Phytop l anktonNutrien t sZoopla nktonLarge-Scale VariabilityUpwellingIslandEffectDomesGyresIron FertilizationBloomsDefinitionsHNLCOligotrophicEutrophic: High ProductivityMesotrophic: ModerateOligotrophic: Low Prod.HNLC: High Nutrient, Low ChlPatterns of ProductivitySpatial-Temporal Patchiness• Steady State vs. Non-Steady State– Box Models– Chaos, Non-linearity– Spectral Analysis• Small-Scale Variability• Medium-Scale Variability• Large-Scale Variability• The Paradox of the PlanktonPatchiness Defined• Patchiness: variance about the meandistribution of some measurement thatis controlled by spatial and/or temporalprocesses• In environmental science, variance of10-30% (or more) is not uncommonMathematical Description• Patchiness is defined statistically, suchthat if there’s no patchiness, we’dexpect a random distribution:Patchiness = variance / mean< 1 = random distribution> 1 = non-uniformSteady-StateOver some appropriate time-space scale, everything balancesInflowOutflowNo changeBiological Pump Box ModelCO2 InflowPOC FluxDecompositionCO2 OutflowEl ViejoLa ViejaEl ViejoLa ViejaParentGlobal Trends: Bottom Up Forcing?Huisman and Weissing, Nature 402: 407-410An Example--Scripps PierKim et al., Progress in Oceanography, 2009An Example--Scripps PierAn Example--Scripps PierWe do not understand the factors responsible for our observed patterns, but theonshore–offshore and longshore continuity (from aerial surveys) of variations show thatthese are near-synchronous and of large spatial dimensions.Jester et al. 2009 Harmful AlgaeRelative Abundance Index, Santa Cruz WharfAge of Dinoflagellates(a short-lived age!)Spectral Analysis• Describesmathematically(statistics) howa measuredvariablechanges as afunction of scale(temporal orphysical)Four examples of Chl-a series that illustrate common annual patterns of variability.Winder M , Cloern J E Phil. Trans. R. Soc. B 2010;365:3215-3226Chaos TheoryChaotic Processes: the dynamical evolution that isaperiodic and sensitively dependent on initialconditions.• Can’t explain futurebehavior (more than afew steps in time)based on the existingstate• You CAN, however,put boundaries on itLagrangian Coherent StructuresStructures that separate dynamically distinct regions offluid in a time-varying system…. Somewhat related tochaotic oscillations (can’t predict with any certainty theinteractions of the fluid at small scales, but at largerscales LCS provides boundaries.Monterey Bay Time-SeriesMooring ‘M1’ Fluorescence01234560 50 100 150 200 250 300 350 400012345672900 3100 3300 3500 3700 3900 4100Spatial VariabilitySmall Scale Variability• Dominated by cell-scale processes– Shear, Viscosity,Diffusion– Sinking, Swimming,AggregationPhysical-Biological Interactions: Cellular LevelPhysical-Biological Interactions: Cellular Level••Increased turbulence and dinoflagellates:Increased turbulence and dinoflagellates:––Increases growth rate (followed by decrease)Increases growth rate (followed by decrease)––Increases chain formationIncreases chain formation––Increases per cell toxicity in Increases per cell toxicity in A. A. fundyensefundyense––Results in morphological changes (flagellaResults in morphological changes (flagellalength, cell size, shape)length, cell size, shape)••Diatoms and dinoflagellates:Diatoms and dinoflagellates:––Evidence for both Evidence for both allelopathy allelopathy andandallelochemical allelochemical interactionsinteractionsJuhl et al. 2001, Smayda and Reynolds 2001, Sullivan et al. 2003Physical Fronts• Langmuir Cells caused by winds• Upwelling• Downwelling• River Fronts caused by changes in density (salinity)Medium Scale VariabilityMedium-Scale patterns of phytoplankton are dominated by physical processes…the physical forcing is at a scale that is larger than the growth-dynamics of the phytoplankton cellsPhysical-Biological Interactions: AssemblagesPhysical-Biological Interactions: AssemblagesThin Layers are prevalentin upwelling systems, andfrequently concentrateharmful species….McManus et al., in prep.Upwelling relaxation:the wrong (common)viewUpwelling relaxationUpwelling relaxation2D upwelling relaxation:what really happensPhysical Fronts• Langmuir Cells caused by winds• Upwelling• Downwelling• River Fronts caused by changes in density (salinity)Columbia River: 4thlargest river in theUS, largest river (byfar) on West CoastTheory predicts a “bulge” circulationwith ~50% of the freshwater in thebulge and 50% transport north (onwest coast)Kudela et al. 2010 GRLKudela et al. 2010 GRL“Bulge-like” circulationsets up with somefrequency in coastalriver plumesDuring anomalousperiods (warm, minimalupwelling) this couldact as a biologicalrefugeProductivity and standing stock are clearlyenhanced when the bulge is present,leading to aggregation of mesozooplanktonbut no change in microzooplanktongrazing—thus leading to enhanced trophictransferKudela et al. 2010 GRLA Line in the SeaUnder the right conditions, a medium-scale event (such as the formation of a front) can become a large-scale phenomenonIsland Mass EffectDownstream from islands, youget enhanced nutrients due toturbulent mixing….Eddies and Gyres“rings” are formed whenwater breaks away froma current. Warm rings spin clockwise, coldrings spin counter-clockwise.Gyres are basin-scalewarm rings (spinningclockwise).Hurricanes and HABsHurricanes, similar to otherlarge-scale events, canpromote plankton blooms(including HABs) by openingand closing niches….Fig. 1. (A) Isopycnal displacements associated with three types of eddies.D J McGillicuddy et al. Science 2007;316:1021-1026Cyclone OpalC R Benitez-Nelson et al. Science 2007;316:1017-1021Fig. 3. Diatom biomass in the DCM.C R Benitez-Nelson et al. Science 2007;316:1017-1021Fig. 3 HYCOM model simulation of anticyclone-induced current velocities at depth.D K Adams et al. Science 2011;332:580-583A unifying theory…• Combining Lagrangian CoherentStructures, hotspots, and “paradox ofthe plankton” concepts may explain howsmall/medium scale variability relates tolarge-scale variability…d’Ovidio F et al. PNAS 2010;107:18366-18370Ecological and physical (sub-)mesoscale structure from satellite data.Identification and history of the fluid dynamical niches.d’Ovidio F et al. PNAS 2010;107:18366-18370©2010 by National Academy of SciencesSummary• The concept of “steady state” and NPZD-typemodels are useful, but biological