminant mixtures. This study explored combining chemical activity of hydrophobic organic contaminants (HOCs) and metals, using zinc as a model. An acute Daphnia magna immobilization test, with protein content as an additional endpoint, revealed an additive sublethal effect.

Enhanced tolerance to narcosis in starved Daphnia magna neonates.

Guidelines for ecotoxicity testing with Daphnia magna specify particular feeding protocols during the exposure, yet standardization for preexposure feeding remains ambiguous despite its recognized significance in affecting organismal metabolic capacity and tolerance. This ambiguity may contribute to disparate responses and heightened uncertainty in determining the effect concentrations of test chemicals, particularly those inducing metabolic effects through narcosis. Here, we address this gap through a three-step dose-response experiment with neonates of D.

Chemical Activity-Based Loading of Artificial Sediments with Organic Pollutants for Bioassays: A Proof of Concept.

Persistent organic pollutants (POPs) pose a risk in aquatic environments. In sediment, this risk is frequently evaluated using total or organic carbon-normalized concentrations. However, complex physicochemical sediment characteristics affect POP bioavailability in sediment, making its prediction a challenging task.

Cardiotoxic and neurobehavioral effects of sucralose and acesulfame in Daphnia: Toward understanding ecological impacts of artificial sweeteners.

Artificial sweeteners are widely used in food and pharmaceuticals, but their stability and persistence raise concerns about their impact on aquatic life. Although standard toxicity tests do not reveal lethal effects, recent studies suggest a potential neurotoxic mode of action. Using environmentally relevant concentrations, we assessed the effects of sucralose and acesulfame, common sugar substitutes, on Daphnia magna focusing on biochemical (acetylcholinesterase activity; AChE), physiological (heart rate), and behavioural (swimming) endpoints.

Flawed risk assessment of antifouling paints leads to exceedance of guideline values in Baltic Sea marinas.

The seasonal variations of dissolved and bioavailable copper (Cu) and zinc (Zn) were studied in two recreational marinas in Sweden and Finland. The time series from the two marinas were characterized by rising concentrations during the spring boat launching, elevated concentrations all through the peak boating season, and decreasing concentrations in autumn when boats were retrieved for winter storage. This pattern shows a clear link between Cu and Zn concentrations and boating activity, with antifouling paints as the principal source.

Monitoring biofouling as a management tool for reducing toxic antifouling practices in the Baltic Sea.

Over two million leisure boats use the coastal areas of the Baltic Sea for recreational purposes. The majority of these boats are painted with toxic antifouling paints that release biocides into the coastal ecosystems and negatively impact non-targeted species. Regulations concerning the use of antifouling paints differ dramatically between countries bordering the Baltic Sea and most of them lack the support of biological data.

Increase in stable isotope ratios driven by metabolic alterations in amphipods exposed to the beta-blocker propranolol.

Anthropogenic pressures, such as contaminant exposure, may affect stable isotope ratios in biota. These changes are driven by alterations in the nutrient allocation and metabolic pathways induced by specific stressors. In a controlled microcosm study with the amphipod Gammarus spp.

How Important is Bioturbation for Sediment-to-Water Flux of Polycyclic Aromatic Hydrocarbons in the Baltic Sea?

In the present study a recently developed benthic flow-through chamber was used to assess the sediment-to-water flux of polycyclic aromatic hydrocarbons (PAHs) at 4 sites on the Swedish Baltic Sea coast. The flow-through chamber allows for assessment of the potential effect of bioturbation on the sediment-to-water flux of hydrophobic organic contaminants. The sediments at the 4 investigated sites have both varying contamination degree and densities of bioturbating organisms.

Transferring mixtures of chemicals from sediment to a bioassay using silicone-based passive sampling and dosing.

Environmental mixtures of chemicals consist of a countless number of compounds with unknown identity and quantity. Yet, chemical regulation is mainly built around the assessment of single chemicals. Existing frameworks for assessing the toxicity of mixtures require that both the chemical composition and quantity are known.

In situ benthic flow-through chambers to determine sediment-to-water fluxes of legacy hydrophobic organic contaminants.

Contaminated sediment can release hydrophobic organic contaminants (HOCs) and thereby act as a secondary source of primarily legacy hazardous substances to the water column. There is therefore a need for assessments of the release of HOCs from contaminated sediment for prioritization of management actions. In situ assessment of HOC sediment-to-water flux is currently done with (closed) benthic flux chambers, which have a sampling time exceeding one month.

Metal contamination in harbours impacts life-history traits and metallothionein levels in snails.

Harbours with limited water exchange are hotspots of contaminant accumulation. Antifouling paints (AF) contribute to this accumulation by leaching biocides that may affect non-target species. In several leisure boat harbours and reference areas in the Baltic Sea, chronic exposure effects were evaluated using caging experiments with the snail Theodoxus fluviatilis.

Mortality and histopathological effects in harbour-transplanted snails with different exposure histories.

Contaminants are important stressors in the aquatic environment and may exert selective pressures on organisms. We hypothesized that snails originating from a metal-contaminated habitat (B) would have increased tolerance to harbour contaminants (e.g.

Biofouling of leisure boats as a source of metal pollution.

The release of harmful metals from antifouling paints to water bodies is a well-known problem. In this study, we measured both the amount of biofouling growth on leisure boats during one season as well as the concentration of metals accumulated by the biofouling matrix. Furthermore, the efficiency of antifouling paints and mechanical boat cleaning as well as the effect of hull colour on biofouling were evaluated.

Pollutant Concentrations and Toxic Effects on the Red Alga Ceramium tenuicorne of Sediments from Natural Harbors and Small Boat Harbors on the West Coast of Sweden.

This investigation set out to analyze the toxicity of surface sediments in a number of natural harbors and small boat harbors on the west coast of Sweden. This was done with the growth inhibition method with Ceramium tenuicorne. Also, concentrations of copper (Cu), lead (Pb), zinc (Zn), irgarol, organotin compounds, and polycyclic aromatic hydrocarbons (PAHs) in the sediments were analyzed.

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.

Sucralose induces biochemical responses in Daphnia magna.

The intense artificial sweetener sucralose has no bioconcentration properties, and no adverse acute toxic effects have been observed in standard ecotoxicity tests, suggesting negligible environmental risk. However, significant feeding and behavioural alterations have been reported in non-standard tests using aquatic crustaceans, indicating possible sublethal effects. We hypothesized that these effects are related to alterations in acetylcholinesterase (AChE) and oxidative status in the exposed animals and investigated changes in AChE and oxidative biomarkers (oxygen radical absorbing capacity, ORAC, and lipid peroxidation, TBARS) in the crustacean Daphnia magna exposed to sucralose (0.

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).

Sucralose - an ecotoxicological challenger?

The non-calorie sweetener sucralose - sucrose containing three chlorine atoms - is intensively sweet and has become a popular substitute for sugar. Its widespread use, exceptional stability in combination with high water solubility have thus resulted in contamination of recipient waters. Earlier studies on sucralose in aquatic organisms indicate low bioaccumulation potential and negligible acute/chronic toxicity, but the close structural resemblance with sucrose in combination with the importance of sugar in nature, warrant a more detailed ecotoxicological assessment.

Avoidance response of sediment living amphipods to zinc pyrithione as a measure of sediment toxicity.

An avoidance test was developed using non-cultured individuals of the sediment dwelling amphipod Monoporeia affinis. As test substance we used zinc pyrithione, an antifouling agent and a common shampoo ingredient. The toxicity to Daphnia and fish is well known but sediment toxicity of this very hydrophobic compound is less known.

Toxicity evaluation by using intact sediments and sediment extracts.

The toxicity of intact sediments and sediment extracts, from both an uncontaminated site and a site contaminated by pulp-mill effluents, was tested in a five months study. The deposit-feeding amphipod Monoporeia affinis was exposed in soft-bottom flow-through water microcosms. To examine potential toxicity a set of reproduction endpoints was used including fecundity and different embryo aberrations such as malformed eggs.

Evaluation of the role of black carbon in attenuating bioaccumulation of polycyclic aromatic hydrocarbons from field-contaminated sediments.

The significance of black carbon (BC) for the bioavailability of polycyclic aromatic hydrocarbons (PAHs) was examined by using historically contaminated intact sediment cores in laboratory exposure experiments with the deposit-feeding amphipod Monoporeia affinis. Log values of amphipod biota-sediment accumulation factors (BSAFs) were significantly related to log BC, whereas log BSAFs were related to log octanol-water partition coefficients only in background sediments containing less BC. In the background sediments, the BSAF for polycyclic aromatic hydrocarbons (PAHs) was 1 to 2 for phenanthrene, with lower values for more hydrophobic PAHs, indicating an increase in nonequilibrium conditions with increasing PAH molecular size.

Dynamics of lipids and polychlorinated biphenyls in a Baltic amphipod (Monoporeia affinis): a field study.

Processes such as accumulation and elimination, which control tissue concentration of polychlorinated biphenyls (PCBs), were examined over time in an in situ study of the amphipod Monoporeia affinis. These processes were studied with respect to individual PCB congeners, percentage lipid and composition, and body weight. A secondary objective was to examine the impact of seasonal variability in percentage lipids and lipid composition on PCB concentration in two coexisting Baltic amphipods, M.

Bioavailability of metals to the amphipod Monoporeia affinis: interactions with authigenic sulfides in urban brackish-water and freshwater sediments.

Could reduced eutrophication be a potential environmental threat because of increased mobility and bioavailability of trace metals? This question was addressed by oxygenating intact sediment cores, varying in redox potential and salinity, in a test system containing the amphipod Monoporeia affinis. Results show a low mobility of metals during oxygenation, and despite high concentrations of metals in sediments, only Pb showed a notable degree of bioaccumulation. Cadmium was bioaccumulated particularly in freshwater sediment, and body burden of Cd was related to salinity, porewater, and sediment concentrations.