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Long term mesozooplankton changes in coastal waters of North Spain

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. The study area.

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Long term mesozooplankton changes in coastal waters of North Spain

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  1. 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 InstitutoEspañol de Oceanografía

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

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

  4. The study variables • Biological variables: • Mesozooplankton variables • Biomass • Fractionated biomass (200-500 μm, 500-1000 μm, > 1000 μm) • Abundance • Phytoplankton variables • Integrated Chl a, from 50 m to the surface • Physical variables: • Temperature • Salinity on the isopycnal 27. 1 Markerfor Central Watermasstypes

  5. Long-term trends Zooplankton time series context in the North Atlantic Ocean • Criteria • Current data: Data at least until 2008 • Sampling frequency: every month 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)http://wg125.net/

  6. Long-term trends Seasonal component Time Long-term trend component Random or noise component Dummy variable seasonal regression Time Time

  7. Long-term trends (1993-2010) Zoo abundance Chl a Zoo BM • Positive trends for all the variables. • Only highly significant for Zoo BM. ** * * *** *** P-value ***<0. 001 **<0.01 * <0. 05 <0. 1

  8. Long-term trends (1998-2010). Fractionated biomass 200-500 µm 500- 1000 µm > 1000 µm • Positive trends • Unexpected compared to other works: More intense, significant and explanatory trends at larger fractions *** *** ** *** *** ** *** P-value ***<0. 001 **<0.01 * <0. 05 <0. 1 *

  9. Long-term trends (1993-2010) Temperature • Warming trends: higher and more significant for the more oceanic station (more stable conditions) • Decreasing significance towards deeper waters • Atm. • Effect

  10. Changes in seasonality 10 m depth Temperature

  11. Changes in seasonality Chl a Earlier spring bloom/more intense spring and autumn bloom

  12. Changes in seasonality Zooplankton biomass more intense spring and autumn peak

  13. Variationsof Central Water masses ENACWsp (subpolar gyre) BBCW (Celtic sea) • BBCWBay of Biscay Central Water • ENACWspEast North Atlantic Central Water subpolar mode • ENACWstEast North Atlantic Central Water subtropical mode • IPCIberianPoleward Current/Navidad IPC ENACWst (Subtropical gyre) Modified from Pérez et al. 2001

  14. Variationsof Central Water masses • Identification: T-S profiles • Markedperiods: • For BBCW • ForENACWst

  15. Variationsof Central Water masses

  16. Variationsof Central Water masses Influence on biological variables ANOVA: No significant differences

  17. Zooabundance • 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

  18. 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 Chla: Earlier spring bloom/more intense spring and autumn bloom. • For zooplankton biomass: more intense spring and autumn peak. • Forvariationsof the Central Water mass regime • Effect on the zooplankton abundance for the shelf-break station.

  19. ACKNOWLEDGEMENTS • This work was supported by a grant from the Ministerio de Educación del gobierno de España (FPU grant) and by the InstitutoEspanñol 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.

  20. BBCW

  21. ENACWst

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