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Accounting for interspecies and intraspecies variation in swimming performance for fish passage solutions
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Across the globe, there are millions of in-stream structures that fragment the world'’s river networks, acting as barriers that can impede the movements of fish. Designing effective solutions to accommodate fish communities requires information about the swimming abilities and behaviours of all species. This should account for different swimming modes, abilities, behaviours, and niches. We investigated the swimming speeds of nine migratory New Zealand species to assess both inter- and intraspecies variation. We then calculated maximum traversable speeds for culverts of a given length, based on the endurance abilities of our lowest performing species (Galaxias maculatus). Our findings reveal significant inter- and intraspecies variation in swimming speeds. Among the species studied, Galaxias brevipinnis, Galaxias argenteus, and Galaxias postvectis were the strongest swimmers. In contrast, Galaxias maculatus was one of the weakest swimmers. Body length positively correlated with Umax indicating that fish passage barriers select against the weakest swimming species, as well as smaller individuals within a species. Maximum water speeds in a culvert must be lower than 0.3 m s−-1, the previously assumed standard rule-of-thumb for New Zealand, to provide adequate passage for a high proportion of a weak-swimming indicator species (Galaxias maculatus). Synthesis and applications: . Previous maximum traversable water speeds for fish passage designs have been based on average swimming ability, but this approach only enables fish that are better than the average swimmers of their species to overcome barriers. This study highlights the importance of evidence-based designs for successful fish passage solutions to account for the ability of all fish. By considering differences between and within species, rather than assuming a “‘one-size-fits-all” ’ approach we can develop more effective passage solutions that better preserve fish communities.
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RBINS Staff Publications 2024
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A New Species of Elpidium (Crustacea, Ostracoda) from Bromeliad and Non-bromeliad Phytotelmata in the Northeast of Argentina
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A new species of the ostracod genus Elpidium (Timiriaseviinae), a group almost exclusively known from Neotropical bromeliad phytotelmata, is here described and illustrated from the northeast of Argentina. Elpidium chacoense n. sp. represents the first record of the genus in this country and brings the total of described Elpidium species to 19. In view of the recently increased knowledge on the distribution of the species in this Neotropical genus, we discuss potential drivers of speciation that might have led to the high (endemic) diversity of the group: allopatry in bromeliad islands, sexual selection and putative co-evolution between ostracod and bromeliad species. We also point out the biogeographical relevance of the present records, which are amongst the most southern of the genus. Finally, also the fact that species of Elpidium can now also be found in non-bromeliad phytotelmata is of relevance.
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RBINS Staff Publications 2024
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An updated subjective global checklist of the extant non-marine Ostracoda (Crustacea)
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We present an updated global checklist of extant non-marine Ostracoda, covering taxonomic changes in the published literature up to 31st December 2023. The checklist is subjective, as apart from published taxonomic changes, also some additional alterations are proposed, including ten candonid tribes which are upgraded to subfamilies, six new combinations, one new name, five synonymies and one new taxonomic placement. The checklist presently includes 2420 accepted species in 295 genera,as well as 84 uncertain species that are too poorly described to be recognisable. We also provide the totals of species numbers for each taxonomic rank, from genera up to order, and numbers of species and endemic species in each of the world’s major zoogeographical regions.
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RBINS Staff Publications 2024
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The late Holocene tsunami in the Shetland Islands (UK) identified in Loch Flugarth, north Mainland
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Tsunami deposits around the North Sea basin are needed to assess the long-term hazard of tsunamis. Here, we present sedimentary evidence of the youngest tsunami on the Shetland Islands from Loch Flugarth, a coastal lake on northern Mainland. Three gravity cores show organic-rich background sedimentation with many sub-centimetre-scale sand layers, reflecting recurring storm overwash and a sediment source limited to the active beach and uppermost subtidal zone. A basal 13-cm-thick sand layer, dated to 426–787 cal. a CE based on 14C, 137Cs and Bayesian age–depth modelling, was found in all cores. High-resolution grain-size analysis identified four normally graded or massive sublayers with inversely graded traction carpets at the base of two sublayers. A thin organic-rich ‘mud’ drape and a ‘mud’ cap cover the two uppermost sublayers, which also contain small rip-up clasts. Grain-size distributions show a difference between the basal sand layer and the coarser and better sorted storm layers above. Multivariate statistical analysis of X-ray fluorescence core scanning data also distinguishes both sand units: Zr, Fe and Ti dominate the thick basal sand, while the thin storm layers are high in K and Si. Enriched Zr and Ti in the basal sand layer, in combination with increased magnetic susceptibility, may be related to higher heavy mineral content reflecting an additional marine sediment source below the storm-wave base that is activated by a tsunami. Based on reinterpretation of chronological data from two different published sites and the chronostratigraphy of the present study, the tsunami seems to date to c. 1400 cal. a BP. Although the source of the tsunami remains unclear, the lack of evidence for this event outside of the Shetland Islands suggests that it had a local source and was smaller than the older Storegga tsunami (8.15 cal. ka BP), which affected most of the North Sea basin.
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RBINS Staff Publications 2024
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A 1500-year record of North Atlantic storm flooding from lacustrine sediments, Shetland Islands (UK)
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Severe storm flooding poses a major hazard to the coasts of north-western Europe. However, the long-term recurrence patterns of extreme coastal flooding and their governing factors are poorly understood. Therefore, high-resolution sedimentary records of past North Atlantic storm flooding are required. This multi-proxy study reconstructs storm-induced overwash processes from coastal lake sediments on the Shetland Islands using grain-size and geochemical data, and the re-analysis of historical data. The chronostratigraphy is based on Bayesian age–depth modelling using accelerator mass spectrometry 14C and 137Cs data. A high XRF-based Si/Ti ratio and the unimodal grain-size distribution link the sand layers to the beach and thus storm-induced overwash events. Periods with more frequent storm flooding occurred 980–1050, 1150–1300, 1450–1550, 1820–1900 and 1950–2000 ce, which is largely consistent with a positive North Atlantic Oscillation mode. The Little Ice Age (1400–1850 ce) shows a gap of major sand layers suggesting a southward shift of storm tracks and a seasonal variance with more storm floods in spring and autumn. Warmer phases shifted winter storm tracks towards the north-east Atlantic, indicating a possible trend for future storm-track changes and increased storm flooding in the northern North Sea region.
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RBINS Staff Publications 2023
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Coastal wetland adaptability to sea level rise: The neglected role of semi-diurnal vs. diurnal tides
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RBINS Staff Publications 2023
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Sample basedwater quality monitoring of coastal seas: How significant is the information loss in patchy time series compared to continuous ones?
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RBINS Staff Publications 2023
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Promoting best practices in ocean forecasting through an Operational Readiness Level
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Predicting the ocean state in a reliable and interoperable way, while ensuring high-quality products, requires forecasting systems that synergistically combine science-based methodologies with advanced technologies for timely, user-oriented solutions. Achieving this objective necessitates the adoption of best practices when implementing ocean forecasting services, resulting in the proper design of system components and the capacity to evolve through different levels of complexity. The vision of OceanPrediction Decade Collaborative Center, endorsed by the UN Decade of Ocean Science for Sustainable Development 2021-2030, is to support this challenge by developing a “predicted ocean based on a shared and coordinated global effort” and by working within a collaborative framework that encompasses worldwide expertise in ocean science and technology. To measure the capacity of ocean forecasting systems, the OceanPrediction Decade Collaborative Center proposes a novel approach based on the definition of an Operational Readiness Level (ORL). This approach is designed to guide and promote the adoption of best practices by qualifying and quantifying the overall operational status. Considering three identified operational categories - production, validation, and data dissemination - the proposed ORL is computed through a cumulative scoring system. This method is determined by fulfilling specific criteria, starting from a given base level and progressively advancing to higher levels. The goal of ORL and the computed scores per operational category is to support ocean forecasters in using and producing ocean data, information, and knowledge. This is achieved through systems that attain progressively higher levels of readiness, accessibility, and interoperability by adopting best practices that will be linked to the future design of standards and tools. This paper discusses examples of the application of this methodology, concluding on the advantages of its adoption as a reference tool to encourage and endorse services in joining common frameworks.
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RBINS Staff Publications 2023
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Intraskeletal histovariability, allometric growth patterns, and their functional implications in bird-like dinosaurs
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RBINS Staff Publications 2018
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Fossil whale barnacles from the lower Pleistocene of Sicily shed light on the coeval Mediterranean cetacean fauna
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RBINS Staff Publications 2018