Streamside mobile mesocosms (MOBICOS): A new modular research infrastructure for hydro‐ecological process studies across catchment‐scale gradients

Abstract

A key research aim for lotic ecosystems is the identification of natural and anthropogenic pressures that impact ecosystem status and functions. As a consequence of these perturbations, many lotic ecosystems are exposed to complex combinations of nonchemical and chemical stressors. These stressors comprise temperature fluctuations, flow alterations, elevated solute loads or xenobiotics, and all these factors can pose stress upon aquatic ecosystems on different temporal, spatial and biological scales. Factorial experiments are essential to reveal causal relationships especially between combined stressors and their effects in the environment. However, experimental tools that account for the complexity of running waters across different ecosystem compartments, levels of biological organisation, natural or anthropogenic environmental gradients, and replicability are rare. Here we present a new research infrastructure consisting of streamside mobile mesocosms (MOBICOS) that allows analysing the effects of stressors and stressor combinations through multifactorial experiments in near-natural settings and across anthropogenic pressure gradients. Consisting of eight container-based running water laboratories operated as bypasses to running surface waters, MOBICOS combines in situ real-time monitoring of physicochemical and biological parameters with manipulative experiments across ranges of environmental conditions. Different flume types can be set up within MOBICOS to separate and combine different ecosystem compartments (pelagic, epibenthic and hyporheic zones) in a flexible and modular way. Due to its compact design, the MOBICOS units can be shifted easily to particular sites of interest. Furthermore, simultaneous operation of multiple MOBICOS units at different sites allows the integration of natural gradients in multifactorial experiments. We highlight the versatility of the MOBICOS -This is an open access article under the terms of the Creative Commons Attribution-NonCommercial License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited and is not used for commercial purposes. Markus Weitere and Dietrich Borchardt are senior authors.

The fate of sulfonamide resistance genes and anthropogenic pollution marker intI1 after discharge of wastewater into a pristine river stream

“…Afterwards, the samples were transported to the laboratory within 3 h in a thermostable box. At Sites 1 and 5, physicochemical parameters pH, water temperature [°C], conductivity [mS/cm] and -N [mg/L] were obtained in the MOBICOS monitoring stations located at the river ( Fink et al, 2020 ). Physicochemical parameters from Site 3 (WWTP effluent) were kindly provided by the WWTP Silstedt.…”

Resource-dependent foraging behaviour of grazers enhances effects of nutrient enrichment on algal biomass

“…The experiment was performed in the MOBICOS mesocosm facility, a container-based laboratory equipped with flumes fed by a river bypass (Fink et al 2020 ) located by the river Holtemme in Wernigerode, central Germany (51°49′00.7″ N, 10°43′29.26″ E) at a relatively pristine site directly downstream of the Harz National Park. At this site, the river still has full canopy cover from riparian broadleaf vegetation and moderate dissolved organic carbon (mostly refractory DOC) and inorganic nitrogen concentrations (approx.…”

“…3 in Weitere et al 2021 ). As a consequence, algal C:N ratios do not respond to changes in nitrogen availability, and phosphorus (< 3 µg L −1 ambient soluble reactive phosphorus, SRP) and light availability are the main limiting factor for primary production at this site (Fink et al 2020 ; Weitere et al 2021 ).…”

Sources and Fate of the Antiandrogenic Fluorescent Dye 4‐Methyl‐7‐Diethylaminocoumarin in Small River Systems

“…The sampling frequency for each subsample was 100 minutes (site 17) or 60 minutes (sites 3, 38). Two of the LVSPE samplers were installed in automated measurement stations (UFZ MOBICOS) located at the Holtemme River (Fink et al, 2020) and one in a closed trailer. The sample inlets for LVSPE were located approximately 50 cm distance from and 15 to 20 cm above the streambed under base flow conditions.…”