1
|
Zhao D, Ali A, Zuck C, Uy L, Morris JG, Wong ACN. Vibrio cholerae Invasion Dynamics of the Chironomid Host Are Strongly Influenced by Aquatic Cell Density and Can Vary by Strain. Microbiol Spectr 2023; 11:e0265222. [PMID: 37074192 PMCID: PMC10269514 DOI: 10.1128/spectrum.02652-22] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2022] [Accepted: 03/24/2023] [Indexed: 04/20/2023] Open
Abstract
Cholera has been a human scourge since the early 1800s and remains a global public health challenge, caused by the toxigenic strains of the bacterium Vibrio cholerae. In its aquatic reservoirs, V. cholerae has been shown to live in association with various arthropod hosts, including the chironomids, a diverse insect family commonly found in wet and semiwet habitats. The association between V. cholerae and chironomids may shield the bacterium from environmental stressors and amplify its dissemination. However, the interaction dynamics between V. cholerae and chironomids remain largely unknown. In this study, we developed freshwater microcosms with chironomid larvae to test the effects of cell density and strain on V. cholerae-chironomid interactions. Our results show that chironomid larvae can be exposed to V. cholerae up to a high inoculation dose (109 cells/mL) without observable detrimental effects. Meanwhile, interstrain variability in host invasion, including prevalence, bacterial load, and effects on host survival, was highly cell density-dependent. Microbiome analysis of the chironomid samples by 16S rRNA gene amplicon sequencing revealed a general effect of V. cholerae exposure on microbiome species evenness. Taken together, our results provide novel insights into V. cholerae invasion dynamics of the chironomid larvae with respect to various doses and strains. The findings suggest that aquatic cell density is a crucial driver of V. cholerae invasion success in chironomid larvae and pave the way for future work examining the effects of a broader dose range and environmental variables (e.g., temperature) on V. cholerae-chironomid interactions. IMPORTANCE Vibrio cholerae is the causative agent of cholera, a significant diarrheal disease affecting millions of people worldwide. Increasing evidence suggests that the environmental facets of the V. cholerae life cycle involve symbiotic associations with aquatic arthropods, which may facilitate its environmental persistence and dissemination. However, the dynamics of interactions between V. cholerae and aquatic arthropods remain unexplored. This study capitalized on using freshwater microcosms with chironomid larvae to investigate the effects of bacterial cell density and strain on V. cholerae-chironomid interactions. Our results suggest that aquatic cell density is the primary determinant of V. cholerae invasion success in chironomid larvae, while interstrain variability in invasion outcomes can be observed under specific cell density conditions. We also determined that V. cholerae exposure generally reduces species evenness of the chironomid-associated microbiome. Collectively, these findings provide novel insights into V. cholerae-arthropod interactions using a newly developed experimental host system.
Collapse
Affiliation(s)
- Dianshu Zhao
- Entomology and Nematology Department, University of Florida, Gainesville, Florida, USA
| | - Afsar Ali
- Emerging Pathogens Institute, University of Florida, Gainesville, Florida, USA
- Department of Environmental and Global Health, College of Public Health and Health Professions, University of Florida, Gainesville, Florida, USA
| | - Cameron Zuck
- Entomology and Nematology Department, University of Florida, Gainesville, Florida, USA
| | - Laurice Uy
- Entomology and Nematology Department, University of Florida, Gainesville, Florida, USA
| | - J. Glenn Morris
- Emerging Pathogens Institute, University of Florida, Gainesville, Florida, USA
| | - Adam Chun-Nin Wong
- Entomology and Nematology Department, University of Florida, Gainesville, Florida, USA
- Genetics Institute, University of Florida, Gainesville, Florida, USA
- Emerging Pathogens Institute, University of Florida, Gainesville, Florida, USA
| |
Collapse
|
2
|
Bespalaya YV, Sousa R, Gofarov MY, Kondakov AV, Kropotin AV, Palatov DM, Vikhrev IV, Bolotov IN. An exploration of the hidden endosymbionts of Corbicula in the native range. Ecology 2023; 104:e3836. [PMID: 36156240 DOI: 10.1002/ecy.3836] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/25/2022] [Revised: 06/28/2022] [Accepted: 07/01/2022] [Indexed: 02/01/2023]
Affiliation(s)
- Yulia V Bespalaya
- N. Laverov Federal Center for Integrated Arctic Research of the Ural Branch of Russian Academy of Sciences, Arkhangelsk, Russia
| | - Ronaldo Sousa
- CBMA - Centre of Molecular and Environmental Biology, Department of Biology, University of Minho, Braga, Portugal
| | - Mikhail Yu Gofarov
- N. Laverov Federal Center for Integrated Arctic Research of the Ural Branch of Russian Academy of Sciences, Arkhangelsk, Russia
| | - Alexander V Kondakov
- N. Laverov Federal Center for Integrated Arctic Research of the Ural Branch of Russian Academy of Sciences, Arkhangelsk, Russia
| | - Alexander V Kropotin
- N. Laverov Federal Center for Integrated Arctic Research of the Ural Branch of Russian Academy of Sciences, Arkhangelsk, Russia
| | - Dmitry M Palatov
- N. Severtsov Institute of Ecology and Evolution of the Russian Academy of Sciences, Moscow, Russia
| | - Ilya V Vikhrev
- N. Laverov Federal Center for Integrated Arctic Research of the Ural Branch of Russian Academy of Sciences, Arkhangelsk, Russia
| | - Ivan N Bolotov
- N. Laverov Federal Center for Integrated Arctic Research of the Ural Branch of Russian Academy of Sciences, Arkhangelsk, Russia
| |
Collapse
|
3
|
Evariste L, Lagier L, Chary C, Mottier A, Cadarsi S, Pinelli E, Flahaut E, Gauthier L, Mouchet F. Exposure of Midge Larvae ( Chironomus riparius) to Graphene Oxide Leads to Development Alterations. Toxics 2022; 10:588. [PMID: 36287868 PMCID: PMC9608897 DOI: 10.3390/toxics10100588] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/31/2022] [Revised: 09/26/2022] [Accepted: 10/02/2022] [Indexed: 06/16/2023]
Abstract
Despite the fast-growing use and production of graphene-based nanomaterials (GBMs), data concerning their effects on freshwater benthic macroinvertebrates are scarce. This study aims to investigate the effects of graphene oxide (GO) on the midge Chironomus riparius. Mortality, growth inhibition, development delay and teratogenicity, assessed using mentum deformity analysis, were investigated after a 7-day static exposure of the first instar larvae under controlled conditions. The collected data indicated that the survival rate was not impacted by GO, whereas chronic toxicity following a dose-dependent response occurred. Larval growth was affected, leading to a significant reduction in larval length (from 4.4 to 10.1%) in individuals reaching the fourth instar at any of the tested concentrations (from 0.1 to 100 mg/L). However, exposure to GO is not associated with an increased occurrence of mouthpart deformities or seriousness in larvae. These results highlight the suitability of monitoring the larval development of C. riparius as a sensitive marker of GO toxicity. The potential ecological consequences of larval size decrease need to be considered for a complete characterization of the GO-related environmental risk.
Collapse
Affiliation(s)
- Lauris Evariste
- Laboratoire d’Ecologie Fonctionnelle et Environnement, UMR 5245 CNRS, Université Paul Sabatier, 31062 Toulouse, France
| | - Laura Lagier
- Laboratoire d’Ecologie Fonctionnelle et Environnement, UMR 5245 CNRS, Université Paul Sabatier, 31062 Toulouse, France
| | - Chloé Chary
- Laboratoire d’Ecologie Fonctionnelle et Environnement, UMR 5245 CNRS, Université Paul Sabatier, 31062 Toulouse, France
| | - Antoine Mottier
- Laboratoire d’Ecologie Fonctionnelle et Environnement, UMR 5245 CNRS, Université Paul Sabatier, 31062 Toulouse, France
| | - Stéphanie Cadarsi
- Laboratoire d’Ecologie Fonctionnelle et Environnement, UMR 5245 CNRS, Université Paul Sabatier, 31062 Toulouse, France
| | - Eric Pinelli
- Laboratoire d’Ecologie Fonctionnelle et Environnement, UMR 5245 CNRS, Université Paul Sabatier, 31062 Toulouse, France
| | - Emmanuel Flahaut
- CIRIMAT, CNRS-INP-UPS, UMR N°5085, Université Toulouse 3 Paul Sabatier, 118 Route de Narbonne, 31062 Toulouse, France
| | - Laury Gauthier
- Laboratoire d’Ecologie Fonctionnelle et Environnement, UMR 5245 CNRS, Université Paul Sabatier, 31062 Toulouse, France
| | - Florence Mouchet
- Laboratoire d’Ecologie Fonctionnelle et Environnement, UMR 5245 CNRS, Université Paul Sabatier, 31062 Toulouse, France
| |
Collapse
|
4
|
Watson VT, Kehler D, Medeiros AS. A paleolimnological context of ecological vulnerability for the freshwater ecosystems of Sable Island National Park Reserve, Canada. Sci Prog 2022; 105:368504221126865. [PMID: 36254564 PMCID: PMC10450601 DOI: 10.1177/00368504221126865] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/27/2023]
Abstract
Protected areas require long-term monitoring to understand the influence and extent of ecosystem stress to inform management and conservation decisions. As long-term data are not always available, paleolimnological methods offer a way of extending our knowledge of past environmental conditions necessary to use as context for remediation. Here, we examine four sediment cores and additional surface sediments from 14 ponds located on Sable Island National Park Reserve Canada (SINPR), where long-term ecological changes and vulnerability to disturbance are not well defined. We develop a paleolimnological approach to assessing environmental vulnerability through the use of biological indicators (Diptera: Chironomidae), where shifts in the environment are inferred by shifts in chironomid assemblages over time. Analysis of surface sediments show four distinct assemblage types reflecting four different habitat conditions; primarily represented by the presence of Glyptotendipes, Chironomus, Microtendipes, and Dicrotendipes. Differences in habitat conditions through time based on these results are then compared to biostratigraphic analysis of sediment cores from four of the ponds. We found that two ponds had large shifts in chironomids assemblages that were associated with changes in habitat over time, while two others that were not as exposed to the influence of erosion and influx of sand dunes did not. Our findings established a baseline of historical change in SINPR, broadening the scope of long-term monitoring, which is essential for defining goals for management and conservation of the ecological integrity of Sable Island.
Collapse
Affiliation(s)
- Victoria Theresa Watson
- Dalhousie University, School for Resource and Environmental Studies, College of Sustainability, Halifax, Canada
| | - Dan Kehler
- Parks Canada Agency, Government of Canada, Halifax, Canada
| | - Andrew Scott Medeiros
- Dalhousie University, School for Resource and Environmental Studies, College of Sustainability, Halifax, Canada
| |
Collapse
|
5
|
Yoshida Y, Tanaka S. Deciphering the Biological Enigma-Genomic Evolution Underlying Anhydrobiosis in the Phylum Tardigrada and the Chironomid Polypedilum vanderplanki. Insects 2022; 13:557. [PMID: 35735894 DOI: 10.3390/insects13060557] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/31/2022] [Revised: 06/13/2022] [Accepted: 06/17/2022] [Indexed: 02/04/2023]
Abstract
Anhydrobiosis, an ametabolic dehydrated state triggered by water loss, is observed in several invertebrate lineages. Anhydrobiotes revive when rehydrated, and seem not to suffer the ultimately lethal cell damage that results from severe loss of water in other organisms. Here, we review the biochemical and genomic evidence that has revealed the protectant molecules, repair systems, and maintenance pathways associated with anhydrobiosis. We then introduce two lineages in which anhydrobiosis has evolved independently: Tardigrada, where anhydrobiosis characterizes many species within the phylum, and the genus Polypedilum, where anhydrobiosis occurs in only two species. Finally, we discuss the complexity of the evolution of anhydrobiosis within invertebrates based on current knowledge, and propose perspectives to enhance the understanding of anhydrobiosis.
Collapse
|
6
|
Rossaro B, Marziali L, Magoga G, Montagna M, Boggero A. Corrections and Additions to Descriptions of Some Species of the Subgenus Orthocladius s. str. (Diptera, Chironomidae, Orthocladiinae). Insects 2022; 13:insects13010051. [PMID: 35055894 PMCID: PMC8782044 DOI: 10.3390/insects13010051] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/07/2021] [Revised: 12/21/2021] [Accepted: 12/30/2021] [Indexed: 02/05/2023]
Abstract
The larvae of some species of the subgenus Orthocladius s. str. (Diptera, Chironomidae) are here described for the first time with corrections and additions to the descriptions of adult males and pupal exuviae. The identification of larvae is generally not possible without association with pupal exuviae and/or adult males, so the descriptions here are based only on reared material or on pupae with the associated larval exuviae. Usually, Chironomidae larvae can be separated on the basis of morphometric characters, the most discriminant ones are: (1) the ratio between the width of median tooth of mentum (Dm) and the width of the first lateral tooth (Dl) = mental ratio (DmDl), (2) the ratio between the length of the first antennal segment (A1) and the combined length of segments 2-5 (A2-5) = antennal ratio (AR). The shape of mandible, maxilla, and other body parts are almost identical in all the species considered in this study. The larva of Orthocladius (Symposiocladius) lignicola is very characteristic and can be separated by the shape of mentum and the larvae of all the known species of Symposiocladius are characterized by the presence of large Lauterborn organs on antennae and of tufts of setae on abdominal segments. The larvae of Orthocladius (Orthocladius) oblidens and Orthocladius (Orthocladius) rhyacobius can be distinguished from other species basing on their large Dm and to each other by AR. A principal component analysis was carried out using 5 characters: (1) Dm, (2) Dl, (3) length of A1, (4) width of A1 (A1W), (5) combined length of segments 2-5 (A2-5). The most discriminant characters were Dm and A1, confirming that DmDl and AR can be used to separate species at larval stage, but the large superposition of morphometric characters in different species confirms that association with pupal exuviae is in any case needed to identify larvae. In future perspective, the development of reference DNA barcodes from specimens identified by specialists is recommended since possibly the best tool for larvae identification, but association of barcodes with morphotypes is in any case fundamental.
Collapse
Affiliation(s)
- Bruno Rossaro
- Dipartimento di Scienze Agrarie ed Ambientali, Università degli Studi di Milano, Via Celoria 2, 20133 Milano, Italy; (G.M.); (M.M.)
- Correspondence:
| | - Laura Marziali
- CNR-IRSA Water Research Institute, National Research Council, Via del Mulino 19, 20861 Brugherio, Italy;
| | - Giulia Magoga
- Dipartimento di Scienze Agrarie ed Ambientali, Università degli Studi di Milano, Via Celoria 2, 20133 Milano, Italy; (G.M.); (M.M.)
| | - Matteo Montagna
- Dipartimento di Scienze Agrarie ed Ambientali, Università degli Studi di Milano, Via Celoria 2, 20133 Milano, Italy; (G.M.); (M.M.)
| | - Angela Boggero
- CNR-IRSA Water Research Institute, National Research Council, Corso Tonolli 50, 28922 Verbania Pallanza, Italy;
| |
Collapse
|
7
|
Laviad-Shitrit S, Sela R, Sharaby Y, Thorat L, Nath BB, Halpern M. Comparative Microbiota Composition Across Developmental Stages of Natural and Laboratory-Reared Chironomus circumdatus Populations From India. Front Microbiol 2021; 12:746830. [PMID: 34899634 PMCID: PMC8661057 DOI: 10.3389/fmicb.2021.746830] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2021] [Accepted: 10/26/2021] [Indexed: 01/04/2023] Open
Abstract
Chironomids are aquatic insects that undergo a complete metamorphosis of four life stages. Here we studied, for the first time, the microbiota composition of Chironomus circumdatus, a tropical midge species, both from the Mula and Mutha Rivers in Pune, India and as a laboratory-reared culture. We generated a comparative microbial profile of the eggs, larvae and pupae, the three aquatic life stages of C. circumdatus. Non-metric multidimensional scaling analysis (NMDS) demonstrated that the developmental stage had a more prominent effect on the microbiota composition compared to the sampling location. Notably, the microbiota composition of the egg masses from the different sampling points clustered together and differed from laboratory culture larvae. Proteobacteria was the dominant phylum in all the environmental and laboratory-reared egg masses and pupal samples, and in the laboratory-reared larvae, while Fusobacteria was the dominant phylum in the larvae collected from the field environment. The most abundant genera were Cetobacterium, Aeromonas, Dysgonomonas, Vibrio, and Flavobacterium. The ten amplicon sequence variants (ASVs) that most significantly contributed to differences in microbiota composition between the three sampled locations were: Burkholderiaceae (ASVs 04 and 37), C39 (Rhodocyclaceae, ASV 14), Vibrio (ASV 07), Arcobacter (ASV 21), Sphaerotilus (ASV 22), Bacteroidia (ASVs 12 and 28), Flavobacterium (ASV 29), and Gottschalkia (ASV 10). No significant differences were found in the microbial richness (Chao1) or diversity (Shannon H’) of the three sampled locations. In contrast, significant differences were found between the microbial richness of the three life stages. Studying the microbiota of this Chironomus species may contribute to a better understanding of the association of C. circumdatus and its microbial inhabitants.
Collapse
Affiliation(s)
- Sivan Laviad-Shitrit
- Department of Evolutionary and Environmental Biology, University of Haifa, Haifa, Israel
| | - Rotem Sela
- Department of Evolutionary and Environmental Biology, University of Haifa, Haifa, Israel
| | - Yehonatan Sharaby
- Department of Evolutionary and Environmental Biology, University of Haifa, Haifa, Israel
| | - Leena Thorat
- Department of Zoology, Savitribai Phule Pune University, Pune, India.,Department of Biology, York University, Toronto, ON, Canada
| | - Bimalendu B Nath
- Department of Zoology, Savitribai Phule Pune University, Pune, India
| | - Malka Halpern
- Department of Evolutionary and Environmental Biology, University of Haifa, Haifa, Israel.,Department of Biology and Environment, University of Haifa, Haifa, Israel
| |
Collapse
|
8
|
Lencioni V, Moubayed J. Synorthocladiusfedericoi sp. nov., a new species occurring in the middle basin of the Adige River, northern Italy (Diptera, Chironomidae, Orthocladiinae). Zookeys 2021; 1057:105-116. [PMID: 34552369 PMCID: PMC8417020 DOI: 10.3897/zookeys.1057.68175] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2021] [Accepted: 07/22/2021] [Indexed: 11/12/2022] Open
Abstract
An adult male Synorthocladius was collected in the middle basin of the Adige River in the city of Verona, northern Italy. A combination of atypical characters for the genus signalled a new species. Synorthocladiusfedericoisp. nov. is here diagnosed and described. The new species is known only from its type locality and is presumed to be a local biogeographical representative of the Italian Pre-Alps. An emended generic diagnosis, a key to known Synorthocladius from Europe and comments on the taxonomic position of the new species are given.
Collapse
Affiliation(s)
- Valeria Lencioni
- Department of Invertebrate Zoology and Hydrobiology, MUSE-Museo delle Scienze, Corso del Lavoro e della Scienza 3, 38122 Trento, Italy Museo delle Scienze Trento Italy
| | - Joel Moubayed
- Freshwater and Marine biology, 10 ruez des Fenouils, 34070 Montpellier, France Freshwater and Marine biology Montpellier France
| |
Collapse
|
9
|
Saulnier-Talbot É, Antoniades D, Pienitz R. Hotspots of biotic compositional change in lakes along vast latitudinal transects in northern Canada. Glob Chang Biol 2020; 26:2270-2279. [PMID: 31995661 DOI: 10.1111/gcb.15016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/08/2019] [Revised: 12/11/2019] [Accepted: 01/17/2020] [Indexed: 06/10/2023]
Abstract
Ecotones mark zones of rapid change in ecological structure at various spatial scales. They are believed to be particularly susceptible to shifts caused by environmental transformation, making them key regions for studying the effects of global change. Here, we explored the variation in assemblage structure of aquatic primary producer and consumer communities across latitudinal transects in northeastern North America (Québec-Labrador) to identify spatial patterns in biodiversity that indicated the location of transition zones across the landscape. We analyzed species richness and the cumulative rate of compositional change (expressed as beta-diversity) of diatoms and chironomids to detect any abrupt shifts in the rate of spatial taxonomic turnover. We used principal coordinates analysis to estimate community turnover with latitude, then applied piecewise linear regression to assess the position of ecotones. Statistically significant changes in assemblage composition occurred at 52 and 55°N, corresponding to the transition between closed- and open-crown forest, and to the southern onset of the forest tundra (i.e., the forest limit), respectively. The spatial distribution of ecotones was most strongly related to air temperature for chironomids and to vegetation- and soil-related chemical attributes of lake water for diatoms, including dissolved organic carbon content and water color. Lakes at mid- to high-latitudes currently face pressures from rapidly rising temperatures, accompanied by large increases in organic carbon inputs from their catchments, often leading to browning and its associated effects. The biota at the base of food webs in lakes located in transition zones are disproportionately affected by the cascading effects of these multi-factorial changes, concurrent with pronounced terrestrial greening observed in these regions. Similar patterns of biotic shifts have been observed along alpine aquatic transects, indicating the potential for widespread restructuring of cold, high-altitude and high-latitude freshwater communities due to global change.
Collapse
Affiliation(s)
- Émilie Saulnier-Talbot
- Laboratoire de paléoécologie aquatique (LPA), Département de géographie and Centre d'études nordiques (CEN: Centre for Northern Studies), Université Laval, Québec, QC, Canada
| | - Dermot Antoniades
- Laboratoire de paléoécologie aquatique (LPA), Département de géographie and Centre d'études nordiques (CEN: Centre for Northern Studies), Université Laval, Québec, QC, Canada
| | - Reinhard Pienitz
- Laboratoire de paléoécologie aquatique (LPA), Département de géographie and Centre d'études nordiques (CEN: Centre for Northern Studies), Université Laval, Québec, QC, Canada
| |
Collapse
|
10
|
Wooller MJ, Saulnier-Talbot É, Potter BA, Belmecheri S, Bigelow N, Choy K, Cwynar LC, Davies K, Graham RW, Kurek J, Langdon P, Medeiros A, Rawcliffe R, Wang Y, Williams JW. A new terrestrial palaeoenvironmental record from the Bering Land Bridge and context for human dispersal. R Soc Open Sci 2018; 5:180145. [PMID: 30110451 PMCID: PMC6030284 DOI: 10.1098/rsos.180145] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/01/2018] [Accepted: 05/01/2018] [Indexed: 06/08/2023]
Abstract
Palaeoenvironmental records from the now-submerged Bering Land Bridge (BLB) covering the Last Glacial Maximum (LGM) to the present are needed to document changing environments and connections with the dispersal of humans into North America. Moreover, terrestrially based records of environmental changes are needed in close proximity to the re-establishment of circulation between Pacific and Atlantic Oceans following the end of the last glaciation to test palaeo-climate models for the high latitudes. We present the first terrestrial temperature and hydrologic reconstructions from the LGM to the present from the BLB's south-central margin. We find that the timing of the earliest unequivocal human dispersals into Alaska, based on archaeological evidence, corresponds with a shift to warmer/wetter conditions on the BLB between 14 700 and 13 500 years ago associated with the early Bølling/Allerød interstadial (BA). These environmental changes could have provided the impetus for eastward human dispersal at that time, from Western or central Beringia after a protracted human population standstill. Our data indicate substantial climate-induced environmental changes on the BLB since the LGM, which would potentially have had significant influences on megafaunal and human biogeography in the region.
Collapse
Affiliation(s)
- Matthew J. Wooller
- Water and Environmental Research Center, Institute of Northern Engineering, Fairbanks, AK, USA
- Alaska Stable Isotope Facility, College of Fisheries and Ocean Sciences, Fairbanks, AK, USA
| | - Émilie Saulnier-Talbot
- Water and Environmental Research Center, Institute of Northern Engineering, Fairbanks, AK, USA
- Alaska Stable Isotope Facility, College of Fisheries and Ocean Sciences, Fairbanks, AK, USA
| | | | - Soumaya Belmecheri
- Laboratory of Tree Ring Research, University of Arizona, Tucson, AZ, USA
| | - Nancy Bigelow
- Alaska Quaternary Center, University of Alaska Fairbanks, Fairbanks, AK, USA
| | - Kyungcheol Choy
- Water and Environmental Research Center, Institute of Northern Engineering, Fairbanks, AK, USA
- Alaska Stable Isotope Facility, College of Fisheries and Ocean Sciences, Fairbanks, AK, USA
| | - Les C. Cwynar
- Department of Biology, University of New Brunswick, Fredericton, New Brunswick, Canada
| | - Kimberley Davies
- Department of Geography and Environment, University of Southampton, Southampton, Hampshire, UK
- School of Geography, Earth and Environmental Sciences, Plymouth University, Plymouth, UK
| | - Russell W. Graham
- Department of Geosciences and Earth and Mineral Sciences Museum & Art Gallery, The Pennsylvania State University, University Park, PA, USA
| | - Joshua Kurek
- Department of Geography and Environment, Mount Allison University, Sackville, New Brunswick, Canada
| | - Peter Langdon
- Department of Geography and Environment, University of Southampton, Southampton, Hampshire, UK
| | | | - Ruth Rawcliffe
- Water and Environmental Research Center, Institute of Northern Engineering, Fairbanks, AK, USA
- Alaska Stable Isotope Facility, College of Fisheries and Ocean Sciences, Fairbanks, AK, USA
| | - Yue Wang
- Department of Geography, University of Wisconsin-Madison, Madison, WI, USA
| | - John W. Williams
- Department of Geography, University of Wisconsin-Madison, Madison, WI, USA
- Center for Climatic Research, University of Wisconsin-Madison, Madison, WI, USA
| |
Collapse
|
11
|
Hambäck PA, Weingartner E, Dalén L, Wirta H, Roslin T. Spatial subsidies in spider diets vary with shoreline structure: Complementary evidence from molecular diet analysis and stable isotopes. Ecol Evol 2016; 6:8431-8439. [PMID: 28031795 PMCID: PMC5167037 DOI: 10.1002/ece3.2536] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2016] [Revised: 09/08/2016] [Accepted: 09/13/2016] [Indexed: 11/10/2022] Open
Abstract
Inflow of matter and organisms may strongly affect the local density and diversity of organisms. This effect is particularly evident on shores where organisms with aquatic larval stages enter the terrestrial food web. The identities of such trophic links are not easily estimated as spiders, a dominant group of shoreline predator, have external digestion. We compared trophic links and the prey diversity of spiders on different shore types along the Baltic Sea: on open shores and on shores with a reed belt bordering the water. A priori, we hypothesized that the physical structure of the shoreline reduces the flow between ecosystem and the subsidies across the sea-land interface. To circumvent the lack of morphologically detectable remains of spider prey, we used a combination of stable isotope and molecular gut content analyses. The two tools used for diet analysis revealed complementary information on spider diets. The stable isotope analysis indicated that spiders on open shores had a marine signal of carbon isotopes, while spiders on reedy shores had a terrestrial signal. The molecular analysis revealed a diverse array of dipteran and lepidopteran prey, where spiders on open and reedy shores shared a similar diet with a comparable proportion of chironomids, the larvae of which live in the marine system. Comparing the methods suggests that differences in isotope composition of the two spider groups occurred because of differences in the chironomid diets: as larvae, chironomids of reedy shores likely fed on terrestrial detritus and acquired a terrestrial isotope signature, while chironomids of open shores utilized an algal diet and acquired a marine isotope signature. Our results illustrate how different methods of diet reconstruction may shed light on complementary aspects of nutrient transfer. Overall, they reveal that reed belts can reduce connectivity between habitats, but also function as a source of food for predators.
Collapse
Affiliation(s)
- Peter A Hambäck
- Department of Ecology, Environment and Plants Sciences Stockholm University Stockholm Sweden
| | - Elisabeth Weingartner
- Department of Ecology, Environment and Plants Sciences Stockholm University Stockholm Sweden
| | - Love Dalén
- Department of Bioinformatics and Genetics Swedish Museum of Natural History Stockholm Sweden
| | - Helena Wirta
- Department of Agricultural Sciences University of Helsinki Helsinki Finland
| | - Tomas Roslin
- Department of Agricultural Sciences University of Helsinki Helsinki Finland; Department of Ecology Swedish University of Agricultural Sciences Uppsala Sweden
| |
Collapse
|
12
|
Matthews‐Bird F, Gosling WD, Coe AL, Bush M, Mayle FE, Axford Y, Brooks SJ. Environmental controls on the distribution and diversity of lentic Chironomidae (Insecta: Diptera) across an altitudinal gradient in tropical South America. Ecol Evol 2016; 6:91-112. [PMID: 26811777 PMCID: PMC4716524 DOI: 10.1002/ece3.1833] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2015] [Revised: 10/15/2015] [Accepted: 10/19/2015] [Indexed: 11/25/2022] Open
Abstract
To predict the response of aquatic ecosystems to future global climate change, data on the ecology and distribution of keystone groups in freshwater ecosystems are needed. In contrast to mid- and high-latitude zones, such data are scarce across tropical South America (Neotropics). We present the distribution and diversity of chironomid species using surface sediments of 59 lakes from the Andes to the Amazon (0.1-17°S and 64-78°W) within the Neotropics. We assess the spatial variation in community assemblages and identify the key variables influencing the distributional patterns. The relationships between environmental variables (pH, conductivity, depth, and sediment organic content), climatic data, and chironomid assemblages were assessed using multivariate statistics (detrended correspondence analysis and canonical correspondence analysis). Climatic parameters (temperature and precipitation) were most significant in describing the variance in chironomid assemblages. Temperature and precipitation are both predicted to change under future climate change scenarios in the tropical Andes. Our findings suggest taxa of Orthocladiinae, which show a preference to cold high-elevation oligotrophic lakes, will likely see range contraction under future anthropogenic-induced climate change. Taxa abundant in areas of high precipitation, such as Micropsectra and Phaenopsectra, will likely become restricted to the inner tropical Andes, as the outer tropical Andes become drier. The sensitivity of chironomids to climate parameters makes them important bio-indicators of regional climate change in the Neotropics. Furthermore, the distribution of chironomid taxa presented here is a vital first step toward providing urgently needed autecological data for interpreting fossil chironomid records of past ecological and climate change from the tropical Andes.
Collapse
Affiliation(s)
- Frazer Matthews‐Bird
- Environment, Earth & EcosystemsThe Open UniversityWalton HallMilton KeynesMK76AAUK
| | - William D. Gosling
- Environment, Earth & EcosystemsThe Open UniversityWalton HallMilton KeynesMK76AAUK
- Palaeoecology & Landscape EcologyInstitute of Biodiversity & Ecosystem Dynamics (IBED)University of AmsterdamScience Park 9041098 XHAmsterdamThe Netherlands
| | - Angela L. Coe
- Environment, Earth & EcosystemsThe Open UniversityWalton HallMilton KeynesMK76AAUK
| | - Mark Bush
- Biological SciencesFlorida Institute of Technology150 West University BoulevardMelbourneFlorida32901
| | - Francis E. Mayle
- Department of Geography and Environmental Science (SAGES)Centre for Past Climate ChangeUniversity of ReadingReadingRG6 6ABUK
| | - Yarrow Axford
- Department of Earth and Planetary SciencesNorthwestern University2145, Sheridan RoadEvanstonIllinois60201
| | - Stephen J. Brooks
- Department of Life SciencesNatural History MuseumCromwell RoadLondonSW7 5BDUK
| |
Collapse
|