Beta diversity of stream fish communities along anthropogenic environmental gradients at multiple spatial scales

ABSTRACT Patterns of species replacement and richness differences along environmental gradients or ecoregions shed light on different ecological and evolutionary mechanisms acting on community structure. Communities of aquatic ecosystems of different watersheds are supposed to host distinct species and lineages. Quantifying and understanding the degree to which these differences are affected by environmental and biogeographical factors remains an open question for these environments, particularly in the Neotropical region. We investigated patterns of taxonomic and phylogenetic composition of headwater streams of the Paraná and Paraguai River basins to understand how local and biogeographical factors affect the assembly of fish communities. We also quantified taxonomic and phylogenetic beta diversity by decomposing them into nestedness and turnover components. We found that local environmental factors are the main factors influencing the composition of stream fish communities. Whereas pH affected both taxonomic and phylogenetic turnover, water velocity was responsible for phylogenetic turnover and pH was the main driver of phylogenetic nestedness. Our results indicate an effect of local environmental factors in determining the structure of headwater stream fish communities through a combination of a species sorting mechanism (water velocity and pH) and phylogenetic habitat filtering (pH).

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Surface water connectivity affects lake and stream fish species richness and composition

Canadian Journal of Fisheries and Aquatic Sciences ◽

10.1139/cjfas-2020-0090 ◽

2020 ◽

Author(s):

Katelyn B.S. King ◽

Mary Tate Bremigan ◽

Dana M Infante ◽

Kendra Spence Cheruvelil

Keyword(s):

Species Richness ◽

Surface Water ◽

Species Diversity ◽

Fish Species ◽

Spatial Scales ◽

Fish Communities ◽

Integrated Approach ◽

Stream Fish ◽

Recreational Resources ◽

Fish Species Diversity

Stream and lake fishes are important economic and recreational resources that respond to alterations in their surrounding watersheds and serve as indicators of ecological stressors on aquatic ecosystems. Research suggests that fish species diversity is largely influenced by surface water connectivity, or the lack thereof; however, few studies consider freshwater connections and their effect on both lake and stream fish communities across broad spatial extents. We used fish data from 559 lakes and 854 streams from the midwestern/northeastern United States to examine the role of surface water connectivity on fish species richness and community composition. We found that although lakes and streams share many species, connectivity had a positive effect on species richness across lakes and streams and helped explain species composition. Taking an integrated approach that includes both lake and stream fish communities and connectivity among freshwaters helps inform scientific understanding of what drives variation in fish species diversity at broad spatial scales and can help managers who are faced with planning for state, regional, or national scale monitoring and restoration.

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Ecotones: Marginal or central areas of transition?

Israel Journal of Ecology and Evolution ◽

10.1560/ijee.52.1.29 ◽

2006 ◽

Vol 52 (1) ◽

pp. 29-53 ◽

Cited By ~ 88

Author(s):

Salit Kark ◽

Berndt J. van Rensburg

Keyword(s):

Environmental Gradients ◽

Spatial Scales ◽

Small Scale ◽

Biodiversity Hotspots ◽

Ecological Communities ◽

Marginal Populations ◽

Multiple Spatial Scales ◽

Scientific Attention

Areas of environmental transition, where ecological communities coincide, are sometimes termed ecotones. These regions often correspond with sharp environmental gradients. Ecotones occur at multiple spatial scales, ranging from transitions between biomes to local small-scale transitions. In recent years ecotones have received increasing scientific attention after being neglected for years, as studies historically often focused on distinct communities. However, it is still debatable whether these transitional regions are speciation and biodiversity hotspots that deserve special conservation interest or are actually areas that hold marginal populations that depend on other parts of the range for the maintenance of their biodiversity and therefore should not deserve primary investment. This paper discusses some of the recent advancements in our understanding of the role of ecotones in ecology, evolution, and conservation.

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Response of Fish Communities to Various Environmental Variables across Multiple Spatial Scales

International Journal of Environmental Research and Public Health ◽

10.3390/ijerph9103629 ◽

2012 ◽

Vol 9 (10) ◽

pp. 3629-3653 ◽

Cited By ~ 19

Author(s):

Yong-Su Kwon ◽

Fengqing Li ◽

Namil Chung ◽

Mi-Jung Bae ◽

Soon-Jin Hwang ◽

...

Keyword(s):

Environmental Variables ◽

Spatial Scales ◽

Fish Communities ◽

Multiple Spatial Scales

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Environmental DNA reveals the fine-grained and hierarchical spatial structure of kelp forest fish communities

Scientific Reports ◽

10.1038/s41598-021-93859-5 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Thomas Lamy ◽

Kathleen J. Pitz ◽

Francisco P. Chavez ◽

Christie E. Yorke ◽

Robert J. Miller

Keyword(s):

Beta Diversity ◽

Aquatic Ecosystems ◽

Species Turnover ◽

Spatial Scales ◽

Regional Scale ◽

Kelp Forest ◽

Fish Communities ◽

Environmental Dna ◽

Underwater Visual Census ◽

Rocky Reefs

AbstractBiodiversity is changing at an accelerating rate at both local and regional scales. Beta diversity, which quantifies species turnover between these two scales, is emerging as a key driver of ecosystem function that can inform spatial conservation. Yet measuring biodiversity remains a major challenge, especially in aquatic ecosystems. Decoding environmental DNA (eDNA) left behind by organisms offers the possibility of detecting species sans direct observation, a Rosetta Stone for biodiversity. While eDNA has proven useful to illuminate diversity in aquatic ecosystems, its utility for measuring beta diversity over spatial scales small enough to be relevant to conservation purposes is poorly known. Here we tested how eDNA performs relative to underwater visual census (UVC) to evaluate beta diversity of marine communities. We paired UVC with 12S eDNA metabarcoding and used a spatially structured hierarchical sampling design to assess key spatial metrics of fish communities on temperate rocky reefs in southern California. eDNA provided a more-detailed picture of the main sources of spatial variation in both taxonomic richness and community turnover, which primarily arose due to strong species filtering within and among rocky reefs. As expected, eDNA detected more taxa at the regional scale (69 vs. 38) which accumulated quickly with space and plateaued at only ~ 11 samples. Conversely, the discovery rate of new taxa was slower with no sign of saturation for UVC. Based on historical records in the region (2000–2018) we found that 6.9 times more UVC samples would be required to detect 50 taxa compared to eDNA. Our results show that eDNA metabarcoding can outperform diver counts to capture the spatial patterns in biodiversity at fine scales with less field effort and more power than traditional methods, supporting the notion that eDNA is a critical scientific tool for detecting biodiversity changes in aquatic ecosystems.

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