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Biological oceanography

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  • The network was initiated by IFREMER from 1993 to 2009 (under the acronym REMORA) to study the rearing performance of the Pacific oyster Crassostrea gigas at a national scale. To do so, the network monitored annually the mortality and growth of standardized batches of 18-month-old oysters. Starting in 1995, the monitoring of the rearing performance of 6-month-old oyster spat was integrated into this network. These sentinel batches were distributed simultaneously each year on 43 sites and were monitored quarterly. These sites were distributed over the main French oyster farming areas and allowed a national coverage of the multiannual evolution of oyster farming performances. Most of the sites were located on the foreshore at comparable levels of immersion. Field studies were carried out by the "Laboratoires Environnement Ressources" (LER) for the sites included in their geographical area of investigation. Following the increase in spat mortality in 2008, the network evolved in 2009 (under the acronym RESCO). From this date, the network selected 13 sites among the 43 sites previously monitored in order to increase the frequency of visits (twice a month) and the number of sentinel batches. More precisely, sentinel batches of oysters corresponding to different origins (wild or hatchery, diploid or triploid) and to two rearing age classes (spat or 18-month-old adults) were selected. The monitoring of environmental variables (temperature, salinity) associated with the 13 sites was also implemented. The actions of the network have thus contributed to disentangle the biotic and abiotic parameters involved in mortality phenomena, taking into account the different compartments (environment / host / infectious agents) likely to interact with the evolution of oyster rearing performance. Finally, since 2015, the network has merged the RESCO and VELYGER networks to adopt the acronym ECOSCOPA. The general objective of this current network is to analyze the causes of spatio-temporal variability of the main life traits (Larval stage - Recruitment - Reproduction - Growth - Survival - Cytogenetic abnormalities) of the cupped oyster in France and to follow their evolution on the long term in the context of climate change. To do this, the network proposes a regular spatio-temporal monitoring of the major proxies of the life cycle of the oyster, organized in three major thematic groups: (1) proxies related to growth, physiological tolerance and survival of experimental sentinel populations over 3 age classes: (2) proxies related to reproduction, larval phase and recruitment of the species throughout its natural range in France, and: (3) proxies related to environmental parameters essential to the species (weather conditions, temperature, salinity, pH, turbidity, chlorophyll a and phytoplankton) at daily or sub-hourly frequencies. Working in a geographical network associating several laboratories, ECOSCOPA provide these monitoring within 8 sites selected among the previous ones to ensure the continuity of the data acquisition. Today, these 8 sites are considered as ecosystems of common interest, contrasted, namely : - The Thau lagoon - The Arcachon basin - The Marennes Oléron basin - The Bourgneuf Bay - The bay of Vilaine - The bay of Brest - The bay of Mont Saint Michel - The bay of Veys The ECOSCOPA network is therefore one of the relevant monitoring tools on a national scale, allowing to objectively measure through different proxies the general state of health of cultivated and wild oyster populations, and this for the different sensitive phases of their life cycle. This network aims at allowing a better evaluation, on the long term, of the biological risks incurred by the sector but also by the ecosystems, in particular under the increasing constraint of climatic and anthropic changes. Figure : Sites monitored by the ECOSCOPA network  

  • French Zostera Marina et Zostera Noltei abundance data are collected during monitoring surveys on the English Channel / Bay of Biscay coasts. Protocols are impletmented in the Water Framework Directive. Data are transmitted in a Seadatanet format (CDI + ODV) to EMODnet Biology european database. 35 ODV files have been generated from period 01/01/2004 to 31/12/2021 for Z. Marina and from 01/01/2011 to 31/12/2021 for Z. Noltei.  

  • 1) Demographic traits These data are published data of age-specific mortality rates, age-specific lengths or weights, length and age at maturity, fecundity-length relationships, and egg size for 84 populations from 49 species of primarily commercial teleost fishes. The populations included are those for which all the life history traits under study have been estimated over a period shorter than 10 years. Traits were estimated from within the ten year window or averaged across it when data were available. Only studies in which reference population, sample size, techniques used for ageing fish and counting eggs, and models used for estimating mortality were reported are included. When only a size or age range was available, the midpoint between the extreme values was used. Raw data were converted into seven demographic traits: - Time-to-5%-survival (T.05): the time elapsed from sexual maturity until 95% of a cohort is dead. T.05 fwas estimated from an exponential mortality model, based on total mortality coefficients estimated by Virtual Population Analysis (age-structured model) in most cases or cohort analysis or catch curves. - Length-at-5%-survival (L.05). In fishes, adult size is difficult to measure because of their indeterminate growth. Adult size reported here is length at time-to-5%-survival. - Age at sexual maturity (Tm): median age at maturity was estimated directly from the data or by fitting a logistic curve to age-specific proportion mature data. When only an age range was available, the midpoint between minimum and maximum is reported. - Length at sexual maturity (Lm): median length at maturity was estimated as age at maturity. - Slope of the fecundity-length relationship (Fb): fish fecundity, defined as the number of eggs present in the ovaries immediately before spawning, is known to increase intraspecifically with the size of females. This increase is usually described by a power-law F = aLb. The exponent of this relationship, b (slope of the log-log fecundity-length regression), accounts for the increase in fecundity with size. - Fecundity at maturity (Fm): fecundity in the year of maturity was estimated from length at maturity, the fecundity-length relationship and the number of spawning bouts per year for batch spawners. - Egg volume (Egg): When information on egg size was unavailable in specific papers, values were borrowed from other studies, using the following criteria in the descending order: from the same period, the same population, the same species. In five species of Perciformes no estimate was available for any population, thus egg volume was estimated from other species of the same family. 2) Fishing pressure Three types of environments with low, moderate and high fishing pressure were defined. - To scale the pressure exerted by fishing to the natural population turn-over, it was expressed as the ratio of fishing mortality to natural mortality rates (F/M). Data were gathered from the literature together with demographic traits. Authors use the following methods to estimate natural mortality rates: intercept of a regression of total mortality on fishing effort, linear relationship known between estimates of natural mortality, growth parameters and the temperature, or multispecies models. Fishing mortality rates were estimated from Virtual Population Analysis or cohort analysis, or as the difference between total and natural mortality. Three levels of fishing pressure were defined: low fishing pressure (fishing mortality lower than natural mortality, F/M < 1), intermediate (1 <= F/M < 2) and high (F/M >= 2).

  • French intertidal and subtidal Macroalgae taxa data are collected during monitoring surveys on the English Channel / Bay of Biscay coasts.  Protocols are implemented in the Water Framework Directive. Data are transmitted in a Seadatanet format (CDI + ODV) to EMODnet Biology european database. 131 ODV files have been generated from period 01/01/2006 to 31/12/2021.

  • The data-set is composed of three tables, Environmental variables, Phytoplankton ( in log+1 abundance)  and the coordinates of the station used in the study. They are the processed data.

  • Worldwide, shellfish aquaculture and fisheries in coastal ecosystems represent crucial activities for human feeding. But these biological productions are under the pressure of climate variability and global change. Anticipating the biological processes affected by climate hazards remains a vital objective for species conservation strategies and human activities that rely on. Within marine species, filter feeders like oysters are real key species in coastal ecosystems due to their economic and societal value (fishing and aquaculture) but also due to their ecological importance. Indeed oysters populations in good health play the role of ecosystem engineers that can give many ecosystem services at several scales: building reef habitats that contribute to biodiversity, benthic-pelagic coupling and phytoplankton bloom control through water filtration, living shorelines against coastal erosion… The Pacific oyster, Crassostrea gigas (Thunberg, 1793), which is currently widespread worldwide, was introduced into the Atlantic European coasts at the end of the 19th century for shellfish culture purposes and becomes the main marine species farmed in France (around 100 000 tons) despite severe mortalities crisis. But in the same time and because of warming, natural oysters beds has spread significantly along the French coast and are supposed to have reach approximately 500 000 tons. In that context, Pacific oyster populations (natural and cultivated) in France are the subjects of many scientific projects. Among them, a specific long-term biological monitoring focuses on the reproduction of these populations at a national scale: the VELYGER national program. With more than 8 years of weekly data at many stations in France, this field-monitoring program offers a valuable dataset for studying processes underpinning reproduction cycle of this key-species in relation to environmental parameters, water quality and climate change.   Database content: Larval concentration (number of individuals per 1.5 m3) monitored, since 2008, at several stations in six bays of the French coast (from south to north): Thau Lagoon and bays of Arcachon, Marennes Oléron, Bourgneuf, Vilaine and Brest (see map below).   Methods used to monitor larval concentration: An important volume of seawater (1.5 m3) is pumped twice a week throughout the spawning season (june-september), at one meter below the surface at high tide (+/- 2h) in several sites within each VELYGER ecosystem. Water is filtered trough plankton net fitted with 40 µm mesh. After a proper rinsing of the net, the retained material is transferred into a polyethylene bottle (1 liter) and fixed with alcohol. At laboratory, sample is then gently filtered and rinse again and transferred into eprouvette. Two sub-samples of 1 mL are then taken using a pipette and examined on a graticule slide for microscope. The microscopic examination is made with a conventional binocular optical microscope with micrometer stage at a magnification of 10 X (or above). During the counting, a special care is necessary as larvae of other bivalves are also collected and confusion is possible. Larvae of C. gigas are also classified into four stage of development: - Stage I = D-shaped straight hinge larvae (shell length <105 µm) - Stage II = Early umbo evolved larvae (shell length between 105 and 150 µm) - Stage III = Medium umbo larvae (shell length between 150 and 235 µm) - Stage IV*= Large umbo eyed pediveliger larvae (shell length > 235 µm) * Larvae that are very closed to settle are sometimes identified into a separated 5th stage, but generally this stage is included in stage IV.   Illustrations: Location of the different Velyger sites along the French coast. From south to north: Thau Lagoon and bays of Arcachon, Marennes Oléron, Bourgneuf, Vilaine and Brest.   Legend: Pacific Oyster Larvae (left side) and Natural oyster bed (right side). Photos : © S. Pouvreau/Ifremer

  • The BenthOBS dataset includes long-term time series on marine benthic macrofauna, since 1967, along the whole French metropolitan coast. It includes 20 sampling location. BenthOBS aims to establish a national network for the observation of macrozoobenthos. In a context of global change, It is essential to have time series capable of highlighting and understanding ongoing changes in the specific diversity within communities and their consequences on the functioning of marine ecosystems. The BenthOBS network provides the scientific community and stackers with validated data on the following parameters: specific abundance, sediment size composition, sediment organic matter, sediment C content, sediment N content.

  • The data come from organisms and pictures collected during the MEDITS annual bottom trawl surveys conducted between 2011 and 2013 (Bertrand et al. 2002). MEDITS surveys cover the continental shelf (10 m to 200 m depth) and the upper part of the continental slope (200 m to 800 m) on the Mediterranean. A total of 1511 individuals from 85 fish species were collected from seven Mediterranean areas (South Adriatic Sea, Sardinia, Gulf of Lions, around Cyprus, Mallorca, Tyrrhenian Sea, and North West Ionian Sea). A set of 14 morphological traits related to the habitat and the diet of the species were measured in the field and on pictures using the ImageJ software (version 1.47, http://imagej.nih.gov/ij/) (see Granger et al. 2015 and Brind'Amour et al. submitted for details) (Figure 1). Replicats of measures vary between 1 (e.g. Scorpaena loppei) to 53 (e.g. Serranus hepatus) according to fish species. Twelve of the chosen traits consist in continuous biological characteristics measured on each individual (measured in cm). The two remaining traits are categorical and determined at the species level.

  • Numerous reef-forming species have declined dramatically in the last century, many of which have been insufficiently documented due to anecdotal or hard-to-access information. One of them, the honeycomb worm Sabellaria alveolata (L.) is a tube-building polychaete that can form large reefs, providing important ecosystem services such as coastal protection and habitat provision. It ranges from Scotland to Morocco, yet little is known about its distribution outside of the United Kingdom, where it is protected and where there is a strong heritage of natural history and sustained observations. As a result, online marine biodiversity information systems currently contain haphazardly distributed records of S. alveolata. One of the objectives of the REEHAB project (http://www.honeycombworms.org) was to combine historical records with contemporary data to document changes in the distribution and abundance of S. alveolata. Here we publish the result of the curation of 331 sources, gathered from literature, targeted surveys, local conservation reports, museum specimens, personal communications by authors and by their research teams, national biodiversity information systems (i.e. the UK National Biodiversity Network (NBN), https://nbn.org.uk/) and validated citizen science observations (i.e. https://www.inaturalist.org/). 80% of these records were not previously referenced in any online information system. Additionally, historic field notebooks from Edouard Fischer-Piette and Gustave Gilson were scanned for S. alveolata information and manually entered.  Each of the 21512 S. alveolata records were checked for spatial and taxonomic accuracy, particularly in the English Channel and the North Sea where incorrectly identified observations of intertidal Sabellaria spinulosa were recorded. A further 54 observations are recorded as ‘Sabellaria spp.’ as the available information did not allow for an identification to species level. Many sources reported abundances based on the semi-quantitative SACFOR scale whilst others simply noted its presence, and others still verified both its absence and presence. The result is a curated and comprehensive dataset spanning over two centuries on the past and present global distribution and abundance of S. alveolata. Sabellaria alveolata records projected onto a 50km grid. When SACFOR scale abundance scores were given to occurrence records, the highest abundance value per grid cell was retained.

  • French benthic invertebrates composition and abundance taxa data are collected during monitoring surveys on the English Channel / Bay of Biscay coasts and Mediterranean coast (Quadrige program code : REBENT_FAU, RSL_FAU). Protocols are implemented in the Water Framework Directive.  Data are transmitted in a Seadatanet format (CDI + ODV) to EMODnet Biology european database. 498 ODV files have been generated from period 01/01/2003 to 31/12/2021.