Geology topics

Anya N. Metcalfe

Publications and source records attributed to Anya N. Metcalfe.

4 recordsLinked to original sources

USGS2022

Applied citizen science in freshwater research

Worldwide, scientists are increasingly collaborating with the general public. Citizen science methods are readily applicable to freshwater research, monitoring, and education. In addition to providing cost-effective data on spatial and temporal scales that are otherwise unattainable, citizen science provides unique opportunities for engagement with local communities and stakeholders in resource management and decision-making. However, these methods are not infallible. Citizen science projects require deliberate planning in order to collect high data quality and sustain meaningful community partnerships. Citizen science practitioners also have an ethical responsibility to ensure that projects are not putting the safety of participants at stake. We discuss here how citizen science is being applied in freshwater research, emerging challenges in project planning and implementation, as well as how citizen science is shaping public understanding, policy, and management of freshwaters.

WIREs Water↗

USGS2021

The application of metacommunity theory to the management of riverine ecosystems

River managers strive to use the best available science to sustain biodiversity and ecosystem function. To achieve this goal requires consideration of processes at different scales. Metacommunity theory describes how multiple species from different communities potentially interact with local-scale environmental drivers to influence population dynamics and community structure. However, this body of knowledge has only rarely been used to inform management practices for river ecosystems. In this article, we present a conceptual model outlining how the metacommunity processes of local niche sorting and dispersal can influence the outcomes of management interventions and provide a series of specific recommendations for applying these ideas as well as research needs. In all cases, we identify situations where traditional approaches to riverine management could be enhanced by incorporating an understanding of metacommunity dynamics. A common theme is developing guidelines for assessing the metacommunity context of a site or region, evaluating how that context may affect the desired outcome, and incorporating that understanding into the planning process and methods used. To maximize the effectiveness of management activities, scientists, and resource managers should update the toolbox of approaches to riverine management to reflect theoretical advances in metacommunity ecology.

WIREs Water↗

USGS2020

Spatial population structure of a widespread aquatic insect in the Colorado River Basin: Evidence for a Hydropsyche oslari species complex

Structural connectivity and dispersal ability are important constraints on functional connectivity among populations. For aquatic organisms that disperse among stream corridors, the regional structure of a river network can, thus, define the boundaries of gene flow. In this study, we used mitochondrial DNA (mtCO1 barcoding gene) to examine the genetic diversity and population structure of a caddisfly with strong dispersal capabilities, Hydropsyche oslari (Trichoptera:Hydropsychidae), in the topologically-diverse Colorado River Basin. We expected to find less genetic differentiation among populations of H . oslari within the Upper Basin, which has a dense dendritic network of perennial tributaries that allow for greater potential dispersal and gene flow, than among populations within the arid and sparse river network of the Lower Basin. We also expected to find genetic differentiation among H. oslari in the Upper and Lower Basins because contemporary populations are geographically distant from each other and have been separated by a >300-km-long reservoir (Lake Powell) for ½ a century. Consistent with these predictions, we found that populations of H . oslari within the Upper Basin had more shared haplotypes and less nucleotide diversity (π = 0.001–0.008) than H . oslari within the Lower Basin ( F ST = 0.01, π = 0.014–0.028). However, populations were genetically more structured in the Upper Basin ( F ST = 0.47) than in the Lower Basin ( F ST = 0.01). We also found that populations in the Upper and Lower Basin are entirely genetically differentiated ( S nn = 1), suggesting that these 2 populations were isolated thousands of years before the 1963 closure of Glen Canyon Dam and subsequent filling of Lake Powell. The most similar haplotypes among the 2 basins represent a 5.4% difference, which indicates the presence of a species complex within H. oslari .

Colorado River Basin↗

USGS2016

Flow management for hydropower extirpates aquatic insects, undermining river food webs

Dams impound the majority of rivers and provide important societal benefits, especially daily water releases that enable on-peak hydroelectricity generation. Such “hydropeaking” is common worldwide, but its downstream impacts remain unclear. We evaluated the response of aquatic insects, a cornerstone of river food webs, to hydropeaking using a life history–hydrodynamic model. Our model predicts that aquatic-insect abundance will depend on a basic life-history trait—adult egg-laying behavior—such that open-water layers will be unaffected by hydropeaking, whereas ecologically important and widespread river-edge layers, such as mayflies, will be extirpated. These predictions are supported by a more-than-2500-sample, citizen-science data set of aquatic insects from the Colorado River in the Grand Canyon and by a survey of insect diversity and hydropeaking intensity across dammed rivers of the Western United States. Our study reveals a hydropeaking-related life history bottleneck that precludes viable populations of many aquatic insects from inhabiting regulated rivers.

BioScience↗