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School of Environment and Sustainability

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Browsing School of Environment and Sustainability by Author "Brinkmann, Markus"

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    Assessing the fate of brown trout (Salmo trutta) environmental DNA in a natural stream using a sensitive and specific dual-labelled probe
    (Elsevier, 2019) Deutschmann, Björn; Müller, Anne-Kathrin; Hollert, Henner; Brinkmann, Markus
    Environmental DNA (eDNA) analysis in the aquatic environment has emerged as a promising tool for diagnosis of the ecological status in comprehensive monitoring strategies and might become useful in context of the European Water Framework Directive (WFD) and other legislations to derive stressor-specific indicators. Despite many studies having made significant progress for the future use of eDNA in terms of ecosystem composition and detection of invasive/rare species in inland waters, much remains unknown about the transport and fate of eDNA under natural environmental conditions. We designed a specific dual-labelled probe to detect brown trout (Salmo trutta, L.) eDNA and used the probe to describe the fate of eDNA released from an aquaculture facility into the low mountain range stream Wehebach, Germany. The probe was shown to be specific to brown trout, as ponds housing rainbow trout (Oncorhynchus mykiss) did not test positive. Even though we observed different strengths of eDNA signals for three ponds containing different brown trout quantities, no significant correlation was found between biomass (kg/L) and eDNA quantity. Our results indicate that the release of DNA from brown trout might be life stage and/or age-dependent. The effluents of the aquaculture facility were a source of high levels of eDNA which resulted in the greatest abundance of brown trout eDNA directly downstream of the facility. Despite the natural occurrence of brown trout in the Wehebach, as shown by ecological investigations conducted by authorities of the federal state of North Rhine-Westphalia (Germany) and personal observations, we observed a significant decrease of relative abundance of eDNA in the Wehebach within the first 1.5 km downstream of the aquaculture. Our results suggest that concentrations of eDNA in running waters rapidly decrease under natural conditions due to dilution and degradation processes, which might have important implications for the utility of eDNA in environmental research.
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    Looking back - looking forward: A novel multi-time slice weight-of-evidence approach for defining reference conditions to assess the impact of human activities on lake systems
    (Elsevier, 2018) Hollert, Henner; Crawford, Sarah E.; Brack, Werner; Brinkmann, Markus; Fischer, Elske; Hartmann, Kai; Keiter, Steffen; Ottermanns, Richard; Ouellet, Jacob; Rinke, Karsten; Roß-Nickoll, Martina; Schäffer, Andreas; Schüth, Christoph; Schulze, Tobias; Schwarz, Anja; Seiler, Thomas-Benjamin; Wessels, Martin; Hinderer, Matthias; Schwalb, Antje
    Lake ecosystems are sensitive recorders of environmental changes that provide continuous archives at annual to decadal resolution over thousands of years. The systematic investigation of land use changes and emission of pollutants archived in Holocene lake sediments as well as the reconstruction of contamination, background conditions, and sensitivity of lake systems offer an ideal opportunity to study environmental dynamics and consequences of anthropogenic impact that increasingly pose risks to human well-being. This paper discusses the use of sediment and other lines of evidence in providing a record of historical and current contamination in lake ecosystems. We present a novel approach to investigate impacts from human activities using chemical-analytical, bioanalytical, ecological, paleolimnological, paleoecotoxicological, archeological as well as modeling techniques. This multi-time slice weight-of-evidence (WOE) approach will generate knowledge on conditions prior to anthropogenic influence and provide knowledge to (i) create a better understanding of the effects of anthropogenic disturbances on biodiversity, (ii) assess water quality by using quantitative data on historical pollution and persistence of pollutants archived over thousands of years in sediments, and (iii) define environmental threshold values using modeling methods. This technique may be applied in order to gain insights into reference conditions of surface and ground waters in catchments with a long history of land use and human impact, which is still a major need that is currently not yet addressed within the context of the European Water Framework Directive.