Biology subjects

Ogonowski, M.

Publications and source records attributed to Ogonowski, M..

9 recordsLinked to original sources

bioRxiv2026

Field-derived temperature correction compromises eDNA-based abundance inference

Environmental DNA (eDNA) has emerged as a promising tool for estimating fish abundance, yet linking eDNA concentration to true density remains a significant challenge in seasonal systems, where the signal is strongly influenced by temperature. We investigated whether eDNA can serve as an abundance index for three-spined stickleback (Gasterosteus aculeatus) in four coastal bays of the Baltic Sea (5.7-20.5{degrees}C, April-July 2023), by pairing eDNA sampling with two trap types of contrasting catchability. Light traps capture fish by phototactic attraction during darkness, so their catchability is driven primarily by night duration rather than temperature, while benthic traps respond to temperature through the same activity-driven mechanism as eDNA production. The temperature sensitivity of eDNA estimated from field data was far higher than physiological expectation (Q10 = 12.4, against a maximum metabolic rate benchmark of Q10 = 3.5), indicating that the field temperature signal reflects ecological change in addition to metabolism. We then compared how well three eDNA predictors tracked a combined trap-based abundance index: uncorrected eDNA, eDNA corrected with the temperature response constrained to the laboratory metabolic rate (a first-principles correction), and eDNA corrected with the response estimated from the field data. Uncorrected and first-principles-corrected eDNA were both strong predictors of abundance (standardised slopes of 0.45 and 0.43), whereas the field-corrected predictor was not (0.08). Uncorrected and first-principles-corrected eDNA performed comparably because temperature and abundance increased together over the season; the first-principles correction is nonetheless preferable, as it remains reliable when this covariation is unknown a priori. We conclude that estimating a temperature correction from field data should be avoided in seasonal eDNA monitoring, because it removes the abundance signal together with the temperature effect and assumes a stability in abundance that cannot be verified without independent reference data.

ecology↗

bioRxiv2026

Optimizing Light Traps for Littoral Mysids and Mesopredatory Fish in the Baltic Sea: Environmental Drivers and Seasonal Monitoring Efficacy

1Littoral mysids facilitate benthic-pelagic coupling through horizontal migration, yet quantitative monitoring in structurally complex habitats remains methodologically challenged where traditional active gears fail. We evaluated the efficacy of standardized light traps for monitoring littoral mysids (Neomysis integer, Praunus flexuosus) and mesopredatory three-spined sticklebacks (Gasterosteus aculeatus) in the northern Baltic proper, Baltic Sea. Using a paired experimental design with predator-exclusion and unmodified traps, alongside concurrent passive benthic trapping, we assessed abiotic drivers affecting catchability, biotic interactions, and statistical power to monitor changes in population size over time. Results indicated significant biotic interference: unmodified traps attracted high densities of sticklebacks, which reduced mysid catches by approximately 85% through predation or behavioural avoidance. Consequently, physical predator exclusion is mandatory for accurate mysid sampling. Generalized Linear Mixed Models (GLMMs) confirmed that catch rates for all taxa were primarily driven by night duration rather than water temperature. While passive benthic trap catches tracked metabolic activity (peaking in warm summer months), light trap efficiency peaked in spring and collapsed during summer, confirming that sampling efficiency was strictly limited by the short duration of the night. Simulation-based power analysis revealed a stark contrast in monitoring utility based on spatial aggregation. For highly aggregated mysids, the method demonstrated low precision (Power < 0.25 to detect a 50% decline), rendering it suitable primarily for detecting substantial population collapses (>90%). In contrast, for less aggregated sticklebacks, the method achieved a more robust statistical power (>0.80 for a 60% decline), validating light traps as a precise tool for monitoring these abundant mesopredators. We conclude that light traps fill a critical methodological gap for winter and early spring monitoring when traditional passive gears underperform. Appropriate abundance indices should be based on statistical models accounting for night duration and strictly employ physical exclusion barriers when targeting mysids.

ecology↗

bioRxiv2022

Temperature moderates eDNA-biomass relationships in northern pike

Support for eDNA as a quantitative monitoring tool is growing worldwide. Despite advances there are still uncertainties regarding the representability of the eDNA signal over varying spatiotemporal scales, influence of abiotic forcing and phenological changes affecting behavior of the study organism, particularly in open environments. To assess the spatiotemporal variability and predictive power of quantitative eDNA analysis, we applied species-specific real-time quantitative PCR on water filtrates during two visits to 22 coastal bays in the Baltic Sea. Within bays, we collected water along four transects across each bay and compared the pooled eDNA concentration to temporally matched catches from standardized angling targeting the northern pike (Esox lucius) a species for which reliable monitoring data is lacking. We found the variability in eDNA concentrations between transects to be moderate (21%) but still considerably lower than across bays and visits (52%), suggesting small scale spatial differences are of less importance during spring when pike spawn. Standardized angling catches, bay area, and water temperature together explained 48% of the variance in eDNA concentrations. DNA concentrations decreased with increasing bay area, likely indicating a dilution effect. Notably, the relationship between eDNA and standardized catches was positive but varied with temperature and the eDNA-abundance relationship was only significant at higher temperatures, which also coincided with a higher proportion of spawning/spent fish. We conclude that temperature is a key moderating factor driving changes in pike behaviour and spring DNA-dynamics. We recommend that future surveys focus on larger spatiotemporal scales during times when the influence of changing temperatures is minimized.

ecology↗

bioRxiv2022

What is particular about microplastics? A meta-analysis of the toxicity of microplastics and suspended sediments

Microplastics (MP) are perceived as a threat to aquatic ecosystems but bear many similarities to suspended sediments which are often considered less harmful. It is, therefore pertinent to determine if and to what extent MPs are different from other particles occurring in aquatic ecosystems in terms of their adverse effects. We applied meta-regressions to hazard data extracted from the literature and harmonized the data to construct Species Sensitivity Distributions (SSDs) for both types of particles. The results demonstrate that the average toxicity of MPs is approximately one order of magnitude higher than that of suspended solids. However, the estimates were associated with large uncertainties and did not provide very strong evidence. In part, this is due to the general lack of comparable experimental studies and dose-dependent point estimates. We, therefore, argue that a precautionary approach should be used and MP in the 1-1000 {micro}m size range should be considered moderately more hazardous to aquatic organisms capable of ingesting such particles. Organisms inhabiting oligotrophic habitats like coral reefs and alpine lakes, with naturally low levels of non-food particles are likely more vulnerable, and it is reasonable to assume that MP pose a relatively higher risk to aquatic life in such habitats. SynopsisA meta-analysis indicates that microplastics are one order of magnitude more toxic than suspended sediments/solids, an estimate surrounded by considerable uncertainty. Graphical abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=110 SRC="FIGDIR/small/514507v2_ufig1.gif" ALT="Figure 1"> View larger version (46K): org.highwire.dtl.DTLVardef@18826c5org.highwire.dtl.DTLVardef@1a98189org.highwire.dtl.DTLVardef@17762d7org.highwire.dtl.DTLVardef@fa4a6d_HPS_FORMAT_FIGEXP M_FIG C_FIG

ecology↗

bioRxiv2019

Disparate effects of antibiotic-induced microbiome change and enhanced fitness in Daphnia magna

It is a common view that an organisms microbiota has a profound influence on host fitness; however, supporting evidence is lacking in many organisms. We manipulated the gut microbiome of Daphnia magna by chronic exposure to different concentrations of the antibiotic Ciprofloxacin (0.01 - 1 mg L-1), and evaluated whether this affected the animals fitness and antioxidant capacity. In line with our expectations, antibiotic exposure altered the microbiome in a concentration-dependent manner. However, contrary to these expectations, the reduced diversity of gut bacteria was not associated with any fitness detriment. Moreover, the growth-related parameters correlated negatively with diversity indices; and, in the daphnids exposed to the lowest ciprofloxacin concentrations, the antioxidant capacity, growth, and fecundity were even higher than in control animals. These findings suggest that ciprofloxacin exerts direct stimulatory effects on growth and reproduction in Daphnia, while microbiome-mediated effects are of lesser importance. Thus, although microbiome profiling of Daphnia may be a sensitive tool to identify early effects of antibiotic exposure, disentangling direct and microbiome-mediated effects on host fitness is not straightforward.

pharmacology and toxicology↗

bioRxiv2018

Microplastic-mediated transport of PCBs? A depuration study with Daphnia magna

The role of microplastic (MP) as a carrier of persistent organic pollutants (POPs) to aquatic organisms has been a topic of debate. However, theoretically, the reverse POP transport can occur at higher relative contaminant concentrations in the organism than in the microplastic. The effect of microplastic on the PCB removal in planktonic animals was evaluated using the cladoceran Daphnia magna with a high body burden of polychlorinated biphenyls (PCB 18, 40, 128 and 209) exposed to a mixture of microplastic and algae (with 77% MP by mass); daphnids exposed to only algae served as the control. As the endpoints, we used PCB body burden, growth, fecundity and elemental composition (%C and %N) of the daphnids. We found that PCB 209 was removed more efficiently in the daphnids fed with microplastic, while there was no difference for the {Sigma}PCBs between the microplastic-exposed and control animals. Effects of the microplastic exposure on fecundity were of low biological significance, even though both the starting PCB body burden and the microplastic exposure concentrations were high and greatly exceeding environmentally relevant concentrations.

pharmacology and toxicology↗

bioRxiv2018

Alterations in swimming behavior of Daphnia exposed to polymer and mineral particles: towards understanding effects of microplastics on planktonic filtrators

Concerns have been raised that microplastics (MP) can impact aquatic organisms by compromising their nutrition. However, little is understood about the mechanisms of the adverse effects of MP in suspension-feeders that routinely ingest particles of low nutritional value, such as mineral particles. We compared effects of non-edible particles (MP and kaolin) mixed with microalgae on the swimming and filtering behavior of a planktonic filtrator Daphnia magna; incubations with only algae served as controls. The following questions were addressed: (1) Are there differences in swimming movements between the daphnids exposed to MP and those exposed to kaolin? and (2) Whether occurrence of biofilm on the particle surface affects daphnid swimming and how these effects differ between the kaolin- and MP-exposed animals? We found that both kaolin and MP altered swimming, yet in opposite way, with a decrease of filtration-related movements in kaolin and their increase in MP. The difference was amplified in biofilm coated particles, indicating that daphnids spend more energy when swimming in suspension with MP, and even more when the MP have biofilm. The increased swimming activity of filtrators exposed to plastic litter decaying to microparticles may translate into changes in energy balance and growth.

ecology↗

bioRxiv2018

A serial dilution method for assessment of microplastic toxicity in suspension

The occurrence of microplastic (MP) in the environment is of global concern. MP risk assessment, however, is currently hampered by lacking ecotoxicological methods due to conceptual and practical problems with particle exposure. Natural particles of similar size as MP, e.g., clay and cellulose, occur abundantly in the environment. For MP risk assessment and regulation it must be established whether the addition of MP to these particles represents an additional hazard. We present a novel approach employing a serial dilution of MP and reference particles, in mixtures, which allows the differentiation of MP effects from other particulates. We demonstrate the applicability of the method using an immobilisation test with Daphnia magna exposed to polyethylene terephthalate (MP) and kaolin clay (reference material). In the concentration range of 0.1 to 10000 mg L-1 of total suspended solids (TSS), with MP contributing 0-100 %, the LC50 values for MP-kaolin mixtures were significantly lower compared to the pure kaolin suspension. MP particles were thus more harmful to daphnids than the reference material. The estimated threshold for %MP contribution above which higher mortality was observed was 1 % MP at 36 mg TSS L-1. This approach has a potential for standardisation of MP ecotoxicological testing as well as other particulate material of anthropogenic origin.\n\n\n\nO_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=112 SRC=\"FIGDIR/small/401331_ufig1.gif\" ALT=\"Figure 1\">\nView larger version (40K):\norg.highwire.dtl.DTLVardef@13e1153org.highwire.dtl.DTLVardef@1e37652org.highwire.dtl.DTLVardef@6d3efborg.highwire.dtl.DTLVardef@420d7a_HPS_FORMAT_FIGEXP M_FIG C_FIG

pharmacology and toxicology↗

bioRxiv2018

Hydrophobic organic contaminants are not linked to microplastic uptake in Baltic Sea herring

It is commonly accepted that microplastic (MP) ingestion can lead to lower food intake and bioaccumulation of hydrophobic organic contaminants (HOCs) in aquatic organisms. However, causal links between MP and contaminant levels in biota are poorly understood and in situ data are very limited. Here, we investigated whether HOC concentrations in herring muscle tissue (Clupea harengus membras) are related to MP ingestion using fish caught along the West coast of the Baltic Sea. The MP occurrence exhibited a large geographic variability, with MP found in 22.3% of the fish examined. The population average was 1.0 MP ind-1; however, when only individuals containing MP were considered, the average MP burden was 4.4 MP ind-1. We also found that MP burden decreased with reproductive stage of the fish but increased with its body size. To predict MP abundance in fish guts, we constructed a mass-balance model using literature data on MP in the water column and physiological rates on ingestion and gut evacuation for clupeids of a similar size. The model output was in agreement with the observed values, thus supporting the validity of the results. Contaminant concentrations in the muscle tissue were unrelated to the MP levels in fish, suggesting a lack of direct links between the levels of HOCs and MP ingestion. Thus, despite their ubiquity, MP are unlikely to have a measurable impact on food intake or the total body burden of hydrophobic contaminants in Baltic herring. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=80 SRC="FIGDIR/small/363127v3_ufig1.gif" ALT="Figure 1"> View larger version (22K): org.highwire.dtl.DTLVardef@4cb5b6org.highwire.dtl.DTLVardef@2de3c8org.highwire.dtl.DTLVardef@c58baborg.highwire.dtl.DTLVardef@154b828_HPS_FORMAT_FIGEXP M_FIG C_FIG

pharmacology and toxicology↗