scholarly journals Leveraging eDNA metabarcoding to characterize nearshore fish communities in Southeast Alaska: Do habitat and tide matter?

2021 ◽  
Author(s):  
Wesley Alan Larson ◽  
Patrick Barry ◽  
William Dokai ◽  
Jacek Maselko ◽  
John Olson ◽  
...  
Keyword(s):  
Species Richness ◽  
Fish Communities ◽  
Single Species ◽  
Southeast Alaska ◽  
Marine Habitats ◽  
Sampling Locations ◽  
Field Samples ◽  
Mitochondrial Locus ◽  
Eelgrass Beds ◽  
Tide Interaction

Nearshore marine habitats are critical for a variety of commercially important fish species, but assessing fish communities in these habitats is costly and time-intensive. Here, we leverage eDNA metabarcoding to characterize nearshore fish communities near Juneau, Alaska, USA, a high-latitude environment with large tidal swings, strong currents, and significant freshwater input. We investigated whether species richness and community composition differed across three habitat types (sand beaches, eelgrass beds, and rocky shorelines) and between high and low tides. Additionally, we tested whether replication of field samples and PCR reactions influenced either species richness or composition. We amplified a 12S mitochondrial locus in our samples and identified 188 fish amplicon sequence variants (ASVs), corresponding to 21 unique taxa, with approximately half of these resolved to single species. Species richness and composition inferred from eDNA differed substantially among habitats, with rock habitats containing fewer taxa and fewer overall detections than sand and eelgrass habitats. The effect of tide was more subtle and suggested a habitat-tide interaction, with differences in taxa between tides largely isolated to sand habitats. Power analyses indicated that additional field sampling is useful to detect subtle changes in species richness such as those due to tide. PCR replicates typically identified a small number of additional taxa. The most notable result from our study was that shore morphology appeared to substantially influence community structure. Rocky shorelines sloped quickly into deep water, while sand and eelgrass habitats descended much more gradually. We hypothesize that differences in taxa observed among habitats were largely due to lack of mixing between bottom and surface water, providing further evidence that eDNA transport is minimal and that many marine eDNA detections are derived from highly localized sampling locations. We suggest that future studies could explore the extent to which habitat and nearshore physical processes influence eDNA detections.

Dominance determines fish community biomass in a temperate seagrass ecosystem

2019 ◽  
Author(s):  
Aaron Matthius Eger ◽  
Rebecca J. Best ◽  
Julia Kathleen Baum
Keyword(s):  
Species Richness ◽  
Ecosystem Function ◽  
Fish Community ◽  
Prey Capture ◽  
Fish Communities ◽  
Functional Trait ◽  
Ecosystem Functions ◽  
Community Biomass ◽  
Ecosystem Valuation ◽  
Species Abundances

Biodiversity and ecosystem function are often correlated, but there are multiple hypotheses about the mechanisms underlying this relationship. Ecosystem functions such as primary or secondary production may be maximized by species richness, evenness in species abundances, or the presence or dominance of species with certain traits. Here, we combined surveys of natural fish communities (conducted in July and August, 2016) with morphological trait data to examine relationships between diversity and ecosystem function (quantified as fish community biomass) across 14 subtidal eelgrass meadows in the Northeast Pacific (54° N 130° W). We employed both taxonomic and functional trait measures of diversity to investigate if ecosystem function is driven by species diversity (complementarity hypothesis) or by the presence or dominance of species with particular trait values (selection or dominance hypotheses). After controlling for environmental variation, we found that fish community biomass is maximized when taxonomic richness and functional evenness is low, and in communities dominated by species with particular trait values – those associated with benthic habitats and prey capture. While previous work on fish communities has found that species richness is positively correlated with ecosystem function, our results instead highlight the capacity for regionally prevalent and locally dominant species to drive ecosystem function in moderately diverse communities. We discuss these alternate links between community composition and ecosystem function and consider their divergent implications for ecosystem valuation and conservation prioritization.

Large-scale patterns in species richness and composition of temperate riverine fish communities, south-eastern Australia

2000 ◽  
Vol 51 (2) ◽  
pp. 165 ◽  
Author(s):  
Peter C. Gehrke ◽  
John H. Harris
Keyword(s):  
Species Richness ◽  
Large Scale ◽  
Fish Communities ◽  
Fish Fauna ◽  
South Coast ◽  
North Coast ◽  
Large Spatial Scale ◽  
River Types ◽  
Eastern Australia ◽  
Riverine Fish

Riverine fish in New South Wales were studied to examine longitudinal trends in species richness and to identify fish communities on a large spatial scale. Five replicate rivers of four types (montane, slopes, regulated lowland and unregulated lowland) were selected from North Coast, South Coast, Murray and Darling regions. Fishwere sampled during summer and winter in two consecutive years with standardized gear that maximized the range of species caught. The composition of fish communities varied among regions and river types, with little temporal variation. Distinct regional communities converged in montane reaches and diverged downstream. The fish fauna can be classified into North Coast, South Coast, Murray and Darling communities, with a distinct montane community at high elevations irrespective of the drainage division. Species richness increased downstream in both North Coast and South Coast regions by both replacement and the addition of new species. In contrast, species richness in the Darling and Murray regions reached a maximum in the slopes reaches and then declined, reflecting a loss of species in lowland reaches. The small number of species is typical of the freshwater fish faunas of similar climatic regions world-wide. Fish communities identified in this study form logical entities for fisheries management consistent with the ecosystem-focused, catchment-based approach to river management and water reform being adopted in Australia.

scholarly journals Do syntopic host species harbour similar symbiotic communities? The case ofChaetopterusspp. (Annelida: Chaetopteridae)

PeerJ ◽  
2017 ◽  
Vol 5 ◽  
pp. e2930 ◽  
Author(s):  
Temir A. Britayev ◽  
Elena Mekhova ◽  
Yury Deart ◽  
Daniel Martin
Keyword(s):  
Species Richness ◽  
Community Structure ◽  
Host Species ◽  
Interspecific Interactions ◽  
Single Species ◽  
Intraspecific Interactions ◽  
Mean Intensity ◽  
Species Dominance ◽  
High Species Richness ◽  
Symbiotic Community

To assess whether closely related host species harbour similar symbiotic communities, we studied two polychaetes,Chaetopterussp. (n = 11) andChaetopteruscf.appendiculatus(n = 83) living in soft sediments of Nhatrang Bay (South China Sea, Vietnam). The former harboured the porcellanid crabsPolyonyxcf.heokandPolyonyxsp., the pinnotherid crabTetriassp. and the tergipedid nudibranchPhestillasp. The latter harboured the polynoid polychaeteOphthalmonoe pettiboneae, the carapid fishOnuxodon fowleriand the porcellanid crabEulenaios cometes, all of which, exceptO. fowleri, seemed to be specialized symbionts. The species richness and mean intensity of the symbionts were higher inChaetopterussp. than inC.cf.appendiculatus(1.8 and 1.02 species and 3.0 and 1.05 individuals per host respectively). We suggest that the lower density ofChaetopterussp. may explain the higher number of associated symbionts observed, as well as the 100% prevalence (69.5% inC.cf.appenciculatus). MostChaetopterussp. harboured two symbiotic species, which was extremely rare inC.cf.appendiculatus, suggesting lower interspecific interactions in the former. The crab and nudibranch symbionts ofChaetopterussp. often shared a host and lived in pairs, thus partitioning resources. This led to the species coexisting in the tubes ofChaetopterussp., establishing a tightly packed community, indicating high species richness and mean intensity, together with a low species dominance. In contrast, the aggressive, strictly territorial species associated withC.cf.appendiculatusestablished a symbiotic community strongly dominated by single species and, thus, low species richness and mean intensity. Therefore, we suggest that interspecific interactions are determining species richness, intensity and dominance, while intraspecific interactions are influencing only intensity and abundance. It is possible that species composition may have influenced the differences in community structure observed. We hypothesize that both host species could originally be allopatric. The evolutionary specialization of the symbiotic communities would occur in separated geographical areas, while the posterior disappearance of the existing geographical barriers would lead to the overlapped distribution.

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

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.

scholarly journals Predicting biodiversity richness in rapidly changing landscapes: climate, low human pressure or protection as salvation?

2020 ◽  
Vol 29 (14) ◽  
pp. 4035-4057
Author(s):  
David W. Macdonald ◽  
Luca Chiaverini ◽  
Helen M. Bothwell ◽  
Żaneta Kaszta ◽  
Eric Ash ◽  
...  
Keyword(s):  
Species Richness ◽  
Gap Analysis ◽  
Current System ◽  
Species Conservation ◽  
Biodiversity Loss ◽  
Single Species ◽  
Central China ◽  
Area Network ◽  
Biodiversity Hotspots ◽  
South Central

Abstract Rates of biodiversity loss in Southeast Asia are among the highest in the world, and the Indo-Burma and South-Central China Biodiversity Hotspots rank among the world’s most threatened. Developing robust multi-species conservation models is critical for stemming biodiversity loss both here and globally. We used a large and geographically extensive remote-camera survey and multi-scale, multivariate optimization species distribution modelling to investigate the factors driving biodiversity across these two adjoining biodiversity hotspots. Four major findings emerged from the work. (i) We identified clear spatial patterns of species richness, with two main biodiverse centres in the Thai-Malay Peninsula and in the mountainous region of Southwest China. (ii) Carnivores in particular, and large ungulates to a lesser degree, were the strongest indicators of species richness. (iii) Climate had the largest effect on biodiversity, followed by protected status and human footprint. (iv) Gap analysis between the biodiversity model and the current system of protected areas revealed that the majority of areas supporting the highest predicted biodiversity are not protected. Our results highlighted several key locations that should be prioritized for expanding the protected area network to maximize conservation effectiveness. We demonstrated the importance of switching from single-species to multi-species approaches to highlight areas of high priority for biodiversity conservation. In addition, since these areas mostly occur over multiple countries, we also advocate for a paradigmatic focus on transboundary conservation planning.

Diver-operated suction sampling in Norwegian cobble grounds: technique and associated fauna

Crustaceana ◽  
2015 ◽  
Vol 88 (2) ◽  
pp. 184-202 ◽  
Author(s):  
Halldis Ringvold ◽  
John-Arvid Grytnes ◽  
Gro I. van der Meeren
Keyword(s):  
Benthic Invertebrates ◽  
Fast Moving ◽  
Low Cost ◽  
Benthic Fauna ◽  
Shannon Index ◽  
Shallow Waters ◽  
Faunal Assemblages ◽  
Marine Habitats ◽  
Sampling Locations ◽  
Suction Sampling

Marine cobble habitats in shallow waters are rich in faunal assemblages and known settling grounds for valuable fishery resources such as lobsters and crabs. Sampling these grounds is challenging as traditional techniques do not efficiently collect fast-moving benthic invertebrates. Typically, fast moving crustaceans are not sampled according to actual densities. This study used airlift suction sampling, pioneered in North America, to quantify benthic faunal assemblages in cobble grounds across 68 sampling locations in south-western Norway. In total, 72 species of benthic invertebrates (5276 individual specimens) were identified, with an overall sampling efficiency of 76.4%. Polychaeta and decapod crustaceans dominated the samples, with species diversity (Shannon Index, ) highest in Location 3. Cluster and Ordination analyses were further used to relate assemblages to a number of selected variables. Overall, the study highlights that suction sampling provides a low-cost and efficient method for quantifying mobile benthic fauna in structurally complex marine habitats (i.e., cobble).

Elasmobranch diversity, conservation and management along Wadge Bank, South India

2019 ◽  
Author(s):  
K. Karuppasamy ◽  
P. Jawahar ◽  
S. David Kingston ◽  
V. K. Venkataramani ◽  
V. Vidhya
Keyword(s):  
Species Richness ◽  
Phylogenetic Diversity ◽  
South India ◽  
Fish Communities ◽  
Taxonomic Diversity ◽  
Management Measures ◽  
Conservation And Management ◽  
D Value

The study was undertaken to document the elasmobranch diversity and their abundance along Wadge Bank. Species were collected fortnightly during June 2015 to May 2016 from three landing centres viz., Chinnamuttom,Colachel and Vizhinjam of Wadge Bank. A total of 1,575 specimens were collected during the period and 44 species were identified belonging to 8 orders, 13 families and 25 genera. Among the recorded \families,Carcharhinidae is the most dominant family with 12 species. The Colachel landing centre was rich in diversity with 43 species followed by Chinnamuttom 39 species and Vizhinjam26 species. The highest Shannon Weiner diversity (H’ value) was observed at Colachel (4.17) followed by Chinnamuttom (4.11) and Vizhinjam (3.76). The Margalef’s species richness (‘d’) value was assessed at Colachel (4.55) followed by Chinnamuttom (4.01) and Vizhinjam (2.91). The Pielou’s evenness (J’) estimated was 0.7786, 0.7700 and 0.8005respectively, for Chinnamuttom, Colachal and Vizhinjam. The highest taxonomic diversity value was observed at Colachel (60.33) and the lowest during at Vizhinjam (54.08). Among the three landing centres studied, the total phylogenetic diversity (sPhi+) was found to be the lowest at Vizhinjam (940) and highest at Colachel landing centre (1720). Bray Curtis similarities measure was also calculated, fish communities were separated into several clusters based on seasons. The conservation of elasmobranchs and the management measures to be followed along the Wadge Bank is also discussed.

The effects of partial cutting on forest plant communities of western hemlock – Sitka spruce stands in southeast Alaska

2001 ◽  
Vol 31 (12) ◽  
pp. 2067-2079 ◽  
Author(s):  
Robert L Deal
Keyword(s):  
Species Richness ◽  
Community Structure ◽  
Plant Community ◽  
Basal Area ◽  
Plant Species Richness ◽  
Plant Community Structure ◽  
Old Growth ◽  
Partial Cutting ◽  
Southeast Alaska ◽  
Clear Cutting

The effects of partial cutting on plant species richness, community structure, and several understory species that are important for deer forage were evaluated on 73 plots in 18 stands throughout southeast Alaska. These partially cut stands were harvested 12–96 years ago when 16–96% of the former stand basal area was removed. The species richness and community structure of understory plants were similar in uncut and partially cut plots. However, plots where more than 50% of the basal area was cut had a significantly different plant community structure. Species composition and abundance also appeared to be distinctly different between hemlock-dominated and spruce-dominated stands. Partial cutting did not significantly change abundance for most of the important forage species for deer. The similarity in plant community structure between partially cut and uncut old-growth stands may be related to forest stand structures. The heterogeneous stand structures that develop after partial cutting are more similar to old-growth stands than to the uniform young-growth stands that develop after stand replacing disturbances such as clear-cutting.

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