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Hernawan UE, van Dijk K, Kendrick GA, Feng M, Berry O, Kavazos C, McMahon K. Ocean connectivity and habitat characteristics predict population genetic structure of seagrass in an extreme tropical setting. Ecol Evol 2023; 13:e10257. [PMID: 37404702 PMCID: PMC10316484 DOI: 10.1002/ece3.10257] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2023] [Revised: 06/15/2023] [Accepted: 06/19/2023] [Indexed: 07/06/2023] Open
Abstract
Understanding patterns of gene flow and processes driving genetic differentiation is important for a broad range of conservation practices. In marine organisms, genetic differentiation among populations is influenced by a range of spatial, oceanographic, and environmental factors that are attributed to the seascape. The relative influences of these factors may vary in different locations and can be measured using seascape genetic approaches. Here, we applied a seascape genetic approach to populations of the seagrass, Thalassia hemprichii, at a fine spatial scale (~80 km) in the Kimberley coast, western Australia, a complex seascape with strong, multidirectional currents greatly influenced by extreme tidal ranges (up to 11 m, the world's largest tropical tides). We incorporated genetic data from a panel of 16 microsatellite markers, overwater distance, oceanographic data derived from predicted passive dispersal on a 2 km-resolution hydrodynamic model, and habitat characteristics from each meadow sampled. We detected significant spatial genetic structure and asymmetric gene flow, in which meadows 12-14 km apart were less connected than ones 30-50 km apart. This pattern was explained by oceanographic connectivity and differences in habitat characteristics, suggesting a combined scenario of dispersal limitation and facilitation by ocean current with local adaptation. Our findings add to the growing evidence for the key role of seascape attributes in driving spatial patterns of gene flow. Despite the potential for long-distance dispersal, there was significant genetic structuring over small spatial scales implicating dispersal and recruitment bottlenecks and highlighting the importance of implementing local-scale conservation and management measures.
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Affiliation(s)
- Udhi E. Hernawan
- School of Science and Centre for Marine Ecosystems ResearchEdith Cowan UniversityJoondalupWestern AustraliaAustralia
- Research Centre for Oceanography (PRO), National Research and Innovation Agency (BRIN)JakartaIndonesia
| | - Kor‐jent van Dijk
- School of Biological SciencesThe University of AdelaideAdelaideSouth AustraliaAustralia
| | - Gary A. Kendrick
- School of Biological Sciences and The Ocean InstituteThe University of Western AustraliaCrawleyWestern AustraliaAustralia
- Western Australian Marine Science InstitutionPerthWestern AustraliaAustralia
| | - Ming Feng
- Western Australian Marine Science InstitutionPerthWestern AustraliaAustralia
- CSIRO Environment, Indian Ocean Marine Research CentreCrawleyWestern AustraliaAustralia
| | - Oliver Berry
- Western Australian Marine Science InstitutionPerthWestern AustraliaAustralia
- CSIRO Environment, Indian Ocean Marine Research CentreCrawleyWestern AustraliaAustralia
| | - Christopher Kavazos
- School of Science and Centre for Marine Ecosystems ResearchEdith Cowan UniversityJoondalupWestern AustraliaAustralia
| | - Kathryn McMahon
- School of Science and Centre for Marine Ecosystems ResearchEdith Cowan UniversityJoondalupWestern AustraliaAustralia
- Western Australian Marine Science InstitutionPerthWestern AustraliaAustralia
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Maas DL, Prost S, de Leeuw CA, Bi K, Smith LL, Purwanto P, Aji LP, Tapilatu RF, Gillespie RG, Becking LE. Sponge diversification in marine lakes: Implications for phylogeography and population genomic studies on sponges. Ecol Evol 2023; 13:e9945. [PMID: 37066063 PMCID: PMC10099488 DOI: 10.1002/ece3.9945] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2022] [Revised: 03/06/2023] [Accepted: 03/08/2023] [Indexed: 04/18/2023] Open
Abstract
The relative influence of geography, currents, and environment on gene flow within sessile marine species remains an open question. Detecting subtle genetic differentiation at small scales is challenging in benthic populations due to large effective population sizes, general lack of resolution in genetic markers, and because barriers to dispersal often remain elusive. Marine lakes can circumvent confounding factors by providing discrete and replicated ecosystems. Using high-resolution double digest restriction-site-associated DNA sequencing (4826 Single Nucleotide Polymorphisms, SNPs), we genotyped populations of the sponge Suberites diversicolor (n = 125) to test the relative importance of spatial scales (1-1400 km), local environmental conditions, and permeability of seascape barriers in shaping population genomic structure. With the SNP dataset, we show strong intralineage population structure, even at scales <10 km (average F ST = 0.63), which was not detected previously using single markers. Most variation was explained by differentiation between populations (AMOVA: 48.8%) with signatures of population size declines and bottlenecks per lake. Although the populations were strongly structured, we did not detect significant effects of geographic distance, local environments, or degree of connection to the sea on population structure, suggesting mechanisms such as founder events with subsequent priority effects may be at play. We show that the inclusion of morphologically cryptic lineages that can be detected with the COI marker can reduce the obtained SNP set by around 90%. Future work on sponge genomics should confirm that only one lineage is included. Our results call for a reassessment of poorly dispersing benthic organisms that were previously assumed to be highly connected based on low-resolution markers.
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Affiliation(s)
- Diede L. Maas
- Marine Animal EcologyWageningen University & ResearchWageningenThe Netherlands
| | - Stefan Prost
- LOEWE Centre for Translational Biodiversity GenomicsSenckenberg Natural History MuseumFrankfurt am MainGermany
- South African National Biodiversity InstituteNational Zoological Gardens of South AfricaPretoriaSouth Africa
| | | | - Ke Bi
- Museum of Vertebrate ZoologyUniversity of California BerkeleyBerkeleyCaliforniaUSA
- Computational Genomics Resource Laboratory, California Institute for Quantitative BiosciencesUniversity of California BerkeleyBerkeleyCaliforniaUSA
| | - Lydia L. Smith
- Museum of Vertebrate ZoologyUniversity of California BerkeleyBerkeleyCaliforniaUSA
| | | | - Ludi P. Aji
- Marine Animal EcologyWageningen University & ResearchWageningenThe Netherlands
- Research Centre for Oceanography, Indonesian Institute of SciencesLembaga Ilmu Pengetahuan IndonesiaJakartaIndonesia
| | - Ricardo F. Tapilatu
- Marine Science and Fisheries Departments and Research Center of Pacific Marine ResourcesState University of PapuaManokwariIndonesia
| | - Rosemary G. Gillespie
- Department of Environmental Science, Policy and ManagementUniversity of California BerkeleyBerkeleyCaliforniaUSA
| | - Leontine E. Becking
- Department of Environmental Science, Policy and ManagementUniversity of California BerkeleyBerkeleyCaliforniaUSA
- Aquaculture and Fisheries, Naturalis Biodiversity CenterWageningen University & ResearchWageningenThe Netherlands
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Sinclair EA, Hovey RK, Krauss SL, Anthony JM, Waycott M, Kendrick GA. Historic and contemporary biogeographic perspectives on range-wide spatial genetic structure in a widespread seagrass. Ecol Evol 2023; 13:e9900. [PMID: 36950371 PMCID: PMC10025079 DOI: 10.1002/ece3.9900] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2022] [Accepted: 02/26/2023] [Indexed: 03/22/2023] Open
Abstract
Historical and contemporary processes drive spatial patterns of genetic diversity. These include climate-driven range shifts and gene flow mediated by biogeographical influences on dispersal. Assessments that integrate these drivers are uncommon, but critical for testing biogeographic hypotheses. Here, we characterize intraspecific genetic diversity and spatial structure across the entire distribution of a temperate seagrass to test marine biogeographic concepts for southern Australia. Predictive modeling was used to contrast the current Posidonia australis distribution to its historical distribution during the Last Glacial Maximum (LGM). Spatial genetic structure was estimated for 44 sampled meadows from across the geographical range of the species using nine microsatellite loci. Historical and contemporary distributions were similar, with the exception of the Bass Strait. Genetic clustering was consistent with the three currently recognized biogeographic provinces and largely consistent with the finer-scale IMCRA bioregions. Discrepancies were found within the Flindersian province and southwest IMCRA bioregion, while two regions of admixture coincided with transitional IMCRA bioregions. Clonal diversity was highly variable but positively associated with latitude. Genetic differentiation among meadows was significantly associated with oceanographic distance. Our approach suggests how shared seascape drivers have influenced the capacity of P. australis to effectively track sea level changes associated with natural climate cycles over millennia, and in particular, the recolonization of meadows across the Continental Shelf following the LGM. Genetic structure associated with IMCRA bioregions reflects the presence of stable biogeographic barriers, such as oceanic upwellings. This study highlights the importance of biogeography to infer the role of historical drivers in shaping extant diversity and structure.
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Affiliation(s)
- Elizabeth A. Sinclair
- School of Biological SciencesUniversity of Western AustraliaCrawleyWestern AustraliaAustralia
- Oceans Institute, University of Western AustraliaCrawleyWestern AustraliaAustralia
- Kings Park Science, Department of Biodiversity Conservation and AttractionsKings ParkWestern AustraliaAustralia
| | - Renae K. Hovey
- School of Biological SciencesUniversity of Western AustraliaCrawleyWestern AustraliaAustralia
- Oceans Institute, University of Western AustraliaCrawleyWestern AustraliaAustralia
| | - Siegfried L. Krauss
- School of Biological SciencesUniversity of Western AustraliaCrawleyWestern AustraliaAustralia
- Kings Park Science, Department of Biodiversity Conservation and AttractionsKings ParkWestern AustraliaAustralia
| | - Janet M. Anthony
- School of Biological SciencesUniversity of Western AustraliaCrawleyWestern AustraliaAustralia
- Kings Park Science, Department of Biodiversity Conservation and AttractionsKings ParkWestern AustraliaAustralia
| | - Michelle Waycott
- School of Biological SciencesUniversity of Adelaide and State Herbarium of South AustraliaAdelaideSouth AustraliaAustralia
| | - Gary A. Kendrick
- School of Biological SciencesUniversity of Western AustraliaCrawleyWestern AustraliaAustralia
- Oceans Institute, University of Western AustraliaCrawleyWestern AustraliaAustralia
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Nguyen XV, Phan TTH, Cao VL, Nguyen Nhat NT, Nguyen TH, Nguyen XT, Lau VK, Hoang CT, Nguyen-Thi MN, Nguyen HM, Dao VH, Teichberg M, Papenbrock J. Current advances in seagrass research: A review from Viet Nam. FRONTIERS IN PLANT SCIENCE 2022; 13:991865. [PMID: 36299785 PMCID: PMC9589349 DOI: 10.3389/fpls.2022.991865] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/12/2022] [Accepted: 09/16/2022] [Indexed: 06/16/2023]
Abstract
Seagrass meadows provide valuable ecosystem services but are fragile and threatened ecosystems all over the world. This review highlights the current advances in seagrass research from Viet Nam. One goal is to support decision makers in developing science-based conservation strategies. In recent years, several techniques were applied to estimate the size of seagrass meadows. Independent from the method used, there is an alarming decline in the seagrass area in almost all parts of Viet Nam. Since 1990, a decline of 46.5% or 13,549 ha was found. Only in a few protected and difficult-to-reach areas was an increase observed. Conditions at those sites could be investigated in more detail to make suggestions for conservation and recovery of seagrass meadows. Due to their lifestyle and morphology, seagrasses take up compounds from their environment easily. Phytoremediation processes of Thalassia hemprichii and Enhalus acoroides are described exemplarily. High accumulation of heavy metals dependent on their concentration in the environment in different organs can be observed. On the one hand, seagrasses play a role in phytoremediation processes in polluted areas; on the other hand, they might suffer at high concentrations, and pollution will contribute to their overall decline. Compared with the neighboring countries, the total C org stock from seagrass beds in Viet Nam was much lower than in the Philippines and Indonesia but higher than that of Malaysia and Myanmar. Due to an exceptionally long latitudinal coastline of 3,260 km covering cool to warm water environments, the seagrass species composition in Viet Nam shows a high diversity and a high plasticity within species boundaries. This leads to challenges in taxonomic issues, especially with the Halophila genus, which can be better deduced from genetic diversity/population structures of members of Hydrocharitaceae. Finally, the current seagrass conservation and management efforts in Viet Nam are presented and discussed. Only decisions based on the interdisciplinary cooperation of scientists from all disciplines mentioned will finally lead to conserve this valuable ecosystem for mankind and biodiversity.
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Affiliation(s)
- Xuan-Vy Nguyen
- Institute of Oceanography, Viet Nam Academy of Science and Technology, Nha Trang, Vietnam
- Faculty of Marine Science and Technology, Graduate University of Science and Technology, Ha Noi, Vietnam
| | | | - Van-Luong Cao
- Faculty of Marine Science and Technology, Graduate University of Science and Technology, Ha Noi, Vietnam
- Institute of Marine Environment and Resources, Viet Nam Academy of Science and Technology, Hai Phong, Vietnam
| | - Nhu-Thuy Nguyen Nhat
- Institute of Oceanography, Viet Nam Academy of Science and Technology, Nha Trang, Vietnam
| | - Trung-Hieu Nguyen
- Institute of Oceanography, Viet Nam Academy of Science and Technology, Nha Trang, Vietnam
| | - Xuan-Thuy Nguyen
- Institute of Oceanography, Viet Nam Academy of Science and Technology, Nha Trang, Vietnam
| | - Va-Khin Lau
- Institute of Oceanography, Viet Nam Academy of Science and Technology, Nha Trang, Vietnam
| | | | - My-Ngan Nguyen-Thi
- Institute of Oceanography, Viet Nam Academy of Science and Technology, Nha Trang, Vietnam
| | - Hung Manh Nguyen
- Dead Sea and Arava Science Center, Central Arava Branch, Hatseva, Israel
- French Associates Institute for Agriculture and Biotechnology of Dryland, The Jacob Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, Sede Boqer Campus, Midreshet Ben-Gurion, Israel
| | - Viet-Ha Dao
- Institute of Oceanography, Viet Nam Academy of Science and Technology, Nha Trang, Vietnam
- Faculty of Marine Science and Technology, Graduate University of Science and Technology, Ha Noi, Vietnam
| | - Mirta Teichberg
- Ecosystems Center, Marine Biological Laboratory (MBL), Woodshole, MA, United States
| | - Jutta Papenbrock
- Institute of Botany, Leibniz University Hannover, Hannover, Germany
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Edgeloe JM, Severn-Ellis AA, Bayer PE, Mehravi S, Breed MF, Krauss SL, Batley J, Kendrick GA, Sinclair EA. Extensive polyploid clonality was a successful strategy for seagrass to expand into a newly submerged environment. Proc Biol Sci 2022; 289:20220538. [PMID: 35642363 PMCID: PMC9156900 DOI: 10.1098/rspb.2022.0538] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Polyploidy has the potential to allow organisms to outcompete their diploid progenitor(s) and occupy new environments. Shark Bay, Western Australia, is a World Heritage Area dominated by temperate seagrass meadows including Poseidon's ribbon weed, Posidonia australis. This seagrass is at the northern extent of its natural geographic range and experiences extremes in temperature and salinity. Our genomic and cytogenetic assessments of 10 meadows identified geographically restricted, diploid clones (2n = 20) in a single location, and a single widespread, high-heterozygosity, polyploid clone (2n = 40) in all other locations. The polyploid clone spanned at least 180 km, making it the largest known example of a clone in any environment on earth. Whole-genome duplication through polyploidy, combined with clonality, may have provided the mechanism for P. australis to expand into new habitats and adapt to new environments that became increasingly stressful for its diploid progenitor(s). The new polyploid clone probably formed in shallow waters after the inundation of Shark Bay less than 8500 years ago and subsequently expanded via vegetative growth into newly submerged habitats.
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Affiliation(s)
- Jane M. Edgeloe
- School of Biological Sciences, University of Western Australia, Crawley, Western Australia, 6009, Australia,Oceans Institute, University of Western Australia, Crawley, Western Australia, 6009, Australia
| | - Anita A. Severn-Ellis
- School of Biological Sciences, University of Western Australia, Crawley, Western Australia, 6009, Australia
| | - Philipp E. Bayer
- School of Biological Sciences, University of Western Australia, Crawley, Western Australia, 6009, Australia
| | - Shaghayegh Mehravi
- School of Biological Sciences, University of Western Australia, Crawley, Western Australia, 6009, Australia
| | - Martin F. Breed
- College of Science and Engineering, Flinders University, Bedford Park, South Australia 5042, Australia
| | - Siegfried L. Krauss
- School of Biological Sciences, University of Western Australia, Crawley, Western Australia, 6009, Australia,Kings Park Science, Department of Biodiversity Conservation and Attractions, 1 Kattidj Close, West Perth, Western Australia 6005, Australia
| | - Jacqueline Batley
- School of Biological Sciences, University of Western Australia, Crawley, Western Australia, 6009, Australia
| | - Gary A. Kendrick
- School of Biological Sciences, University of Western Australia, Crawley, Western Australia, 6009, Australia,Oceans Institute, University of Western Australia, Crawley, Western Australia, 6009, Australia
| | - Elizabeth A. Sinclair
- School of Biological Sciences, University of Western Australia, Crawley, Western Australia, 6009, Australia,Oceans Institute, University of Western Australia, Crawley, Western Australia, 6009, Australia,Kings Park Science, Department of Biodiversity Conservation and Attractions, 1 Kattidj Close, West Perth, Western Australia 6005, Australia
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Ruocco M, Jahnke M, Silva J, Procaccini G, Dattolo E. 2b-RAD Genotyping of the Seagrass Cymodocea nodosa Along a Latitudinal Cline Identifies Candidate Genes for Environmental Adaptation. Front Genet 2022; 13:866758. [PMID: 35651946 PMCID: PMC9149362 DOI: 10.3389/fgene.2022.866758] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Accepted: 04/19/2022] [Indexed: 11/18/2022] Open
Abstract
Plant populations distributed along broad latitudinal gradients often show patterns of clinal variation in genotype and phenotype. Differences in photoperiod and temperature cues across latitudes influence major phenological events, such as timing of flowering or seed dormancy. Here, we used an array of 4,941 SNPs derived from 2b-RAD genotyping to characterize population differentiation and levels of genetic and genotypic diversity of three populations of the seagrass Cymodocea nodosa along a latitudinal gradient extending across the Atlantic-Mediterranean boundary (i.e., Gran Canaria—Canary Islands, Faro—Portugal, and Ebro Delta—Spain). Our main goal was to search for potential outlier loci that could underlie adaptive differentiation of populations across the latitudinal distribution of the species. We hypothesized that such polymorphisms could be related to variation in photoperiod-temperature regime occurring across latitudes. The three populations were clearly differentiated and exhibited diverse levels of clonality and genetic diversity. Cymodocea nodosa from the Mediterranean displayed the highest genotypic richness, while the Portuguese population had the highest clonality values. Gran Canaria exhibited the lowest genetic diversity (as observed heterozygosity). Nine SNPs were reliably identified as outliers across the three sites by two different methods (i.e., BayeScan and pcadapt), and three SNPs could be associated to specific protein-coding genes by screening available C. nodosa transcriptomes. Two SNPs-carrying contigs encoded for transcription factors, while the other one encoded for an enzyme specifically involved in the regulation of flowering time, namely Lysine-specific histone demethylase 1 homolog 2. When analyzing biological processes enriched within the whole dataset of outlier SNPs identified by at least one method, “regulation of transcription” and “signalling” were among the most represented. Our results highlight the fundamental importance signal integration and gene-regulatory networks, as well as epigenetic regulation via DNA (de)methylation, could have for enabling adaptation of seagrass populations along environmental gradients.
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Affiliation(s)
| | - Marlene Jahnke
- Department of Marine Sciences, Tjärnö Marine Laboratory, University of Gothenburg, Gothenburg, Sweden
| | - João Silva
- Centre of Marine Sciences, University of Algarve, Faro, Portugal
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Sousa R, Vasconcelos J, Vera-Escalona I, Pinto AR, Hawkins SJ, Freitas M, Delgado J, González JA, Riera R. Pleistocene expansion, anthropogenic pressure and ocean currents: Disentangling the past and ongoing evolutionary history of Patella aspera Röding, 1798 in the archipelago of Madeira. MARINE ENVIRONMENTAL RESEARCH 2021; 172:105485. [PMID: 34715642 DOI: 10.1016/j.marenvres.2021.105485] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/10/2021] [Revised: 09/12/2021] [Accepted: 09/18/2021] [Indexed: 06/13/2023]
Abstract
AIMS Rising sea-level following the Last Glacial Maximum lead to fragmentation of coastal limpet populations between islands of the Archipelago of Madeira. This fragmentation is reinforced by recent heavy exploitation reducing effective population size on Madeira Island. We use the limpet P. aspera to understand how the role of processes at different time scales (i.e. changes in the sea level and overexploitation) can influence the genetic composition of an extant species, relating these processes to reproductive phenology and seasonal shifts in ocean currents. LOCATION Madeira Island, Porto Santo and Desertas (Archipelago of Madeira, NE Atlantic Ocean). TAXON The limpet Patella aspera. METHODS Twelve microsatellite genetic markers were used. A power analysis was used to evaluate the power of the microsatellite markers to detect a signal of population differentiation. Long-term past migrations were assessed using a Bayesian Markov Montecarlo approach in the software MIGRATE-n to estimate mutation-scaled migration rates (M = m/μ; m, probability of a lineage immigrating per generation; μ, mutation rate). Two scenarios were evaluated using an Approximate Bayesian Computation (ABC) in the software DIYABC 2.1 (i) Scenario 1: considered a population scenario from a reduced Ne at time t3 to a higher Ne at time t2; and (ii) Scenario 2 considering a reduction of Ne from a time t3 to a time t2. RESULTS Colonization of the archipelago by Portuguese settlers six centuries ago probably led to an important decrease in the genetic diversity of the species (Ne). Contemporary gene flow strongly support a pattern of high asymmetric connectivity explained by the reproductive phenology of the species and spatio-temporal seasonal changes in the ocean currents. Spatio-temporal reconstructions using Bayesian methods, including coalescent and Approximate Bayesian Computation (ABC) approaches, suggest changes in the migration patterns from highly symmetric to highly asymmetric connectivity with subtle population differentiation as consequence of post-glacial maximum sea level rise during the Holocene. MAIN CONCLUSIONS Our results suggest that anthropogenic activity could have had serious effects on the genetic diversity of heavily exploited littoral species since the end of the Pleistocene, probably accelerating in recent years.
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Affiliation(s)
- Ricardo Sousa
- Observatório Oceânico da Madeira, Agência Regional para o Desenvolvimento da Investigação Tecnologia e Inovação (OOM/ARDITI) - Edifício Madeira Tecnopolo, Funchal, Madeira, Portugal; Direção Regional do Mar (DRM)/ Direção de Serviços de Monitorização, Estudos e Investigação do Mar (DSEIMar), 9004-562, Funchal, Madeira, Portugal; MARE - Marine and Environmental Sciences Centre, Agência Regional para o Desenvolvimento da Investigação Tecnologia e Inovação (ARDITI), Edifício Madeira Tecnopolo Piso 0, Caminho da Penteada, 9020-105, Funchal, Madeira, Portugal
| | - Joana Vasconcelos
- MARE - Marine and Environmental Sciences Centre, Agência Regional para o Desenvolvimento da Investigação Tecnologia e Inovação (ARDITI), Edifício Madeira Tecnopolo Piso 0, Caminho da Penteada, 9020-105, Funchal, Madeira, Portugal; Faculdade de Ciências de Vida, Universidade da Madeira, Campus Universitário da Madeira, Caminho da Penteada, 9020-020, Funchal, Madeira, Portugal; Departamento de Ecología, Facultad de Ciencias, Universidad Católica de la Santísima Concepción, Casilla 297, Concepción, Chile
| | - Iván Vera-Escalona
- CIBAS, Facultad de Ciencias, Universidad Católica de la Santísima Concepción, Casilla 297, Concepción, Chile; IU-ECOAQUA, Group of Biodiversity and Conservation (BIOCON), Universidad de Las Palmas de Gran Canaria, Las Palmas de Gran Canaria, Spain
| | - Ana Rita Pinto
- Direção Regional do Mar (DRM)/ Direção de Serviços de Monitorização, Estudos e Investigação do Mar (DSEIMar), 9004-562, Funchal, Madeira, Portugal
| | - S J Hawkins
- Marine Biological Association of the UK, Plymouth, PL1 2PB, UK; School of Ocean and Earth Science, University of Southampton, National Oceanography Centre, Southampton, SO14 3ZH, UK
| | - Mafalda Freitas
- Observatório Oceânico da Madeira, Agência Regional para o Desenvolvimento da Investigação Tecnologia e Inovação (OOM/ARDITI) - Edifício Madeira Tecnopolo, Funchal, Madeira, Portugal; Direção Regional do Mar (DRM)/ Direção de Serviços de Monitorização, Estudos e Investigação do Mar (DSEIMar), 9004-562, Funchal, Madeira, Portugal; MARE - Marine and Environmental Sciences Centre, Agência Regional para o Desenvolvimento da Investigação Tecnologia e Inovação (ARDITI), Edifício Madeira Tecnopolo Piso 0, Caminho da Penteada, 9020-105, Funchal, Madeira, Portugal
| | - João Delgado
- Direção Regional do Mar (DRM)/ Direção de Serviços de Monitorização, Estudos e Investigação do Mar (DSEIMar), 9004-562, Funchal, Madeira, Portugal; Centro Interdisciplinar de Investigação Marinha e Ambiental (CIIMAR/CIMAR), Porto, Portugal
| | - José A González
- Ecología Marina Aplicada y Pesquerías (i-UNAT), Universidad de Las Palmas de Gran Canaria, Las Palmas de Gran Canaria, Spain
| | - Rodrigo Riera
- Departamento de Ecología, Facultad de Ciencias, Universidad Católica de la Santísima Concepción, Casilla 297, Concepción, Chile; IU-ECOAQUA, Group of Biodiversity and Conservation (BIOCON), Universidad de Las Palmas de Gran Canaria, Las Palmas de Gran Canaria, Spain.
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Zheng SS, Jiang XL, Huang QJ, Deng M. Historical Dynamics of Semi-Humid Evergreen Forests in the Southeast Himalaya Biodiversity Hotspot: A Case Study of the Quercus franchetii Complex (Fagaceae). FRONTIERS IN PLANT SCIENCE 2021; 12:774232. [PMID: 35035389 PMCID: PMC8753985 DOI: 10.3389/fpls.2021.774232] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/11/2021] [Accepted: 10/28/2021] [Indexed: 06/14/2023]
Abstract
The Oligocene and Miocene are key periods in the formation of the modern topography and flora of East Asian and Indo-China. However, it is unclear how geological and climatic factors contributed to the high endemism and species richness of this region. The Quercus franchetii complex is widespread in the southeast Himalaya fringe and northern Indo-China with a long evolutionary history. It provides a unique proxy for studying the diversity pattern of evergreen woody lineages in this region since the Oligocene. In this study, we combined chloroplast (cpDNA) sequences, nuclear microsatellite loci (nSSRs), and species distribution modeling (SDM) to investigate the impacts of geological events on genetic diversity of the Q. franchetii complex. The results showed that the initial cpDNA haplotype divergence was estimated to occur during the middle Oligocene (30.7 Ma), which might have been raised by the tectonic activity at this episode to the Miocene. The nSSR results revealed two major groups of populations, the central Yunnan-Guizhou plateau (YGP) group and the peripheral distribution group when K = 2, in responding to the rapid YGP uplift during the late Miocene, which restricted gene flow between the populations in core and marginal areas. SDM analysis indicated that the distribution ranges of the Q. franchetii complex expanded northwards after the last glacial maximum, but the core distribution range in YGP was stable. Our results showed that the divergence of Q. franchetii complex is rooted in the mid-Oligocene. The early geological events during the Oligocene, and the late Miocene may play key roles to restrict seed-mediated gene flow among regions, but the pollen-mediated gene flow was less impacted. The uplifts of the YGP and the climate since LGM subsequently boosted the divergence of the populations in core and marginal areas.
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Affiliation(s)
- Si-Si Zheng
- Shanghai Chenshan Botanical Garden, Shanghai, China
- School of Ecological Technique and Engineering, Shanghai Institute of Technology, Shanghai, China
| | - Xiao-Long Jiang
- The Laboratory of Forestry Genetics, Central South University of Forestry and Technology, Changsha, China
| | - Qing-Jun Huang
- School of Ecological Technique and Engineering, Shanghai Institute of Technology, Shanghai, China
| | - Min Deng
- School of Ecology and Environmental Science, Yunnan University, Kunming, China
- Yunnan Key Laboratory of Plant Reproductive Adaptation and Evolutionary Ecology, Yunnan University, Kunming, China
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9
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Buckee J, Hetzel Y, Nyegaard M, Evans S, Whiting S, Scott S, Ayvazian S, van Keulen M, Verduin J. Catastrophic loss of tropical seagrass habitats at the Cocos (Keeling) Islands due to multiple stressors. MARINE POLLUTION BULLETIN 2021; 170:112602. [PMID: 34237606 DOI: 10.1016/j.marpolbul.2021.112602] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/22/2020] [Revised: 05/29/2021] [Accepted: 06/01/2021] [Indexed: 06/13/2023]
Abstract
Seagrass habitats at the Cocos (Keeling) Islands (CKI), a remote atoll in the Indian Ocean, have suffered a catastrophic decline over the last decade. Seagrass monitoring (1996-2020) in relation to dredging and coastal development works (2009 to 2011) provide a historical baseline, and document the decline of mixed tropical seagrass Thalassia hemprichii and macroalgal (predominantly Caulerpa spp.) beds over a decadal scale time series. Attribution of loss to coastal development is confounded by lagoon-wide die-off events in 2007, 2009 and 2012 and high air and water temperatures from 2009 to 2016, with evidence of broad scale changes, visible in satellite imagery between 2006 and 2018. We conclude that up to 80% of seagrass habitats in the CKI lagoon (~1200 ha) have been lost due to multiple stressors including episodic die-off events related to high temperatures and calm conditions, and loss due to sediment disturbance and increased turbidity. Grazing pressure from the resident green sea turtles (Chelonia mydas) may have also exacerbated the loss of seagrass, which in turn poses a dire threat to their ongoing health and survival. This study highlights the fragility of tropical seagrass habitats and the cascading effect of system imbalance as a result of anthropogenic pressures and climate drivers. Although small in comparison to global estimates, the loss of seagrass habitats at CKI could change the entire ecosystem of a remote atoll. Due to the significance of the Thalassia beds for coastal stability, as food for an isolated population of green sea turtles and as a fish nursery, rehabilitation efforts are warranted.
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Affiliation(s)
- Joanna Buckee
- Centre for Sustainable Aquatic Ecosystems, Harry Butler Institute, Murdoch University, 90 South St, Murdoch, Western Australia 6150, Australia.
| | - Yasha Hetzel
- University of Western Australia, Indian Ocean Marine Research Centre, Crawley, Western Australia 6009, Australia
| | - Marianne Nyegaard
- Centre for Sustainable Aquatic Ecosystems, Harry Butler Institute, Murdoch University, 90 South St, Murdoch, Western Australia 6150, Australia
| | - Scott Evans
- Western Australian Fisheries and Marine Research Laboratories, Department of Primary Industries and Regional Development, Government of Western Australia, P.O. Box 20, North Beach, WA 6920, Australia
| | - Scott Whiting
- Biomarine International, P.O. Box 1212, Bentley DC, Western Australia 6983, Australia
| | - Sarah Scott
- BMT, Level 4, Parkland Road, Osborne Park, Western Australia 6017, Australia
| | | | - Mike van Keulen
- Centre for Sustainable Aquatic Ecosystems, Harry Butler Institute, Murdoch University, 90 South St, Murdoch, Western Australia 6150, Australia
| | - Jennifer Verduin
- Centre for Sustainable Aquatic Ecosystems, Harry Butler Institute, Murdoch University, 90 South St, Murdoch, Western Australia 6150, Australia
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10
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Hu ZM, Zhang QS, Zhang J, Kass JM, Mammola S, Fresia P, Draisma SGA, Assis J, Jueterbock A, Yokota M, Zhang Z. Intraspecific genetic variation matters when predicting seagrass distribution under climate change. Mol Ecol 2021; 30:3840-3855. [PMID: 34022079 DOI: 10.1111/mec.15996] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2021] [Revised: 05/13/2021] [Accepted: 05/14/2021] [Indexed: 01/01/2023]
Abstract
Seagrasses play a vital role in structuring coastal marine ecosystems, but their distributional range and genetic diversity have declined rapidly in recent decades. To improve conservation of seagrass species, it is important to predict how climate change may impact their ranges. Such predictions are typically made with correlative species distribution models (SDMs), which can estimate a species' potential distribution under present and future climatic scenarios given species' presence data and climatic predictor variables. However, these models are typically constructed with species-level data, and thus ignore intraspecific genetic variability, which can give rise to populations with adaptations to heterogeneous climatic conditions. Here, we explore the link between intraspecific adaptation and niche differentiation in Thalassia hemprichii, a seagrass broadly distributed in the tropical Indo-Pacific Ocean and a crucial provider of habitat for numerous marine species. By retrieving and re-analysing microsatellite data from previous studies, we delimited two distinct phylogeographical lineages within the nominal species and found an intermediate level of differentiation in their multidimensional environmental niches, suggesting the possibility for local adaptation. We then compared projections of the species' habitat suitability under climate change scenarios using species-level and lineage-level SDMs. In the Central Tropical Indo-Pacific region, models for both levels predicted considerable range contraction in the future, but the lineage-level models predicted more severe habitat loss. Importantly, the two modelling approaches predicted opposite patterns of habitat change in the Western Tropical Indo-Pacific region. Our results highlight the necessity of conserving distinct populations and genetic pools to avoid regional extinction due to climate change and have important implications for guiding future management of seagrasses.
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Affiliation(s)
- Zi-Min Hu
- Ocean School, YanTai University, Yantai, China
| | | | - Jie Zhang
- Key Laboratory of Experimental Marine Biology, Center for Ocean Mega-Science, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China
| | - Jamie M Kass
- Biodiversity and Biocomplexity Unit, Okinawa Institute of Science and Technology Graduate University, Okinawa, Japan
| | - Stefano Mammola
- Laboratory for Integrative Biodiversity Research (LIBRe), Finnish Museum of Natural History (LUOMUS), University of Helsinki, Helsinki, Finland.,Molecular Ecology Group (MEG), Water Research Institute (IRSA, National Research Council of Italy (CNR, Verbania Pallanza, Italy
| | - Pablo Fresia
- Pasteur+INIA Joint Unit (UMPI), Institut Pasteur de Montevideo, Montevideo, Uruguay
| | - Stefano G A Draisma
- Excellence Center for Biodiversity of Peninsular Thailand, Faculty of Science, Prince of Songkla University, Hat Yai, Songkhla, Thailand
| | - Jorge Assis
- CCMAR, University of Algarve, Faro, Portugal
| | - Alexander Jueterbock
- Algal and Microbial Biotechnology Division, Faculty of Biosciences and Aquaculture, Nord University, Bodø, Norway
| | - Masashi Yokota
- Graduate School of Marine Science and Technology, Tokyo University of Marine Science and Technology, Tokyo, Japan
| | - Zhixin Zhang
- Arctic Research Center, Hokkaido University, Sapporo, Japan
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11
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Jahnke M, Moksnes PO, Olsen JL, Serra Serra N, Nilsson Jacobi M, Kuusemäe K, Corell H, Jonsson PR. Integrating genetics, biophysical, and demographic insights identifies critical sites for seagrass conservation. ECOLOGICAL APPLICATIONS : A PUBLICATION OF THE ECOLOGICAL SOCIETY OF AMERICA 2020; 30:e02121. [PMID: 32159897 DOI: 10.1002/eap.2121] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/29/2019] [Revised: 01/28/2020] [Accepted: 01/30/2020] [Indexed: 06/10/2023]
Abstract
The eelgrass Zostera marina is an important foundation species of coastal areas in the Northern Hemisphere, but is continuing to decline, despite management actions. The development of new management tools is therefore urgent in order to prioritize limited resources for protecting meadows most vulnerable to local extinctions and identifying most valuable present and historic meadows to protect and restore, respectively. We assessed 377 eelgrass meadows along the complex coastlines of two fjord regions on the Swedish west coast-one is currently healthy and the other is substantially degraded. Shoot dispersal for all meadows was assessed with Lagrangian biophysical modeling (scale: 100-1,000 m) and used for barrier analysis and clustering; a subset (n = 22) was also assessed with population genetic methods (20 microsatellites) including diversity, structure, and network connectivity. Both approaches were in very good agreement, resulting in seven subpopulation groupings or management units (MUs). The MUs correspond to a spatial scale appropriate for coastal management of "waterbodies" used in the European Water Framework Directive. Adding demographic modeling based on the genetic and biophysical data as a third approach, we are able to assess past, present, and future metapopulation dynamics to identify especially vulnerable and valuable meadows. In a further application, we show how the biophysical approach, using eigenvalue perturbation theory (EPT) and distribution records from the 1980s, can be used to identify lost meadows where restoration would best benefit the present metapopulation. The combination of methods, presented here as a toolbox, allows the assessment of different temporal and spatial scales at the same time, as well as ranking of specific meadows according to key genetic, demographic and ecological metrics. It could be applied to any species or region, and we exemplify its versatility as a management guide for eelgrass along the Swedish west coast.
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Affiliation(s)
- Marlene Jahnke
- Department of Marine Sciences - Tjärnö Marine Laboratory, University of Gothenburg, SE-45296, Strömstad, Sweden
| | - Per-Olav Moksnes
- Department of Marine Science, University of Gothenburg, SE-40530, Gothenburg, Sweden
| | - Jeanine L Olsen
- Groningen Institute for Evolutionary Life Sciences, Section: Ecology and Evolutionary Genomics in Nature (GREEN), University of Groningen, P.O. Box 11103, 9700 CC, Groningen, The Netherlands
| | - Núria Serra Serra
- Groningen Institute for Evolutionary Life Sciences, Section: Ecology and Evolutionary Genomics in Nature (GREEN), University of Groningen, P.O. Box 11103, 9700 CC, Groningen, The Netherlands
| | - Martin Nilsson Jacobi
- Complex Systems Group, Department of Energy and Environment, Chalmers University of Technology, 41296, Gothenburg, Sweden
| | | | - Hanna Corell
- DHI Sverige, Svartmangatan 18, SE-111 29, Stockholm, Sweden
| | - Per R Jonsson
- Department of Marine Sciences - Tjärnö Marine Laboratory, University of Gothenburg, SE-45296, Strömstad, Sweden
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12
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Coolen JWP, Boon AR, Crooijmans R, van Pelt H, Kleissen F, Gerla D, Beermann J, Birchenough SNR, Becking LE, Luttikhuizen PC. Marine stepping-stones: Connectivity of Mytilus edulis populations between offshore energy installations. Mol Ecol 2020; 29:686-703. [PMID: 31989703 PMCID: PMC7065051 DOI: 10.1111/mec.15364] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2018] [Revised: 12/10/2019] [Accepted: 01/20/2020] [Indexed: 12/21/2022]
Abstract
Recent papers have suggested that epifaunal organisms use artificial structures as stepping-stones to spread to areas that are too distant to reach in a single generation. With thousands of artificial structures present in the North Sea, we test the hypothesis that these structures are connected by water currents and act as an interconnected reef. Population genetic structure of the blue mussel, Mytilus edulis, was expected to follow a pattern predicted by a particle tracking model (PTM). Correlation between population genetic differentiation, based on microsatellite markers, and particle exchange was tested. Specimens of M. edulis were found at each location, although the PTM indicated that locations >85 km offshore were isolated from coastal subpopulations. The fixation coefficient FST correlated with the number of arrivals in the PTM. However, the number of effective migrants per generation as inferred from coalescent simulations did not show a strong correlation with the arriving particles. Isolation by distance analysis showed no increase in isolation with increasing distance and we did not find clear structure among the populations. The marine stepping-stone effect is obviously important for the distribution of M. edulis in the North Sea and it may influence ecologically comparable species in a similar way. In the absence of artificial shallow hard substrates, M. edulis would be unlikely to survive in offshore North Sea waters.
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Affiliation(s)
- Joop W. P. Coolen
- Wageningen Marine ResearchDen HelderThe Netherlands
- Aquatic Ecology and Water Quality Management GroupWageningen UniversityWageningenThe Netherlands
| | - Arjen R. Boon
- Deltares, Marine and Coastal SystemsDelftThe Netherlands
| | - Richard Crooijmans
- Animal Breeding and Genomics CentreWageningen UniversityWageningenThe Netherlands
| | | | - Frank Kleissen
- Deltares, Marine and Coastal SystemsDelftThe Netherlands
| | - Daan Gerla
- Wageningen Marine ResearchDen HelderThe Netherlands
| | - Jan Beermann
- Department of Functional EcologyAlfred Wegener Institute Helmholtz Centre for Polar and Marine ResearchBremerhavenGermany
- Helmholtz Institute for Functional Marine BiodiversityOldenburgGermany
| | | | - Leontine E. Becking
- Wageningen Marine ResearchDen HelderThe Netherlands
- Marine Animal Ecology GroupWageningen UniversityWageningenThe Netherlands
| | - Pieternella C. Luttikhuizen
- Department of Coastal SystemsNIOZ Royal Netherlands Institute for Sea ResearchUtrecht UniversityDen BurgThe Netherlands
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13
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Phair NL, Toonen RJ, Knapp ISS, von der Heyden S. Anthropogenic pressures negatively impact genomic diversity of the vulnerable seagrass Zostera capensis. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2020; 255:109831. [PMID: 32063316 DOI: 10.1016/j.jenvman.2019.109831] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/06/2019] [Revised: 11/03/2019] [Accepted: 11/05/2019] [Indexed: 06/10/2023]
Abstract
Zostera capensis is a keystone species providing essential ecosystem services to southern African coastal systems. Like most seagrasses globally, Z. capensis is declining and under threat from anthropogenic pressures, and indicators of seagrass health and resilience may be of interest in preventing further declines. As intraspecific diversity is an important component of resilience, we used a pooled RADseq approach to generate genome-wide measures of variation across the entire South African distribution of Z. capensis. Using nucleotide diversity, heterozygosity and allelic richness we tested for associations with fine-scale anthropogenic pressure data compiled by the South African National Biodiversity Assessment using generalised linear models. Increased fishing effort, habitat loss, sand mining and a change in estuary flow dynamics were found to play an important role in decreasing nucleotide diversity and expected heterozygosity, most likely due to the loss of less resilient genotypes as a result of direct physical damage or indirect consequences. As the building block for adaptation, nucleotide diversity is particularly important for resilience. Because of this, as well as the fact that nucleotide diversity displayed the most distinct difference between the west and east coast, and responded most strongly to anthropogenic pressures, we suggest that this may be a useful measure for monitoring genetic or genomic variation. As genomic diversity influences resilience and resistance to disturbances, the remaining diversity in South African seagrass beds urgently needs to be conserved through restoration efforts and careful management of pressures.
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Affiliation(s)
- Nikki Leanne Phair
- Evolutionary Genomics Group, Department of Botany and Zoology, University of Stellenbosch, Private Bag X1, Matieland, South Africa.
| | - Robert John Toonen
- Hawai'i Institute of Marine Biology, School of Ocean and Earth Science and Technology, University of Hawai'i at Mānoa, USA.
| | - Ingrid Sally Sigrid Knapp
- Hawai'i Institute of Marine Biology, School of Ocean and Earth Science and Technology, University of Hawai'i at Mānoa, USA.
| | - Sophie von der Heyden
- Evolutionary Genomics Group, Department of Botany and Zoology, University of Stellenbosch, Private Bag X1, Matieland, South Africa.
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14
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Jahnke M, Gullström M, Larsson J, Asplund ME, Mgeleka S, Silas MO, Hoamby A, Mahafina J, Nordlund LM. Population genetic structure and connectivity of the seagrass Thalassia hemprichii in the Western Indian Ocean is influenced by predominant ocean currents. Ecol Evol 2019; 9:8953-8964. [PMID: 31462994 PMCID: PMC6706205 DOI: 10.1002/ece3.5420] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2019] [Revised: 05/24/2019] [Accepted: 06/08/2019] [Indexed: 01/04/2023] Open
Abstract
This study is the first large-scale genetic population study of a widespread climax species of seagrass, Thalassia hemprichii, in the Western Indian Ocean (WIO). The aim was to understand genetic population structure and connectivity of T. hemprichii in relation to hydrodynamic features. We genotyped 205 individual seagrass shoots from 11 sites across the WIO, spanning over a distance of ~2,700 km, with twelve microsatellite markers. Seagrass shoots were sampled in Kenya, Tanzania (mainland and Zanzibar), Mozambique, and Madagascar: 4-26°S and 33-48°E. We assessed clonality and visualized genetic diversity and genetic population differentiation. We used Bayesian clustering approaches (TESS) to trace spatial ancestry of populations and used directional migration rates (DivMigrate) to identify sources of gene flow. We identified four genetically differentiated groups: (a) samples from the Zanzibar channel; (b) Mozambique; (c) Madagascar; and (d) the east coast of Zanzibar and Kenya. Significant pairwise population genetic differentiation was found among many sites. Isolation by distance was detected for the estimated magnitude of divergence (D EST), but the three predominant ocean current systems (i.e., East African Coastal Current, North East Madagascar Current, and the South Equatorial Current) also determine genetic connectivity and genetic structure. Directional migration rates indicate that Madagascar acts as an important source population. Overall, clonality was moderate to high with large differences among sampling sites, indicating relatively low, but spatially variable sexual reproduction rates. The strongest genetic break was identified for three sites in the Zanzibar channel. Although isolation by distance is present, this study suggests that the three regionally predominant ocean current systems (i.e., East African Coastal Current, North East Madagascar Current, and the South Equatorial Current) rather than distance determine genetic connectivity and structure of T. hemprichii in the WIO. If the goal is to maintain genetic connectivity of T. hemprichii within the WIO, conservation planning and implementation of marine protection should be considered at the regional scale-across national borders.
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Affiliation(s)
- Marlene Jahnke
- Department of Marine Sciences—TjärnöUniversity of GothenburgStrömstadSweden
- Groningen Institute for Evolutionary Life Sciences, Section: Ecology and Evolutionary Genomics in Nature (GREEN)University of GroningenGroningenThe Netherlands
| | - Martin Gullström
- Department of Ecology, Environment and Plant SciencesStockholm UniversityStockholmSweden
- Department of Biological and Environmental SciencesUniversity of GothenburgGothenburgSweden
| | - Josefine Larsson
- School of Natural Science, Technology and Environmental StudiesSödertörn UniversityStockholmSweden
| | - Maria E. Asplund
- Department of Ecology, Environment and Plant SciencesStockholm UniversityStockholmSweden
- The Lovén CentreUniversity of GothenburgGothenburgSweden
| | - Said Mgeleka
- Department of Ecology, Environment and Plant SciencesStockholm UniversityStockholmSweden
- Tanzania Fisheries Research Institute (TAFIRI)Dar es SalaamTanzania
| | - Mathew Ogalo Silas
- Department of Ecology, Environment and Plant SciencesStockholm UniversityStockholmSweden
- Tanzania Fisheries Research Institute (TAFIRI)Dar es SalaamTanzania
| | - Arielle Hoamby
- Institut Halieutique et des Science Marine Toliara (IH.SM)ToliaraMadagascar
| | - Jamal Mahafina
- Institut Halieutique et des Science Marine Toliara (IH.SM)ToliaraMadagascar
| | - Lina Mtwana Nordlund
- Department of Ecology, Environment and Plant SciencesStockholm UniversityStockholmSweden
- Department of Earth SciencesUppsala UniversityVisbySweden
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15
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Phair NL, Toonen RJ, Knapp I, von der Heyden S. Shared genomic outliers across two divergent population clusters of a highly threatened seagrass. PeerJ 2019; 7:e6806. [PMID: 31106053 PMCID: PMC6497040 DOI: 10.7717/peerj.6806] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2019] [Accepted: 03/18/2019] [Indexed: 12/15/2022] Open
Abstract
The seagrass, Zostera capensis, occurs across a broad stretch of coastline and wide environmental gradients in estuaries and sheltered bays in southern and eastern Africa. Throughout its distribution, habitats are highly threatened and poorly protected, increasing the urgency of assessing the genomic variability of this keystone species. A pooled genomic approach was employed to obtain SNP data and examine neutral genomic variation and to identify potential outlier loci to assess differentiation across 12 populations across the ∼9,600 km distribution of Z. capensis. Results indicate high clonality and low genomic diversity within meadows, which combined with poor protection throughout its range, increases the vulnerability of this seagrass to further declines or local extinction. Shared variation at outlier loci potentially indicates local adaptation to temperature and precipitation gradients, with Isolation-by-Environment significantly contributing towards shaping spatial variation in Z. capensis. Our results indicate the presence of two population clusters, broadly corresponding to populations on the west and east coasts, with the two lineages shaped only by frequency differences of outlier loci. Notably, ensemble modelling of suitable seagrass habitat provides evidence that the clusters are linked to historical climate refugia around the Last Glacial Maxi-mum. Our work suggests a complex evolutionary history of Z. capensis in southern and eastern Africa that will require more effective protection in order to safeguard this important ecosystem engineer into the future.
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Affiliation(s)
- Nikki Leanne Phair
- Department of Botany and Zoology, University of Stellenbosch, Stellenbosch, South Africa
| | - Robert John Toonen
- Hawaii Institute of Marine Biology, University of Hawaii at Manoa, Kaneohe, Hawai’i, United States of America
| | - Ingrid Knapp
- Hawaii Institute of Marine Biology, University of Hawaii at Manoa, Kaneohe, Hawai’i, United States of America
| | - Sophie von der Heyden
- Department of Botany and Zoology, University of Stellenbosch, Stellenbosch, South Africa
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16
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Vera-Escalona I, Habit E, Ruzzante DE. Invasive species and postglacial colonization: their effects on the genetic diversity of a Patagonian fish. Proc Biol Sci 2019; 286:20182567. [PMID: 30963839 PMCID: PMC6408905 DOI: 10.1098/rspb.2018.2567] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2018] [Accepted: 02/01/2019] [Indexed: 01/18/2023] Open
Abstract
The present distribution of Patagonian species is the result of a complex history involving Quaternary refugial populations, Holocene range expansions and demographic changes occurring during the Anthropocene. Invasive salmonids were introduced in Patagonia during the last century, occupying most rivers and lakes, preying on and competing with native species, including the fish Galaxias platei. Here, we used G. platei as a case study to understand how long-term (i.e. population differentiation during the Holocene) and short-term historical processes (salmonid introductions) affect genetic diversity. Using a suite of microsatellite markers, we found that the number of alleles is negatively correlated with the presence of salmonids (short-term processes), with G. platei populations from lakes with salmonids exhibiting significantly lower genetic diversity than populations from lakes without salmonids. Simulations (100 years backwards) showed that this difference in genetic diversity can be explained by a 99% reduction in population size. Allelic richness and observed heterozygosities were also negatively correlated with the presence of salmonids, but also positively correlated with long-term processes linked to Quaternary glaciations. Our results show how different genetic parameters can help identify processes taking place at different scales and their importance in terms of conservation.
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Affiliation(s)
- Iván Vera-Escalona
- Department of Biology, Dalhousie University, 1355 Oxford Street, Halifax, Nova Scotia, Canada B3H 4R2
- Centro de Investigación en Biodiversidad y Ambientes Sustentables (CIBAS), Universidad Católica de la Santísima Concepción, Alonso de Ribera 2850, Concepción, Chile
| | - Evelyn Habit
- Departamento de Sistemas Acuáticos, Facultad de Ciencias Ambientales y Centro EULA-Chile, Universidad de Concepción, Barrio Universitario s/n. Concepción, Casilla 160-C, Chile
| | - Daniel E. Ruzzante
- Department of Biology, Dalhousie University, 1355 Oxford Street, Halifax, Nova Scotia, Canada B3H 4R2
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17
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Sinclair EA, Ruiz‐Montoya L, Krauss SL, Anthony JM, Hovey RK, Lowe RJ, Kendrick GA. Seeds in motion: Genetic assignment and hydrodynamic models demonstrate concordant patterns of seagrass dispersal. Mol Ecol 2018; 27:5019-5034. [DOI: 10.1111/mec.14939] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2017] [Revised: 10/18/2018] [Accepted: 10/23/2018] [Indexed: 01/03/2023]
Affiliation(s)
- Elizabeth A. Sinclair
- School of Biological Sciences University of Western Australia Crawley Western Australia Australia
- Kings Park Science, Department of Biodiversity, Conservation, and Attractions West Perth Western Australia Australia
- Oceans Institute University of Western Australia Crawley Western Australia Australia
| | - Leonardo Ruiz‐Montoya
- School of Biological Sciences University of Western Australia Crawley Western Australia Australia
- Oceans Institute University of Western Australia Crawley Western Australia Australia
| | - Siegfried L. Krauss
- School of Biological Sciences University of Western Australia Crawley Western Australia Australia
- Kings Park Science, Department of Biodiversity, Conservation, and Attractions West Perth Western Australia Australia
| | - Janet M. Anthony
- School of Biological Sciences University of Western Australia Crawley Western Australia Australia
- Kings Park Science, Department of Biodiversity, Conservation, and Attractions West Perth Western Australia Australia
| | - Renae K. Hovey
- School of Biological Sciences University of Western Australia Crawley Western Australia Australia
- Oceans Institute University of Western Australia Crawley Western Australia Australia
| | - Ryan J. Lowe
- Oceans Institute University of Western Australia Crawley Western Australia Australia
- ARC Centre of Excellence for Coral Reef Studies University of Western Australia Crawley Western Australia Australia
| | - Gary A. Kendrick
- School of Biological Sciences University of Western Australia Crawley Western Australia Australia
- Oceans Institute University of Western Australia Crawley Western Australia Australia
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18
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Zhang X, Zhou Y, Li YL, Liu JX. Development of microsatellite markers for the seagrass Zostera japonica using next-generation sequencing. Mol Biol Rep 2018; 46:1335-1341. [PMID: 30448896 DOI: 10.1007/s11033-018-4491-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2018] [Accepted: 11/10/2018] [Indexed: 10/27/2022]
Abstract
The seagrass Zostera japonica Asch. & Graebn. is among the few seagrass species that thrive both in temperate and tropical intertidal zones. The degradation of Z. japonica in its native range and continued expansion in some localities have raised concerns with regard to its conservation and management. Population genetic studies of Z. japonica across its biogeographic range and within meadows are scarce. Previously developed microsatellites via traditional methods are not sufficient in quantity and perform inconsistently between the temperate and tropical populations. Thus, this study aimed to develop more reliable polymorphic markers for Z. japonica using next generation sequencing. In total, 6479 sequences containing loci were identified and 1619 pairs of primers were successfully designed. Of these, 63 loci were selected for primary validation in 16 individuals from four populations, with 48 (76.2%) polymorphic loci detected. Seventeen polymorphic loci were selected for further evaluation in 62 individuals from one temperate and one tropical population. The overall probability of identity (PID) for both populations was 2.375e-22 (PIDsib = 3.557e-08). The number of alleles, and expected and observed heterozygosity in the two populations were both relatively high and not significantly different from each other. The pairwise FST = 0.232 (p < 0.0001) and Principal Coordinates Analysis both suggested a large and significant genetic divergence between the two populations. This study makes abundant molecular markers available for genetic studies in Z. japonica, and facilitates its conservation and management strategies.
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Affiliation(s)
- Xiaomei Zhang
- CAS Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, 266071, China.,Laboratory for Marine Ecology and Environmental Science, Qingdao National Laboratory for Marine Science and Technology, Qingdao, 266237, China.,Center for Ocean Mega-Science, Chinese Academy of Sciences, Qingdao, 266071, China
| | - Yi Zhou
- CAS Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, 266071, China. .,Laboratory for Marine Ecology and Environmental Science, Qingdao National Laboratory for Marine Science and Technology, Qingdao, 266237, China. .,Center for Ocean Mega-Science, Chinese Academy of Sciences, Qingdao, 266071, China.
| | - Yu-Long Li
- CAS Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, 266071, China.,Laboratory for Marine Ecology and Environmental Science, Qingdao National Laboratory for Marine Science and Technology, Qingdao, 266237, China.,Center for Ocean Mega-Science, Chinese Academy of Sciences, Qingdao, 266071, China
| | - Jin-Xian Liu
- CAS Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, 266071, China. .,Laboratory for Marine Ecology and Environmental Science, Qingdao National Laboratory for Marine Science and Technology, Qingdao, 266237, China. .,Center for Ocean Mega-Science, Chinese Academy of Sciences, Qingdao, 266071, China.
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Otwoma LM, Diemel V, Reuter H, Kochzius M, Meyer A. Genetic population structure of the convict surgeonfish Acanthurus triostegus: a phylogeographic reassessment across its range. JOURNAL OF FISH BIOLOGY 2018; 93:597-608. [PMID: 29956317 DOI: 10.1111/jfb.13686] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/06/2017] [Accepted: 06/05/2018] [Indexed: 06/08/2023]
Abstract
This study investigates the genetic population structure and connectivity of Acanthurus triostegus in five Indo-Pacific biogeographic regions (western and eastern Indian Ocean, western, central and eastern Pacific Ocean), using a mitochondrial DNA marker spanning the ATPase8 and ATPase6 gene regions. In order to assess the phylogeography and genetic population structure of A. triostegus across its range, 35 individuals were sampled from five localities in the western Indian Ocean and complemented with 227 sequences from two previous studies. Results from the overall analysis of molecular variance (AMOVA) without a priori grouping showed evidence of significant differentiation in the Indo-Pacific, with 25 (8.3%) out of 300 pairwise ΦST comparisons being significant. However, the hierarchical AMOVA grouping of Indian and Pacific Ocean populations failed to support the vicariance hypothesis, showing a lack of a genetic break between the two ocean basins. Instead, the correlation between pairwise ΦST values and geographic distance showed that dispersal of A. triostegus in the Indo-Pacific Ocean follows an isolation-by-distance model. Three haplogroups could be deduced from the haplotype network and phylogenetic tree, with haplogroup 1 and 2 dominating the Indian and the Pacific Ocean, respectively, while haplogroup 3 exclusively occurring in the Hawaiian Archipelago of the central Pacific Ocean.
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Affiliation(s)
- Levy M Otwoma
- Leibniz Centre for Tropical Marine Research (ZMT), Bremen, Germany
- Kenya Marine and Fisheries Research Institute (KMFRI), Mombasa, Kenya
- Faculty Biology and Chemistry, University of Bremen, Bremen, Germany
| | - Valeska Diemel
- Leibniz Centre for Tropical Marine Research (ZMT), Bremen, Germany
| | - Hauke Reuter
- Leibniz Centre for Tropical Marine Research (ZMT), Bremen, Germany
- Faculty Biology and Chemistry, University of Bremen, Bremen, Germany
| | | | - Achim Meyer
- Leibniz Centre for Tropical Marine Research (ZMT), Bremen, Germany
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Unsworth RKF, Ambo-Rappe R, Jones BL, La Nafie YA, Irawan A, Hernawan UE, Moore AM, Cullen-Unsworth LC. Indonesia's globally significant seagrass meadows are under widespread threat. THE SCIENCE OF THE TOTAL ENVIRONMENT 2018; 634:279-286. [PMID: 29627551 DOI: 10.1016/j.scitotenv.2018.03.315] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/08/2018] [Revised: 03/06/2018] [Accepted: 03/25/2018] [Indexed: 06/08/2023]
Abstract
Indonesia's marine ecosystems form a fundamental part of the world's natural heritage, representing a global maxima of marine biodiversity and supporting the world's second largest production of seafood. Seagrasses are a key part of that support. In the absence of empirical data we present evidence from expert opinions as to the state of Indonesia's seagrass ecosystems, their support for ecosystem services, with a focus on fisheries, and the damaging activities that threaten their existence. We further draw on expert opinion to elicit potential solutions to prevent further loss. Seagrasses and the ecosystem services they support across the Indonesian archipelago are in a critical state of decline. Declining seagrass health is the result of shifting environmental conditions due largely to coastal development, land reclamation, and deforestation, as well as seaweed farming, overfishing and garbage dumping. In particular, we also describe the declining state of the fisheries resources that seagrass meadows support. The perilous state of Indonesia's seagrasses will compromise their resilience to climate change and result in a loss of their high ecosystem service value. Community supported management initiatives provide one mechanism for seagrass protection. Exemplars highlight the need for increased local level autonomy for the management of marine resources, opening up opportunities for incentive type conservation schemes.
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Affiliation(s)
- Richard K F Unsworth
- Seagrass Ecosystem Research Group, College of Science, Wallace Building, Swansea University, SA2 8PP, UK; Project Seagrass, 33 Park Place, Cardiff CF10 3BA, UK
| | - Rohani Ambo-Rappe
- Department of Marine Science, Faculty of Marine Science and Fisheries, Hasanuddin University, Tamalanrea Km. 10, Makassar 90245, Indonesia
| | - Benjamin L Jones
- Project Seagrass, 33 Park Place, Cardiff CF10 3BA, UK; Sustainable Places Research Institute, Cardiff University, 33 Park Place, Cardiff, CF10 3BA, UK
| | - Yayu A La Nafie
- Department of Marine Science, Faculty of Marine Science and Fisheries, Hasanuddin University, Tamalanrea Km. 10, Makassar 90245, Indonesia
| | - A Irawan
- Research Center for Deep Sea - Indonesian Institute of Sciences, Y. Syaranamual Street, Ambon 97233, Indonesia
| | - Udhi E Hernawan
- Research Centre for Oceanography, Indonesian Institute of Sciences, Indonesia
| | - Abigail M Moore
- Department of Marine Science, Faculty of Marine Science and Fisheries, Hasanuddin University, Tamalanrea Km. 10, Makassar 90245, Indonesia
| | - Leanne C Cullen-Unsworth
- Project Seagrass, 33 Park Place, Cardiff CF10 3BA, UK; Sustainable Places Research Institute, Cardiff University, 33 Park Place, Cardiff, CF10 3BA, UK.
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van Dijk K, Bricker E, van Tussenbroek BI, Waycott M. Range-wide population genetic structure of the Caribbean marine angiosperm Thalassia testudinum. Ecol Evol 2018; 8:9478-9490. [PMID: 30377516 PMCID: PMC6194253 DOI: 10.1002/ece3.4443] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2018] [Revised: 07/03/2018] [Accepted: 07/14/2018] [Indexed: 11/07/2022] Open
Abstract
Many marine species have widespread geographic ranges derived from their evolutionary and ecological history particularly their modes of dispersal. Seagrass (marine angiosperm) species have ranges that are unusually widespread, which is not unexpected following recent reviews of reproductive strategies demonstrating the potential for long-distance dispersal combined with longevity through clonality. An exemplar of these dual biological features is turtle grass (Thalassia testudinum) which is an ecologically important species throughout the tropical Atlantic region. Turtle grass has been documented to have long-distance dispersal via floating fruits and also extreme clonality and longevity. We hypothesize that across its range, Thalassia testudinum will have very limited regional population structure due to these characteristics and under typical models of population structure would expect to detect high levels of genetic connectivity. There are very few studies of range-wide genetic connectivity documented for seagrasses or other sessile marine species. This study presents a population genetic dataset that represents a geographic area exceeding 14,000 km2. Population genetic diversity was evaluated from 32 Thalassia testudinum populations sampled across the Caribbean and Gulf of Mexico. Genotypes were based on nine microsatellites, and haplotypes were based on chloroplast DNA sequences. Very limited phylogeographic signal from cpDNA reduced the potential comparative analyses possible. Multiple analytical clustering approaches on population genetic data revealed two significant genetic partitions: (a) the Caribbean and (b) the Gulf of Mexico. Genetic diversity was high (H E = 0.641), and isolation by distance was significant; gene flow and migration estimates across the entire range were however modest, we suggest that the frequency of successful recruitment across the range is uncommon. Thalassia testudinum maintains genetic diversity across its entire distribution range. The genetic split may be explained by genetic drift during recolonization from refugia following relatively recent reduction in available habitat such as the last glacial maxima.
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Affiliation(s)
- Kor‐jent van Dijk
- School of Biological SciencesEnvironment InstituteAustralian Centre for Evolutionary Biology and BiodiversityThe University of AdelaideAdelaideSouth AustraliaAustralia
- Unidad Académica Puerto MorelosInstituto de Ciencias del Mar y LimnologíaUniversidad Nacional Autónoma de México (UNAM)CancúnMéxico
| | - Eric Bricker
- Department of Environmental SciencesThe University of VirginiaCharlottesvilleVirginia
| | - Brigitta I. van Tussenbroek
- Unidad Académica Puerto MorelosInstituto de Ciencias del Mar y LimnologíaUniversidad Nacional Autónoma de México (UNAM)CancúnMéxico
| | - Michelle Waycott
- School of Biological SciencesEnvironment InstituteAustralian Centre for Evolutionary Biology and BiodiversityThe University of AdelaideAdelaideSouth AustraliaAustralia
- Department for Environment and WaterState Herbarium of South AustraliaBotanic Gardens and State HerbariumAdelaideSouth AustraliaAustralia
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Triest L, Sierens T, Menemenlis D, Van der Stocken T. Inferring Connectivity Range in Submerged Aquatic Populations ( Ruppia L.) Along European Coastal Lagoons From Genetic Imprint and Simulated Dispersal Trajectories. FRONTIERS IN PLANT SCIENCE 2018; 9:806. [PMID: 29951080 PMCID: PMC6008504 DOI: 10.3389/fpls.2018.00806] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/15/2017] [Accepted: 05/25/2018] [Indexed: 06/07/2023]
Abstract
Coastal salt- and brackish water lagoons are unique shallow habitats characterized by beds of submerged seagrasses and salt-tolerant Ruppia species. Established long-term and large-scale patterns of connectivity in lagoon systems can be strongly determined by patterns of nearshore and coastal currents next to local bird-mediated seed dispersal. Despite the importance of dispersal in landscape ecology, characterizing patterns of connectivity remains challenging in aquatic systems. Here, we aimed at inferring connectivity distances of Ruppia cirrhosa along European coastal lagoons using a population genetic imprint and modeled dispersal trajectories using an eddy-resolving numerical ocean model that includes tidal forcing. We investigated 1,303 individuals of 46 populations alongside subbasins of the Mediterranean (Balearic, Tyrrhenian, Ionian) and the Atlantic to Baltic Sea coastline over maximum distances of 563-2,684 km. Ten microsatellite loci under an autotetraploid condition revealed a mixed sexual and vegetative reproduction mode. A pairwise FST permutation test of populations revealed high levels of historical connectivity only for distance classes up to 104-280 km. Since full range analysis was not fully explanatory, we assessed connectivity in more detail at coastline and subbasin level using four approaches. Firstly, a regression over restricted geographical distances (300 km) was done though remained comparable to full range analysis. Secondly, piecewise linear regression analyses yielded much better explained variance but the obtained breakpoints were shifted toward greater geographical distances due to a flat slope of regression lines that most likely reflect genetic drift. Thirdly, classification and regression tree analyses revealed threshold values of 47-179 km. Finally, simulated ocean surface dispersal trajectories for propagules with floating periods of 1-4 weeks, were congruent with inferred distances, a spatial Bayesian admixed gene pool clustering and a barrier detection method. A kinship based spatial autocorrelation showed a contemporary within-lagoon connectivity up to 20 km. Our findings indicate that strong differentiation or admixtures shaped historical connectivity and that a pre- and post LGM genetic imprint of R. cirrhosa along the European coasts was maintained from their occurrence in primary habitats. Additionally, this study demonstrates the importance of unraveling thresholds of genetic breaks in combination with ocean dispersal modeling to infer patterns of connectivity.
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Affiliation(s)
- Ludwig Triest
- Ecology and Biodiversity Research Group, Plant Biology and Nature Management, Vrije Universiteit Brussel, Brussels, Belgium
| | - Tim Sierens
- Ecology and Biodiversity Research Group, Plant Biology and Nature Management, Vrije Universiteit Brussel, Brussels, Belgium
| | - Dimitris Menemenlis
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, United States
| | - Tom Van der Stocken
- Ecology and Biodiversity Research Group, Plant Biology and Nature Management, Vrije Universiteit Brussel, Brussels, Belgium
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, United States
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Jahnke M, Jonsson PR, Moksnes P, Loo L, Nilsson Jacobi M, Olsen JL. Seascape genetics and biophysical connectivity modelling support conservation of the seagrass Zostera marina in the Skagerrak-Kattegat region of the eastern North Sea. Evol Appl 2018; 11:645-661. [PMID: 29875808 PMCID: PMC5979629 DOI: 10.1111/eva.12589] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2017] [Accepted: 12/08/2017] [Indexed: 01/02/2023] Open
Abstract
Maintaining and enabling evolutionary processes within meta-populations are critical to resistance, resilience and adaptive potential. Knowledge about which populations act as sources or sinks, and the direction of gene flow, can help to focus conservation efforts more effectively and forecast how populations might respond to future anthropogenic and environmental pressures. As a foundation species and habitat provider, Zostera marina (eelgrass) is of critical importance to ecosystem functions including fisheries. Here, we estimate connectivity of Z. marina in the Skagerrak-Kattegat region of the North Sea based on genetic and biophysical modelling. Genetic diversity, population structure and migration were analysed at 23 locations using 20 microsatellite loci and a suite of analytical approaches. Oceanographic connectivity was analysed using Lagrangian dispersal simulations based on contemporary and historical distribution data dating back to the late 19th century. Population clusters, barriers and networks of connectivity were found to be very similar based on either genetic or oceanographic analyses. A single-generation model of dispersal was not realistic, whereas multigeneration models that integrate stepping-stone dispersal and extant and historic distribution data were able to capture and model genetic connectivity patterns well. Passive rafting of flowering shoots along oceanographic currents is the main driver of gene flow at this spatial-temporal scale, and extant genetic connectivity strongly reflects the "ghost of dispersal past" sensu Benzie, 1999. The identification of distinct clusters, connectivity hotspots and areas where connectivity has become limited over the last century is critical information for spatial management, conservation and restoration of eelgrass.
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Affiliation(s)
- Marlene Jahnke
- Department of Marine Sciences – TjärnöUniversity of GothenburgStrömstadSweden
- Groningen Institute for Evolutionary Life SciencesSection: Ecology and Evolutionary Genomics in Nature (GREEN)University of GroningenGroningenThe Netherlands
| | - Per R. Jonsson
- Department of Marine Sciences – TjärnöUniversity of GothenburgStrömstadSweden
| | - Per‐Olav Moksnes
- Department of Marine ScienceUniversity of GothenburgGothenburgSweden
| | - Lars‐Ove Loo
- Department of Marine Sciences – TjärnöUniversity of GothenburgStrömstadSweden
| | - Martin Nilsson Jacobi
- Complex Systems GroupDepartment of Energy and EnvironmentChalmers University of TechnologyGothenburgSweden
| | - Jeanine L. Olsen
- Groningen Institute for Evolutionary Life SciencesSection: Ecology and Evolutionary Genomics in Nature (GREEN)University of GroningenGroningenThe Netherlands
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McMahon KM, Evans RD, van Dijk KJ, Hernawan U, Kendrick GA, Lavery PS, Lowe R, Puotinen M, Waycott M. Disturbance Is an Important Driver of Clonal Richness in Tropical Seagrasses. FRONTIERS IN PLANT SCIENCE 2017; 8:2026. [PMID: 29259609 PMCID: PMC5723400 DOI: 10.3389/fpls.2017.02026] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/27/2017] [Accepted: 11/14/2017] [Indexed: 05/26/2023]
Abstract
Clonality is common in many aquatic plant species, including seagrasses, where populations are maintained through a combination of asexual and sexual reproduction. One common measure used to describe the clonal structure of populations is clonal richness. Clonal richness is strongly dependent on the biological characteristics of the species, and how these interact with the environment but can also reflect evolutionary scale processes especially at the edge of species ranges. However, little is known about the spatial patterns and drivers of clonal richness in tropical seagrasses. This study assessed the spatial patterns of clonal richness in meadows of three tropical seagrass species, Thalassia hemprichii, Halodule uninervis, and Halophila ovalis, spanning a range of life-history strategies and spatial scales (2.5-4,711 km) in Indonesia and NW Australia. We further investigated the drivers of clonal richness using general additive mixed models for two of the species, H. uninervis and H. ovalis, over 8° latitude. No significant patterns were observed in clonal richness with latitude, yet disturbance combined with sea surface temperature strongly predicted spatial patterns of clonal richness. Sites with a high probability of cyclone disturbance had low clonal richness, whereas an intermediate probability of cyclone disturbance and the presence of dugong grazing combined with higher sea surface temperatures resulted in higher levels of clonal richness. We propose potential mechanisms for these patterns related to the recruitment and mortality rates of individuals as well as reproductive effort. Under a changing climate, increased severity of tropical cyclones and the decline in populations of mega-grazers have the potential to reduce clonal richness leading to less genetically diverse populations.
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Affiliation(s)
- Kathryn M. McMahon
- School of Science and Centre for Marine Ecosystems Research, Edith Cowan University, Joondalup, WA, Australia
- Western Australian Marine Science Institution, Crawley, WA, Australia
| | - Richard D. Evans
- Marine Science Program, Science and Conservation Division, Department of Biodiversity, Conservation and Attractions, Kensington, WA, Australia
- School of Biological Sciences, University of Western Australia, Crawley, WA, Australia
- UWA Oceans Institute, Crawley, WA, Australia
| | - Kor-jent van Dijk
- School of Biological Sciences, University of Adelaide, Adelaide, SA, Australia
| | - Udhi Hernawan
- School of Science and Centre for Marine Ecosystems Research, Edith Cowan University, Joondalup, WA, Australia
- Pusat Penelitian Oseanografi - Lembaga Ilmu Pengetahuan Indonesia, Jakarta, Indonesia
| | - Gary A. Kendrick
- School of Biological Sciences, University of Western Australia, Crawley, WA, Australia
- UWA Oceans Institute, Crawley, WA, Australia
| | - Paul S. Lavery
- School of Science and Centre for Marine Ecosystems Research, Edith Cowan University, Joondalup, WA, Australia
- Western Australian Marine Science Institution, Crawley, WA, Australia
- Centro de Estudios Avanzados de Blanes, Consejo Superior de Investigaciones Cientificas, Blanes, Spain
| | - Ryan Lowe
- UWA Oceans Institute, Crawley, WA, Australia
- School of Earth Sciences, University of Western Australia, Crawley, WA, Australia
| | - Marji Puotinen
- Indian Ocean Marine Research Centre, Australian Institute of Marine Science, University of Western Australia, Crawley, WA, Australia
| | - Michelle Waycott
- School of Biological Sciences, University of Adelaide, Adelaide, SA, Australia
- State Herbarium of South Australia, Department of Environment, Water and Natural Resources, Adelaide, SA, Australia
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