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Physico-chemical and biological characteristics of the Blanes site

Physico-chemical and biological characteristics of the Blanes site.

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Physico-chemical and biological characteristics of the Blanes site

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  1. Physico-chemical and biological characteristics of the Blanes site

  2. Sampling siteHalf mile from Blanes harbour, depth of 20 mParameters to be collected • Vertical profiles of temperature and salinity • Seawater for nutrients, pigments, electron microscopy, flow cytometry, picoeukaryal isolations and DNA extraction

  3. General characteristics of Blanes BayTypical Mediterranean waters: warm, salty and nutrient-poorBlanes Bay: oligotrophic coastal waters (annual average chlorophyll of 0.87 µg l-1) Less affected by human influence than systems closer to the Barcelona area (70 km south)Relatively large data set from other projects

  4. HydrographyFront in the continental slope (generally 10-20 miles offshore) that separates coastal from oceanic waters. There is an associated current flowing southwestThis current can be deflected near the Blanes canyon, causing episodic intrusions of oceanic waters near the coast

  5. Surface drifter General currents 5 days in May 1992

  6. ClimateTemperate system with strong climate fluctuationsUnimodal seasonality only for temperature; most other forcing factors show a much complex variance structureMinves de gener: winter period of high pressure and low sea level that allows a phytoplankton bloom (2-4 weeks) Strong influence of episodic rain storms

  7. TemperatureMinimum in late January to March (11-12°C), maximum in August-September (25-26°C)Thermocline from May-June to September-October

  8. SalinityRange from 37‰(coastal waters) to 38.4‰ (open-sea waters), with episodic intrusions of lower salinity waters (down to 32‰) from the Rhone river plume or rainfall

  9. NutrientsRelatively low and highly variable Two-year average (in µmol l-1):1.18 ammonium0.11 nitrite0.96 nitrate0.29 phosphate

  10. Seasonality of phytoplanktonMain peak of chlorophyll a during late winter, driven by high atmospheric pressures together with irradiances and temperatures higher than similar latitudes in the AtlanticSmaller peaks in early fall

  11. Average biovolume of phytoplankton Centric diatoms dominate in the winter and fall peaks, whereas dinoflagellates dominate in summer Picoeukaryotes: 29% in 1992-1993 19% in 1993-1994 Cyanobacteria: 7% in 1992-1993 12% in 1993-1994

  12. BacteriaFlagellatesCiliates Seasonality of other microbial components

  13. Related projects CEAB sampling in Blanes (1992-1997)ICM sampling in Blanes (and other coastal sites) in 1998Hivern cruises in the Catalan Sea. February 1999 and 2000ARO cruise in the Catalan Sea. June 2000Next cruise above the Blanes canyon in May 2001

  14. CEAB sampling in BlanesHigh periodicity from 1992 to 1997 (at least once a week) Parameters measuredMetereology: rain, irradiance, sea level, wave actionSurface temperature and salinityBiomass of bacteria, protists, algae and zooplankton Primary production, community respiration

  15. ICM sampling in three coastal sitesBarcelona, Masnou and Blanes plus Barcelona harbourOnce a month during 1998. Fractions 0.2-1.6 µm and 0.2-5 µm Parameters measuredSurface temperatureFractionated chlorphyll a, bacteria and picophytoplankton Samples for environmental DNA

  16. Seasonal succession of bacterioplankton in Blanes DGGE with primers Bact338f and Un907r

  17. Bacterial succession

  18. Seasonal succession of picoeukaryotes in Blanes Jan February March Apr Jun Jul Sep Oct Nov Dec ANT12 27 5 25 3 11 18 26 29 3 2 29 3 9 4 1 DGGE with primers Euk1f and Euk516r

  19. Picoeukaryal succession in Blanes 26 MARCH---- +--------- 11 MARCH ---- | +----------------------------------- 26 MARCH ------- | | +-- | | 29 APRIL ------+ | | | | | | | 3 MARCH --- | | | | +-- | | | 25 FEBRUARY --- | | | | | +-- | | | 5 FEBRUARY ----- | | | +---- | 27 JANUARY --------- | +------- 1 DECEMBER ----------- | +------- | 3 SEPTEMBER --------- | | | +-- | | 4 NOVEMBER ------ | | | +--- | | 3 JUNE ------ | | +------------------------------ 2 JULY --------- | +----- | 29 JULY --------- | | +---- 9 OCTOBER -------------- Winter and Spring Summer and Fall

  20. Spatial differences of bacterial assemblages in three coastal sites

  21. Spatial differences in some coastal systems Summer Winter Spring

  22. Summary of Blanes siteOligotrophic coastal system with weak human influenceEpisodic intrusions on oceanic waters near the coast and strong effect of rain storms on water-column conditionsUnimodal seasonality only in surface temperatureMost important phytoplankton bloom in late winterTemporal succession of most groups studied, including bacteria and picoeukaryotes

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