@article {6741, title = {Changes in marine phytoplankton diversity: Assessment under the Marine Strategy Framework Directive}, journal = {Ecological Indicators}, volume = {102}, year = {2019}, pages = {265 - 277}, abstract = {The Marine Strategy Framework Directive requires EU Member States to assess the Good Environmental Status (GES) of their marine waters in a coherent and strategic manner. For the regional assessment of biodiversity, the OSPAR Intersessional Coordination Group of Biodiversity Assessment and Monitoring (ICG-COBAM) provides substantial advice. Through expert working groups, phytoplankton indicators are currently being developed to measure the state and the change in pelagic diversity, to quantify food web dynamics and to measure the extent of eutrophication impacts. We developed a multi-metric indicator that is compliant with the common OSPAR indicator {\textquotedblleft}Changes in plankton diversity{\textquotedblright} (PH3). The aim was to describe the structure of the phytoplankton community (alpha diversity) and to detect significant temporal changes (beta diversity) to evaluate the health of pelagic habitats. In this pilot study, we used three coastal time-series in the Western Channel and the north of the Bay of Biscay (North Atlantic, France) to test the efficiency and the performance of several existing diversity indices. We validated two alpha diversity indices, namely the Menhinick Index (D) and the Hulburt Index (δ), based on their complementary ecological information, their strong relationship with habitat characteristics, and their relative ease of interpretation for stakeholders. Temporal shifts or rate of change in community structure were detected by the Local Contributions to Beta Diversity index (LCBD; a beta diversity measure). For the years where significantly high LCBD values were found, the Importance Value Index (IVI) was calculated to potentially identify the taxa (genus) responsible for the {\textquotedblleft}unusual{\textquotedblright} community structure. For example, at the Ouest Loscolo site in 2008, an elevated LCBD (0.45) coincided with a high dominance value (Hulburt{\textquoteright}s Index) caused by the occurrence of a monospecific bloom of Leptocylindrus spp. (IVI = 73\%) in July (2.22 {\texttimes} 106 cells L-1) and October (8 {\texttimes} 106 cells L-1). In this way, PH3 informs on different aspects of phytoplankton diversity from a community to a genus level. At the current stage of development, however, PH3 acts as a {\textquotedblleft}surveillance{\textquotedblright} rather than an operational indicator since the relationship to GES is not directly tracked. In the future, by additional testing of PH3 and extending the geographical scope, the robustness of the assessment could be further determined across the OSPAR Maritime Area.}, keywords = {community composition, Good environmental status, Indicators, Marine policy, MSFD, OSPAR, Pelagic habitat, Plankton}, issn = {1470-160X}, doi = {https://doi.org/10.1016/j.ecolind.2019.02.009}, url = {http://www.sciencedirect.com/science/article/pii/S1470160X19301190}, author = {Rombouts, I. and Nathalie Simon and Anais Aubert and T. Cariou and Eric Feunteun and Laurent Guerin and M. Hoebeke and A. McQuatters-Gollop and F. Rigaut-Jalabert and Luis Felipe Artigas} } @article {6894, title = {Cross-linking plankton indicators to better define GES of pelagic habitats - EcApRHA Deliverable WP1.4}, year = {2017}, abstract = {The multimetric approach is a methodological tool which can be used to study a range of systems, including GES assessment of marine waters. Three indicators (PH1, PH2 and PH3) are currently being developed in the frame of the OSPAR convention for the pelagic habitat component. The three PH indicators provide information on different and complementary aspects of the plankton community that, only when considered altogether, provide a holistic vision of the ecosystem which is central to GES assessment. The present document aims at combining their information for the first time, following a multimetric approach. For this purpose, it was decided that the Plymouth Marine Laboratory L4 station would be the focus of this deliverable for the period 2000-2014.

Different results were obtained from PH1, PH2 and PH3 regarding dates characterized by atypical plankton community structures, stressing their complementarity. However, similar results were also found for some sampling dates, suggesting that the complementary information conveyed by the three PH indicators shows potential for generating a higher-level indicator.

This work has also evidenced a number of gaps and issues in the integration of the three PH indicators that we address with guidelines. In particular, efforts should be devoted to overcome technical difficulties in the integration the PH3 indicators, especially regarding differences in temporal resolution. Future development of the indicators could involve complementary techniques to classical methods to overcome taxonomic constraints. In the frame of this project, the access to data in certain format was identified also found problematic. Creating a central database of pre-formatted data managed by a group of experts could also benefit the regional calibration of the indicators for areas where appropriate data are available. Establishing a clear and easily accessible report which details all the monitoring guidelines concerning the metrics used for the OSPAR PH indicators could also be beneficial for homogenising the monitoring and inter-comparability of data among contracting parties in the goal of regional marine management.}, author = {Budria, Alexandre and Anais Aubert and Rombouts, Isabelle and Ostle, Clare and Angus Atkinson and Widdicombe, Claire and Goberville, Eric and Luis Felipe Artigas and Johns, David and Padegimas, Bernardas and Corcoran, Emily and McQuatters-Gollop, Abigail} } @article {4340, title = {The fate of C4 and C3 macrophyte carbon in central Amazon floodplain waters: Insights from a batch experiment}, journal = {Limnologica - Ecology and Management of Inland Waters}, volume = {59}, year = {2016}, pages = {90-98}, abstract = {

The central Amazon floodplains are particularly productive ecosystems, where a large diversity of organic carbon sources are available for aquatic organisms. Despite the fact that C4 macrophytes generally produce larger biomasses than C3 macrophytes, food webs in the central Amazon floodplains appear dominantly based on a C3 carbon source.

In order to investigate the respective fate and degradation patterns of C4 and C3 aquatic plant-derived material in central Amazon floodplains, we developed a 23-days batch experiment. Fatty acid and carbon concentrations as well as stable isotope compositions were monitored over time in 60\ L tanks. These tanks contained Amazon water, with different biomasses of C3 and C4 macrophyte, representative of in situ densities occurring in central Amazon floodplains.

In the C4Paspalum repens treatments, organic (POC, DOC) and inorganic carbon (DIC) got rapidly enriched in 13C, whereas in the C3Salvinia auriculata treatments, POC and DOC showed little change in concentration and isotopic composition, and DIC got depleted in 13C. The contribution of P. repens to POC and DOC was estimated to reach up to 94.2 and 70.7\%, respectively. In contrast, no differences were reported between the C3S. auriculata and control treatments, an observation attributed to the lower C3 biomass encountered in the field, to a slower degradation rate of C3 compared to C4 compounds, and to similar isotopic compositions for river POC and DOC, and C3 compounds.

The 13C enrichments of POC, DOC, and DIC from P. repens treatments were attributed to an enhanced bacterially-mediated hydrolysis and mineralization of C4 material. Evolutions of bacterial abundance and branched fatty acid concentrations confirmed the role of heterotrophic microbial communities in the high P. repens decomposition rate. Our experiment highlights the predominant role of C4 aquatic plants, as a large source of almost entirely biodegradable organic matter available for heterotrophic activity and CO2 outgassing to the atmosphere.

}, keywords = {Central amazon, Degradation, fatty acids, Floodplains, Macrophytes, Stables isotopes}, doi = {doi:10.1016/j.limno.2016.03.008}, author = {Jean-Michel Mortillaro and Passarelli, C and Gwena{\"e}l Abril and C{\'e}dric Hubas and Luis Felipe Artigas and Marc F Benedetti and Najet Thiney and Moreira-Turcq, P and P{\'e}rez, M A and Vidal, L and Tarik Meziane} } @article {Abril2014, title = {{Amazon River carbon dioxide outgassing fuelled by wetlands}}, journal = {Nature}, volume = {505}, year = {2014}, pages = {395-398}, publisher = {Nature}, doi = {10.1038/nature12797}, author = {Gwena{\"e}l Abril and Martinez, Jean Michel and Luis Felipe Artigas and Moreira-Turcq, Patricia and Marc F Benedetti and Vidal, Luciana and Tarik Meziane and Kim, Jung-Hyun and Bernardes, Marcelo C and Savoye, Nicolas and Deborde, Jonathan and Lima Souza, Edivaldo and Alb{\'e}ric, Patrick and Fernandes, Marcelo and de Souza, Landim and Roland, Fabio} }