Arctic marine forest distribution models showcase potentially severe habitat losses for cryophilic species under climate change

The Arctic is among the fastest-warming areas of the globe. Understanding the impact of climate change on foundational Arctic marine species is needed to provide insight on ecological resilience at high latitudes. Marine forests, the underwater seascapes formed by seaweeds, are predicted to expand their ranges further north in the Arctic in a warmer climate. Here, we investigated whether northern habitat gains will compensate for losses at the southern range edge by modelling marine forest distributions according to three distribution categories: cryophilic (species restricted to the Arctic environment), cryotolerant (species with broad environmental preferences inclusive but not limited to the Arctic environment), and cryophobic (species restricted to temperate conditions) marine forests. Using stacked MaxEnt models, we predicted the current extent of suitable habitat for contemporary and future marine forests under Representative Concentration Pathway Scenarios of increasing emissions (2.6, 4.5, 6.0, and 8.5). Our analyses indicate that cryophilic marine forests are already ubiquitous in the north, and thus cannot expand their range under climate change, resulting in an overall loss of habitat due to severe southern range contractions. The extent of marine forests within the Arctic basin, however, is predicted to remain largely stable under climate change with notable exceptions in some areas, particularly in the Canadian Archipelago. Succession may occur where cryophilic and cryotolerant species are extirpated at their southern range edge, resulting in ecosystem shifts towards temperate regimes at mid to high latitudes, though many aspects of these shifts, such as total biomass and depth range, remain to be field validated. Our results provide the first global synthesis of predicted changes to pan-Arctic coastal marine forest ecosystems under climate change and suggest ecosystem transitions are unavoidable now for some areas.publishedVersio

Spatial Variation in Population Structure and Its Relation to Movement and the Potential for Dispersal in a Model Intertidal Invertebrate

Dispersal, the movement of an individual away from its natal or breeding ground, has been studied extensively in birds and mammals to understand the costs and benefits of movement behavior. Whether or not invertebrates disperse in response to such attributes as habitat quality or density of conspecifics remains uncertain, due in part to the difficulties in marking and recapturing invertebrates. In the upper Bay of Fundy, Canada, the intertidal amphipod Corophium volutator swims at night around the new or full moon. Furthermore, this species is regionally widespread across a large spatial scale with site-to-site variation in population structure. Such variation provides a backdrop against which biological determinants of dispersal can be investigated. We conducted a large-scale study at nine mudflats, and used swimmer density, sampled using stationary plankton nets, as a proxy for dispersing individuals. We also sampled mud residents using sediment cores over 3 sampling rounds (20–28 June, 10–17 July, 2–11 August 2010). Density of swimmers was most variable at the largest spatial scales, indicating important population-level variation. The smallest juveniles and large juveniles or small adults (particularly females) were consistently overrepresented as swimmers. Small juveniles swam at most times and locations, whereas swimming of young females decreased with increasing mud presence of young males, and swimming of large juveniles decreased with increasing mud presence of adults. Swimming in most stages increased with density of mud residents; however, proportionally less swimming occurred as total mud resident density increased. We suggest small juveniles move in search of C. volutator aggregations which possibly act as a proxy for better habitat. We also suggest large juveniles and small adults move if potential mates are limiting. Future studies can use sampling designs over large spatial scales with varying population structure to help understand the behavioral ecology of movement, and dispersal in invertebrate taxa

Contrasting new and available reference genomes to highlight uncertainties in assemblies and areas for future improvement: an example with monodontid species

Abstract Background Reference genomes provide a foundational framework for evolutionary investigations, ecological analysis, and conservation science, yet uncertainties in the assembly of reference genomes are difficult to assess, and by extension rarely quantified. Reference genomes for monodontid cetaceans span a wide spectrum of data types and analytical approaches, providing the context to derive broader insights related to discrepancies and regions of uncertainty in reference genome assembly. We generated three beluga (Delphinapterus leucas) and one narwhal (Monodon monoceros) reference genomes and contrasted these with published chromosomal scale assemblies for each species to quantify discrepancies associated with genome assemblies. Results The new reference genomes achieved chromosomal scale assembly using a combination of PacBio long reads, Illumina short reads, and Hi-C scaffolding data. For beluga, we identified discrepancies in the order and orientation of contigs in 2.2–3.7% of the total genome depending on the pairwise comparison of references. In addition, unsupported higher order scaffolding was identified in published reference genomes. In contrast, we estimated 8.2% of the compared narwhal genomes featured discrepancies, with inversions being notably abundant (5.3%). Discrepancies were linked to repetitive elements in both species. Conclusions We provide several new reference genomes for beluga (Delphinapterus leucas), while highlighting potential avenues for improvements. In particular, additional layers of data providing information on ultra-long genomic distances are needed to resolve persistent errors in reference genome construction. The comparative analyses of monodontid reference genomes suggested that the three new reference genomes for beluga are more accurate compared to the currently published reference genome, but that the new narwhal genome is less accurate than one published. We also present a conceptual summary for improving the accuracy of reference genomes with relevance to end-user needs and how they relate to levels of assembly quality and uncertainty

A DNA barcode survey of marine macroalgae from Bergen (Norway)

Safeguarding the services provided by marine forests inherently depends on an accurate understanding of macroalgal species diversity. Here, we provide the first DNA barcode survey of marine macroalgae from Norway, with a focus on the Bergen area, and compared our findings to morphological listings for the corresponding location. Specimens were sampled 14–20 April and 3–13 June 2016, and variously sequenced for several genetic markers, including the five prime end of the cytochrome c oxidase subunit I gene (COI-5P), elongation factor tufA, and the ribulose-1, 5-biphosphate carboxylase large subunit gene (rbcL). We generated 655 new barcode records for COI-5P, 11 for tufA, and 50 for rbcL, representing nine species of Chlorophyta, 51 species of Phaeophyceae, and 74 species of Rhodophyta. Sequence data confirmed the presence of 113 morphological species. A further 17 genetic groups indicated the presence of new species for the area, only six of which were linked to formally described species. The remaining four genetic records were uncertain in terms of morphological species assignment and relation to the local flora. We recommend further DNA barcoding surveys in the area, as only a third of the listed morphological species were genetically confirmed

A DNA barcode survey of marine macroalgae from Bergen (Norway)

Safeguarding the services provided by marine forests inherently depends on an accurate understanding of macroalgal species diversity. Here, we provide the first DNA barcode survey of marine macroalgae from Norway, with a focus on the Bergen area, and compared our findings to morphological listings for the corresponding location. Specimens were sampled 14–20 April and 3–13 June 2016, and variously sequenced for several genetic markers, including the five prime end of the cytochrome c oxidase subunit I gene (COI-5P), elongation factor tufA, and the ribulose-1, 5-biphosphate carboxylase large subunit gene (rbcL). We generated 655 new barcode records for COI-5P, 11 for tufA, and 50 for rbcL, representing nine species of Chlorophyta, 51 species of Phaeophyceae, and 74 species of Rhodophyta. Sequence data confirmed the presence of 113 morphological species. A further 17 genetic groups indicated the presence of new species for the area, only six of which were linked to formally described species. The remaining four genetic records were uncertain in terms of morphological species assignment and relation to the local flora. We recommend further DNA barcoding surveys in the area, as only a third of the listed morphological species were genetically confirmed

Updates to the Marine Algal Flora of the Boulder Patch in the Beaufort Sea off Northern Alaska as Revealed by DNA Barcoding + Supplementary Appendix 1 (See Article Tools)

Since its discovery four decades ago, the Boulder Patch kelp bed community in the Beaufort Sea has been an important site for long-term ecological studies in northern Arctic Alaska. Given the difficulties associated with identifying species of marine algae on the basis of morphology, we sought to DNA barcode a portion of the flora from the area and update a recently published species list. Genetic data were generated for 20 species in the area. Fifty-five percent of the barcoded flora confirmed the morphological species identifications. Five barcoded species revealed what are likely misapplied names to the Boulder Patch flora; the updated names include Ahnfeltia borealis, Phycodrys fimbriata, Pylaiella washingtoniensis, Rhodomela lycopodioides f. flagellaris, and Ulva prolifera. The remaining four species require taxonomic work and possibly represent new records for the Boulder Patch. Our observations indicate that we need considerably more research to understand marine macroalgal biodiversity in the Arctic. Supplementing Arctic species lists using genetic data will be essential in establishing an accurate and reliable baseline for monitoring changes in ecosystem biodiversity driven by long-term changes in regional climate.Depuis sa découverte il y a quatre décennies, le peuplement d’algues brunes de la Boulder Patch dans la mer de Beaufort représente un site important pour les études écologiques à long terme dans l’Extrême-Arctique, en Alaska. Étant donné les difficultés liées à l’identification des espèces d’algues marines en fonction de leur morphologie, nous avons cherché à effectuer le codage à barres de l’ADN d’une partie de la flore de la région et avons mis à jour une liste d’espèces récemment publiée. Des données génétiques ont été produites pour 20 espèces de la région. Les identifications morphologiques ont été confirmées dans le cas de 55 % des espèces de la flore dont le code à barres a été établi. Pour cinq espèces dont le code à barres a été généré, nous avons constaté que des noms erronés avaient probablement été attribués à la flore de la Boulder Patch. Les noms à jour sont les suivants : Ahnfeltia borealis, Phycodrys fimbriata, Pylaiella washingtoniensis, Rhodomela lycopodioides f. flagellaris et Ulva prolifera. Les quatre autres espèces nécessitent une classification taxonomique et représentent peut-être de nouveaux signalements d’espèces pour la Boulder Patch. Nos observations indiquent que beaucoup d’autres recherches sont nécessaires pour comprendre la biodiversité des macroalgues marines de l’Arctique. Il sera essentiel de compléter les listes des espèces de l’Arctique à l’aide de données génétiques pour établir des données de base précises et fiables afin de surveiller les changements dans la biodiversité de l’écosystème causés par des changements à long terme du climat régional

Revisiting a DNA barcode survey of Haida Gwaii kelp: the quest for Eisenia arborea (Arthrothamnaceae, Laminariales)

Eisenia arborea Areschoug is a temperate kelp first described from California, and commonly reported as far south as Mexico. Floristic surveys in cold-temperate waters of the Northeast Pacific, however, have revealed its presence on the Canadian archipelago of Haida Gwaii (at latitude 53.3799o N), last reported from the area in 2000 by Sloan and Bartier. Here, we present COI-5P data for E. arborea and confirm its presence at two sites on the west coast of Haida Gwaii in the years 2015 and 2018. These collections update a recently published list of genetically confirmed kelp species from Haida Gwaii. Our surveys suggest that northern populations of E. arborea are likely scattered throughout the western portions of the archipelago. The Haida Gwaii populations reported here represent potential monitoring sites for ecological and evolutionary investigations of E. arborea.The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author

Bringloe et al. Master Literature Search Additive Partitioning

This excel file includes 114 articles reviewed for difficulties identifying species when morphology is used in diversity component studies. Publication information, categorizations and focal taxa information are included