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See detailThe challenge of using phytoplankton composition for Mediterranean ecosystem health assessment
Goffart, Anne ULiege; Coudray, Sylvain

Conference (2020, October)

In recent times, a wide variety of marine ecosystem health indicators has been developed. The first aim of these indicators is to distinguish between healthy from degraded ecosystems with sufficient ... [more ▼]

In recent times, a wide variety of marine ecosystem health indicators has been developed. The first aim of these indicators is to distinguish between healthy from degraded ecosystems with sufficient precision to identify measures or actions that need to be taken in order to maintain or retrieve good environmental status. In Mediterranean coastal waters, only a few phytoplankton composition indicators have been developed in compliance with the EU environmental legislation. This can be in part attributed to the difficulties to describe the causal chain from driving forces (e.g. human activities) through pressures (e.g. nutrient discharges) to impacts on phytoplankton composition. In this work, we present a new phytoplankton composition index (PPCI, Pressure Pigments Composition Index), which uses phytopigments for identifying and quantifying phytoplankton functional groups. PPCI is a multimetric index that integrates group-specific chemotaxonomic indicators (carotenoids) responding to pressures. The index was developed in the Corsican coastal waters (NW Mediterranean) where well known reference conditions deliver a baseline against which other phytoplankton variables can be anchored. Being very sensitive to human pressures, PPCI detects the effects of anthropogenic disturbances on both quantitative and qualitative phytoplankton communities structure over different spatial and temporal scales. PPCI is transferable over a broad range of coastal zones, and is therefore a useful tool for assessing the marine ecosystem health. Synergies between in situ pigment data and satellite-derived phytoplankton functional types, obtained using a regionalized version of PHYSAT (downscaling), are presented. In the framework of the MSFD obligations, the next objective will be to identify patterns of homogeneous phytoplankton composition in the French Mediterranean subregion. [less ▲]

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See detailRapport intermédiaire du projet « Indices phytoplanctoniques pour les eaux côtières de La Réunion »
Goffart, Anne ULiege

Report (2020)

Dans la 1ère phase du projet « Indices phytoplanctoniques pour les eaux côtières de La Réunion », la dynamique saisonnière des communautés phytoplanctoniques de la zone de référence Ermitage Large a été ... [more ▼]

Dans la 1ère phase du projet « Indices phytoplanctoniques pour les eaux côtières de La Réunion », la dynamique saisonnière des communautés phytoplanctoniques de la zone de référence Ermitage Large a été étudiée de manière approfondie. Les variations temporelles de la biomasse et de la composition du phytoplancton sont décrites et mises en relation avec les facteurs environnementaux. Les résultats fournissent la ligne de base sur laquelle s’appuieront les observations réalisées dans les autres sites. Les mesures in situ et celles issues de l’imagerie satellitaire et/ou de la modélisation sont comparées. [less ▲]

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See detailSatellite and In Situ Monitoring of Chl-a, Turbidity, and Total Suspended Matter in CoastalWaters: Experience of the Year 2017 along the French Coasts
Gohin, Francis; Bryère, Philippe; Lefebvre, Alain et al

in Journal of Marine Science and Engineering (2020), 8

Satellite retrievals were derived from MODIS/AQUA, VIIRS/NPP and OLCI-A/Sentinel-3 spectral reflectance. In situ data were obtained from the coastal phytoplankton networks SOMLIT (CNRS), REPHY (Ifremer ... [more ▼]

Satellite retrievals were derived from MODIS/AQUA, VIIRS/NPP and OLCI-A/Sentinel-3 spectral reflectance. In situ data were obtained from the coastal phytoplankton networks SOMLIT (CNRS), REPHY (Ifremer) and associated networks. Satellite and in situ retrievals of the year 2017 were compared to the historical seasonal cycles and percentiles, 10 and 90, observed in situ. Regarding the sampling frequency in the Mediterranean Sea, a weekly in situ sampling allowed all major peaks in Chl-a caught from space to be recorded at sea, and, conversely, all in situ peaks were observed from space in a frequently cloud-free atmosphere. In waters of the Eastern English Channel, lower levels of Chl-a were observed, both in situ and from space, compared to the historical averages. However, despite a good overall agreement for low to moderate biomass, the satellite method, based on blue and green wavelengths, tends to provide elevated and variable Chl-a in a high biomass environment. Satellite-derived TSM and Turbidity were quite consistent with in situ measurements. Moreover, satellite retrievals of the water clarity parameters often showed a lower range of variability than their in situ counterparts did, being less scattered above and under the seasonal curves of percentiles 10 and 90. [less ▲]

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See detailPhytoplankton biomass and composition as useful tools for assessing the impact of early anthropogenic pressure in the Western Mediterranean
Goffart, Anne ULiege

Conference (2020, February 14)

In accordance with Article 1 (3) of Directive 2008/56/EC (Marine Strategy Framework Directive, MSFD), the collective pressure of human activities needs to be kept within levels compatible with the ... [more ▼]

In accordance with Article 1 (3) of Directive 2008/56/EC (Marine Strategy Framework Directive, MSFD), the collective pressure of human activities needs to be kept within levels compatible with the achievement of Good Environmental Status (GES), ensuring that the capacity of marine ecosystems to respond to human-induced changes is not compromised. Focusing on long-term time series of environmental and phytoplankton data acquired in Corsican coastal waters, we show how phytoplankton biomass and composition can be used to assess the impact of climate variation and early eutrophication processes. We identify some gaps in information required to implement the MSFD at a regional scale and we propose key directions to overcome them. [less ▲]

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See detailRelationships between environmental conditions and phytoplankton in the Mellah lagoon (south western Mediterranean, Algeria), with an emphasis on HAB species
Draredja, Mohamed Anis; Frihi, Hocine; Boualleg, Chahinez et al

in Hess, Philipp (Ed.) Harmful Algae 2018 – from ecosystems to socioecosystems. Proceedings of the 18th International Conference on Harmful Algae. International Society for the Study of Harmful Algae, 2020. 214 pages. (2020)

A bi-weekly monitoring of environmental parameters and microphytoplankton assemblages was conducted in the well-preserved Mellah lagoon ecosystem (south western Mediterranean). Sampling was performed at 3 ... [more ▼]

A bi-weekly monitoring of environmental parameters and microphytoplankton assemblages was conducted in the well-preserved Mellah lagoon ecosystem (south western Mediterranean). Sampling was performed at 3 stations in 2016. We aimed to study the evolution of the phytoplankton community with a focus on harmful species in relation with the environmental characteristics. Phytoplankton of Mellah Lagoon was characterized by a mixture of marine, brackish-water and freshwater taxa. In all of the stations, 227 species of phytoplankton were identified (160 diatoms and 53 dinoflagellates). The overall mean phytoplankton abundance was higher at station A (2.24·105 cells l-1, early September) and B (2.98·105 cells l-1, early October) near of marine inputs, compared to station C (1.73·105 cells l-1, early June) located in the south of the lagoon. Diatoms dominated in spring and dinoflagellates developed in summer and early autumn in the Mellah. The dynamic of the phytoplankton in Mellah was influenced by temperature and salinity. For the first time, a number of potentially toxic species have been identified, including 2 diatom species: Pseudo-nitzschia delicatissima-group (max.: 2.52·103 cells l-1), Pseudo-nitzschia seriata-group (max.: 700 cells l-1) and 6 dinoflagellate species: Alexandrium minutum (max.: 1.42·103 cells l-1), Alexandrium tamarense/catenella (max.: 1.35·103 cells l-1), Dinophysis acuminata (max.: 180 cells l-1), Dinophysis sacculus (max.: 120 cells l-1), Akashiwo sanguinea (max.: 7.20·103 cells l-1), Prorocentrum lima (max.: 110 cells l-1). Even the abundances of the HABs species were relatively low in Mellah lagoon, they could potentially form blooms in the coming decades at the favor of warming and trophic status changes observed in Mediterranean marine systems. Monitoring program of HABs species must be established to gain more insight in the development of potentially toxic species and the toxins produced [less ▲]

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See detailDiagnostic phytoplankton pigments as indicators for measuring restoration success in coastal waters
Goffart, Anne ULiege

Conference (2019, September)

The coastal zones are where more than half the world’s human population lives and this percentage continues to increase. Given the increasing pressure on coastal ecosystems, accelerated by human activity ... [more ▼]

The coastal zones are where more than half the world’s human population lives and this percentage continues to increase. Given the increasing pressure on coastal ecosystems, accelerated by human activity, restoration is needed where ecosystem services have declined, together with conservation of healthy sites. As key primary producers, phytoplankton are the first link in the conversion of nutrients and sunlight into biomass, and they reflect immediate effects of changes in the input of nutrients in coastal ecosystems. They are therefore excellent indicators of water quality, marine ecosystem change and effectiveness of restoration efforts. In this work, we use phytopigments that are diagnostic for phytoplankton functional groups to develop a new phytoplankton composition index (PPCI). PPCI is a multimetric index that integrates group-specific chemotaxonomic indicators (carotenoids) responding to pressures. The index was initially developed in the Mediterranean coastal waters where well known reference conditions deliver a baseline against which other phytoplankton variables can be anchored. Being very sensitive to human pressures, PPCI detects the effects of anthropogenic disturbances on both quantitative and qualitative phytoplankton communities structure over different spatial and temporal scales. PPCI is therefore a useful tool for assessing long-term effects of restoration measures and benefits of nutrient reduction strategies. PPCI is transferable over a broad range of coastal zones (e.g. French Atlantic coastal waters). PPCI is easily implemented which enables it to be used by environment managers who are not experts in phytoplankton taxonomy. An example of phytoplankton recovery after aquaculture closure is presented. [less ▲]

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See detailSeasonal variations of phytoplankton community in relation to environmental factors in a protected meso-oligotrophic southern Mediterranean marine ecosystem (Mellah lagoon, Algeria) with an emphasis of HAB species
Draredja, Mohamed Anis; Frihi, Hocine; Chahinaise, Boualleg et al

in Environmental Monitoring and Assessment (2019), 191(603),

The spatial and temporal variation of phytoplankton communities including HAB species in relation to the environmental characteristics was investigated in the protected meso-oligotrophic Mellah lagoon ... [more ▼]

The spatial and temporal variation of phytoplankton communities including HAB species in relation to the environmental characteristics was investigated in the protected meso-oligotrophic Mellah lagoon located in the South Western Mediterranean. During 2016, a biweekly monitoring of phytoplankton assemblages and the main abiotic factors were realized at three representative stations. Taxonomic composition, abundance, and diversity index were determined. In total, 227 phytoplankton species (160 diatoms and 53 dinoflagellates) were inventoried. There was a clear dominance of diatoms (62.9%) compared with dinoflagellates (36.8%). Diatoms dominated in spring and dinoflagellates developed in summer and early autumn in Mellah showing a marked seasonal trend. Data showed that the dynamic of the phytoplankton taxa evolving in the lagoon was mainly driven by temperature and salinity. For the first time, a number of potentially toxic species have been identified, including 2 diatoms (Pseudo-nitzschia group delicatissima, Pseudo-nitzschia group seriata) and 5 dinoflagellates (Alexandrium minutum, Alexandrium tamarense/catenella, Dinophysis acuminata, Dinophysis sacculus, Prorocentrum lima). These harmful species could threat the functioning of the Mellah lagoon and human health and require the establishment of a monitoring network. Finally, our study suggests that the observed decrease of the phytoplankton diversity between 2001 and 2016 could result from the reduction in water exchanges between the lagoon and the adjacent coast following the gradual clogging of the channel. [less ▲]

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See detailResponse of phytoplankton to climate-driven changes in a Mediterranean coastal area : results from 4 decades of observations (1979 - 2018)
Goffart, Anne ULiege; Lejeune, Pierre; Gohin, Francis et al

Conference (2019, June)

In the Mediterranean coastal areas, most of the long-term studies of plankton dynamics concern highly urbanized areas, where long-term variability reflects the combined effects of climate and ... [more ▼]

In the Mediterranean coastal areas, most of the long-term studies of plankton dynamics concern highly urbanized areas, where long-term variability reflects the combined effects of climate and anthropogenic forcing. Here we use a unique long-term time series (1979-2018) performed at a fixed station in a well-preserved NW Mediterranean coastal area (Bay of Calvi, Corsica) to understand how climate variation drives changes in phytoplankton biomass and composition. From a high-frequency data set, which combines environmental parameters and HPLC pigments, we highlight the importance of winter conditions to determine the state of phytoplankton community structure in surface waters. We show high variability in total biomass and phytoplankton composition resulting from changes in winter intensity associated with both interannual and decadal fluctuations. We identify three distinct periods. The 1980s (1979-1988), the 1990s (1989-1998) and the 2000s (1999-2018) are characterized by moderate, mild and highly variable winters, respectively. The last years (2014-2018) show very mild winters and increasing winter water temperature, associated with decreasing trends in rainfall, total phytoplankton biomass and diatom abundance. Moderate and severe winters are favorable for diatoms, which do not develop during mild winters, when nutrient replenishment is not sufficient to support their growth. In situ measurements and satellite-derived temperature and Tchl a in the Western Corsican Current are consistent with in situ data from the Bay of Calvi. This suggests that changes observed in the Bay of Calvi reflect phenomena occurring at a larger scale, and that our data set can contribute to predict changes of phytoplankton dynamics under different climatic scenarios. [less ▲]

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See detailEvaluation croisée de la composition phytoplanctonique des eaux côtières métropolitaines par les indices ICPP et ICBC
Goffart, Anne ULiege

Report (2019)

En Méditerranée et en Manche-Atlantique, les travaux sur l’utilisation de la signature pigmentaire du phytoplancton ont abouti à la mise au point des indices de composition ICPP Médit et ICBC, développés ... [more ▼]

En Méditerranée et en Manche-Atlantique, les travaux sur l’utilisation de la signature pigmentaire du phytoplancton ont abouti à la mise au point des indices de composition ICPP Médit et ICBC, développés respectivement par Anne Goffart et Luis Lampert. Dans le cadre de cette étude, les méthodologies développées en Méditerranée et en Manche-Atlantique ont été croisées. Elles ont été appliquées aux nouveaux jeux de données (nutriments et pigments) acquis en 2016 et 2017 dans les eaux côtières des trois façades métropolitaines. Les résultats obtenus montrent qu’il n’y a pas un indice de composition « universel » applicable partout, mais que les spécificités régionales doivent être prises en compte pour l’évaluation de la qualité de la composition phytoplanctonique. La méthodologie développée en Méditerranée a été transposée aux eaux côtières atlantiques en intégrant les caractéristiques des communautés phytoplanctoniques qui y sont présentes. L’indice ICPP Atlantique est un indice multimétrique qui intègre les cinq groupes phytoplanctoniques qui répondent le mieux aux pressions (diatomées, dinoflagellés, cryptophycées, prasinophycées, chlorophycées). Une très bonne corrélation (R2 = 0.98) est obtenue entre les EQRs issus de l’application de l’ICPP Atlantique et de l’ICBC. En Atlantique, l’évaluation croisée aboutit à un classement cohérent des sites échantillonnés, mais seul l’ICPP Atlantique répond aux proxys de pression. En Méditerranée, l’ICPP Médit et l’ICBC, exprimé en EQR, répondent aux pressions exercées par les nutriments. Les résultats de l’évaluation de la qualité de la composition phytoplanctonique par les deux indices sont fortement corrélés (R2 = 0.93). Cependant, dans 2 cas sur 15, l’application de l’ICPP Médit ou de l’ICBC induit des différences importantes dans le classement final des points, qui, sur base des grilles de qualité actuelles, sortent ou non du bon état écologique. Sur base de notre expertise en Méditerranée, le classement résultant de l’application de l’ICPP Médit nous parait mieux caractériser la réalité du terrain. En Manche, où les masses d’eau sont régulièrement soumises à des blooms de Phaeocystis, un seul pigment (l’alloxanthine) répond positivement aux proxys de pressions. Il en résulte que la méthodologie développée en Méditerranée n’est pas applicable. En Méditerranée comme en Atlantique, et au-delà de la caractérisation de la qualité de la composition phytoplanctonique, l’ICPP fournit des informations sur la saisonnalité des perturbations. En cela, il peut apporter des informations complémentaires utiles aux gestionnaires de l’environnement côtier. [less ▲]

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See detailConsolidation de l’indice de composition phytoplanctonique ICPP Médit pour les eaux côtières méditerranéennes
Goffart, Anne ULiege

Report (2019)

Lors d’un premier travail, nous avions élaboré l’indice de composition phytoplanctonique IC Médit 2014 à partir des données pigmentaires du phytoplancton des eaux côtières corses sur un jeu de données ... [more ▼]

Lors d’un premier travail, nous avions élaboré l’indice de composition phytoplanctonique IC Médit 2014 à partir des données pigmentaires du phytoplancton des eaux côtières corses sur un jeu de données restreint. Dans cette étude, nous avons fait évoluer l’indice IC Médit 2014 en complétant le premier jeu de données par des données acquises dans des sites côtiers méditerranéens soumis à des forces de pression d’intensité croissante. Le nouvel indice, ICPP Médit, est un indice multimétrique qui répond aux pressions et apporte des informations sur la saisonnalité des perturbations. Le protocole de calcul a été défini et la grille d’évaluation proposée. ICPP Médit a été conçu pour être robuste scientifiquement mais facile à mettre en œuvre par des acteurs ne disposant pas d’expertise spécifique en biodiversité et en écologie du phytoplancton. L’évaluation des incertitudes sur le classement des masses d’eau et/ou des sites échantillonnés et l’éventuel ajustement de la grille nécessitent l’acquisition de données complémentaires, idéalement sur un plan de gestion. Cependant, l’application croisée de l’ICPP Médit et de l’ICBC sur le jeu de données de Méditerranée montre une bonne cohérence des classements issus de l’application des deux méthodologies, ce qui conforte les choix posés dans l’élaboration de l’indice ICCP Médit. [less ▲]

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See detailElaboration d’une méthode de surveillance de la composition phytoplanctonique à grande échelle
Goffart, Anne ULiege

Report (2019)

Au cours de la dernière décennie, les mesures spectrales effectuées par les capteurs spatiaux de couleur de l’océan ont été corrélées à la présence des grands groupes phytoplanctoniques identifiés par ... [more ▼]

Au cours de la dernière décennie, les mesures spectrales effectuées par les capteurs spatiaux de couleur de l’océan ont été corrélées à la présence des grands groupes phytoplanctoniques identifiés par leur composition pigmentaire. La méthodologie, appelée PHYSAT, permet de détecter les grands groupes phytoplanctoniques depuis l’espace et d’élaborer des cartes de distribution à grande échelle (Alvain et al. 2008). Récemment, l’algorithme PHYSAT a été adapté à la Méditerranée dans son ensemble (PHYSAT-MED; Navarro et al. 2014, Navarro et al. 2017). La mise en commun des expertises de Sylvain Coudray (IFREMER, traitement des signaux satellitaire) et d’Anne Goffart (Université de Liège, dynamique du phytoplancton méditerranéen, données pigmentaires, chémotaxonomie) a permis d’adapter l’outil PHYSAT-MED à une échelle locale (downscaling), utile au suivi et à la caractérisation du phytoplancton des eaux côtières de la Méditerranée française. L’adaptation de l’outil PHYSAT-MED a conduit au développement du prototype OC5-PHYSAT. OC5-PHYSAT a été testé et validé sur un premier jeu de données pigmentaires acquis au cours d’une année de référence (2015) en milieu oligotrophe (Baie de Calvi, Corse). L’algorithme a permis de reproduire de manière très satisfaisante les variations hebdomadaires de la biomasse phytoplanctonique totale (Tchl a) et des groupes phytoplanctoniques dominants (prymnesiophycées, cyanobactéries, diatomées et autres eucaryotes), identifiés par leur signature pigmentaire. Au terme de cette étude, il est nécessaire de compléter le travail engagé en validant OC5-PHYSAT sur des jeux de données pluriannuels et dans des masses d’eau côtières caractérisées par des propriétés optiques contrastées (turbidité, matière en suspension non algale, …). Des cartes synthétiques de distribution des groupes phytoplanctoniques dominants pourront alors être fournies pour les masses d’eau DCE et les zones DCSMM. [less ▲]

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See detailRelationships between environmental conditions and phytoplankton in the Mellah lagoon (South Western Mediterranean, Algeria), with an emphasis on HABs species
Draredja, Mohamed Anis; Frihi, Hocine; Boualleg, Chahinez et al

Poster (2018, October)

For the first time, a bi-monthly monitoring of environmental parameters (temperature, salinity, nutrients) and phytoplankton assemblages was conducted in the well-preserved Mellah lagoon ecosystem (South ... [more ▼]

For the first time, a bi-monthly monitoring of environmental parameters (temperature, salinity, nutrients) and phytoplankton assemblages was conducted in the well-preserved Mellah lagoon ecosystem (South Western Mediterranean, Algeria). Sampling was performed at 3 stations in 2016. The objective was to study the evolution of the microphytoplankton community with a focus on HABs species in relation with the environmental characteristics. In total, 227 microphytoplankton species belonging mainly to Diatomophyceae (160 species) and Dinophyceae (53 species), were inventoried in the Mellah lagoon. There was a clear dominance of diatoms (63%), compared to dinoflagellates (37%). Proliferations of some potentially toxic species such as Prorocentrum micans (7 200 cells.l-1) and Gymnodinium sanguineum (6 000 cells.l-1), were observed in summer and autumn respectively. Other HABs species as Alexandrium tamarense/catenella (1 350 cells.l-1) and Alexandrium minutum (1 420 cells.l-1), were present in winter and spring respectively. Temporal differences in the qualitative composition and quantitative phytoplankton communities in the three stations are discussed in relation with environmental variables. Microphytoplankton populations in the Mellah show diversity and equitability indices of 3.04 bits.cell-1 and 0.94 respectively, showing a structured community during winter and spring. The rest of the year is characterized by unstable phytoplankton populations, where only opportunistic species develop. [less ▲]

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See detailInteraction between climate forcing and plankton communities in a pristine NW Mediterranean site, the Bay of Calvi (Corsica) : a long term study
Goffart, Anne ULiege; Hecq, Jean-Henri ULiege; Baldi et al

Conference (2018, May)

In the Mediterranean coastal areas, most of the long-term studies of plankton dynamics concern highly urbanized areas, where long-term variability reflects the combined effects of climate and ... [more ▼]

In the Mediterranean coastal areas, most of the long-term studies of plankton dynamics concern highly urbanized areas, where long-term variability reflects the combined effects of climate and anthropogenic forcing. Here we use a unique long-term time series (1979-) performed in a NW Mediterranean coastal area unbiased by local anthropogenic pressure (Bay of Calvi, Corsica) to understand how climate variation drives changes in plankton communities. From high-frequency field data, we describe a mechanism that links winter physics, nutrient replenishment of the surface layer and plankton biomass and composition under the different combinations of meteorological conditions that occurred during the 4 decades of observations. Focusing on phytoplankton, we point out how climate variation affected (i) the timing, duration and magnitude of the winter-spring phytoplankton blooms, (ii) the mean yearly biomasses, (iii) the abundance of phytoplankton functional groups. We identify threshold values of physical variables below and above which they strongly impact nutrient availability, phytoplankton bloom characteristics and seasonal succession of functional groups. We show that food webs are resource controlled. Striking similarities between our observations and events elsewhere in the NW Mediterranean Sea are presented. We explore ecological consequences of changes occurring at the base of the food webs on services provided by plankton in the Mediterranean coastal waters. [less ▲]

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See detailThresholds of plankton community change in a Mediterranean coastal area : results from a long-term (1979-2014) time series
Goffart, Anne ULiege; Collignon, Amandine; Lejeune, Pierre et al

Poster (2017, September)

In the Mediterranean Sea, which has been identified as a hotspot for climate change, there is evidence for impacts of climate change on marine organisms. However, the lack of information on environmental ... [more ▼]

In the Mediterranean Sea, which has been identified as a hotspot for climate change, there is evidence for impacts of climate change on marine organisms. However, the lack of information on environmental drivers and associated thresholds limits our ability to forecast possible changes in biodiversity and ecological interactions. In this presentation, we use a unique long-term (1979-2014) time series performed in a Mediterranean coastal area unbiased by local anthropogenic pressure (Bay of Calvi, Corsica) to understand how climate variation controls phyto- and zooplankton dynamics and possibly affect artisanal and small-scale fisheries exploiting areas near the coast. From high-frequency field data, we describe a mechanism that links winter physics, nutrient replenishment of the surface layer and plankton dynamics under the different combinations of meteorological conditions that occurred during the 36 years of observations. We identify threshold values of physical variables below and above which they strongly impact nutrient availability, phyto- and zooplankton bloom characteristics and seasonality succession of plankton functional groups. We provide identification of environmental thresholds beyond which diatoms, which are crucial for sustaining fish populations, collapse. We discuss links between climate-related changes in plankton availability, fish recruitment and the success of small-scale fisheries. We show that the mechanism we identified from the 1979 to 2014 period of observation in the Bay of Calvi is pertinent to other Northwestern Mediterranean areas, stressing the importance of winter conditions in determining the state of Mediterranean pelagic ecosystems. We highlight that the thresholds obtained from our long-term time series provide key information for improving model scenarios of the impact of climate change on Mediterranean ecosystems. [less ▲]

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See detailNorth Atlantic Ocean
Bode, A.; Bange, H.W.; Boersma, M. et al

in O'Brien, T.D.; Lorenzoni, L.; Isensee, K. (Eds.) et al What are Marine Ecological Time Series telling us about the ocean? A status report (2017)

Executive Summary (with an focus on the North Atlantic. For the whole summary, see the report). Sustained ocean observations, including ships, autonomous platforms, and satellites, are critical for ... [more ▼]

Executive Summary (with an focus on the North Atlantic. For the whole summary, see the report). Sustained ocean observations, including ships, autonomous platforms, and satellites, are critical for monitoring the health of our marine ecosystems and developing effective management strategies to ensure longterm provision of the marine ecosystem services upon which human societies depend. Ocean observations are also essential in the development and validation of ocean and climate models used to predict future conditions. Ship‐ based biogeochemical time series provide the high‐ quality biological, physical and chemical measurements that are needed to detect climate change‐ driven trends in the ocean, assess associated impacts on marine food webs, and to ultimately improve our understanding of changes in marine biodiversity and ecosystems. While the spatial ‘footprint’ of a single time series may be limited, coupling observations from multiple time series with synoptic satellite data can improve our understanding of critical processes such as ocean productivity, ecosystem variability, and carbon fluxes on a larger spatial scale. The International Group for Marine Ecological Time Series (IGMETS) analyzed over 340 open ocean and coastal datasets, ranging in duration from five years to greater than 50 years. Their locations are displayed in a world map (Discover Ocean Time Series, http://igmets.net/discover) and in the IGMETS information database (http://igmets.net/metabase). These cross‐ time‐ series analyses yielded important insights on climate trends occurring both on a global and regional scale. At a global level, a generalized warming trend is observed over the past thirty years, consistent with what has been published by the IPCC (2013) report as well as other research. There are regional differences in temperature trends, depending on the time window considered, which are driven by regional and temporal expressions of large‐ scale climatic forcing and atmospheric teleconnections. This warming is accompanied by shifts in the biology and biogeochemical cycling (i.e. oxygen, nutrient, carbon), which impact marine food webs and ecosystem services. …/… The first comprehensive analysis of in situ time series provided for the North Atlantic Ocean revealed that, despite being the most studied region of the global ocean, there are large areas in this region still lacking multidisciplinary in situ observations. However, over the 25‐ and 30‐ year analysis periods, > 95% of the North Atlantic Ocean significantly warmed and the chlorophyll concentrations decreased (p < 0.05). At the same time, negative trends in salinity, oxygen and nutrients , as exemplified by nitrate, were noted. The analysis of existing time series showed that even in adjacent areas that appear to be relatively homogenous, there is large variability in ecosystem behaviour over time, as observed in the continental shelves at both sides of the North Atlantic Ocean. In general, over the 5‐year period prior to 2012, ~70% of the area of the South Atlantic showed cooling and 66% decreasing chlorophyll concentrations. However, over the past 30 years, > 85% of the South Atlantic increased in temperature. The paucity of in situ time series in this region, and the striking changes that have been reported in South Atlantic ecosystems over the past two decades, highlight the need to have a better observing system in place. …/… The IGMETS effort highlights the value of biogeochemical time series as essential tools for assessing, and predicting, global and regional climate change and its impacts on ecosystem services. The capacity to identify and differentiate anthropogenic and natural climate variations and trends depends largely on the length of the time‐ series, as well as on the location. Most of the ship based ecological time series are concentrated in the coastal ocean. While coastal zones in North America and Europe are being monitored, there is a conspicuous lack of biogeochemical time‐ series in other coastal regions around the world, and an almost complete absence of such observational platforms in the open ocean, which limits the capacity of analyses such as this. A more globally distributed network of time‐ series observations over multiple decades will be needed to differentiate between natural and anthropogenic variability. [less ▲]

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See detailContrôle de la variabilité interannuelle de la composition du phytoplancton de la Baie de Calvi (Corse) par les facteurs environnementaux
Goffart, Anne ULiege; Andral, Bruno; Baldi, Yoann et al

Conference (2016, November)

Le but de la présentation est de synthétiser les connaissances sur le contrôle de la dynamique du phytoplancton par les contraintes environnementales dans un site de référence méditerranéen. L’étude est ... [more ▼]

Le but de la présentation est de synthétiser les connaissances sur le contrôle de la dynamique du phytoplancton par les contraintes environnementales dans un site de référence méditerranéen. L’étude est réalisée en Baie de Calvi (Corse) à la station PHYTOCLY (42°34.85'N, 08°43.71'E) où des séries temporelles haute fréquence de données physiques, chimiques et biologiques sont réalisées depuis 1979. Depuis 2006, l’acquisition des données de subsurface et le traitement des échantillons, qui inclut des analyses HPLC de contenu pigmentaire du phytoplancton et des comptages de flore totale, sont réalisés grâce au soutien de la DCE. En Baie de Calvi, l’intensité de la rigueur hivernale, identifiée par deux proxys, la température de l’eau et le nombre de jours de vent fort, contrôle le réapprovisionnement en sels nutritifs des couches de surface et le développement du bloom phytoplanctonique (détails dans Goffart et al., 2015, Progress in Oceanography). Lors des années caractérisées par un hiver rigoureux (e.g. 2010), le bloom phytoplanctonique hivernal se développe pendant la période d’eau froide (eau de subsurface ≤13.5°C). Il est dominé par les diatomées et les cryptophycées, deux groupes qui montrent une préférence marquée pour les eaux froides et riches en sels nutritifs. Lorsque l’hiver est très doux (e.g. 2007), la disponibilité en sels nutritifs est réduite et le bloom ne se développe pas. Les diatomées et les cryptophycées sont absentes, et les communautés phytoplanctoniques sont dominées par les prymnesiophycées pico- et nanoplanctoniques et les cyanobactéries. Les résultats de l’étude permettent aussi : • de fixer les limites de la variabilité naturelle du phytoplancton dans un site de référence méditerranéen, • d’expliquer les variations interannuelles de biomasse et de composition phytoplanctonique, • de définir les préférences écologiques des différents groupes phytoplanctoniques, • d’établir des courbes d’évolution saisonnière des principaux groupes phytoplanctoniques qui intègrent la variabilité interannuelle liée aux variations climatiques. La connaissance acquise au cours de cette étude permet de contribuer au développement d’indices de qualité intégrant la composition du phytoplancton (e.g. indice de composition I C MEDIT) et de tester des méthodes de surveillance à grande échelle (e.g. croisement des suivis pigmentaires réalisés à haute fréquence et de l’imagerie satellitaire), contribuant ainsi à la mise en œuvre des politiques publiques (DCE, DCSMM). [less ▲]

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See detailDéveloppement d’un indice de composition phytoplanctonique adapté aux eaux côtières méditerranéennes
Goffart, Anne ULiege

Scientific conference (2015, December)

L'indice de composition phytoplanctonique ICMedit : bilan et perspectives.

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See detailSTAtion of Reference and rEsearch on Change of local and global Anthropogenic Pressures on Mediterranean Ecosystems Drifts: The STARECAPMED project
Richir, Jonathan ULiege; Abadie, Arnaud ULiege; Binard, Marc ULiege et al

Conference (2015, November 08)

The Marine and Oceanographic Research Station STARESO in the Calvi Bay, Corsica (France), is a unique tool in a preserved natural site that includes all the characteristic ecosystems of the Mediterranean ... [more ▼]

The Marine and Oceanographic Research Station STARESO in the Calvi Bay, Corsica (France), is a unique tool in a preserved natural site that includes all the characteristic ecosystems of the Mediterranean littoral. The station, established in 1970, has archived environmental data for decades. The STARECAPMED project, multidisciplinary, articulates itself around these two main features. Its objective is to understand how human activities can interact with the fundamental processes that govern the functioning of the different coastal ecosystems of a Mediterranean bay. The understanding of these interactions involves: (i) the identification of the anthropogenic pressures; (ii) the quantification of their impacts on the ecosystems; (iii) the prioritization of these impacts. STARECAPMED also aims to confirm the relevance of the use of the Calvi Bay as a reference in the study of local and global pressures and the changes they may cause on the structure and the functioning of Mediterranean coastal ecosytems. [less ▲]

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See detailPlankton ecosystem response to the decadal variation of winter intensity in the Mediterranean Sea : a long-term study (1979-2014)
Goffart, Anne ULiege; Collignon, Amandine ULiege; Hecq, Jean-Henri ULiege et al

Poster (2015, October)

In the Mediterranean Sea, several studies with distinct data sets indicate that the pelagic ecosystem underwent periods of change in the late 1980s and in the early 2000s. Here we used a unique long-term ... [more ▼]

In the Mediterranean Sea, several studies with distinct data sets indicate that the pelagic ecosystem underwent periods of change in the late 1980s and in the early 2000s. Here we used a unique long-term time series of data collected in the well-preserved Bay of Calvi (Corsica island, Ligurian Sea, NW Mediterranean) from 1979 and 2014 to explore the synchrony between changes in environmental conditions and phyto- and zooplankton dynamics. We identified an almost decadal, long-term variability in winter intensity, with three distinct periods: the 1980s (1979-1988), the 1990s (1989-1998) and the 2000s (1999-2014), which were characterized by moderate, mild and highly variable winters, respectively. We pointed out how the decadal changes in winter intensity affected (i) the duration and intensity of phyto- and zooplankton blooms, (ii) the mean yearly biomasses, and (iii) the nature of the assemblages. High phyto- and zooplankton biomasses were observed in years characterized by moderate and severe winters, and low phyto- and zooplankton abundances were recorded in years with mild winters. Moderate/severe and mild winters were favorable for diatoms and gelatinous zooplankton, respectively. Focusing on meroplanktonic species, we explored ecological consequences of decadal variations observed in the Bay of Calvi for resource management. We highlighted parallelisms with other European seas. [less ▲]

Detailed reference viewed: 39 (6 ULiège)
Peer Reviewed
See detailPlankton ecosystem response to the decadal variation of winter intensity in the Mediterranean Sea : a long-term study (1979-2014)
Goffart, Anne ULiege; Collignon, Amandine ULiege; Hecq, Jean-Henri ULiege et al

Conference (2015, October)

In the Mediterranean Sea, several studies with distinct data sets indicate that the pelagic ecosystem underwent periods of change in the late 1980s and in the early 2000s. Here we used a unique long-term ... [more ▼]

In the Mediterranean Sea, several studies with distinct data sets indicate that the pelagic ecosystem underwent periods of change in the late 1980s and in the early 2000s. Here we used a unique long-term time series of data collected in the well-preserved Bay of Calvi (Corsica island, Ligurian Sea, NW Mediterranean) from 1979 and 2014 to explore the synchrony between changes in environmental conditions and phyto- and zooplankton dynamics. We identified an almost decadal, long-term variability in winter intensity, with three distinct periods: the 1980s (1979-1988), the 1990s (1989-1998) and the 2000s (1999-2014), which were characterized by moderate, mild and highly variable winters, respectively. We pointed out how the decadal changes in winter intensity affected (i) the duration and intensity of phyto- and zooplankton blooms, (ii) the mean yearly biomasses, and (iii) the nature of the assemblages. High phyto- and zooplankton biomasses were observed in years characterized by moderate and severe winters, and low phyto- and zooplankton abundances were recorded in years with mild winters. Moderate/severe and mild winters were favorable for diatoms and gelatinous zooplankton, respectively. Focusing on meroplanktonic species, we explored ecological consequences of decadal variations observed in the Bay of Calvi for resource management. We highlighted parallelisms with other European seas. [less ▲]

Detailed reference viewed: 59 (6 ULiège)