The Plankton Lifeform Extraction Tool: a digital tool to increase the discoverability and usability of plankton time-series data

Publication history: Accepted - 25 October 2021; Published online - 6 December 2021.Plankton form the base of the marine food web and are sensitive indicators of environmental change. Plankton time series are therefore an essential part of monitoring progress towards global biodiversity goals, such as the Convention on Biological Diversity Aichi Targets, and for informing ecosystem-based policy, such as the EU Marine Strategy Framework Directive. Multiple plankton monitoring programmes exist in Europe, but differences in sampling and analysis methods prevent the integration of their data, constraining their utility over large spatio-temporal scales. The Plankton Lifeform Extraction Tool brings together disparate European plankton datasets into a central database from which it extracts abundance time series of plankton functional groups, called “lifeforms”, according to shared biological traits. This tool has been designed to make complex plankton datasets accessible and meaningful for policy, public interest, and scientific discovery. It allows examination of large-scale shifts in lifeform abundance or distribution (for example, holoplankton being partially replaced by meroplankton), providing clues to how the marine environment is changing. The lifeform method enables datasets with different plankton sampling and taxonomic analysis methodologies to be used together to provide insights into the response to multiple stressors and robust policy evidence for decision making. Lifeform time series generated with the Plankton Lifeform Extraction Tool currently inform plankton and food web indicators for the UK's Marine Strategy, the EU's Marine Strategy Framework Directive, and for the Convention for the Protection of the Marine Environment of the North-East Atlantic (OSPAR) biodiversity assessments. The Plankton Lifeform Extraction Tool currently integrates 155 000 samples, containing over 44 million plankton records, from nine different plankton datasets within UK and European seas, collected between 1924 and 2017. Additional datasets can be added, and time series can be updated. The Plankton Lifeform Extraction Tool is hosted by The Archive for Marine Species and Habitats Data (DASSH) at https://www.dassh.ac.uk/lifeforms/ (last access: 22 November 2021, Ostle et al., 2021). The lifeform outputs are linked to specific, DOI-ed, versions of the Plankton Lifeform Traits Master List and each underlying dataset.Funding that supports this work and the data collected has come from the European Commission, European Union (EU) grant no. 11.0661/2015/712630/SUB/ENVC.2 OSPAR; UK Natural Environment Research Council (grant nos. NE/R002738/1 and NE/M007855/1); EMFF, Climate Linked Atlantic Sector Science (grant no. NE/R015953/1), Department for Environment, Food and Rural Affairs, UK Government (grant nos. ME-5308 and ME-414135), NSF USA OCE-1657887, DFO CA F5955150026/001/HAL, Natural Environment Research Council UK (grant no. NC-R8/H12/100); Horizon 2020 (MISSION ATLANTIC (grant no. 862428)); iCPR (grant no. SBFF-2019-36526), IMR Norway; DTU Aqua Denmark; and the French Ministry of Environment, Energy, and the Sea (MEEM). Recent funding for the development of PLET and the Pelagic Habitats Indicator has been provided by HBDSEG/Defra and MMO/EMFF. The MSS Scottish Coastal Observatory data and analyses are funded and maintained by the Scottish Government Schedules of Service (grant nos. ST05a and ST02H), MSS Stonehaven Samplers, North Atlantic Fisheries College, Shetland, Orkney Islands Harbour Council, and Isle Ewe Shellfish

BETTER KNOWLEDGE OF C, N, P ELEMENTS AND STOICHIOMETRY THROUGH THE SECONDARY PRODUCERS CALANOID COPEPODS IN ARCTIC AREAS

participantGeochemical fluxes have received particular attention in marine ecosystems in the context of climate changes and potential CO2 sequestration by the oceans. In addition, areas where changes are expected to be the most important and the fastest are the polar ones and especially the Arctic Ocean. It is thus particularly important to better understand the role played by marine biological pump in regulating the essential elements, which are carbon, nitrogen but also phosphorous, in Arctic seas. Most of the regulation through the biological pump is realised by primary and secondary producers. In the arctic, few data are available on C, N and P elements and ratios of secondary producers. Those ratios can change according to several parameters including species, development stage, feeding mode, etc... Secondary producers are represented by zooplankton, of which 90% are copepods. One result of their feeding activities is the creation of faecal pellets, which can sink out of the euphotic zone and contribute to chemical fluxes. Faecal pellets produced by copepods in the first 50m depth are equivalent to 20% of the particulate carbon flux and 12% of the particulate nitrogen flux in the Arctic seas. Moreover copepods are known to ingest on average 45% of the primary production in Arctic water. It stress the point for an understanding of how stochiometric changes in C, N and P in food sources (primary producers) influence the contents and ratios of these elements in faecal pellets for future predictions of potential changes of the biochemical fluxes

Light-Switchable Nanoparticles Based on Amphiphilic Diblock, Triblock and Heterograft Polyoxazoline

International audiencePhoto-active nanoparticles (NPD, NPT, NPH) were elaborated in water from amphiphilic diblock (D), triblock (T) and heterograft (H) copolymers based on a chromatic unit, coumarin, linked to an alkyl chain and a hydrophilic polyoxazoline chain. Under UV-exposure, for graft copolymers, the coumarin moieties crosslink the nanoparticle core (NPHx) while a simple dimerization chain by chain happens with linear diblock and triblock copolymers (NPDx and NPT). The self-assembly of these copolymers was examined as well as the UV-activity and UV-reversibility of the corresponding NPs by UV spectroscopy. Their stability under light exposure and temperature was also monitored by dynamic light scattering (DLS). Finally, the loading of a lipophilic fluorescent probe (Nile Red) into the NP core was evaluated by fluorescence emission. All these data illustrate the tunable size, UV-activity, stability and loading efficiency of the NPs by the starting macromolecular architecture of the amphiphilic copolymers. Triblock copolymers seem to be a promising tool for switchable NPs characterized by two opposite states: NPs with and without photo-dimerized core alternatively

Proposition of indicators of anthropogenic pressure in the Bay of Toulon (Mediterranean Sea) based on zooplankton time-series

International audienceZooplankton present characteristics of high interest in the frame of investigation for organisms sensitive to environmental changes and/or anthropogenic pressures. Such indicators are particularly needed in the present context of European legislation (Marine Strategy Framework Directive). However, zooplankton have not been given the interest they should have in regards to these issues. The aim of the present study is to provide an attempt of proposition of indicators of good environmental status and associated thresholds based on zooplankton data. Zooplankton time-series (2002–2013) from the Toulon Bay in the Mediterranean was used. This time-series presents the great characteristics that the sampling has be done jointly in two areas of the Bay of Toulon known to differ in term of anthropogenic pressures. The study focus on the copepod assemblage and different potential indicators are tested: ratio of copepod families on total copepod and diversity index (Piélou's evenness). The indicators relevance was evaluated per season by looking at the importance of the overlapping region between density's distributions for each indicator in both bays. This methodology well-recognized is commonly used, particularly in the medical sector, for a long time. The results show that the Oithonidae relative abundance and the Piélou's evenness index are the best indicators of anthropogenic pollution for this case study. Thresholds related to the selected indicators are also proposed in order to characterize the degree of anthropogenic pressure for the Toulon Bay and to provide a first evaluation for potential environmental management. Applicability of the selected indicators and future development needed are also discussed. This study is a first step in the investigation for operational zooplankton indicators and should open the way for additional studies in coastal anthropized area such as the Mediterranean coast where it is more urgently needed.

Copepods (Crustacea: Copepoda) in the Belgian part of the North Sea : trends, dynamics and anomalies

Copepods are a dominant component of mesozooplankton communities and are unambiguously important in marine food webs. Climate change and rising sea surface temperatures are likely to induce biogeographical range shifts and phenological changes for all zooplankton species, which include copepods. Consequently, consistent time-series are fundamental to monitor the status of plankton communities and predict future changes that can greatly affect the whole food-chain. Here, a recent time series (2014-2020) of image-based copepod abundance data from the Belgian Part of the North Sea has been explored and compared with previously collected (2009-2010) microscopy-based datasets for the same study area. The time series revealed distinct discrepancies in copepod phenology, abundances and total biomass between nearshore and offshore regions. The nearshore area was characterised by an altered copepod dynamics through time, with the occurrence of a single annual spring peak in both abundance and total biomass, and no autumn peak usually described and present in that area. Conversely, the autumn peak was clearly observed at the offshore stations, together with a distinct additional early spring peak in comparison to the nearshore and midshore regions which has not been documented before. Remarkable anomalies were detected within the time-serie of copepod for both abundance and biomass, notably in autumn of 2018 and in a lesser extend in 2014 and 2019, with values dropping to near-zero for the nearshore stations. The various heat waves during the summer periods of these years are considered potential causes for these copepod decreases, since they corresponded to the physiological thermal limit of many copepods species known to be present in the area. These heat waves events could have also favoured predators of copepods such as jellyfishes as well as enhancing the occurrence of d harmful algal blooms. Both anomalies in 2018 and 2019 actually coincided with important phytoplankton autumn blooms. The results from this copepod time-series analysis illustrates the changes affecting this essential marine trophic level and highlights the value and relevance of copepod long-term data series in the context of climate change and ecosystem management

No more reason for ignoring gelatinous zooplankton in ecosystem assessment and marine management: Concrete cost-effective methodology during routine fishery trawl surveys

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High frequency mesozooplankton monitoring: Can imaging systems and automated sample analysis help us describe and interpret changes in zooplankton community composition and size structure — An example from a coastal site

International audienceThe present work aims to show that high throughput imaging systems can be useful to estimatemesozooplankton community size and taxonomic descriptors that can be the base for consistent largescale monitoring of plankton communities. Such monitoring is required by the European Marine StrategyFramework Directive (MSFD) in order to ensure the Good Environmental Status (GES) of Europeancoastal and offshore marine ecosystems. Time and cost-effective, automatic, techniques are of highinterest in this context. An imaging-based protocol has been applied to a high frequency time series(every second day between April 2003 to April 2004 on average) of zooplankton obtained in a coastalsite of the NW Mediterranean Sea, Villefranche Bay. One hundred eighty four mesozooplankton netcollected samples were analysed with a Zooscan and an associated semi-automatic classificationtechnique. The constitution of a learning set designed to maximize copepod identification with morethan 10,000 objects enabled the automatic sorting of copepods with an accuracy of 91% (true positives)and a contamination of 14% (false positives). Twenty seven samples were then chosen from the totalcopepod time series for detailed visual sorting of copepods after automatic identification. This methodenabled the description of the dynamics of two well-known copepod species, Centropages typicus andTemora stylifera, and 7 other taxonomically broader copepod groups, in terms of size, biovolume andabundance–size distributions (size spectra). Also, total copepod size spectra underwent significantchanges during the sampling period. These changes could be partially related to changes in thecopepod assemblage taxonomic composition and size distributions. This study shows that the use ofhigh throughput imaging systems is of great interest to extract relevant coarse (i.e. total abundance,size structure) and detailed (i.e. selected species dynamics) descriptors of zooplankton dynamics.Innovative zooplankton analyses are therefore proposed and open the way for further development ofzooplankton community indicators of change

Regionalisation of the Mediterranean basin, a MERMEX synthesis

International audienceRegionalisation aims at delimiting provinces within which physical conditions, chemical properties, andbiological communities are reasonably homogeneous. This article proposes a synthesis of the manyrecent regionalisations of the open-sea regions of the Mediterranean Sea. The nine studies consideredhere defined regions based on different, and sometimes complementary, criteria: dynamics of surfacechlorophyll concentration, ocean currents, three-dimensional hydrological and biogeochemicalproperties, or the distribution of organisms. Although they identified different numbers and patterns ofhomogeneous regions, their compilation in the epipelagic zone identifies nine consensus frontiers,eleven consensus regions with relatively homogeneous conditions, and four heterogeneous regions withhighly dynamical conditions. The consensus frontiers and regions are in agreement with well-knownhydrodynamical features of the Mediterranean Sea, which constrain the distribution of hydrological andecological variables. The heterogeneous regions are rather defined by intense mesoscale activity. Thesynthesis proposed here could constitute a reference step for management actions and spatialplanning, such as the application of the European Marine Strategy Framework Directive, and for futurebiogeochemical and ecological studies in the Mediterranean Sea