Long term mesozooplankton changes in coastal waters of North Spain Ricardo González-Gil F. González-Taboada, J. Höfer, R. Anadón University of Oviedo Department of Biology of Organisms and Systems In colaboration with Instituto Español de Oceanografía

Ricardo González-Gil Long-term monitoring program RADIALES by the Spanish Institute of Oceanography (Instituto Español de Oceanografía, IEO) in collaboration with the UO Cantabrian Sea Offshore of Cudillero (Asturias) Monthly sampling  January 1993 to December 2010 The study area Coastal Station Shelf-break Station Oceanic Station

Ricardo González-Gil Analysis of mesozooplankton changes 1. Long-term trends 2. Other underlying aspects of these long- term trends: 1. Modifications in seasonality 2. Effects from changes in the interannual environmental conditions: variations of the Central Water mass regime

Ricardo González-Gil The study variables Biological variables: Mesozooplankton variables Biomass Fractionated biomass ( μm, μm, > 1000 μm) Abundance Phytoplankton variables Integrated Chl a, from 50 m to the surface Physical variables : Temperature Salinity on the isopycnal  Marker for Central Water mass types

Ricardo González-Gil Long-term trends Zooplankton time series context in the North Atlantic Ocean Data from Global comparisons of zooplankton time series (SCOR WG 123). Time series also associated with the ICES- WGZE(ICES Working Group on Zooplankton Ecology) Criteria Current data: Data at least until 2008 Sampling frequency: every month

Ricardo González-Gil Long-term trends Dummy variable seasonal regression Time Long-term trend component Time Seasonal component Time Random or noise component

Ricardo González-Gil * ** *** * Long-term trends ( ) P-value *** < ** <0.01 * <0. 05 <0. 1 Positive trends for all the variables. Only highly significant for Zoo BM. Chl aZoo BM Zoo abundance

Ricardo González-Gil P-value *** < ** <0.01 * <0. 05 <0. 1 * ** *** ** Long-term trends ( ). Fractionated biomass Positive trends Unexpected compared to other works: More intense, significant and explanatory trends at larger fractions µm µm> 1000 µm

Ricardo González-Gil Long-term trends ( ) Temperature Warming trends: higher and more significant for the more oceanic station (more stable conditions) Decreasing significance towards deeper waters Atm. Effect

Ricardo González-Gil Changes in seasonality 10 m depth Temperature

Ricardo González-Gil Changes in seasonality Chl a Earlier spring bloom/more intense spring and autumn bloom

Ricardo González-Gil Changes in seasonality Zooplankton biomass more intense spring and autumn peak

Ricardo González-Gil ENACWsp (subpolar gyre) BBCW (Celtic sea) ENACWst (Subtropical gyre) IPC Modified from Pérez et al BBCW  Bay of Biscay Central Water ENACWsp  East North Atlantic Central Water subpolar mode ENACWst  East North Atlantic Central Water subtropical mode IPC  Iberian Poleward Current/Navidad Variations of Central Water masses

Ricardo González-Gil Variations of Central Water masses Identification: T-S profiles Marked periods: For BBCW For ENACWst

Ricardo González-Gil Variations of Central Water masses

Ricardo González-Gil Variations of Central Water masses Influence on biological variables ANOVA: No significant differences

Ricardo González-Gil ANOVA and Tukey tests results: Significant differences for E2 (shelf-break station) Highly significant differences between ENACWst and ENACWsp Significant differnces between ENACWst and BBCW Zoo abundance

Ricardo González-Gil Conclusions For the long term trends : Detection of significant positive trend for Zooplankton biomass. Positive long term trends for all the biomass fractions. Unexpected more intense and markedly positive long term trends for larger zooplankton fraction sizes. For Changes in seasonality : For Chl a: Earlier spring bloom/more intense spring and autumn bloom. For zooplankton biomass: more intense spring and autumn peak. For variations of the Central Water mass regime Effect on the zooplankton abundance for the shelf-break station.

ACKNOWLEDGEMENTS This work was supported by a grant from the Ministerio de Educación del gobierno de España (FPU grant) and by the Instituto Espanñol de Oceanografía (Project Radiales) Thanks to: The crew of the research vessel José Rioja ; The people from the ecology area of the University of Oviedo for advice and guidance; Thank you also for all the support and advice from loved ones.

Ricardo González-Gil P-value for long term trend(Seasonal regression): P-value for long term trend(Seasonal regression): Stationlog10_Chla log10_Bm_ zooplank log10_abund _zooplank log10_Bm_200_ zooplank log10_Bm_ 500_zooplank log10_Bm_ 1000_zooplank E E E

Ricardo González-Gil BBCW

Ricardo González-Gil ENACWst