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- Genetic structure of amphi-Atlantic Laminaria digitata (Laminariales, Phaeophyceae) reveals a unique range-edge gene pool and suggests post-glacial colonization of the NW AtlanticPublication . Neiva, J.; Serrao, Ester; Paulino, Cristina; Gouveia, Licínia; Want, Andrew; Tamigneaux, Éric; Ballenghien, Marion; Mauger, Stéphane; Fouqueau, Louise; Engel-Gautier, Carolyn; Destombe, Christophe; Valero, MyriamIn the North-east (NE) Atlantic, most intertidal fucoids and warm-temperate kelps show unique low-latitude gene pools matching long-term climatic refugia. For cold-temperate kelps data are scarcer despite their unique cultural, ecological and economic significance. Here we test whether the amphi-Atlantic range of Laminaria digitata is derived from past glacial survival (and vicariance) in both NE and North-west (NW) Atlantic refugia (as suggested by niche modelling), or post-glacial (re)colonization (as suggested by low mtDNA divergence). We screened 14 populations from across the species range for 12 microsatellite loci to identify and map major gene pools and refugia. We assessed if NW Atlantic survival was supported by unique endemic variation, and if genetic diversity and structure were, as predicted from larger hindcasted glacial ranges, higher in the NE Atlantic. Microsatellite data subdivided L. digitata into three main genetic groups matching Brittany, northern Europe and the NW Atlantic, with finer-scale sub-structuring within European clusters. The relatively diverse NE Atlantic lineages probably survived the Last Glacial Maximum along unglaciated periglacial shorelines of the Armorican and Celtic Seas (Brittany cluster) and Ireland (northern European cluster), and remain well differentiated despite their relative proximity. The unique Brittany gene pool, at the contemporary European rear edge, is projected to disappear in the near future under high greenhouse gas emission scenarios. Low allelic diversity and low endemism in the NW Atlantic are consistent with recent post-glacial colonization from Europe, challenging the long-standing hypothesis of in situ glacial survival. Confusion with Hedophyllum nigripes may have led to underestimation of regional diversity of L. digitata, but also to overestimation of its presence along putative trans-Atlantic migration routes. Partial incongruence between modelling and genetic-based biogeographic inferences highlights the benefits of comparing both approaches to understand how shifting climatic conditions affect marine species distributions and explain large-scale patterns of spatial genetic structure.
- Ecological traits, genetic diversity and regional distribution of the macroalga Treptacantha elegans along the Catalan coast (NW Mediterranean Sea)Publication . Medrano, Alba; Hereu, Bernat; Mariani, Simone; Neiva, J.; Pagès-Escolà, Marta; Paulino, Cristina; Rovira, Graciel·la; Serrao, Ester; Linares, CristinaThe widespread decline of canopy-forming macroalgal assemblages has been documented in many regions during the last decades. This pattern is often followed by the replacement of structurally complex algal canopies by more simplified habitats (e.g., turfs or sea urchin barren grounds). Against all odds, the fucoid Treptacantha elegans, a large Mediterranean brown macroalga, broadened its depth range to deeper and exposed environments and displayed an unexpected range expansion along the northern coast of Catalonia over the last two decades. Here, we reconstruct the spread of T. elegans in time and space and unravel ecological and demographic traits such as population dynamics and genetic patterns to provide a comprehensive and integrated view of the current status and geographical expansion for this species. Fast-growing dynamics, early fertile maturity, and high turnover rate are the main competitive advantages that allow the exposed populations of T. elegans to colonize available substrata and maintain dense and patchy populations. We also provided evidence that the deeper and exposed populations of T. elegans constitute a single group across the Catalan coast, with little genetic differentiation among populations. This seems to support the hypothesis of a unique source of spread in the last decades from the Medes Islands No-Take Zone towards both southern and northern waters.
- Algae as food in Europe: an overview of species diversity and their applicationPublication . Mendes, Madalena; Navalho, Sofia; Ferreira, Alice; Paulino, Cristina; Figueiredo, Daniel; Silva, Daniel; Gao, Fengzheng; Gama, Florinda; Bombo, Gabriel; Jacinto, Rita; Aveiro, Susana; Schulze, Peter S.C.; Gonçalves, Ana Teresa; Pereira, Hugo; Gouveia, Luisa; Patarra, Rita F.; Abreu, Maria Helena; Silva, Joana L.; Navalho, João; Varela, João; Galileu Speranza, LaisAlgae have been consumed for millennia in several parts of the world as food, food supplements, and additives, due to their unique organoleptic properties and nutritional and health benefits. Algae are sustainable sources of proteins, minerals, and fiber, with well-balanced essential amino acids, pigments, and fatty acids, among other relevant metabolites for human nutrition. This review covers the historical consumption of algae in Europe, developments in the current European market, challenges when introducing new species to the market, bottlenecks in production technology, consumer acceptance, and legislation. The current algae species that are consumed and commercialized in Europe were investigated, according to their status under the European Union (EU) Novel Food legislation, along with the market perspectives in terms of the current research and development initiatives, while evaluating the interest and potential in the European market. The regular consumption of more than 150 algae species was identified, of which only 20% are approved under the EU Novel Food legislation, which demonstrates that the current legislation is not broad enough and requires an urgent update. Finally, the potential of the European algae market growth was indicated by the analysis of the trends in research, technological advances, and market initiatives to promote algae commercialization and consumption.
- Trans-Arctic asymmetries, melting pots and weak species cohesion in the low-dispersal amphiboreal seaweed Fucus distichusPublication . Neiva, J.; Assis, Jorge; Fragkopoulou, Eliza; Pearson, Gareth; Raimondi, Peter T.; Anderson, Laura; Krause-Jensen, Dorte; Marbà, Núria; Want, Andrew; Selivanova, Olga; Nakaoka, Masahiro; Grant, W. Stewart; Konar, Brenda; Roleda, Michael Y.; Sejr, Mikael K.; Paulino, Cristina; Serrao, EsterAmphiboreal taxa are often composed of vicariant phylogroups and species complexes whose divergence and phylogeographic affinities reflect a shared history of chronic isolation and episodic trans-Arctic dispersal. Ecological filters and shifting selective pressures may also promote selective sweeps, niche shifts and ecological speciation during colonization, but these are seldom considered at biogeographical scales. Here we integrate genetic data and Ecologic Niche Models (ENMs) to investigate the historical biogeography and cohesion of the polymorphic rockweed Fucus distichus throughout its immense amphiboreal range, focusing on trans-Arctic asymmetries, glacial/interglacial dynamics, and integrity of sympatric eco-morphotypes. Populations were sampled throughout the Pacific and the Atlantic, from southern rear-edges to the high-Arctic. They were genotyped for seven microsatellites and an mtDNA spacer, and genetic diversity and structure were assessed from global to local scales. ENMs were used to compare niche divergence and magnitude of post-glacial range shifts in Pacific versus Atlantic sub-ranges. Haplotypic and genotypic data revealed distinct and seemingly isolated Pacific vs Arctic/Atlantic gene-pools, with finer-scale regional sub-structuring pervasive in the Pacific. MtDNA diversity was highly structured and overwhelmingly concentrated in the Pacific. Regionally, Alaska showed the highest intra-population diversity but the lowest levels of endemism. Some sympatric/parapatric ecotypes exhibited distinct genotypic/haplotypic compositions. Strikingly, niche models revealed higher Pacific tolerance to maximum temperatures and predicted a much more consolidated presence in the NE Atlantic. Glacial and modern ranges overlapped extensively in the Pacific, whereas the modern Atlantic range was largely glaciated or emerged during the Last Glacial Maximum. Higher genetic and ecogeographic diversity supports a primary Pacific diversification and secondary Atlantic colonization, also likely reflecting the much larger and more stable climatic refugia in the Pacific. The relic distribution and reduced ecological/morphological plasticity in the NE Atlantic are hypothesized to reflect functional trans-Arctic bottlenecks, recent colonization or competition with congeners. Within the Pacific, Alaska showed signatures of a post-glacial melting pot of eastern and southern populations. Genetic/ecotypic variation was generally not sufficiently discontinuous or consistent to justify recognizing multiple taxonomic entities, but support a separate species in the eastern Pacific, at the southern rear-edge. We predict that layered patterns of phylogeographic structure, incipient speciation and niche differences might be common among widespread low-dispersal amphiboreal taxa.
- Past and future climate effects on population structure and diversity of North Pacific surfgrassesPublication . Tavares, Ana I; Assis, Jorge; Anderson, Laura; Raimondi, Pete; Coelho, Nelson; Paulino, Cristina; Ladah, Lydia; Nakaoka, Masahiro; Pearson, Gareth Anthony; Serrao, Ester A.Understanding the impacts of past and future climate change on genetic diversity and structure is a current major research gap. We ask whether past range shifts explain the observed genetic diversity of surfgrass species and if future climate change projections anticipate genetic diversity losses. Our study aims to identify regions of long-term climate suitability with higher and unique seagrass genetic diversity and predict future impacts of climate change on them.LocationNortheast Pacific.Time PeriodAnalyses considered a timeframe from the Last Glacial Maximum (LGM; 20 kybp) until one Representative Concentration Pathway (RCP) scenario of future climate changes (RCP 8.5; 2100).Major Taxa StudiedTwo seagrass species belonging to the genus Phyllospadix.MethodsWe estimated population genetic diversity and structure using 11 polymorphic microsatellite markers. We predicted the distribution of the species for the present, LGM, and near future (RCP 8.5, no climate mitigation) using Species Distribution Models (SDMs).ResultsSDMs revealed southward range shifts during the LGM and potential poleward expansions in the future. Genetic diversity of Phyllospadix torreyi decreases from north to south, but in Phyllospadix scouleri the trend is variable. Phyllospadix scouleri displays signals of genome admixture at the southernmost and northernmost edges of its distribution.Main ConclusionsThe genetic patterns observed in the present reveal the influence of climate-driven range shifts in the past and suggest further consequences of climate change in the future, with potential loss of unique gene pools. This study also shows that investigating climate links to present genetic information at multiple timescales can establish a historical context for analyses of the future evolutionary history of populations.