DEVelopment Of innovative Tools for understanding marine biodiversity and assessing good Environmental Status

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Using bio-optical parameters as a tool for detecting changes in the phytoplankton community (SW Portugal)

Publication . Goela, Priscila; Icely, John; Cristina, Sonia; Danchenko, Sergei; Angel DelValls, T.; Newton, Alice

Upwelling events off the Southwest coast of Portugal can trigger phytoplankton blooms that are important for the fisheries and aquaculture sectors in this region. However, climate change scenarios forecast fluctuations in the intensity and frequency of upwelling events, thereby potentially impacting these sectors. Shifts in the phytoplankton community were analysed from the end of 2008 until the beginning of 2012 by examining the bio-optical properties of the water column, namely the absorption coefficients for phytoplankton, non-algal particles and coloured dissolved organic matter (CDOM). The phytoplankton community was assessed by microscopy, with counts from an inverted microscope, and by chemotaxonomic methodologies, using pigment concentrations determined by High-Performance Liquid Chromatography (HPLC). Results both from microscopy and from chemotaxonomic methods showed a shift from diatom dominance related to bloom conditions matching upwelling events, to small flagellate dominance related to no-bloom conditions matching relaxation of upwelling. During bloom conditions, light absorption from phytoplankton increased markedly, while non-algal particles and CDOM absorption remained relatively constant. The dynamics of CDOM in the study area was attributed to coastal influences rather than from phytoplankton origin. Changes in phytoplankton biomass and consequent alterations in phytoplankton absorption coefficients were attributed to upwelling regimes in the area. Bio-optical parameters can contribute to environmental monitoring of coastal and oceanic waters, which in the case of the European Union, involves the implementation of the Water Framework, Marine Strategy Framework and Marine Spatial Planning Directives. (C) 2015 The Authors.Published by Elsevier Ltd.

2015-12Journal article

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An overview of ecological status, vulnerability and future perspectives of European large shallow, semi-enclosed coastal systems, lagoons and transitional waters

Publication . Newton, Alice; Icely, John; Cristina, Sónia; Brito, Ana; Cardoso, Ana Cristina; Colijn, Franciscus; Riva, Simona Dalla; Gertz, Flemming; Hansen, Jens Würgler; Holmer, Marianne; Ivanova, Kateryna; Leppäkoski, Erkki; Canu, Donata Melaku; Mocenni, Chiara; Mudge, Stephen; Murray, Nicholas; Pejrup, Morten; Razinkovas, Arturas; Reizopoulou, Sofia; Pérez-Ruzafa, Angel; Schernewski, Gerard; Schubert, Hendrik; Carr, Laishalla; Solidoro, Cosimo; PierluigiViaroli, null; Zaldívar, José-Manuel

The paper gives an overview of some of the large, shallow, semi-enclosed coastal systems (SECS) in Europe, These SECS are important both from the ecological and the economic perspective (socioecological systems) and provide many valuable ecosystem goods and services. Although some of the systems are transitional waters under theWater Framework Directive, this is not the case for all of the systems. The paper adopts a Driver-Pressure-State-Impact-Response approach to analyse the ecological status, vulnerability and future perspectives of these systems in the context of global change.

2014Journal article

Open Access

MERIS phytoplankton time series products from the SW Iberian Peninsula (Sagres) using seasonal-trend decomposition based on loess

Publication . Cristina, Sónia; Cordeiro, Clara; Lavender, Samantha; Goela, Priscila; Icely, John; Newton, Alice

The European Space Agency has acquired 10 years of data on the temporal and spatial distribution of phytoplankton biomass from the MEdium Resolution Imaging Spectrometer (MERIS) sensor for ocean color. The phytoplankton biomass was estimated with the MERIS product Algal Pigment Index 1 (API 1). Seasonal-Trend decomposition of time series based on Loess (STL) identified the temporal variability of the dynamical features in the MERIS products for water leaving reflectance ((w)()) and API 1. The advantages of STL is that it can identify seasonal components changing over time, it is responsive to nonlinear trends, and it is robust in the presence of outliers. One of the novelties in this study is the development and the implementation of an automatic procedure, stl.fit(), that searches the best data modeling by varying the values of the smoothing parameters, and by selecting the model with the lowest error measure. This procedure was applied to 10 years of monthly time series from Sagres in the Southwestern Iberian Peninsula at three Stations, 2, 10 and 18 km from the shore. Decomposing the MERIS products into seasonal, trend and irregular components with stl.fit(), the (w)() indicated dominance of the seasonal and irregular components while API 1 was mainly dominated by the seasonal component, with an increasing effect from inshore to offshore. A comparison of the seasonal components between the (w)() and the API 1 product, showed that the variations decrease along this time period due to the changes in phytoplankton functional types. Furthermore, inter-annual seasonal variation for API 1 showed the influence of upwelling events and in which month of the year these occur at each of the three Sagres stations. The stl.fit() is a good tool for any remote sensing study of time series, particularly those addressing inter-annual variations. This procedure will be made available in R software.

2016-07Journal article

Open Access

Technical note: Algal Pigment Index 2 in the Atlantic off the southwest Iberian Peninsula: standard and regional algorithms

Publication . Goela, Priscila; Cristina, Sónia; Kajiyama, Tamito; Icely, John; Moore, Gerald; Fragoso, Bruno; Newton, Alice

In this study, Algal Pigment Index 2 (API2) is investigated in Sagres, an area located in the Atlantic off the southwestern Iberian Peninsula. Standard results provided by the MEdium Resolution Image Spectrometer (MERIS) ocean colour sensor were compared with alternative data products, determined through a regional inversion scheme, using both MERIS and in situ remote sensing reflectances (R-rs) as input data. The reference quantity for performance assessment is in situ total chlorophyll a (TChl a) concentration estimated through a phytoplankton absorption coefficient (i.e. equivalent to API2). Additional comparison of data products has also been addressed for TChl a concentration determined by high-performance liquid chromatography. The MERIS matchup analysis revealed a systematic underestimation of TChl a, which was confirmed with an independent comparison of product map analysis. The study demonstrates the importance of regional algorithms for the study area that could complement upcoming standard results of the current Sentinel-3/OLCI space mission.

2016-12Journal article

Open Access

Biomarkers as indicators of sedimentary organic matter sources and early diagenetic transformation of pentacyclic triterpenoids in a tropical mangrove ecosystem

Publication . Kumar, Mukesh; Boski, T.; Lima-Filho, Francisco P.; Bezerra, Francisco H. R.; Gonzalez-Vila, Francisco J.; Alam Bhuiyan, Md Khurshid; Gonzalez-Perez, Jose A.

Mangrove vegetation covers extensive areas along Brazilian tropical coasts and accumulates large amounts of organic carbon in the intertidal sediments. We have investigated the molecular biomarker composition of mangrove sediments from the Potengi estuary North-East Brazil. To characterise sources and fate of sedimentary organic matter (OM), a direct analytical pyrolysis approach was used. The sediment pyrolysates yielded homologous series of aliphatic compounds (n-alkane/n-alkene doublets, n-alkanoic acid and n-alkan-2-ones), triterpenoids and lignin-derived methoxphenols, indicating that most of the sedimentary OM input originates from terrestrial vascular plants. High abundance of long-chain n-alk-1-ene series with an even carbon number predominance peaking at C-28:1-most likely originated from local mangrove vegetation-is found co-eluted with the saturated odd carbon n-alkane series. The occurrence of lignin and n-alkan-2-one biomarkers in the sediments has provided parallel information about the input from vascular plants dominating the intertidal zone. This was further corroborated by the presence of the triterpenols (beta-amyrin, and germanicol), that provided chemotaxonomic information on mangrove derived leaf wax in sedimentary OM. The unsaturated triterpenoid including teraxerol acetate, olean-12-ene, olean-18-ene, oleana-11, 13(18)-diene, a-neoursa-3(5), 12-diene and aneooleana-3(5), 12-diene, were also observed in sediment pyrolysates. The presence of these unsaturated pentacyclic triterpenoids revealed an early diagenetic alteration of terrestrial OM in the sediments. This study has demonstrated that routine application of analytical pyrolysis may provide important insight into the sources of sedimentary OM and its diagenetic fate in mangrove intertidal sediments.

2019-11Journal article

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