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Kelps across the portuguese coast: evidence of top-down and bottom-up influences

2014; Frontiers Media; Volume: 1; Linguagem: Inglês

10.3389/conf.fmars.2014.02.00086

2296-7745

João N. Franco, João N. Franco, Thomas Wernberg, Brezo Martínez, Pedro Duarte, David Jacinto, Nuno Vasco-Rodrigues, Fernando Tuya,

Coastal wetland ecosystem dynamics

Event Abstract Back to Event Kelps across the portuguese coast: evidence of top-down and bottom-up influences Joao N. Franco1, 2*, Thomas Wernberg3, Iacopo Bertocci2, Francisco Arenas2, Brezo Martínez4, Pedro Duarte5, David Jacinto6, Nuno Vasco-Rodrigues7, Isabel Sousa-Pinto1, 2 and Fernando Tuya8 1 Department of Biology, Faculty of Sciences, University of Porto., Portugal 2 (CIIMAR/CIMAR) - Interdisciplinary Centre of Marine and Environmental Research , Portugal 3 UWA Oceans Institute & School of Plant Biology, Australia 4 Rey Juan Carlos University, Spain 5 Norwegian Polar Institute, Norway 6 Laboratório de Ciências do Mar , Universidade de Évora, Portugal 7 GIRM - Marine Resources Research Group, Polytecnic Institute of Leiria, Portugal 8 BIOGES, Universidad de Las Palmas de Gran Canaria, Spain Kelps (large brown seaweeds) are conspicuous elements of the Portuguese coast, although kelp abundance is declining, especially at central and southern Portugal. While many studies point out increased seawater temperature as the main factor explaining kelp decline, little attention has been given to top-down (predatory) influences. Through in situ experiments, we tested how herbivory affects the distribution and abundance of kelp recruits. We compared the abundance and survivorship of recruits, the intensity of grazing on recruits and the abundance of herbivores between Viana do Castelo (northern Portugal) and Peniche (central Portugal). In addition, through an outdoor mesocosm experiment, we disentangled the independent and interactive effects of both seawater temperature and nutrients on kelp recruits performance (mortality, growth, C, N and carbohydrate contents, and photosynthetic potential and efficiency). Our main results showed that herbivores and herbivory intensity is higher at central compared to northern Portugal and that the growth of juvenile sporophytes was larger under a high-nutrient scenarios, particularly when temperatures were low (12, 15 and 16ºC). Despite the presence and fitness of kelps across southern European waters has been exclusively linked to bottom-up influences, our results highlights the importance of top-down effects for kelp survivorship and performance. Acknowledgements Financial support was provided by the ‘Programa Operacional Factores de Competitividade’ (POFC-COMPETE) within the Portuguese Fundação para a Ciência e a Tecnologia (FCT) through the projects ‛Efeitos do clima oceânico na macroecologia e resiliência a perturbações dos povoamentos de kelps’ - OCEANKELP (PTDC/MAR/109954/2009) and a PhD grant (SFRH/BD/84933/2012) to J. N. Franco. We thank Prof. Paulo Maranhão and ‘Escola Superior de Tecnologias do Mar – Instituto Politecnico de Leiria’ (ESTM –IPL) Keywords: Climate Change, Herbivory, Nutrients, temperature, latitudinal gradient, rocky reefs Conference: IMMR | International Meeting on Marine Research 2014, Peniche, Portugal, 10 Jul - 11 Jul, 2014. Presentation Type: Oral Presentation Topic: BIODIVERSITY, CONSERVATION AND COASTAL MANAGEMENT Citation: Franco JN, Wernberg T, Bertocci I, Arenas F, Martínez B, Duarte P, Jacinto D, Vasco-Rodrigues N, Sousa-Pinto I and Tuya F (2014). Kelps across the portuguese coast: evidence of top-down and bottom-up influences. Front. Mar. Sci. Conference Abstract: IMMR | International Meeting on Marine Research 2014. doi: 10.3389/conf.fmars.2014.02.00086 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: 14 Apr 2014; Published Online: 18 Jul 2014. * Correspondence: Mr. Joao N Franco, Department of Biology, Faculty of Sciences, University of Porto., Porto, Portugal, joaonunofranco@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 Joao N Franco Thomas Wernberg Iacopo Bertocci Francisco Arenas Brezo Martínez Pedro Duarte David Jacinto Nuno Vasco-Rodrigues Isabel Sousa-Pinto Fernando Tuya Google Joao N Franco Thomas Wernberg Iacopo Bertocci Francisco Arenas Brezo Martínez Pedro Duarte David Jacinto Nuno Vasco-Rodrigues Isabel Sousa-Pinto Fernando Tuya Google Scholar Joao N Franco Thomas Wernberg Iacopo Bertocci Francisco Arenas Brezo Martínez Pedro Duarte David Jacinto Nuno Vasco-Rodrigues Isabel Sousa-Pinto Fernando Tuya PubMed Joao N Franco Thomas Wernberg Iacopo Bertocci Francisco Arenas Brezo Martínez Pedro Duarte David Jacinto Nuno Vasco-Rodrigues Isabel Sousa-Pinto Fernando Tuya 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.