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Maurizio Ribera d’Alcalà Stazione Zologica Anton Dohrn, Napoli, Italy

Water masses properties, chemical signatures and biological processes in coastal marine environment. Maurizio Ribera d’Alcalà Stazione Zologica Anton Dohrn, Napoli, Italy. Stazione Zoologica Anton Dohrn. 1872. 2007. Napoli of... Maradona. Brief overview.

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Maurizio Ribera d’Alcalà Stazione Zologica Anton Dohrn, Napoli, Italy

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  1. Water masses properties, chemical signatures and biological processes in coastal marine environment Maurizio Ribera d’Alcalà Stazione Zologica Anton Dohrn, Napoli, Italy

  2. Stazione Zoologica Anton Dohrn 1872 2007

  3. Napoli of...Maradona

  4. Brief overview Tuning the language: definitions and basic concepts Coastal environments: main traits, key processes, benthic vs. pelagic, biogeochemistry vs. ecology General framework: the COSCAT synthesis Biogeochemical processes: case studies Cuba case: nitrogen budget Filling the gaps: observational requirements and tools

  5. Definitions and basic concepts • Coastal areas: from low-tide mark inland extending seaward, including ecosystems near shore: (barrier islands, mangrove swamps, salt marshes, seagrass beds, coral reefs, etc.)

  6. Definitions and basic concepts • Coastal areas: from low-tide mark inland extending seaward, including ecosystems near shore: (barrier islands, mangrove swamps, salt marshes, seagrass beds, coral reefs, etc.) • The focus is the biotic component of the ecosystem

  7. Definitions and basic concepts • Coastal areas: from low-tide mark inland extending seaward, including ecosystems near shore: (barrier islands, mangrove swamps, salt marshes, seagrass beds, coral reefs, etc.) • The focus is the biotic component of the ecosystem • Biota grow, reproduce and die, and all runs on the continuous transformation of inorganic substances into biomolecules and back, based (dominantly) on oxygenic photosynthesis

  8. Definitions and basic concepts • Coastal areas: from low-tide mark inland extending seaward, including ecosystems near shore: (barrier islands, mangrove swamps, salt marshes, seagrass beds, coral reefs, etc.) • The focus is the biotic component of the ecosystem • Biota grow, reproduce and die, and all runs on the continuous transformation of inorganic substances into biomolecules and back, based (dominantly) on oxygenic photosynthesis • Our jargon includes (with the relative units): • biomass (chlorophyll, dry weight, abundance, etc.), nutrients (with the constraint of mass balance) • primary producers and consumers • new production, export production, trophic regime • Biodiversity

  9. Importance for Caribbean • Steep slopes and rapid changes in topography create small, scattered ecosystems • Small size of ecosystems • Concentration of population and activities in small areas intensifies stress conditions • High frequency and variety of natural disasters • Close coupling of terrestrial, coastal and marine systems results in fast-spreading impacts among systems Roger-Mark De Souza

  10. Main traits Vicinity to land implies: • freshwater runoff

  11. Main traits Vicinity to land implies: • freshwater runoff  • coastal Ekman transport

  12. Main traits Vicinity to land implies: • freshwater runoff  • coastal Ekman transport • significant tidal dynamics

  13. Key processes Terrestrial runoff: modifies the water budget and the thermohaline circulation confers a strong signature (amount and ratios) to nutrient inputs

  14. Key processes Terrestrial runoff: modifies the water budget and the thermohaline circulation confers a strong signature (amount and ratios) to nutrient inputs Ekman transport: Upwelling Tidal dynamics: strong periodic currents, mixing

  15. Key processes Terrestrial runoff: modifies the water budget and the thermohaline circulation confers a strong signature (amount and ratios) to nutrient inputs Ekman transport: Upwelling Tidal dynamics: strong periodic currents, mixing Land drivenvs. ocean driven systems

  16. Benthic vs. pelagic barrier islands mangrove swamps salt marshes seagrass beds coral reefs Seasonal cycle of phytoplankton Red Tides Crustaceans, Jelly fish, Clupeids

  17. Benthic vs. pelagic Daily Primary production in the Caribbean Region Margalef, 1962

  18. Benthic vs. pelagic Distribution of Sardinella and choral reefs Margalef, 1962

  19. Biogeochemistry vs. ecology (a drastic schematization) Focus on fluxes and biomass Functional groups Almost always bottom-up driven Focus on the biology of species Interactions among the species Emergent properties neither bottom-up or top-down

  20. The COSCAT (COastal Segmentation and related CATchment) The land ocean interface Endorheic drainage Exorheic drainage Meybeck et al, 2007

  21. The mega filters Open regional sea Enclosed sea Archipelago coast Extended platform Semi-enclosed sea Meybeck et al, 2007

  22. Zooming in Meybeck & Vorosmarty, 2005

  23. The COSCAT synthesis Meybeck et al. , 2006

  24. Anthropocene: a big change Meybeck & Vorosmarty, 2005

  25. Major regional seas and other megafilters Meybeck et al., 2007

  26. Catchment area (Ab) over basin area (Ars) Meybeck et al., in press

  27. Yearly average water runoff Meybeck et al., 2007

  28. Average population distribution over the catchment area Meybeck et al., 2007

  29. Population in the coastal areas over that in the catchment area Meybeck et al., 2007

  30. Human pressure in the Caribbean • 60 percent of the Caribbean population lives less than 100 kilometers from a coast • 30 percent of the population is under age 15 • 7 percent is over age 65 • All capital cities in insular Caribbean are on coasts • Coastal areas identified with principal industrial complexes, trade centers, and resort tourism enclaves Roger-Mark De Souza

  31. Nitrogen load increase from pre-industrial to industrial time Meybeck et al., 2007

  32. Eutophication Vitousek et al.,1997

  33. Riverine transport vs. input in the wtershed Vitousek et al.,1997

  34. River nutrient inputs • Other models make use of statistical rules and fuzzy logics (RIVERSTRAHLER, SOIL/SOILN). • Less direct measurements are needed • Lower computational demand allows combined N-P tracking in ecological coupled processes • Most of N-retention occur when agricultural leach passes through riparian wetlands (Billen & Garnier, 2000) • But low predictive power for changes in individual sources Garnier et al (2002) Forsman et al (2003) Escaravage, Herman, Carlo Heip: NIOO

  35. River nutrient inputs • Residence time in upper aquifer 1-2000 yrs (Kunkel & Wedland, 1997). • Fertilizers added last century will continue to leach from aquifers to rivers for decades (Grimval et al., 2002) • Significant amounts of nutrients are directly brought from groundwater to the sea (Gregerson, 2003) Escaravage, Herman, Carlo Heip: NIOO

  36. Atmospheric Nutrient Inputs Atmospheric input are intermittent • Large deposition of nitrogen may occur during short periods (de Leeuw et al., 2003) • Kattegat Strait: events of high deposition increase chlorophyll by 20% (Hasager et al., 2003) • About 30% of new production off Ireland supported by atmospheric N-inputs in May 1997 (Spokes et al, 2000) • 38% of summer new production off Creta sustained by P-deposition (Markaki et al., 2003) de Leeuw et al (2003) Escaravage, Herman, Carlo Heip: NIOO

  37. Fate of nutrients in coastal areas • Black Sea P, Si benthic regeneration is in the same range as Danube discharge, but intense denitrification occurs (Friedl et al., 1996). • Intense nutrient regeneration sustains the high productivity in the Black Sea coastal zone (Friedrich et al., 2002) Friedrich et al (2002) Escaravage, Herman, Carlo Heip: NIOO

  38. Fate of nutrients in coastal areas • Benthic Fe and Ca act as buffer pools that sequester P, not available for primary production (de Wit et al. 2001) • Increasing nutrient loadings push the system towards reduced states (Wijsman et al, 2002). • Eventually toxic H2S and Ca/Fe-bound P are released (Heijs et al., 2000) • Benthic system reaches a new stable state, highly reactive to nutrient enrichments (Heijs et al., 2000) Stable states Sediment Buffering H2S Nutrient enrichment Wijsman et al (2002) Escaravage, Herman, Carlo Heip: NIOO

  39. Christensen et al. (1990) Fate of nutrients in coastal areas 1.-Denitrification 2.-DNRA 3.-Nitrification • Empirically calculated denitrification rates f(NO3,O2) are no more accurate when micro/macro- benthic algae and/or macrofauna are active (Nielsen et al., 2001) • Without model improvement, nitrogen retention should still been estimated by either mass balance or in situ direct measurements (Nielsen et al., 2001). • Newly evidenced processes (DNRA, AMMANOX) are alternative pathways for denitrification (Welsh et al., 2001, Dalsgaard & Thamdrup, 2002) Kelso et al. (1997) AMMANOX Escaravage, Herman, Carlo Heip: NIOO

  40. NO3 Fate of nutrients in coastal areas DenitrificationNitrification • Micro-algae efficiently incorporate mineralized nitrogen that is no more available to bacteria for denitrification • The auto/heterotrophy of the system determines whether it acts as a sink or source of nutrients. (Risgaard & Petersen, 2003) Escaravage, Herman, Carlo Heip: NIOO

  41. DenitrificationFixation DenitrificationFixation Fate of nutrients in coastal areas • Seagrass beds act as N-sink; biomass is eventually buried or exported (Welsh et al, 2000). • Denitrification is at low rates in seagrass beds but chemistry there is far to be understood (Welsh et al., 2001) Welsh et al (2000) Escaravage, Herman, Carlo Heip: NIOO

  42. Effect of altered discharge • Six-fold increase of the non-diatom bloom (1960/1992) in Black Sea with increased nitrogen discharge (Humborg et al., 1997). • Unbalanced nutrient additions (N≫P,Si) to North Sea ecosystem induce Phaeocystis colony blooms, not grazed by copepods (Rousseau et al., 2000). • Field observations (Gasparini, 2000) and mesocosm experiments (Escaravage & Prins, 2002) suggest efficient grazing on Phaeocystiscells by ciliates after collapse of the colony bloom Rousseau et al (2000) Escaravage & Prins (2002) Escaravage, Herman, Carlo Heip: NIOO

  43. Effect of altered discharge Detritus • Acute eutrophication effects on benthic fauna through habitat alteration are rather well documented (Pearson & Rosenberg, 1978). • Tracer experiments show that benthic organisms primarily feed on fresh vegetal matter rather than detritus (Herman et al., 2000) • Macrofauna biomass also show a tight link with benthic primary production (Herman et al., 2000). Microphytobenthos Phytoplankton Escaravage, Herman, Carlo Heip: NIOO

  44. Red Tides Southern California

  45. Red Tides Florida

  46. The Redfield ratio: a key issue Is the Redfield ratio fixed? Klausmeier et al.,2004

  47. New insights

  48. Riverine transport vs. population Vitousek et al.,1997

  49. Cuba nitrogen budget Fertilizers Atmospheric deposition N import (food) Anthropogenic biological N fixation Baisre, 2006

  50. Cuba nitrogen budget Total fluxes Trend of anthrogenic impact Impact on fisheries (?) Baisre, 2006

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