Metacommunities, metaecosystems and the environmental fate of chemical contaminants

Abstract

Although pollution is a major driver of ecosystem change, models predicting the environmental fate of contaminants suffer from critical uncertainties related to oversimplifying the dynamics of the biological compartment. It is increasingly recognized that contaminant processing is an outcome of ecosystem functioning, that ecosystem functioning is contingent on community structure and that community structure is influenced by organismal dispersal. We propose a conceptual organization of the contribution of organismal dispersal to local contaminant fate. Direct dispersal effects occur when the dispersing organism directly couples contaminant stocks in spatially separate ecosystems by transporting contaminants in its biomass. Indirect dispersal effects occur when the dispersing organism indirectly influences contaminant fate via community assembly. This can occur either when the dispersing organism is a contaminant processor or when the dispersing organism alters, via species interactions, the abundance of contaminant biotransporters or processors already established in the ecosystem. The magnitude of direct and indirect dispersal effects is modulated by many factors, including other contaminants. These will influence population growth rates of the dispersing species in the donor ecosystem, or the probability that a dispersing individual reaches the recipient ecosystem. We provide a review of pertinent literature demonstrating that these two mechanisms, and their chemical modulation, are well supported or likely to occur in many natural and human‐modified landscapes. The literature also demonstrates that they can operate in concert with each other. Synthesis and applications. Managed ecosystems thought to be important contaminant and nutrient sinks, such as artificial ponds and constructed wetlands, should be monitored and controlled for in‐and‐out animal movement if contaminant export is found to be relevant. Uncontaminated fishing grounds linked to contaminated sites via movement of dispersing species should be monitored and resident species evaluated for health consumption advisories. Assessing the success of contaminated site remediation can be improved by better matching the spatial extent of site remediation and the home range of monitored species. Finally, interagency research fund programmes should be developed that narrow the current gap between the fields of ecology and ecotoxicology.

Contaminant Subsidies to Riparian Food Webs in Appalachian Streams Impacted by Mountaintop Removal Coal Mining

“…Furthering our understanding of the ecological processes that govern contaminant fate and exposure is a key step toward managing risks in these linked aquatic−terrestrial food webs impacted by mining activities. 80 ■ ASSOCIATED CONTENT * sı Supporting Information The Supporting Information is available free of charge at https://pubs.acs.org/doi/10.1021/acs.est.9b05907.…”

Spatial avoidance as a response to contamination by aquatic organisms in nonforced, multicompartmented exposure systems: A complementary approach to the behavioral response

“…Therefore, it is assumed that if mobile organisms are able to identify either lethal or sublethal contaminant concentrations, they might avoid the continuous exposure (Cherry et al ; Gray ; Tierney ). The ability to move and escape from contaminants might determine the spatial distribution of organisms and the migration behavior (Gray ; Åtland and Barlaup ; Hansen et al ) and, consequently, affect the ecosystem's dynamics and functioning (Hidaka and Tatsukawa ; Schiesari et al ). For instance, behavior related to movement patterns has been used with Daphnia magna as an early warning of environmental disturbance by online biomonitoring (Ren et al ; Cano et al ; Parolini et al ).…”

“…The absence of attractive areas or even the absence of connectivity between ecosystems could lead to a mandatory and continuous exposure to contaminants. Because many aquatic ecosystems/habitats are connected, ecotoxicological studies should also complementarily focus on integrated ecosystem assessment rather than local ecosystems alone (Schiesari et al ). Despite the limited spatial scale of laboratory simulations, connectivity has been tested by simulating the chemical fragmentation of a habitat in a nonforced exposure system (Araújo et al ).…”

A diverse suite of pharmaceuticals contaminates stream and riparian food webs

“…This study examines the fate of pharmaceutical contaminants within the aquatic biota as well as the inferred transfer of contaminants from emerging adult insects to riparian predators, thus employing a meta-community approach that is uncommon in the field of ecotoxicology 17 . Recent laboratory and field studies demonstrate that a diversity of pharmaceuticals can be found in aquatic animals and riparian consumers in water bodies receiving wastewater effluents 18 , but each of these studies focused on a limited number of species and chemicals 19 – 21 .…”