Biology subjects

Friedrichs-Manthey, M.

Publications and source records attributed to Friedrichs-Manthey, M..

3 recordsLinked to original sources

bioRxiv2025

Unraveling long-term trends and drivers of fish biodiversity change using environmental DNA metabarcoding of archived samples

AbstractLong-term biodiversity data are critical for assessing, understanding, and predicting ecosystem change globally, but are often limited by their availability. We present the longest eDNA metabarcoding time series for freshwater fishes based on archived suspended particulate matter (SPM) from Germanys Environmental Specimen Bank, covering 17 years (2005-2021) across six major European river systems (Rhine, Danube, Elbe, and their tributaries). From 211 annual samples collected according to highly standardized procedures at 13 sites, we detected 63 fish and lamprey species and traced their spatio-temporal trajectories. eDNA metabarcoding captured significantly declining trends at multiple sites with no recoveries. Common and sensitive species declined at nearly half of sites while invasive species spread. Site occupancy and relative read abundance trends were correlated, providing semi-quantitative indicators. Alpha and beta diversity shifted over time and Bayesian hierarchical models revealed that 19% of species showed significant declines in relative read abundance. The eDNA-derived trends showed strong concordance with long-term regulatory fish monitoring data, validating the patterns across methodological approaches. Random forest models and multivariate analyses identified multiple anthropogenic pollutants, measured from the same SPM samples, as drivers of biodiversity patterns. Pesticides, heavy metals, temperature, and fine sediment negatively affected species richness, with site-specific stressor combinations explaining 29% of community variation. Our results demonstrate that archived SPM, originally collected for chemical monitoring, provides a reliable, dual-purpose monitoring matrix integrating pollution and biodiversity trend assessments simultaneously. This approach enables holistic monitoring of global freshwater ecosystem change and can provide an early warning framework supporting evidence-based environmental management.

ecology↗

bioRxiv2024

Using nature-based citizen science initiatives to enhance nature connection and mental health.

The global rise in mental health issues underscores the critical importance of assessing the mental health benefits of engaging with nature. Beyond their primary aim of involving citizens in scientific data collection, nature-based citizen science initiatives offer significant potential for enhancing conservation (e.g. connection to nature) and human health and wellbeing (e.g. emotions, depression, stress, anxiety) outcomes. However, the effectiveness of various types of initiatives in achieving specific health outcomes remain unclear. This study evaluates changes in eight nature connection and health and wellbeing outcomes before and after participation in five such initiatives, specifically three dimensions of connection to nature (Self, Experience and Perspective) measured by the Nature Relatedness scale), and mental health outcomes--depression, stress and anxiety--measured by the DASS-21 scale; along with positive and negative emotions assessed using the Scale of Positive and Negative Experience (SPANE). We found that participants generally reported improvements across all outcomes, but only positive emotions and reduced anxiety and stress symptoms were significantly enhanced. This suggests that short-term nature-based interventions are effective in boosting emotions and alleviating anxiety and stress, though significant changes in nature connection and depression may require prolonged or more intensive engagement. We also found that the Queensland Trust for Nature initiative, characterized by its extended duration and social interactions, emerged as a particularly effective model in achieving synergies between biodiversity and human health goals. Consequently, we advocate for the reimagining of these nature-based initiatives as integral components of broader health-promoting strategies. By aligning citizen science efforts with health promotion frameworks, we can amplify the utility and impact of nature-based citizen science initiatives, enhancing their contributions to scientific knowledge, nature conservation and human health.

ecology↗

bioRxiv2021

300 years of change for native fish species in the upper Danube River Basin - historical flow alterations versus future climate change

River ecosystems belong to the most threatened ecosystems on Earth. Historical anthropogenic alterations have, and future climate change will further affect river ecosystems and the species therein. While many studies assess the potential effects of expected future changes on species, little is known about the severity of these changes compared to historical alterations. Here, we used a unique 300-year time series of hydrological and climate data to assess the vulnerability of 48 native fish species in the upper Danube River Basin. We calculated species-specific vulnerability estimates relative to the reference period (1970-2000) for the periods 1800-1830, 1900-1930, and 2070-2100, including two Representative Concentration Pathways (RCP 4.5 and 8.5) and identified the environmental drivers of vulnerability estimates. Models showed that future changes under RCP 4.5 would result in moderate species vulnerability compared to historical conditions, while under RCP 8.5, the vulnerability for all species increased substantially. In addition, species vulnerability was mainly driven by hydrology in the past and is likely to be driven by temperature in the future. Our results show that future climate change would alter environmental conditions for riverine fish species at a similar magnitude as historical anthropogenic hydrological river alterations have. Shedding light on such long-term historical and possible future anthropogenic alterations provides valuable insights for prioritising conservation actions for riverine fish species.

ecology↗