Browsing by Author "Serrao, Ester A."
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- Acidification increases abundances of Vibrionales and Planctomycetia associated to a seaweed-grazer system: potential consequences for disease and prey digestion efficiencyPublication . Aires, Tânia; Serebryakova, Alexandra; Viard, Frederique; Serrao, Ester A.; Engelen, Aschwin H.Ocean acidification significantly affects marine organisms in several ways, with complex interactions. Seaweeds might benefit from rising CO2 through increased photosynthesis and carbon acquisition, with subsequent higher growth rates. However, changes in seaweed chemistry due to increased CO2 may change the nutritional quality of tissue for grazers. In addition, organisms live in close association with a diverse microbiota, which can also be influenced by environmental changes, with feedback effects. As gut microbiomes are often linked to diet, changes in seaweed characteristics and associated microbiome can affect the gut microbiome of the grazer, with possible fitness consequences. In this study, we experimentally investigated the effects of acidification on the microbiome of the invasive brown seaweed Sargassum muticum and a native isopod consumer Synisoma nadejda. Both were exposed to ambient CO2 conditions (380 ppm, pH 8.16) and an acidification treatment (1,000 ppm, pH 7.86) for three weeks. Microbiome diversity and composition were determined using high-throughput sequencing of the variable regions V5-7 of 16S rRNA. We anticipated that as a result of acidification, the seaweed-associated bacterial community would change, leading to further changes in the gut microbiome of grazers. However, no significant effects of elevated CO2 on the overall bacterial community structure and composition were revealed in the seaweed. In contrast, significant changes were observed in the bacterial community of the grazer gut. Although the bacterial community of S. muticum as whole did not change, Oceanospirillales and Vibrionales (mainly Pseudoalteromonas) significantly increased their abundance in acidified conditions. The former, which uses organic matter compounds as its main source, may have opportunistically taken advantage of the possible increase of the C/N ratio in the seaweed under acidified conditions. Pseudoalteromonas, commonly associated to diseased seaweeds, suggesting that acidification may facilitate opportunistic/pathogenic bacteria. In the gut of S. nadejda, the bacterial genus Planctomycetia increased abundance under elevated CO2. This shift might be associated to changes in food (S. muticum) quality under acidification. Planctomycetia are slow-acting decomposers of algal polymers that could be providing the isopod with an elevated algal digestion and availability of inorganic compounds to compensate the shifted C/N ratio under acidification in their food. In conclusion, our results indicate that even after only three weeks of acidified conditions, bacterial communities associated to ungrazed seaweed and to an isopod grazer show specific, differential shifts in associated bacterial community. These have potential consequences for seaweed health (as shown in corals) and isopod food digestion. The observed changes in the gut microbiome of the grazer seem to reflect changes in the seaweed chemistry rather than its microbial composition.
- Behind the mask: cryptic genetic diversity of Mytilus galloprovincialis along southern European and northern African shoresPublication . Lourenço, Carla R.; Nicastro, Katy; Serrao, Ester A.; Castilho, Rita; Zardi, GerardoMorphological uniformity in geographically widespread species may cause genetically distinct entities to pass unnoticed if they can only be detected by molecular approaches. The importance of uncovering such cryptic diversity is prompted by the need to understand the putative adaptive potential of populations along species ranges and to manage biodiversity conservation efforts. In this study, we aim to assess cryptic intraspecific genetic diversity and taxonomic status of the widely distributed intertidal mussel Mytilus galloprovincialis, along Atlantic southwestern (SW) Iberian, Atlantic northwestern (NW) Moroccan and Mediterranean Tunisian shores. By using mitochondrial (16S restriction-fragment length polymorphism) and nuclear (polyphenolic adhesive protein gene, Glu-5') markers, we discovered a more complex taxonomic diversity of M. galloprovincialis than previously known. Both Atlantic and Mediterranean haplogroups of M. galloprovincialis were detected along Atlantic SW Iberian shores along with M. galloprovincialis/edulis hybrids (92.2% Atlantic, 3.9% Mediterranean and 3.9% hybrids). In contrast, NW Moroccan populations consisted solely of Atlantic M. galloprovincialis. The Mediterranean populations did not include M. galloprovincialis/ edulis hybrids, but both Atlantic (58%) and Mediterranean (42%) lineages were detected. Divergent selection between coastlines and/or indirect larval dispersal by human activities may be the drivers of this geographically structured genetic diversity.
- Coastal oceanographic connectivity at the global scale: a dataset of pairwise probabilities and travel times derived from biophysical modelingPublication . Assis, Jorge; Fragkopoulou, Eliza; Serrao, Ester A.; Bastos Araújo, MiguelOcean currents are fundamental drivers of marine biodiversity distribution, mediating the exchange of genetic material and individuals between populations. Their effect ranges from creating barriers that foster isolation to facilitating long-distance dispersal, which is crucial for species expansion and resilience in the face of climate change. Despite the significance of oceanographic connectivity, comprehensive global estimates remain elusive, hindering our understanding of species' dispersal ecology and limiting the development of effective conservation strategies. We present the first dataset of connectivity estimates (including probability of connectivity and travel time) along the world's coastlines. The dataset is derived from Lagrangian simulations of passive dispersal driven by 21 years of ocean current data and can be combined with species' biological traits, including seasonality and duration of planktonic dispersal stages. Alongside, we provide coastalNet, an R package designed to streamline access, analysis, and visualization of connectivity estimates. The dataset provides a new benchmark for research in oceanographic connectivity, enabling a deeper exploration of the complex dynamics of coastal marine ecosystems and informing more effective conservation strategies.
- Cryptic diversity in southern African kelpPublication . Madeira, Pedro; Reddy, Maggie M.; Assis, Jorge; Bolton, John J.; Rothman, Mark D.; Anderson, Robert J.; Kandjengo, Lineekela; Kreiner, Anja; Coleman, Melinda A.; Wernbergh, Tomas; De Clerck, Olivier; Leliaert, Frederik; Bandeira, Salomão; Ada, Abdul M.; Miranda Neiva, João; Pearson, Gareth Anthony; Serrao, Ester A.The southern coast of Africa is one of the few places in the world where water temperatures are predicted to cool in the future. This endemism-rich coastline is home to two sister species of kelps of the genus Ecklonia maxima and Ecklonia radiata, each associated with specific thermal niches, and occuring primarily on opposite sides of the southern tip of Africa. Historical distribution records indicate that E. maxima has recently shifted its distribution similar to 70 km eastward, to sites where only E. radiata was previously reported. The contact of sister species with contrasting thermal affinities and the occurrence of mixed morphologies raised the hypothesis that hybridization might be occurring in this contact zone. Here we describe the genetic structure of the genus Ecklonia along the southern coast of Africa and investigate potential hybridization and cryptic diversity using a combination of nuclear microsatellites and mitochondrial markers. We found that both species have geographically discrete genetic clusters, consistent with expected phylogeographic breaks along this coastline. In addition, depth-isolated populations were found to harbor unique genetic diversity, including a third Ecklonia lineage. Mito-nuclear discordance and high genetic divergence in the contact zones suggest multiple hybridization events between Ecklonia species. Discordance between morphological and molecular identification suggests the potential influence of abiotic factors leading to convergent phenotypes in the contact zones. Our results highlight an example of cryptic diversity and hybridization driven by contact between two closely related keystone species with contrasting thermal affinities.
- Disentangling the Influence of Mutation and Migration in Clonal Seagrasses Using the Genetic Diversity Spectrum for MicrosatellitesPublication . ARNAUD-HAOND, Sophie; Moalic, Yann; Hernandez-Garcia, Emilio; Eguíluz, Víctor M.; Alberto, Filipe; Serrao, Ester A.; Duarte, Carlos M.The recurrent lack of isolation by distance reported at regional scale in seagrass species was recently suggested to stem from stochastic events of large-scale dispersal. We explored the usefulness of phylogenetic information contained in microsatellite loci to test this hypothesis by using the Genetic Diversity Spectrum (GDS) on databases containing, respectively, 7 and 9 microsatellites genotypes for 1541 sampling units of Posidonia oceanica and 1647 of Cymodocea nodosa. The simultaneous increase of microsatellite and geographic distances that emerges reveals a coherent pattern of isolation by distance in contrast to the chaotic pattern previously described using allele frequencies, in particular, for the long-lived P. oceanica. These results suggest that the lack of isolation by distance, rather than the resulting from rare events of large-scale dispersal, reflects at least for some species a stronger influence of mutation over migration at the scale of the distribution range. The global distribution of genetic polymorphism may, therefore, result predominantly from ancient events of step-by-step (re) colonization followed by local recruitment and clonal growth, rather than contemporary gene flow. The analysis of GDS appears useful to unravel the evolutionary forces influencing the dynamics and evolution at distinct temporal and spatial scales by accounting for phylogenetic information borne by microsatellites, under an appropriate mutation model. This finding adds nuance to the generalization of the influence of large-scale dispersal on the dynamics of seagrasses.
- A European biobanking strategy for safeguarding macroalgal genetic material to ensure food security, biosecurity and conservation of biodiversityPublication . Hofmann, Laurie C.; Brakel, Janina; Bartsch, Inka; Arismendi, Gabriel Montecinos; Bermejo, Ricardo; Parente, Manuela I.; Creis, Emeline; Clerck, Olivier De; Jacquemin, Bertrand; Knoop, Jessica; Lorenz, Maike; Machado, Levi Pompermayer; Orfanidis, Sotiris; Probert, Ian; Menendez, , Cecilia Rad; Ross, Michael; Rautenberger, Ralf; Schiller, Jessica; Serrao, Ester A.; Steinhagen, Sophie; Sulpice, Ronan; Valero, Myriam; Wichard, Thomas; Serrao, Ester A.; Martins, neuzaBiobanking (also known as germplasm banking) of genetic material is a well-established concept for preserving plant genetic diversity and also contributes to food security, conservation and restoration. Macroalgae currently represent a very small percentage of the strains in publicly accessible European germplasm banks, despite the increasing recognition of their contribution to achieving several of the United Nations Sustainable Development Goals. There is no strategic coordination of existing macroalgal strains, which could have severe ecological and economic implications as species and their genetic diversity disappear rapidly due to local and global environmental stressors. In this opinion paper, we stress the importance of a coordinated European effort for preserving macroalgal genetic diversity and suggest the development of a three-pillared system to safeguard European macroalgal genetic material consisting of (1) a European Board of Macroalgal Genetic Resources (EBMGR) to provide supervision, support and coordination, (2) a network of germplasm banks consisting of currently existing and newly established infrastructures and (3) an interoperable databank integrating existing databanks. While it will be the task of the EBMGR to identify and coordinate priorities, we offer initial recommendations for preserving macroalgal genetic material, discuss the risks of inaction, and highlight the challenges that must be overcome.
- Extinction risk of the endemic soft coral Phyllogorgia dilatata (Esper, 1806) in a remote island of the Brazilian coastPublication . Anderson, A. B.; Gouvêa, Lidiane; Assis, Jorge; Serrao, Ester A.; Pinheiro, H. T.; Vilar, C.; Francini-Filho, R. B.; Horta, P. A.; Bernardino, A. F.; Cordeiro, C. A. M. M.; Gomes, L. E. O.; Joyeux, J.-C.; Ferreira, C. E. L.The Brazilian endemic octocoral Phyllogorgia dilatata (elephant ear sea fan) plays a crucial ecological role in the marine ecosystems of the Brazilian coast. Our work investigates the local extinction of P. dilatata on Trindade Island, a remote oceanic island in the Southwestern Atlantic, and assesses the potential impacts of climate change on its distribution. Field surveys conducted over two years (2016-2019) revealed no live individuals of P. dilatata, with only dead peduncles remaining, marking the first observed local extinction of this species. Species distribution models (SDMs) incorporating current and historical climate data were used to estimate the species' habitat suitability and project future distribution under different climate scenarios. Results indicate that P. dilatata currently inhabits approximately 93,090 km2 of suitable area, primarily within tropical ecoregions, but faces significant habitat loss under future climate projections. By 2090-2100, models predict a 63.38 % loss of habitat under the high-emission RCP 8.5 scenario, with severe impacts on tropical regions, including Trindade Island. Environmental variables such as temperature, oxygen concentration, and salinity were identified as key drivers of the species' distribution, while non-climatic factors like seawater velocity, were also significant. The extinction on Trindade Island is attributed to a combination of historical isolation, climate change, and local anthropogenic stressors, including pollution and overfishing. The current investigation highlights the urgent need for conservation efforts, including the establishment of marine protected areas and restoration programs, to protect this vulnerable species and similar marine organisms again climate change.
- Fine‐scale genetic structure and flowering output of the seagrass Enhalus acoroides undergoing disturbancePublication . Yu, Shuo; Wu, Yunchao; Serrao, Ester A.; Zhang, Jingping; Jiang, Zhijian; Huang, Chi; Cui, Lijun; Thorhaug, Anitra; Huang, XiaopingSeagrass are under great stress in the tropical coast of Asia, where Enhalus acoroides is frequently the dominant species with a large food web. Here, we investigate the question of the fine-scale genetic structure of this ecologically important foundation species, subject to severe anthropogenic disturbance in China. The genetic structure will illuminate potential mechanisms for population dynamics and sustainability, which are critical for preservation of biodiversity and for decision-making in management and restoration. We evaluated the fine-scale spatial genetic structure (SGS) and flowering output of E. acoroides, and indirectly estimated the relative importance of sexual versus asexual reproduction for population persistence using spatial autocorrelation analysis. Results reveal high clonal diversity for this species, as predicted from its high sexual reproduction output. The stronger Sp statistic at the ramet-level compared with genet-level indicates that clonality increases the SGS pattern for E. acoroides. Significant SGS at the genet-level may be explained by the aggregated dispersal of seed/pollen cohorts. The estimated gene dispersal variance suggests that dispersal mediated by sexual reproduction is more important than clonal growth in this study area. The ongoing anthropogenic disturbance will negatively affect the mating pattern and the SGS patterns in the future due to massive death of shoots, and less frequency of sexual reproduction.
- The first record of Lysmata rauli Laubenheimer and Rhyne, 2010 (Decapoda: Caridea: Lysmatidae) from the tropical eastern AtlanticPublication . Wirtz, Peter; Moura, Carlos; Nhanquê, Filipe T.; Barbosa, Castro; Serrao, Ester A.Here we report the first record of the shrimp Lysmata rauli Laubenheimer and Rhyne, 2010 in the eastern Atlantic, from the intertidal at Kere Island, Bijag & oacute;s archipelago, Guinea-Bissau.
- A framework for optimising opportunistic collaborative syntheses to propel ecological conservationPublication . Sequeira, Ana M.M.; Bates, Amanda E.; Hays, Graeme; Sims, David W.; Andrzejaczek, Samantha; Audzijonyte, Asta; Baum, Julia K.; Beal, Martin; Block, Barbara; Cinner, Joshua; Cowley, Kaitlyn; Gilman, Eric; Gleason, Arthur; Harrison, Autumn-Lynn; Hudson, Charlotte; Ishimura, Gakushi; Jabado, Rima W.; Landrum, Jason P.; Mangubhai, Sangeeta; McClenachan, Loren; Meagher, Laura; Riginos, Cynthia; Serrao, Ester A.; Sherley, Richard B.; Stuart-Smith, Rick D.; Wambiji, Nina; Marley, Sarah A.Ecological data are being opportunistically synthesised at unprecedented scales in response to the global biodiversity and climate crises. Such syntheses are often only possible through large-scale, international, multidisciplinary collaborations and provide important pathways for addressing urgent conservation questions. Although large collaborative data syntheses can lead to high-impact successes, they can also be plagued with difficulties. Challenges include the standardisation of data originally collected for different purposes, integration and interpretation of knowledge sourced across different disciplines and spatio-temporal scales, and management of differing perspectives from contributors with distinct academic and cultural backgrounds. Here, we use the collective expertise of a global team of conservation ecologists and practitioners to highlight common benefits and hurdles that arise with the development of opportunistic collaborative syntheses. We outline a framework of "best practice" for developing such collaborations, encompassing the design, implementation, and deliverable phases. Our framework addresses common challenges, highlighting key actions for successful collaboration and emphasizing the support requirements. We identify funding as a major constraint to sustaining the large, international, multidisciplinary teams required to advance collaborative syntheses in a just, equitable, diverse, and inclusive way. We further advocate for thinking strategically from the outset and highlight the need for reshaping funding agendas to prioritize the structures required to propel global scientific networks. Our framework will advance the science needed for ecological conservation and the sustainable use of global natural resources by supporting proto-groups initiating new syntheses, leaders and participants of ongoing projects, and funders who want to facilitate such collaborations in the future.