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Standardising research on marine biological carbon pathways required to estimate sequestration at Polar and sub-Polar latitudes
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Marine biological (‘blue’) carbon pathways are crucial components of the global carbon budget due to the ecosystem services they provide through the fixation of CO2 from the atmosphere. CO2 is removed from biosphere through long-term sequestration into seafloor sediments, removing it from the carbon cycle. Coincident with marine ice loss, little studied negative (mitigating) feedbacks to climate change are emerging in polar waters, which is important to quantify and comprehend. Understanding the mechanisms driving these pathways, that could lead to change, is a massive task and to ensure studies are comparable requires standardisation and prioritisation of future research. The expertise of scientists within the EU grant, Coastal ecosystem carbon balance in times of rapid glacier melt (CoastCarb), identified the 23 most important high latitude pathways through a modified Delphi scoring system. Metrics were selected as priorities for future research and for syntheses across broader geographic regions. The metrics with the highest importance scores also scored as the metrics that could be most readily standardised in the next five years. This review provides a definition and description of how each metric is measured, including its central role to blue carbon pathways. It also provides recommendations for standardisation, emphasising the requirement for modelling studies to scale from geographically limited regions where high-resolution data is available. Where methods cannot be standardised, cross calibration between methods is required to ensure reproducibility. An increasing use of remote sensing and innovative technologies will be necessary to scale measurements across this vast and remote region.
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RBINS Staff Publications 2025
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Carbon burial in two Greenland fjords shows no direct link to glacier type
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Fjord systems play a crucial role in the burial and long-term storage of organic carbon (OC). Despite their importance, Greenland's fjords remain underrepresented in global carbon budgets, even though accelerated melt of the Ice Sheet alters these ecosystems through increased freshwater discharge and iceberg calving, ultimately driving glacier retreat inland. This study compares sediment TOC, TN, and Chl-a content as well as δ13C, δ15N and organic carbon burial rates (OCBRs) in two neighbouring Greenland fjords: Nuup Kangerlua, dominated by marine-terminating glaciers (MTGs), and Ameralik, influenced by a land-terminating glacier (LTG). Although subglacial upwelling enhances primary productivity in Nuup Kangerlua, this does not translate into correspondingly higher surface sediment organic matter content or significantly higher OCBRs compared to Ameralik, where no such upwelling occurs. Instead, the average OCBRs were similar between the two fjords with 18.0 ± 1.6 g C m−2 yr−1 in Nuup Kangerlua and 16.2 ± 1.7 g C m−2 yr−1 in Ameralik. In Nuup Kangerlua, sediment Chl-a content in the upper 10 cm ranged from 0.08 to 9.8 µg g−1 and TOC from 0.05 \% to 1.32 \%, whereas in Ameralik they ranged from 0.35 to 20.1 µg g−1 and 0.13 \% to 2.43 \%, respectively. The elevated values in Ameralik are linked to a deep depositional basin that promotes OC accumulation and strongly contributes to the relatively high average OCBR. Furthermore, between 8 \% and 28 \% of the annual surface production in Nuup Kangerlua is ultimately buried in the sediments, whereas this proportion is substantially higher in Ameralik: 25 \% to 62 \%. The weaker coupling between surface production and sedimentary OC burial in Nuup Kangerlua versus Ameralik underscores the need for further research to disentangle the interactions driving primary production, carbon transfer in the food web, and the lateral and vertical transport, degradation and preservation of OC in fjord sediments.
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RBINS Staff Publications 2025
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New insights on the Lower Ordovician linguliformean brachiopods of the Anglo-Brabant Massif and the Stavelot-Venn Inlier (Belgium)
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The Lower Ordovician (Tremadocian) linguliformean brachiopods of the southeastern part of the Anglo-Brabant Massif are documented systematically for the first time. The material belongs to a single Belgian locality (La Roche-en-Brabant), situated in one of the few valleys that incise the Mesozoic-Cenozoic cover, and more precisely from the topmost part of the siliciclastic Mousty Formation (Tangissart Member). Here, minute, poorly diverse linguliformeans are associated with planktic graptolites (Rhabdinopora) and nileid trilobites (Platypeltoides). They consist of three species belonging to three genera (Obolidae and Elkaniidae), of which only Broeggeria is known with certainty, due to the poor preservation of the material. In the Belgian part of the Stavelot-Venn Inlier, the presence of linguliformean brachiopods within the Floian Les Plattes Member of the Ottré Formation, which were reported more than 150 years ago, remains unconfirmed. The genus Broeggeria, known from several Belgian Tremadocian localities, is a relic from the Cambrian brachiopod fauna. By the Tremadocian it is well established globally between the Low-Latitude and High-Latitude provinces. The Belgian assemblage has strong similarities with assemblages from Baltica reflecting the early Palaeozoic changing palaeogeography.
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RBINS Staff Publications 2025
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Designation of a Brazilian topotypic neotype for Dardanus pectinatus (Ortmann, 1892) and establishment of D. ctenodon sp. nov. for the East Atlantic hermit crab previously misidentified with it (Crustacea, Decapoda, Anomura, Diogenidae)
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The type locality of the hermit crab, Pagurus striatus var. pectinata Ortmann, 1892, as given in its original description, is Brazil. After its original brief taxonomic account, the species was first treated as amphi-Atlantic and later the name Dardanus pectinatus (Ortmann, 1892) was systematically applied to an African Atlantic species. No explicit reason has ever been given for this application. However, it transpires from the literature that carcinologists believed that the gastropod shell, Tonna galea (Linnaeus, 1758), occupied by the holotype of Pagurus striatus var. pectinata Ortmann, 1892 was endemic to the Mediterranean and Eastern Atlantic, and that the specimen had therefore been mislabelled. In fact, Tonna galea is amphi-Atlantic and the shell occupied by the hermit crab cannot be used to argue that it has been mislabelled. The holotype of Pagurus striatus var. pectinata Ortmann, 1892 is lost and its original description and illustration are insufficient to establish its true identity. Two steps are taken to stabilise the nomenclature in accepting the hypothesis by far most likely, i.e. that the holotype of Pagurus striatus var. pectinata did indeed come from Brazil. First action: a Brazilian neotype is designated for Pagurus striatus var. pectinata, with a specimen of a species compatible with its original description, namely Dardanus insignis (de Saussure, 1857). As a result of this action, Dardanus pectinatus (Ortmann, 1892) becomes a junior synonym of Dardanus insignis (de Saussure, 1857). Second action: the African Atlantic species is described as a new species, Dardanus ctenodon sp. nov., with a holotype from Senegal. The three similar Atlantic species Dardanus arrosor (Herbst, 1796), Dardanus ctenodon sp. nov. and Dardanus insignis (de Saussure, 1857) are the subject of an illustrated taxonomic account and an identification key is given for all the Atlantic species of Dardanus.
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RBINS Staff Publications 2025
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Weather and climate related spatial varability of high turbidity areas in the North Sea and the English Channel
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Pending old publications
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Limits of calcium isotopes diagenesis in fossil bone and enamel
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Diagenesis has been recognized for decades to significantly alter the trace elements biogenic signatures in fossil tooth enamel and bone that are routinely used for paleobiological and paleoenvironmental reconstructions. This signature is modified during diagenesis according to a complex continuum between two main processes, addition and substitution. For an additive-like, or early diagenesis, the trace elements biogenic profiles can be restored by leaching secondary minerals, but this technique is inefficient for a substitutive-like, or extensive diagenesis for which secondary trace elements are incorporated into the biogenic mineral. This scheme is however unclear for Ca, the major cation in tooth enamel and bone hydroxylapatite, whose stable isotope composition (δ44/42Ca) also conveys biological and environmental information. We present a suite of leaching experiments for monitoring δ44/42Ca values in artificial and natural fossil enamel and bone from different settings. The results show that enamel δ44/42Ca values are insensitive to an additive-like diagenesis that involves the formation of secondary Ca- carbonate mineral phases, while bone shows a consistent offset toward 44Ca-enriched values, that can be restored to the biogenic baseline by a leaching procedure. In the context of a substitutive-like diagenesis, bone exhibits constant δ44/42Ca values, insensitive to leaching, and shows a REE pattern symptomatic of extensive diagenesis. Such a REE pattern can be observed in fossil enamel for which δ44/42Ca values are still fluctuating and follow a trophic pattern. We conclude that Ca isotopes in fossil enamel are probably not prone to extensive diagenesis and argue that this immunity is due to the very low porosity of enamel that cannot accommodate enough secondary minerals to significantly modify the isotopic composition of the enamel Ca pool.
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RBINS Staff Publications 2023
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Taxonomic Revision of the Genus Trictenotoma Gray, 1832 (Coleoptera: Trictenotomidae). Part 3 – Species from the Philippine Archipelago, with Description of a New Species
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RBINS Staff Publications 2021
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Food nutrient availability affects epibiont prevalence and richness in natural Daphnia populations
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RBINS Staff Publications 2020
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Quality-control tests for OC4, OC5 and NIR-red satellite chlorophyll-a algorithms applied to coastal waters
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Reliable satellite estimates of chlorophyll-a concentration (Chl-a) are needed in coastal waters for applications such as eutrophication monitoring. However, because of the optical complexity of coastal waters, retrieving accurate Chl-a is still challenging. Many algorithms exist and give quite different performance for different optical conditions but there is no clear definition of the limits of applicability of each algorithm and no clear basis for deciding which algorithm to apply to any given image pixel (reflectance spectrum). Poor quality satellite Chl-a data can easily reach end-users. To remedy this and provide a clear decision on when a specific Chl-a algorithm can be used, we propose simple quality control tests, based on MERIS water leaving reflectance (ρw) bands, to determine on a pixel-by-pixel basis if any of three popular and complementary algorithms can be used. The algorithms being tested are: 1. the OC4 blue-green band ratio algorithm which was designed for open ocean waters; 2. the OC5 algorithm which is based on look-up tables and corrects OC4 overestimation in moderately turbid waters and 3. a near infrared-red (NIR-red) band ratio algorithm designed for eutrophic waters. Using a dataset of 348 in situ Chl-a / MERIS matchups, the conditions for reliable performance of each of the selected algorithms are determined. The approach proposed here looks for the best compromise between the minimization of the relative difference between In situ measurements and satellite estimations and the number of pixels processed. Conditions for a reliable application of OC4 and OC5 depend on ρw412/ρw443 and ρw560, used as proxies of coloured dissolved organic matter and suspended particulate matter (SPM), as compared to ρw560/ρw490, used as a proxy for Chl-a. Conditions for reliable application of the NIR-red band ratio algorithm depend on Chl-a and SPM. These conditions are translated into pixel-based quality control (QC) tests with appropriately chosen thresholds. Results show that by removing data which do not pass QC, the performance of the three selected algorithms is significantly improved. After combining these algorithms, 70\% of the dataset could be processed with a median absolute percent difference of 30.5\%. The QC tests and algorithm merging methodology were then tested on four MERIS images of European waters. The OC5 algorithm was found to be suitable for most pixels, except in very turbid and eutrophic waters along the coasts where the NIR-red band ratio algorithm helps to fill the gap. Finally, a test was performed on an OLCI-S3A image. Although some validations of water reflectance are still needed for the OLCI sensors, results show similar behavior to the MERIS applications which suggests that when applied to OLCI data the present methodology will help to accurately estimate Chl-a in coastal waters for the next decade.
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RBINS Staff Publications 2022
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Monitoring of high biomass Phaeocystis globosa blooms in the Southern North Sea by in situ and future spaceborne hyperspectral radiometry
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Phaeocystis globosa (P. globosa hereafter) is a phytoplankton species which commonly blooms at high biomass in April–May in the Southern North Sea and forms undesirable foam which accumulates on the beaches. Monitoring of this species is required by EU directives. Measurement of phytoplankton species composition has historically been made by pigment or microscopic analysis of water samples, which is spatially sparse and temporally infrequent e.g. weekly/monthly. In-water instruments such as flow cytometers can provide very high frequency data but at high acquisition and maintenance cost. Automated in situ above water radiometry has the potential to provide very high frequency data at single locations but requires very careful design of processing algorithms in turbid waters with high non-algal absorption. Spaceborne radiometry could provide both very good spatial coverage and moderate/high frequency of data, e.g. daily/weekly, but accurate determination of phytoplankton species composition is considerably more difficult in turbid waters than in open ocean waters. Prior studies based on a limited number of shipborne reflectance measurements suggested feasibility of P. globosa detection in turbid waters from hyperspectral radiometry. The availability of a new autonomous above water hyperspectral radiometer system has enabled further refinement and intensive testing of these techniques. From a time-series of 4356 water reflectance spectra measured near Ostend harbour in Belgian coastal waters from 2020/04/01 to 2020/08/18, two existing algorithms for P. globosa detection were successfully applied. Results show a high biomass P. globosa bloom occurring in late-April/early-May as found every year in water sample analyses for Belgian coastal waters. The high temporal resolution of the radiometric data allows to capture the evolution of the bloom at time scales sufficiently short (hourly and daily) compared to growth/decay and tidal processes. The challenges of extending the methods to future spaceborne instruments are also tested by simulating the impact of errors in sensor inter-band calibration, atmospheric correction and radiometric noise. Results show that because of their spectral coherence, atmospheric correction errors impact only slightly P. globosa detection whereas inaccuracy in inter-band calibration and radiometric noise are much more problematic as they affect each spectral band independently. Because radiometric noise should be reduced in the new generation of hyperspectral sensors and can always be reduced by spatial binning, the inter-band relative calibration uncertainty appears to be the main challenge for spaceborne mission design. Indeed, it was demonstrated that inter-band calibration error should be 0.25\% and ideally 0.1\% at top of the atmosphere highlighting the need for particular attention to inter-band calibration in sensor design and post processing treatments including vicarious calibration.
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RBINS Staff Publications 2022
