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Adams AJ, Kamoroff C, Daniele NR, Grasso RL, Halstead BJ, Kleeman PM, Mengelt C, Powelson K, Seaborn T, Goldberg CS. From eDNA to decisions using a multi-method approach to restoration planning in streams. Sci Rep 2024; 14:14335. [PMID: 38906892 PMCID: PMC11192730 DOI: 10.1038/s41598-024-64612-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2023] [Accepted: 06/11/2024] [Indexed: 06/23/2024] Open
Abstract
Reintroduction efforts are increasingly used to mitigate biodiversity losses, but are frequently challenged by inadequate planning and uncertainty. High quality information about population status and threats can be used to prioritize reintroduction and restoration efforts and can transform ad hoc approaches into opportunities for improving conservation outcomes at a landscape scale. We conducted comprehensive environmental DNA (eDNA) and visual encounter surveys to determine the distribution of native and non-native aquatic species in two high-priority watersheds to address key uncertainties-such as the distribution of threats and the status of existing populations-inherent in restoration planning. We then used these occurrence data to develop a menu of potential conservation actions and a decision framework to benefit an endangered vertebrate (foothill yellow-legged frog, Rana boylii) in dynamic stream systems. Our framework combines the strengths of multiple methods, allowing managers and conservation scientists to incorporate conservation science and site-specific knowledge into the planning process to increase the likelihood of achieving conservation goals.
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Affiliation(s)
- A J Adams
- School of the Environment, Washington State University, Pullman, WA, 99164, USA.
- Earth Research Institute, University of California, Santa Barbara, CA, 93106, USA.
| | - C Kamoroff
- Resource Management and Science, Yosemite National Park, El Portal, CA, 95318, USA
- Stillwater Sciences, Davis, CA, 95618, USA
| | - N R Daniele
- Resource Management and Science, Yosemite National Park, El Portal, CA, 95318, USA
| | - R L Grasso
- Resource Management and Science, Yosemite National Park, El Portal, CA, 95318, USA
| | - B J Halstead
- Western Ecological Research Center, Dixon Field Station, U.S. Geological Survey, Dixon, CA, 95620, USA
| | - P M Kleeman
- Western Ecological Research Center, Point Reyes Field Station, U.S. Geological Survey, Point Reyes Station, CA, 94956, USA
| | - C Mengelt
- Ecosystems Mission Area, U.S. Geological Survey, Modoc Hall, Sacramento, CA, 95819, USA
| | - K Powelson
- Tahoe National Forest, U.S. Forest Service, Nevada City, CA, 94949, USA
| | - T Seaborn
- School of Biological Sciences, Washington State University, Pullman, WA, 99164, USA
- School of Natural Resource Sciences, North Dakota State University, Fargo, ND, 58047, USA
| | - C S Goldberg
- School of the Environment, Washington State University, Pullman, WA, 99164, USA
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2
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Carvalho T, Belasen AM, Toledo LF, James TY. Coevolution of a generalist pathogen with many hosts: the case of the amphibian chytrid Batrachochytrium dendrobatidis. Curr Opin Microbiol 2024; 78:102435. [PMID: 38387210 DOI: 10.1016/j.mib.2024.102435] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2023] [Revised: 12/22/2023] [Accepted: 01/21/2024] [Indexed: 02/24/2024]
Abstract
Generalist pathogens maintain infectivity in numerous hosts; how this broad ecological niche impacts host-pathogen coevolution remains to be widely explored. Batrachochytrium dendrobatidis (Bd) is a highly generalist pathogenic fungus that has caused devastating declines in hundreds of amphibian species worldwide. This review examines amphibian chytridiomycosis host-pathogen interactions and available evidence for coevolution between Bd and its numerous hosts. We summarize recent evidence showing that Bd genotypes vary in geographic distribution and virulence, and that amphibian species also vary in Bd susceptibility according to their geographic distribution. How much variation can be explained by phenotypic plasticity or genetic differences remains uncertain. Recent research suggests that Bd genotypes display preferences for specific hosts and that some hosts are undergoing evolution as populations rebound from Bd outbreaks. Taken together, these findings suggest the potential for coevolution to occur and illuminate a path for addressing open questions through integrating historical and contemporary genetic data.
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Affiliation(s)
- Tamilie Carvalho
- Department of Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, MI 48109, United States
| | - Anat M Belasen
- Department of Integrative Biology, University of Texas at Austin, Austin, TX 78712, United States
| | - L Felipe Toledo
- Laboratório de História Natural de Anfíbios Brasileiros (LaHNAB), Departamento de Biologia Animal, Instituto de Biologia, Unicamp, Campinas, São Paulo, Brazil
| | - Timothy Y James
- Department of Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, MI 48109, United States.
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3
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Belasen AM, Peek RA, Adams AJ, Russell ID, De León ME, Adams MJ, Bettaso J, Breedveld KGH, Catenazzi A, Dillingham CP, Grear DA, Halstead BJ, Johnson PG, Kleeman PM, Koo MS, Koppl CW, Lauder JD, Padgett-Flohr G, Piovia-Scott J, Pope KL, Vredenburg V, Westphal M, Wiseman K, Kupferberg SJ. Chytrid infections exhibit historical spread and contemporary seasonality in a declining stream-breeding frog. ROYAL SOCIETY OPEN SCIENCE 2024; 11:231270. [PMID: 38298390 PMCID: PMC10827429 DOI: 10.1098/rsos.231270] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/26/2023] [Accepted: 12/18/2023] [Indexed: 02/02/2024]
Abstract
Species with extensive geographical ranges pose special challenges to assessing drivers of wildlife disease, necessitating collaborative and large-scale analyses. The imperilled foothill yellow-legged frog (Rana boylii) inhabits a wide geographical range and variable conditions in rivers of California and Oregon (USA), and is considered threatened by the pathogen Batrachochytrium dendrobatidis (Bd). To assess drivers of Bd infections over time and space, we compiled over 2000 datapoints from R. boylii museum specimens (collected 1897-2005) and field samples (2005-2021) spanning 9° of latitude. We observed a south-to-north spread of Bd detections beginning in the 1940s and increase in prevalence from the 1940s to 1970s, coinciding with extirpation from southern latitudes. We detected eight high-prevalence geographical clusters through time that span the species' geographical range. Field-sampled male R. boylii exhibited the highest prevalence, and juveniles sampled in autumn exhibited the highest loads. Bd infection risk was highest in lower elevation rain-dominated watersheds, and with cool temperatures and low stream-flow conditions at the end of the dry season. Through a holistic assessment of relationships between infection risk, geographical context and time, we identify the locations and time periods where Bd mitigation and monitoring will be critical for conservation of this imperilled species.
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Affiliation(s)
- A. M. Belasen
- Department of Integrative Biology, University of Texas at Austin, Austin, TX, USA
- Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, NY, USA
| | - R. A. Peek
- California Department of Fish and Wildlife, West Sacramento, CA, USA
| | - A. J. Adams
- Earth Research Institute, University of California, Santa Barbara, CA, USA
| | - I. D. Russell
- Department of Ecology, Evolution, and Marine Biology, University of California, Santa Barbara, CA, USA
| | - M. E. De León
- Genome Center, University of California, Davis, CA, USA
| | - M. J. Adams
- U.S. Geological Survey, Forest and Rangeland Ecosystem Science Center, Corvallis, OR, USA
| | - J. Bettaso
- Six Rivers National Forest, Lower Trinity Ranger District, USDA Forest Service, P.O. Box 68, Willow Creek, CA, USA
| | | | - A. Catenazzi
- Department of Biological Sciences, Florida International University, Miami, FL, USA
| | | | - D. A. Grear
- U.S. Geological Survey, National Wildlife Health Center, Madison, WI, USA
| | - B. J. Halstead
- Point Reyes Field Station, U.S. Geological Survey, Western Ecological Research Center, Point Reyes Station, CA, USA
| | - P. G. Johnson
- Pinnacles National Park, National Park Service, Paicines, CA, USA
| | - P. M. Kleeman
- Point Reyes Field Station, U.S. Geological Survey, Western Ecological Research Center, Point Reyes Station, CA, USA
| | - M. S. Koo
- Museum of Vertebrate Zoology, University of California, Berkeley, CA
| | - C. W. Koppl
- Plumas National Forest, USDA Forest Service, Quincy, CA, USA
| | | | | | - J. Piovia-Scott
- School of Biological Sciences, Washington State University, Vancouver, WA, USA
| | - K. L. Pope
- Pacific Southwest Research Station, USDA Forest Service, Arcata, CA, USA
| | - V. Vredenburg
- Department of Biology, San Francisco State University, San Francisco, CA, USA
| | - M. Westphal
- Central Coast Field Office, United States Bureau of Land Management, Marina, CA, USA
| | - K. Wiseman
- Department of Herpetology, California Academy of Sciences, San Francisco, CA, USA
| | - S. J. Kupferberg
- Department of Integrative Biology, University of California, Berkeley, CA, USA
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Ghose SL, Yap TA, Byrne AQ, Sulaeman H, Rosenblum EB, Chan-Alvarado A, Chaukulkar S, Greenbaum E, Koo MS, Kouete MT, Lutz K, McAloose D, Moyer AJ, Parra E, Portik DM, Rockney H, Zink AG, Blackburn DC, Vredenburg VT. Continent-wide recent emergence of a global pathogen in African amphibians. FRONTIERS IN CONSERVATION SCIENCE 2023. [DOI: 10.3389/fcosc.2023.1069490] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/17/2023] Open
Abstract
IntroductionEmerging infectious diseases are increasingly recognized as a global threat to wildlife. Pandemics in amphibians, caused by the fungal pathogen Batrachochytrium dendrobatidis (Bd), have resulted in biodiversity loss at a global scale. Genomic data suggest a complex evolutionary history of Bd lineages that vary in pathogenicity. Africa harbors a significant proportion of global amphibian biodiversity, and multiple Bd lineages are known to occur there; yet, despite the decline of many host species, there are currently no described Bd-epizootics. Here, we describe the historical and recent biogeographical spread of Bd and assess its risk to amphibians across the continent of Africa.MethodsWe provide a 165-year view of host-pathogen interactions by (i) employing a Bd assay to test 4,623 specimens (collected 1908–2013); (ii) compiling 12,297 published Bd records (collected 1852–2017); (iii) comparing the frequency of Bd-infected amphibians through time by both country and region; (iv) genotyping Bd lineages; (v) histologically identifying evidence of chytridiomycosis, and (vi) using a habitat suitability model to assess future Bd risk.ResultsWe found a pattern of Bd emergence beginning largely at the turn of the century. From 1852–1999, we found low Bd prevalence (3.2% overall) and limited geographic spread, but after 2000 we documented a sharp increase in prevalence (18.7% overall), wider geographic spread, and multiple Bd lineages that may be responsible for emergence in different regions. We found that Bd risk to amphibians was highest in much of eastern, central, and western Africa.DiscussionOur study documents a largely overlooked yet significant increase in a fungal pathogen that could pose a threat to amphibians across an entire continent. We emphasize the need to bridge historical and contemporary datasets to better describe and predict host-pathogen dynamics over larger temporal scales.
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Distributions of Cisco (Coregonus artedi) in the upper Great Lakes in the mid-twentieth century, when populations were in decline. PLoS One 2022; 17:e0276109. [PMID: 36548254 PMCID: PMC9778937 DOI: 10.1371/journal.pone.0276109] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2021] [Accepted: 09/28/2022] [Indexed: 12/24/2022] Open
Abstract
The restoration of the once abundant Cisco (Coregonus artedi) is a management interest across the Laurentian Great Lakes. To inform the restoration, we (1) described historical distributions of Cisco and (2) explored whether non-indigenous Rainbow Smelt (Osmerus mordax) and Alewife (Alosa pseudoharengus) played a role in the decline of Cisco populations across the upper Great Lakes (i.e., Lakes Superior, Michigan, and Huron). Our source data were collected from fishery-independent surveys conducted by the U.S. Fish and Wildlife Service's research vessel R/V Cisco in 1952-1962. By analyzing data collected by gill-net surveys, we confirmed the importance of embayment and shallow-water habitats to Cisco. We found that Cisco was abundant in Whitefish Bay and Keweenaw Bay, Lake Superior, and in Green Bay, Lake Michigan, but we also found a sign of Cisco extirpation in Saginaw Bay, Lake Huron. Our results also showed that Ciscoes generally stayed in waters <80 m in bottom depth throughout the year. However, a substantial number of Ciscoes stayed in very deep waters (>150 m in bottom depth) in summer and fall in Lake Michigan, although we cannot exclude the possibility that these Ciscoes had hybridized with the other Coregonus species. By comparing complementary data collected from bottom-trawl surveys, we concluded that the spatiotemporal overlap between Rainbow Smelt and Cisco likely occurred across the upper Great Lakes throughout 1952-1962. These data were consistent with the hypothesis that Rainbow Smelt played a role in the decline of Cisco populations across the upper Great Lakes in the period. We also found that the spatiotemporal overlap between Alewife and Cisco likely occurred only in Saginaw Bay in fall 1956 and in Lake Michigan after 1960. Thus, any potential recovery of Cisco after the 1950s could have been inhibited by Alewife in Lakes Michigan and Huron.
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Adams AJ, Bushell J, Grasso RL. To treat or not to treat? Experimental pathogen exposure, treatment, and release of a threatened amphibian. Ecosphere 2022. [DOI: 10.1002/ecs2.4294] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Affiliation(s)
- Andrea J. Adams
- Resources Management and Science Division Yosemite National Park El Portal California USA
- Earth Research Institute University of California Santa Barbara California USA
| | | | - Robert L. Grasso
- Resources Management and Science Division Yosemite National Park El Portal California USA
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Womack MC, Steigerwald E, Blackburn DC, Cannatella DC, Catenazzi A, Che J, Koo MS, McGuire JA, Ron SR, Spencer CL, Vredenburg VT, Tarvin RD. State of the Amphibia 2020: A Review of Five Years of Amphibian Research and Existing Resources. ICHTHYOLOGY & HERPETOLOGY 2022. [DOI: 10.1643/h2022005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Molly C. Womack
- Department of Biology, Utah State University, Logan, Utah 84322; . ORCID: 0000-0002-3346-021X
| | - Emma Steigerwald
- Museum of Vertebrate Zoology, University of California, Berkeley, Berkeley, California 94720; (ES) ; (MSK) ; (JAM) ; (CS) ; (VTV) ; and (RDT)
| | - David C. Blackburn
- Department of Natural History, Florida Museum of Natural History, University of Florida, Gainesville, Florida 32611; . ORCID: 0000-0002-1810-9886
| | - David C. Cannatella
- Department of Integrative Biology, University of Texas at Austin, Austin, Texas 78712; . ORCID: 0000-0001-8675-0520
| | | | - Jing Che
- State Key Laboratory of Genetic Resources and Evolution & Yunnan Key Laboratory of Biodiversity and Ecological Security of Gaoligong Mountain, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, China; . ORCID: 0000-0003-4246-6
| | - Michelle S. Koo
- Museum of Vertebrate Zoology, University of California, Berkeley, Berkeley, California 94720; (ES) ; (MSK) ; (JAM) ; (CS) ; (VTV) ; and (RDT)
| | - Jimmy A. McGuire
- Museum of Vertebrate Zoology, University of California, Berkeley, Berkeley, California 94720; (ES) ; (MSK) ; (JAM) ; (CS) ; (VTV) ; and (RDT)
| | - Santiago R. Ron
- Museo de Zoología, Escuela de Biología, Pontificia Universidad Católica del Ecuador, Quito, Ecuador; . ORCID: 0000-0001-6300-9350
| | - Carol L. Spencer
- Museum of Vertebrate Zoology, University of California, Berkeley, Berkeley, California 94720; (ES) ; (MSK) ; (JAM) ; (CS) ; (VTV) ; and (RDT)
| | - Vance T. Vredenburg
- Museum of Vertebrate Zoology, University of California, Berkeley, Berkeley, California 94720; (ES) ; (MSK) ; (JAM) ; (CS) ; (VTV) ; and (RDT)
| | - Rebecca D. Tarvin
- Museum of Vertebrate Zoology, University of California, Berkeley, Berkeley, California 94720; (ES) ; (MSK) ; (JAM) ; (CS) ; (VTV) ; and (RDT)
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8
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LaFond J, Martin KR, Dahn H, Richmond JQ, Murphy RW, Rollinson N, Savage AE. Invasive Bullfrogs Maintain MHC Polymorphism Including Alleles Associated with Chytrid Fungal Infection. Integr Comp Biol 2022; 62:262-274. [PMID: 35588059 DOI: 10.1093/icb/icac044] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Revised: 04/19/2022] [Accepted: 05/16/2022] [Indexed: 11/14/2022] Open
Abstract
Maintenance of genetic diversity at adaptive loci may facilitate invasions by non-native species by allowing populations to adapt to novel environments, despite the loss of diversity at neutral loci that typically occurs during founder events. To evaluate this prediction, we compared genetic diversity at major histocompatibility complex (MHC) and cytochrome b (cytb) loci from 20 populations of the American bullfrog (Rana catesbeiana) across theinvasive and native ranges in North America and quantified the presence of the pathogen Batrachochytrium dendrobatidis (Bd). Compared to native populations, invasive populations had significantly higher Bd prevalence and intensity, significantly higher pairwise MHC and cytb FST, and significantly lower cytb diversity, but maintained similar levels of MHC diversity. The two most common MHC alleles (LiCA_B and Rapi_33) were associated with a significant decreased risk of Bd infection, and we detected positive selection acting on four peptide binding residues. Phylogenetic analysis suggested invasive populations likely arose from a single founding population in the American Midwest with a possible subsequent invasion in the northwest. Overall, our study suggests that the maintenance of diversity at adaptive loci may contribute to invasion success and highlights the importance of quantifying diversity at functional loci to assess the evolutionary potential of invasive populations.
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Affiliation(s)
- Jacob LaFond
- Department of Biology, University of Central Florida, Orlando, FL 32816, USA
- Department of Biology, University of Tampa, Tampa, FL 33606, USA
| | - Katherine R Martin
- Department of Biology, University of Central Florida, Orlando, FL 32816, USA
| | - Hollis Dahn
- Department of Biology, University of Toronto, Toronto, ON, Canada
| | - Jonathan Q Richmond
- U.S. Geological Survey, 4165 Spruance Rd. Suite 200, San Diego, CA 92101, USA
| | - Robert W Murphy
- Department of Biology, University of Toronto, Toronto, ON, Canada
| | - Njal Rollinson
- Department of Biology, University of Toronto, Toronto, ON, Canada
| | - Anna E Savage
- Department of Biology, University of Central Florida, Orlando, FL 32816, USA
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North S, Richmond JQ, Santana FE, Peralta-García A, Gallegos EA, Backlin AR, Hitchcock CJ, Hollingsworth BD, Valdez-Villavicencio JH, Principe Z, Fisher RN, Winchell CS. Taking the Leap: A Binational Translocation Effort to Close the 420-Km Gap in the Baja California Lineage of the California Red-Legged Frog (Rana draytonii). FRONTIERS IN CONSERVATION SCIENCE 2022. [DOI: 10.3389/fcosc.2022.908929] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Conservation translocations, the human-mediated movement and release of a living organism for a conservation benefit, are increasingly recommended in species’ recovery plans as a technique for mitigating population declines or augmenting genetic diversity. However, translocation protocols for species with broad distributions may require regionally specific considerations to increase success, as environmental gradients may pose different constraints on population establishment and persistence in different parts of the range. Here we report on ongoing, genetically informed translocations of a threatened amphibian, California red-legged frog (Rana draytonii), from Baja California, México, to extirpated parts of the range in southern California in the United States, where contemporary stressors related to urbanization, invasive species, and aridification add to the natural environmental challenges already present for amphibians at this ‘warm edge’ of the range. We describe the collaborative binational planning required to jumpstart the effort, the fine-tuning of protocols for collection, transport, headstarting, and release of individuals, and results of multiple translocations, where time will tell whether the successes to date have reached their full potential. The steps outlined in this paper can serve as a template to inform future conservation translocations of imperiled amphibians across the U.S./México border, where the phylogenetics, historical biogeography and future habitat availability of a focal species are blind to political boundaries and critical to guiding recovery actions across the range.
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Harjoe CC, Buck JC, Rohr JR, Roberts CE, Olson DH, Blaustein AR. Pathogenic fungus causes density‐ and trait‐mediated trophic cascades in an aquatic community. Ecosphere 2022. [DOI: 10.1002/ecs2.4043] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Affiliation(s)
- Carmen C. Harjoe
- Department of Integrative Biology Oregon State University Corvallis Oregon USA
| | - Julia C. Buck
- Department of Biology and Marine Biology University of North Carolina Wilmington Wilmington North Carolina USA
| | - Jason R. Rohr
- Department of Biological Sciences University of Notre Dame, Eck Institute for Global Health, and Environmental Change Initiative Notre Dame Indiana USA
| | - Claire E. Roberts
- Department of Integrative Biology Oregon State University Corvallis Oregon USA
| | - Deanna H. Olson
- Pacific Northwest Research Station USDA Forest Service Corvallis Oregon USA
| | - Andrew R. Blaustein
- Department of Integrative Biology Oregon State University Corvallis Oregon USA
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11
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Belasen AM, Russell ID, Zamudio KR, Bletz MC. Endemic Lineages of Batrachochytrium dendrobatidis Are Associated With Reduced Chytridiomycosis-Induced Mortality in Amphibians: Evidence From a Meta-Analysis of Experimental Infection Studies. Front Vet Sci 2022; 9:756686. [PMID: 35310410 PMCID: PMC8931402 DOI: 10.3389/fvets.2022.756686] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2021] [Accepted: 02/08/2022] [Indexed: 01/13/2023] Open
Abstract
Emerging infectious wildlife diseases have caused devastating declines, particularly when pathogens have been introduced in naïve host populations. The outcome of disease emergence in any host population will be dictated by a series of factors including pathogen virulence, host susceptibility, and prior opportunity for coevolution between hosts and pathogens. Historical coevolution can lead to increased resistance in hosts and/or reduced virulence in endemic pathogens that allows stable persistence of host and pathogen populations. Adaptive coevolution may also occur on relatively short time scales following introduction of a novel pathogen. Here, we performed a meta-analysis of multi-strain Batrachochytrium dendrobatidis (Bd) infection experiments to test whether: (1) amphibian hosts exhibit lower mortality rates when infected with strains belonging to endemic Bd lineages relative to the Global Panzootic Lineage (Bd-GPL), hypothetically owing to long co-evolutionary histories between endemic Bd lineages and their amphibian hosts; and (2) amphibians exhibit lower mortality rates when infected with local Bd-GPL strains compared with non-local Bd-GPL strains, hypothetically owing to recent selection for tolerance or resistance to local Bd-GPL strains. We found that in a majority of cases, amphibians in endemic Bd treatments experienced reduced mortality relative to those in Bd-GPL treatments. Hosts presumed to have historically coexisted with endemic Bd did not show reduced mortality to Bd-GPL compared with hosts that have not historically coexisted with endemic Bd. Finally, we detected no overall difference in amphibian mortality between local and non-local Bd-GPL treatments. Taken together, our results suggest that long-term historical coexistence is associated with less disease-induced mortality potentially due to hypovirulence in endemic Bd lineages, and that more recent coexistence between amphibians and Bd-GPL has not yet resulted in reduced host susceptibility or pathogen virulence. This corroborates previous findings that Bd-GPL introduced via the global amphibian trade has a high capacity for causing disease-induced mortality.
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Affiliation(s)
- Anat M. Belasen
- Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, NY, United States
- Society for Conservation Biology, Washington, DC, United States
- Department of Integrative Biology, University of Texas at Austin, Austin, TX, United States
| | - Imani D. Russell
- Department of Ecology, Evolution, and Marine Biology, University of California-Santa Barbara, Santa Barbara, CA, United States
| | - Kelly R. Zamudio
- Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, NY, United States
- Department of Integrative Biology, University of Texas at Austin, Austin, TX, United States
| | - Molly C. Bletz
- Department of Biology, University of Massachusetts-Boston, Boston, MA, United States
- *Correspondence: Molly C. Bletz
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Adams AJ, Peralta-García A, Flores-López CA, Valdez-Villavicencio JH, Briggs CJ. High fungal pathogen loads and prevalence in Baja California amphibian communities: The importance of species, elevation, and historical context. Glob Ecol Conserv 2022. [DOI: 10.1016/j.gecco.2021.e01968] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
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Koo MS, Vredenburg VT, Deck JB, Olson DH, Ronnenberg KL, Wake DB. Tracking, Synthesizing, and Sharing Global Batrachochytrium Data at AmphibianDisease.org. Front Vet Sci 2021; 8:728232. [PMID: 34692807 PMCID: PMC8527349 DOI: 10.3389/fvets.2021.728232] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2021] [Accepted: 09/02/2021] [Indexed: 11/13/2022] Open
Abstract
Emerging infectious diseases have been especially devastating to amphibians, the most endangered class of vertebrates. For amphibians, the greatest disease threat is chytridiomycosis, caused by one of two chytridiomycete fungal pathogens Batrachochytrium dendrobatidis (Bd) and Batrachochytrium salamandrivorans (Bsal). Research over the last two decades has shown that susceptibility to this disease varies greatly with respect to a suite of host and pathogen factors such as phylogeny, geography (including abiotic factors), host community composition, and historical exposure to pathogens; yet, despite a growing body of research, a comprehensive understanding of global chytridiomycosis incidence remains elusive. In a large collaborative effort, Bd-Maps was launched in 2007 to increase multidisciplinary investigations and understanding using compiled global Bd occurrence data (Bsal was not discovered until 2013). As its database functions aged and became unsustainable, we sought to address critical needs utilizing new technologies to meet the challenges of aggregating data to facilitate research on both Bd and Bsal. Here, we introduce an advanced central online repository to archive, aggregate, and share Bd and Bsal data collected from around the world. The Amphibian Disease Portal (https://amphibiandisease.org) addresses several critical community needs while also helping to build basic biological knowledge of chytridiomycosis. This portal could be useful for other amphibian diseases and could also be replicated for uses with other wildlife diseases. We show how the Amphibian Disease Portal provides: (1) a new repository for the legacy Bd-Maps data; (2) a repository for sample-level data to archive datasets and host published data with permanent DOIs; (3) a flexible framework to adapt to advances in field, laboratory, and informatics technologies; and (4) a global aggregation of Bd and Bsal infection data to enable and accelerate research and conservation. The new framework for this project is built using biodiversity informatics best practices and metadata standards to ensure scientific reproducibility and linkages across other biological and biodiversity repositories.
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Affiliation(s)
- Michelle S Koo
- Museum of Vertebrate Zoology, University of California, Berkeley, Berkeley, CA, United States
| | - Vance T Vredenburg
- Museum of Vertebrate Zoology, University of California, Berkeley, Berkeley, CA, United States.,Department of Biology, San Francisco State University, San Francisco, CA, United States
| | - John B Deck
- Berkeley Natural History Museums, University of California, Berkeley, Berkeley, CA, United States
| | - Deanna H Olson
- US Department of Agriculture, Forest Service, Pacific Northwest Research Station, Corvallis, OR, United States
| | - Kathryn L Ronnenberg
- US Department of Agriculture, Forest Service, Pacific Northwest Research Station, Corvallis, OR, United States
| | - David B Wake
- Museum of Vertebrate Zoology, University of California, Berkeley, Berkeley, CA, United States
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14
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Bedwell ME, Hopkins KVS, Dillingham C, Goldberg CS. Evaluating Sierra Nevada Yellow‐Legged Frog Distribution Using Environmental DNA. J Wildl Manage 2021. [DOI: 10.1002/jwmg.22053] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Affiliation(s)
| | | | - Colin Dillingham
- U.S. Forest Service R5, 39696 State Highway 70 Quincy CA 95971 USA
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15
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Rose JP, Kupferberg SJ, Wheeler CA, Kleeman PM, Halstead BJ. Estimating the survival of unobservable life stages for a declining frog with a complex life history. Ecosphere 2021. [DOI: 10.1002/ecs2.3381] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Affiliation(s)
- Jonathan P. Rose
- Santa Cruz Field Station Western Ecological Research Center U.S. Geological Survey 2885 Mission Street Santa Cruz California95060USA
| | - Sarah J. Kupferberg
- Department of Integrative Biology University of California, Berkeley 3040 Valley Life Sciences Building #3140 Berkeley California94720USA
| | - Clara A. Wheeler
- Pacific Southwest Research Station Redwood Science Lab USDA Forest Service Arcata California95521USA
| | - Patrick M. Kleeman
- Point Reyes Field Station Western Ecological Research Center U.S. Geological Survey 1 Bear Valley Road Point Reyes Station California94956USA
| | - Brian J. Halstead
- Dixon Field Station Western Ecological Research Center U.S. Geological Survey 800 Business Park Drive, Suite D Dixon California95620USA
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16
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Adams AJ, Pessier A, Cranston P, Grasso RL. Chytridiomycosis-induced mortality in a threatened anuran. PLoS One 2020; 15:e0241119. [PMID: 33156870 PMCID: PMC7647137 DOI: 10.1371/journal.pone.0241119] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2020] [Accepted: 08/26/2020] [Indexed: 11/20/2022] Open
Abstract
Effectively planning conservation introductions involves assessing the
suitability of both donor and recipient populations, including the landscape of
disease risk. Chytridiomycosis, caused by the fungal pathogen
Batrachochytrium dendrobatidis (Bd), has caused extensive
amphibian declines globally and may hamper reintroduction attempts. To determine
Bd dynamics in potential source populations for conservation translocations of
the threatened California red-legged frog (Rana draytonii) to
Yosemite National Park, we conducted Bd sampling in two populations in the
foothills of the Sierra Nevada Mountains, California, U.S.A. At one of two
sites, we observed lethally high Bd loads in early post-metamorphic life stages
and confirmed one chytridiomycosis-induced mortality, the first such report for
this species. These results informed source population site selection for
subsequent R. draytonii conservation
translocations. Conservation efforts aimed at establishing new populations of
R. draytonii in a landscape where Bd is
ubiquitous can benefit from an improved understanding of risk through disease
monitoring and ex situ infection studies.
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Affiliation(s)
- Andrea J. Adams
- Yosemite National Park, El Portal, California, United States of
America
- Earth Research Institute, University of California Santa Barbara, Santa
Barbara, California, United States of America
- * E-mail:
| | - Allan Pessier
- Department of Veterinary Microbiology and Pathology, College of
Veterinary Medicine, Washington State University, Pullman, Washington, United
States of America
| | - Peggy Cranston
- Mother Lode Field Office, U.S. Bureau of Land Management, Fair Oaks,
California, United States of America
| | - Robert L. Grasso
- Yosemite National Park, El Portal, California, United States of
America
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17
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Olivares-Miranda M, Vredenburg VT, García-Sánchez JC, Byrne AQ, Rosenblum EB, Rovito SM. Fungal infection, decline and persistence in the only obligate troglodytic Neotropical salamander. PeerJ 2020; 8:e9763. [PMID: 33024623 PMCID: PMC7518159 DOI: 10.7717/peerj.9763] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2020] [Accepted: 07/28/2020] [Indexed: 01/02/2023] Open
Abstract
The fungal pathogen Batrachochytrium dendrobatidis (Bd) is implicated in global mass die-offs and declines in amphibians. In Mesoamerica, the Bd epidemic wave hypothesis is supported by detection of Bd in historic museum specimens collected over the last century, yet the timing and impact of the early stages of the wave remain poorly understood. Chiropterotriton magnipes, the only obligate troglodytic Neotropical salamander, was abundant in its small range in the decade following its description in 1965, but subsequently disappeared from known localities and was not seen for 34 years. Its decline is roughly coincident with that of other populations of Neotropical salamanders associated with the invasion and spread of Bd. To determine the presence and infection intensity of Bd on C. magnipes and sympatric amphibian species (which are also Bd hosts), we used a noninvasive sampling technique and qPCR assay to detect Bd on museum specimens of C. magnipes collected from 1952 to 2012, and from extant populations of C. magnipes and sympatric species of amphibians. We also tested for the presence of the recently discovered Batrachochytrium salamandivorans (Bsal), another fungal chytridiomycete pathogen of salamanders, using a similar technique specific for Bsal. We did not detect Bd in populations of C. magnipes before 1969, while Bd was detected at low to moderate prevalence just prior to and during declines. This pattern is consistent with Bd-caused epizootics followed by host declines and extirpations described in other hosts. We did not detect Bsal in any extant population of C. magnipes. We obtained one of the earliest positive records of the fungus to date in Latin America, providing additional historical evidence consistent with the Bd epidemic wave hypothesis. Genotyping results show that at least one population is currently infected with the Global Panzootic Lineage of Bd, but our genotyping of the historical positive samples was unsuccessful. The lack of large samples from some years and the difficulty in genotyping historical Bd samples illustrate some of the difficulties inherent in assigning causality to historical amphibian declines. These data also provide an important historical baseline for actions to preserve the few known remaining populations of C. magnipes.
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Affiliation(s)
- Mizraim Olivares-Miranda
- Unidad de Genómica Avanzada (Langebio), Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Irapuato, Guanajuato, México
| | - Vance T Vredenburg
- Department of Biology, San Francisco State University, San Francisco, CA, USA
| | - Julio C García-Sánchez
- Unidad de Genómica Avanzada (Langebio), Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Irapuato, Guanajuato, México
| | - Allison Q Byrne
- Department of Environmental Science, Policy, and Management, University of California, Berkeley, Berkeley, CA, USA
| | - Erica B Rosenblum
- Department of Environmental Science, Policy, and Management, University of California, Berkeley, Berkeley, CA, USA
| | - Sean M Rovito
- Unidad de Genómica Avanzada (Langebio), Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Irapuato, Guanajuato, México
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18
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Zumbado‐Ulate H, García‐Rodríguez A, Searle CL. Species distribution models predict the geographic expansion of an enzootic amphibian pathogen. Biotropica 2020. [DOI: 10.1111/btp.12863] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Affiliation(s)
| | - Adrián García‐Rodríguez
- Departamento de Zoología Instituto de Biología Universidad Nacional Autónoma de MéxicoUNAM Ciudad de México México
- Museo de Zoología Escuela de Biología Universidad de Costa Rica San José Costa Rica
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19
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Sette CM, Vredenburg VT, Zink AG. Differences in Fungal Disease Dynamics in Co-occurring Terrestrial and Aquatic Amphibians. ECOHEALTH 2020; 17:302-314. [PMID: 33237500 DOI: 10.1007/s10393-020-01501-z] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/14/2019] [Revised: 09/14/2020] [Accepted: 10/04/2020] [Indexed: 06/11/2023]
Abstract
The fungal pathogen, Batrachochytrium dendrobatidis (Bd), has devastated biodiversity and ecosystem health and is implicated as a driver of mass amphibian extinctions. This 100-year study investigates which environmental factors contribute to Bd prevalence in a fully terrestrial species, and determines whether infection patterns differ between a fully terrestrial amphibian and more aquatic host species. We performed a historical survey to quantify Bd prevalence in 1127 Batrachoseps gregarius museum specimens collected from 1920 to 2000, and recent data from 16 contemporary (live-caught) B. gregarius populations from the southwestern slopes of the Sierra Nevada mountains in California, USA. We compared these results to Bd detection rates in 1395 historical and 1033 contemporary specimens from 10 species of anurans and 427 historical Taricha salamander specimens collected throughout the Sierra Nevada mountains. Our results indicate that Bd dynamics in the entirely terrestrial species, B. gregarius, differ from aquatic species in the same region in terms of both seasonal patterns of Bd abundance and in the possible timing of Bd epizootics.
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Affiliation(s)
- Carla M Sette
- University of California, Santa Cruz, EEB/CBB mailstop, UCSC/Coastal Biology Building, 130 McAllister Way, Santa Cruz, CA, 95060, USA.
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20
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Phillips P, Livieri TM, Swanson BJ. Genetic signature of disease epizootic and reintroduction history in an endangered carnivore. J Mammal 2020. [DOI: 10.1093/jmammal/gyaa043] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
AbstractEmerging infectious diseases have recently increased in wildlife and can result in population declines and the loss of genetic diversity in susceptible populations. As populations of impacted species decline, genetic diversity can be lost, with ramifications including reduced effective population size and increased population structuring. For species of conservation concern, which may already have low genetic diversity, the loss of genetic diversity can be especially important. To investigate the impacts of a novel pathogen on genetic diversity in a genetically depauperate endangered species, we assessed the ramifications of a sylvatic plague-induced bottleneck in black-footed ferrets (Mustela nigripes). Following a plague epizootic, we genotyped 184 ferrets from Conata Basin and Badlands National Park, South Dakota, at seven microsatellite loci. We compared our results to pre-plague studies in the same population. We observed population substructuring into three genetic clusters. These clusters reflect founder effects from ferret reintroduction events followed by genetic drift. Compared to the pre-plague population, we observed losses of allelic diversity in all clusters, as well as significantly reduced heterozygosity in one cluster. These results indicate that disease epizootics may reduce population size and also genetic diversity. Our results suggest the importance of early and sustained management in mitigating disease epizootics in naïve populations for the maintenance of genetic diversity.
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Affiliation(s)
- Payton Phillips
- Department of Biology, Central Michigan University, Mount Pleasant, MI, USA
- Department of Biology, Temple University, Philadelphia, PA, USA
| | | | - Bradley J Swanson
- Department of Biology, Central Michigan University, Mount Pleasant, MI, USA
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21
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Effects of invasive larval bullfrogs (Rana catesbeiana) on disease transmission, growth and survival in the larvae of native amphibians. Biol Invasions 2020. [DOI: 10.1007/s10530-020-02218-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
AbstractThe mechanisms by which invasive species negatively affect native species include competition, predation, and the introduction of novel pathogens. Moreover, if an invasive species is a competent disease reservoir, it may facilitate the long-term maintenance and spread of pathogens in ecological assemblages and drive the extinction of less tolerant or less resistant species. Disease-driven loss of biodiversity is exemplified by the amphibian–chytrid fungus system. The disease chytridiomycosis is caused by the aquatic chytrid fungus Batrachochytrium dendrobatidis (Bd) in anurans and is associated with worldwide amphibian population declines and extinctions. For amphibian species that metamorphose and leave infected aquatic habitats, the mechanisms by which Bd persists over winter in these habitats remains a critical open question. A leading hypothesis is that American bullfrogs (Rana catesbeiana), a worldwide invasive species, are tolerant to Bd and serve as a reservoir host for Bd during winter months and subsequently infect native species that return to breed in spring. Using outdoor mesocosms, we experimentally examined if two strains of Bd could overwinter in aquatic systems, in the presence or absence of bullfrog tadpoles, and if overwintered Bd could be transmitted to tadpoles of two spring-breeding species: Pacific treefrogs (Pseudacris regilla) and Cascades frogs (Rana cascadae). We found that only 4 of 448 total animals (one bullfrog and three spring breeders) tested positive for Bd after overwintering. Moreover, two of the three infected spring breeders emerged from tanks that contained overwintered Bd but in the absence of infected bullfrogs. This suggests that Bd can persist over winter without bullfrogs as a reservoir host. We found no effect of Bd strain on bullfrog survival after overwintering. For Pacific treefrogs, Bd exposure did not significantly affect mass at or time to metamorphosis while exposure to bullfrogs reduced survival. For Cascades frogs, we found an interactive effect of Bd strain and bullfrog presence on time to metamorphosis, but no main or interactive effects on their survival or mass at metamorphosis. In short, bullfrog tadpoles rarely retained and transmitted Bd infection in our experiment and we found limited evidence that Bd successfully overwinters in the absence of bullfrog tadpoles and infects spring-breeding amphibians.
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22
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Bedwell ME, Goldberg CS. Spatial and temporal patterns of environmental DNA detection to inform sampling protocols in lentic and lotic systems. Ecol Evol 2020; 10:1602-1612. [PMID: 32076537 PMCID: PMC7029092 DOI: 10.1002/ece3.6014] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2019] [Revised: 12/23/2019] [Accepted: 12/24/2019] [Indexed: 12/31/2022] Open
Abstract
The development of efficient sampling protocols for the capture of environmental DNA (eDNA) could greatly help improve accuracy of occupancy monitoring for species that are difficult to detect. However, the process of developing a protocol in situ is complicated for rare species by the fact that animal locations are often unknown. We tested sampling designs in lake and stream systems to determine the most effective eDNA sampling protocols for two rare species: the Sierra Nevada yellow-legged frog (Rana sierrae) and the foothill yellow-legged frog (Rana boylii). We varied water volume, spatial sampling, and seasonal timing in lakes and streams; in lakes we also tested multiple filter types. We found that filtering 2 L versus 1 L increased the odds of detection in streams 5.42X (95% CI: 3.2-9.19X) in our protocol, from a probability of 0.51-0.85 per technical replicate. Lake sample volumes were limited by filter clogging, and we found no effect of volume or filter type. Sampling later in the season increased the odds of detection in streams by 1.96X for every 30 days (95% CI: 1.3-2.97X) but there was no effect for lakes. Spatial autocorrelation of the quantity of yellow-legged frog eDNA captured in streams ceased between 100 and 200 m, indicating that sampling at close intervals is important.
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23
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Ghimire TR, Regmi GR, Huettmann F. When Micro Drives the Macro: A Fresh Look at Disease and its Massive Contributions in the Hindu Kush-Himalaya. HINDU KUSH-HIMALAYA WATERSHEDS DOWNHILL: LANDSCAPE ECOLOGY AND CONSERVATION PERSPECTIVES 2020. [PMCID: PMC7197387 DOI: 10.1007/978-3-030-36275-1_40] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The outbreaks of emerging and reemerging diseases have a high impact on the human and animal health because they are the underlying causes of disability, death, and long-term illness. For many regions those details are not, or just poorly known. Here we present on the morbidity and mortality in faunal diversities including domestic and wild species caused by various viral, bacterial, parasitic, and fungal diseases prevalent in Nepal and relevant for the wider Hindu Kush Himalaya. In addition, we provide details how antibiotic resistivity, vectors, and zoonosis have resulted on a landscape-scale in the huge public and veterinary health problem has been dealt with in the context of Nepal and the wider region.
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24
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Hantzschmann AM, Gollmann B, Gollmann G, Sinsch U. The fast-slow continuum of longevity among yellow-bellied toad populations ( Bombina variegata): intrinsic and extrinsic drivers of variation. PeerJ 2019; 7:e8233. [PMID: 31871841 PMCID: PMC6921980 DOI: 10.7717/peerj.8233] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2019] [Accepted: 11/18/2019] [Indexed: 01/04/2023] Open
Abstract
Yellow-bellied toad populations (Bombina variegata) show a wide fast-slow continuum of the life-history trait longevity ranging from 5 to 23 years. We investigated populations in Germany (n = 8) and Austria (n = 1) to determine their position within the continuum of longevity and the potential drivers of adult survival at the local and the continental scale. Intrinsic and extrinsic factors considered were local weather, nutritional state, allocation of ingested energy to somatic growth, pathogen prevalence, and geographical clines (latitude, altitude, and longitude). Capture-mark-recapture (CMR) monitoring and direct age assessment by skeletochronology allowed for reliable estimates of longevity and adult survival. Raw and corrected recapture rates as well as a probabilistic estimate of the lifespan of the eldest 1% adults of a cohort (CMR data) were used as surrogates for adult survival and thus longevity in a population. Additionally, survival rates were calculated from static life tables based on the age structure (skeletochronological data) of eight populations. Populations in Germany were short-lived with a maximum lifespan of annual cohorts varying from 5 to 8 years, whereas the population in Austria was long-lived with a cohort longevity of 13 to 23 years. We provide evidence that annual survival rates and longevity differ among years and between short- and long-lived populations, but there was no decrease of survival in older toads (i.e. absence of senescence). Variation of weather among years accounted for 90.7% of variance in annual survival rates of short-lived populations, whereas the sources of variation in the long-lived population remained unidentified. At the continental scale, longevity variation among B. variegata populations studied so far did not correspond to geographical clines or climate variation. Therefore, we propose that a population's position within the fast-slow continuum integrates the response to local environmental stochasticity (extrinsic source of variation) and the efficiency of chemical antipredator protection determining the magnitude of longevity (intrinsic source of variation).
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Affiliation(s)
| | - Birgit Gollmann
- Department of Limnology and Bio-Oceanography, University of Vienna, Wien, Austria
| | - Günter Gollmann
- Department of Theoretical Biology, University of Vienna, Wien, Austria
| | - Ulrich Sinsch
- Department of Biology, University of Koblenz-Landau, Koblenz, Germany
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25
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McKeon S, Weber L, Adams AJ, Fleischner TL. Human Dimensions: Natural History as the Innate Foundation of Ecology. ACTA ACUST UNITED AC 2019. [DOI: 10.1002/bes2.1656] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
- Seabird McKeon
- National Center for Integrated Coastal ResearchUniversity of Central Florida 364 Research 14353 Scorpius Drive Orlando Florida 32816‐2368 USA
| | - Louise Weber
- University of Saint Francis 2701 Spring Street Fort Wayne Indiana 46808 USA
| | - Andrea J. Adams
- University of California, Santa Barbara 6832 Ellison Hall Santa Barbara California 93106‐3060 USA
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26
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Reinke BA, Miller DA, Janzen FJ. What Have Long-Term Field Studies Taught Us About Population Dynamics? ANNUAL REVIEW OF ECOLOGY EVOLUTION AND SYSTEMATICS 2019. [DOI: 10.1146/annurev-ecolsys-110218-024717] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Long-term studies have been crucial to the advancement of population biology, especially our understanding of population dynamics. We argue that this progress arises from three key characteristics of long-term research. First, long-term data are necessary to observe the heterogeneity that drives most population processes. Second, long-term studies often inherently lead to novel insights. Finally, long-term field studies can serve as model systems for population biology, allowing for theory and methods to be tested under well-characterized conditions. We illustrate these ideas in three long-term field systems that have made outsized contributions to our understanding of population ecology, evolution, and conservation biology. We then highlight three emerging areas to which long-term field studies are well positioned to contribute in the future: ecological forecasting, genomics, and macrosystems ecology. Overcoming the obstacles associated with maintaining long-term studies requires continued emphasis on recognizing the benefits of such studies to ensure that long-term research continues to have a substantial impact on elucidating population biology.
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Affiliation(s)
- Beth A. Reinke
- Department of Ecosystem Science and Management, Pennsylvania State University, University Park, Pennsylvania 16802, USA
| | - David A.W. Miller
- Department of Ecosystem Science and Management, Pennsylvania State University, University Park, Pennsylvania 16802, USA
| | - Fredric J. Janzen
- Department of Ecology, Evolution, and Organismal Biology, Iowa State University, Ames, Iowa 50011, USA
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27
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Adelizzi R, Portmann J, Van Meter R. Effect of Individual and Combined Treatments of Pesticide, Fertilizer, and Salt on Growth and Corticosterone Levels of Larval Southern Leopard Frogs (Lithobates sphenocephala). ARCHIVES OF ENVIRONMENTAL CONTAMINATION AND TOXICOLOGY 2019; 77:29-39. [PMID: 31020372 DOI: 10.1007/s00244-019-00629-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/05/2018] [Accepted: 04/08/2019] [Indexed: 06/09/2023]
Abstract
Human activities have introduced a variety of chemicals, including pesticides, fertilizers, and salt, into the environment, which may have deleterious effects on the organisms inhabiting these areas. Amphibians are especially susceptible to absorption of chemical pollutants. To determine the possible combined effects of these chemicals on amphibian development and stress levels, Southern leopard frog (Lithobates sphenocephala) larvae were exposed to one of eight individual or combined treatments of atrazine, ammonium nitrate fertilizer, and sodium chloride salt. Stress levels, indicated by release of the stress hormone corticosterone, were measured premetamorphosis at week 8 of development. Water hormone samples were processed to analyze corticosterone levels. Changes in tadpole growth were determined by surface area measurements taken from biweekly photographs. The combined chemical treatment of atrazine, salt, and fertilizer had a significant interactive effect by increasing stress levels before metamorphosis (p = 0.003). After a month of larval development, tadpoles exposed to ammonium nitrate had larger surface area (p = 0.035). Tadpoles exposed to atrazine had a lower growth rate throughout larval development (p = 0.025) and the lowest number of individuals reaching metamorphosis at 33%. However, the frogs in the atrazine treatment that did successfully metamorphose did so in fewer days (p = 0.002). Because amphibians are exposed to multiple chemicals simultaneously in the environment, assessing the effects of a combination of contaminants is necessary to improve application strategies and ecosystem health.
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Affiliation(s)
- Rose Adelizzi
- Departments of Biology and Environmental Science & Studies, Washington College, 300 Washington Avenue, Chestertown, MD, 21620, USA
| | - Julia Portmann
- Departments of Biology and Environmental Science & Studies, Washington College, 300 Washington Avenue, Chestertown, MD, 21620, USA
| | - Robin Van Meter
- Departments of Biology and Environmental Science & Studies, Washington College, 300 Washington Avenue, Chestertown, MD, 21620, USA.
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28
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Eskew EA, Shock BC, LaDouceur EEB, Keel K, Miller MR, Foley JE, Todd BD. Gene expression differs in susceptible and resistant amphibians exposed to Batrachochytrium dendrobatidis. ROYAL SOCIETY OPEN SCIENCE 2018; 5:170910. [PMID: 29515828 PMCID: PMC5830717 DOI: 10.1098/rsos.170910] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
Chytridiomycosis, the disease caused by the fungal pathogen Batrachochytrium dendrobatidis (Bd), has devastated global amphibian biodiversity. Nevertheless, some hosts avoid disease after Bd exposure even as others experience near-complete extirpation. It remains unclear whether the amphibian adaptive immune system plays a role in Bd defence. Here, we describe gene expression in two host species-one susceptible to chytridiomycosis and one resistant-following exposure to two Bd isolates that differ in virulence. Susceptible wood frogs (Rana sylvatica) had high infection loads and mortality when exposed to the more virulent Bd isolate but lower infection loads and no fatal disease when exposed to the less virulent isolate. Resistant American bullfrogs (R. catesbeiana) had high survival across treatments and rapidly cleared Bd infection or avoided infection entirely. We found widespread upregulation of adaptive immune genes and downregulation of important metabolic and cellular maintenance components in wood frogs after Bd exposure, whereas American bullfrogs showed little gene expression change and no evidence of an adaptive immune response. Wood frog responses suggest that adaptive immune defences may be ineffective against virulent Bd isolates that can cause rapid physiological dysfunction. By contrast, American bullfrogs exhibited robust resistance to Bd that is likely attributable, at least in part, to their continued upkeep of metabolic and skin integrity pathways as well as greater antimicrobial peptide expression compared to wood frogs, regardless of exposure. Greater understanding of these defences will ultimately help conservationists manage chytridiomycosis.
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Affiliation(s)
- Evan A. Eskew
- Graduate Group in Ecology, University of California, Davis, One Shields Avenue, Davis, CA 95616, USA
- EcoHealth Alliance, 460 West 34th Street – 17th Floor, New York, NY 10001, USA
- Author for correspondence: Evan A. Eskew e-mail:
| | - Barbara C. Shock
- Department of Biology, Lincoln Memorial University, 6965 Cumberland Gap Parkway, Harrogate, TN 37752, USA
- Department of Pathology, Microbiology, and Immunology, School of Veterinary Medicine, University of California, Davis, One Shields Avenue, Davis, CA 95616, USA
| | | | - Kevin Keel
- Department of Pathology, Microbiology, and Immunology, School of Veterinary Medicine, University of California, Davis, One Shields Avenue, Davis, CA 95616, USA
| | - Michael R. Miller
- Department of Animal Science, University of California, Davis, One Shields Avenue, Davis, CA 95616, USA
| | - Janet E. Foley
- Department of Medicine and Epidemiology, School of Veterinary Medicine, University of California, Davis, One Shields Avenue, Davis, CA 95616, USA
| | - Brian D. Todd
- Department of Wildlife, Fish, and Conservation Biology, University of California, Davis, One Shields Avenue, Davis, CA 95616, USA
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29
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Adams AJ, Pessier AP, Briggs CJ. Rapid extirpation of a North American frog coincides with an increase in fungal pathogen prevalence: Historical analysis and implications for reintroduction. Ecol Evol 2017; 7:10216-10232. [PMID: 29238549 PMCID: PMC5723621 DOI: 10.1002/ece3.3468] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2017] [Revised: 08/06/2017] [Accepted: 08/19/2017] [Indexed: 01/14/2023] Open
Abstract
As extinctions continue across the globe, conservation biologists are turning to species reintroduction programs as one optimistic tool for addressing the biodiversity crisis. For repatriation to become a viable strategy, fundamental prerequisites include determining the causes of declines and assessing whether the causes persist in the environment. Invasive species-especially pathogens-are an increasingly significant factor contributing to biodiversity loss. We hypothesized that Batrachochytrium dendrobatidis (Bd), the causative agent of the deadly amphibian disease chytridiomycosis, was important in the rapid (<10 years) localized extirpation of a North American frog (Rana boylii) and that Bd remains widespread among extant amphibians in the region of extirpation. We used an interdisciplinary approach, combining interviews with herpetological experts, analysis of archived field notes and museum specimen collections, and field sampling of the extant amphibian assemblage to examine (1) historical relative abundance of R. boylii; (2) potential causes of R. boylii declines; and (3) historical and contemporary prevalence of Bd. We found that R. boylii were relatively abundant prior to their rapid extirpation, and an increase in Bd prevalence coincided with R. boylii declines during a time of rapid change in the region, wherein backcountry recreation, urban development, and the amphibian pet trade were all on the rise. In addition, extreme flooding during the winter of 1969 coincided with localized extirpations in R. boylii populations observed by interview respondents. We conclude that Bd likely played an important role in the rapid extirpation of R. boylii from southern California and that multiple natural and anthropogenic factors may have worked in concert to make this possible in a relatively short period of time. This study emphasizes the importance of recognizing historical ecological contexts in making future management and reintroduction decisions.
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Affiliation(s)
- Andrea J Adams
- Department of Ecology, Evolution and Marine Biology University of California, Santa Barbara Santa Barbara CA USA
| | - Allan P Pessier
- Department of Veterinary Microbiology and Pathology College of Veterinary Medicine Washington State University Pullman WA USA
| | - Cheryl J Briggs
- Department of Ecology, Evolution and Marine Biology University of California, Santa Barbara Santa Barbara CA USA
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