DISTRIBUTION OF SOFT-BOTTOM POLYCHAETES ASSEMBLAGES AT DIFFERENT SCALES IN SHALLOW WATERS OF THE NORTHERN MEDITERRANEAN SPANISH COAST Letzi Graciela Serrano Samaniego Rafael Sardá Borroy Barcelona, June 2012 DISTRIBUTION OF SOFT-BOTTOM POLYCHAETES ASSEMBLAGES AT DIFFERENT SCALES IN SHALLOW WATERS OF THE NORTHERN MEDITERRANEAN SPANISH COAST Doctorate dissertation To obtain the Doctoral Degree in Marine Sciences Marine Sciences Doctoral Program UPC-UB-CSIC Developed in the Marine Engineering Laboratory (Laboratori d'Enginyeria Marítima, LIM/UPC) and in the Center for Advance Studies of Blanes (Centre d’Estudis Avançats de Blanes-CEAB) By Letzi Graciela Serrano Samaniego Dissertation supervisor: Rafael Sardá Borroy, CEAB-CSIC June 2012 Barcelona, Spain To my dear family: My dearly husband: Carlos I love you. My beloved kids Carlos Letzy Yenia Kelsy DISTRIBUTION OF SOFT-BOTTOM POLYCHAETES ASSEMBLAGES AT DIFFERENT SCALES IN SHALLOW WATERS OF THE NORTHERN MEDITERRANEAN SPANISH COAST TABLE OF CONTENTS Acknowledgements ......................................................................................................... ix Summary ......................................................................................................................... 11 Introduction .................................................................................................................... 12 Polychaetes as a zoological model ................................................................................. 12 Common generalities about Polychaetes ........................................................................ 12 Systematics ..................................................................................................................... 14 Morphology .................................................................................................................... 17 Feeding Strategies .......................................................................................................... 19 The Mediterranean Sea ................................................................................................... 21 Oceanographic features .................................................................................................. 21 Thesis structure ............................................................................................................... 26 References ...................................................................................................................... 30 Chapter 1 ........................................................................................................................ 30 A polychaete-dominated community in the Nw Mediterranean sea, 20 years after cessation of sewage discharges....................................................................................... 30 Abstract ........................................................................................................................... 30 Introduction .................................................................................................................... 31 Material and methods ..................................................................................................... 33 Study site ................................................................................................................................. 33 Sampling and laboratory procedures ....................................................................................... 36 Measurement methods and secondary production estimates .................................................. 37 Computation of indices for the analyzed benthic assemblages ............................................... 39 Results ............................................................................................................................ 40 Sedimentology ......................................................................................................................... 40 Community structure and dynamics ........................................................................................ 42 Secondary production .............................................................................................................. 49 Discussion …………………………………………………………………………51 Chapter 2 ........................................................................................................................ 58 Long-term comparison of Polychete assemblages within soft-bottoms off the Alt Empordà (North western Mediterranean coast).............................................................. 58 Abstract ........................................................................................................................... 58 Introduction .................................................................................................................... 58 Material and methods ..................................................................................................... 61 Study sites ............................................................................................................................... 61 vii The sampling effort ................................................................................................................. 63 Data analysis and assemblage classification ........................................................................... 64 Diversity measures .................................................................................................................. 65 Results ............................................................................................................................ 65 Gulf of Roses study ................................................................................................................. 65 The Littoral surf beach assemblage ......................................................................................... 70 The Littoral fine sand assemblage ........................................................................................... 71 The Littoral sandy mud assemblage ........................................................................................ 73 Discussion ....................................................................................................................... 78 Chapter 3 ........................................................................................................................ 84 Spatial distribution and diversity of polychaete faunal in the northern Mediterranean Spanish coast .................................................................................................................. 84 Abstract ........................................................................................................................... 84 Introduction .................................................................................................................... 84 Material and methods ..................................................................................................... 86 Study area ................................................................................................................................ 86 Sampling and laboratory procedures ....................................................................................... 89 Data analysis ........................................................................................................................... 90 Results ............................................................................................................................ 91 Granulometry .......................................................................................................................... 91 Species richness, abundances and heterogeneity diversity...................................................... 93 Spatial distribution and faunal assemblages ............................................................................ 97 Discussion ..................................................................................................................... 107 Granulometry ........................................................................................................................ 107 Species richness, abundances and heterogeneity diversity.................................................... 107 Spatial distribution and faunal assemblages .......................................................................... 108 Acknowledgements ...................................................................................................... 111 Chapter 4 ...................................................................................................................... 115 Assessment of soft-bottom polychaete assemblages in Littoral Fine Sands (LFS) community based on a mesoscales survey: .................................................................. 115 Abstract ......................................................................................................................... 115 Introduction .................................................................................................................. 115 Material and methods ................................................................................................... 118 Sampling and laboratory procedures ..................................................................................... 118 Data analysis ........................................................................................................................