Event Abstract Back to Event Characterization of phytoplankton communities and relation with environmental conditions in two retention areas of SW Iberia Mariana Santos1, 2*, Paulo B. Oliveira1, Alexandra Silva1, Maria T. Moita1, 3 and Ana Amorim2, 4 1 IPMA - Portuguese Institute for the Sea and Atmosphere, Portugal 2 MARE - Marine and Environmental Sciences Centre, Faculty of Science University of Lisbon, Portugal 3 CCMAR – Centre of Marine Sciences, Portugal 4 Department of Plant Biology, Faculty of Science University of Lisbon, Portugal Recent studies have highlighted the role of wind variability, coastal bathymetry and topography in sustaining high phytoplankton biomass in coastal upwelling regions. It has also been observed that plankton may accumulate in transient retention zones, north and south of a promontory or headland, allowing the plankton assemblage to maintain a coherent population in the region. Considering this, two retention areas located near two prominent Iberian headlands were used in this study, Cascais and Lagos bays (Fig. 1). The first bay, situated on the west coast of Portugal, SE of Cape Roca, is under strong influence of northerly winds, which favor upwelling conditions. Lagos bay, located on the south coast of Portugal, NE of Cape St. Vicente, is under the influence of alternating westerly and easterly currents. Given the short distance between Lagos and the Cape St. Vicente, this bay is also affected by strong upwelling events that occurred along the SW coast. The aim of the present study is to characterize the phytoplankton assemblages and succession and relate them with physical processes associated with these two prominent headlands. In particular, how the environmental setting may influence the dynamics of regional harmful algal blooms. During 2015, water samples were collected fortnightly on both study sites. The phytoplankton communities (e.g. in Fig. 2) were identified and quantified by the Utermöhl method. In situ data of surface temperature and salinity were collected on both study sites. In Lagos bay, a complete year of temperature data at 3 and 25 m depth was collected by using “TidbiT Temperature Data Logger”. Between July and middle of November an Acoustic Doppler Current Profiler (ADCP) was also moored off Lagos, at 30 m depth, to measure the local currents. Considering the high number of total identified taxa (>100), the species were grouped according to their ecological group (e.g. benthic vs. planktonic, colonial vs. single cell, harmful vs. non-harmful). Multivariate statistical analyses were performed using the software PRIMER-E 6 & PERMANOVA+ in order to search for patterns of community structure in space. Results show that there are significant differences between the phytoplankton communities from the two bays (P<0.01). The groups that contribute to about 40% of the dissimilarity between the bays are the phytoplankton less than 15 μm (e.g. small flagellates, small coccolithophores and small dinoflagellates). Lagos bay presents higher phytoplankton diversity. The assemblage in Lagos bay showed a higher abundance of planktonic harmful algal species and of benthic harmful and non-harmful species. When planktonic harmful species and benthic species are considered as categories, they contribute respectively to ca. 14% and 12% of the dissimilarity between the two bays. These results confirm Lagos bay as a potential high-risk area for Benthic Harmful Algal Blooms (BHABs) in the Iberian Atlantic coast. Figure 1 Figure 2 Keywords: Phytoplankton, Oceanographic conditions, Retention areas, Harmful algal species, Portugal Conference: XIX Iberian Symposium on Marine Biology Studies, Porto, Portugal, 5 Sep - 9 Sep, 2016. Presentation Type: Oral Presentation Topic: 1. ECOLOGY, BIODIVERSITY AND VULNERABLE ECOSYSTEMS Citation: Santos M, Oliveira PB, Silva A, Moita MT and Amorim A (2016). Characterization of phytoplankton communities and relation with environmental conditions in two retention areas of SW Iberia. Front. Mar. Sci. Conference Abstract: XIX Iberian Symposium on Marine Biology Studies. doi: 10.3389/conf.FMARS.2016.05.00051 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters. The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated. Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed. For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions. Received: 30 Apr 2016; Published Online: 02 Sep 2016. * Correspondence: Dr. Mariana Santos, IPMA - Portuguese Institute for the Sea and Atmosphere, Lisbon, Portugal, marianasantinho@gmail.com Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract The Authors in Frontiers Mariana Santos Paulo B Oliveira Alexandra Silva Maria T Moita Ana Amorim Google Mariana Santos Paulo B Oliveira Alexandra Silva Maria T Moita Ana Amorim Google Scholar Mariana Santos Paulo B Oliveira Alexandra Silva Maria T Moita Ana Amorim PubMed Mariana Santos Paulo B Oliveira Alexandra Silva Maria T Moita Ana Amorim Related Article in Frontiers Google Scholar PubMed Abstract Close Back to top Javascript is disabled. Please enable Javascript in your browser settings in order to see all the content on this page.