Variability in Plankton and Particle Size Distributions (PSDs) in different ocean basins

Romagnan, J.B., Roullier, F., Guidi, L., Forest A., Vandromme, P., Picheral, M., Jackson, G., Checkley, D., Stemmann, L.

UPMC Université Paris 06, UMR7093, Laboratoire d’Océanographie de Villefranche,

Takuvik Joint International Laboratory, Université Laval (Canada) - CNRS (France),

Department of Oceanography Texas A&M

Scripps Institution of Oceanography, University of California,

SS72: Studies of Zooplankton and other Particles using Optical Instruments

The same questions, new toolsThe same questions, new tools

What (species, size)?

How many ?

What are they doing ?

PLANKTONVictor Hensen (1835 - 1924)

MARINE SNOWSuzuki and Kato, 1953

Particle-zooplankton interactions in the ocean using new tools

(images, optics)

Particle-zooplankton interactions in the ocean using new tools

(images, optics)

Stemmann and Boss, 2012in the Med Sea, zooplankton 15% of total objectsin the Arctic, zooplankton 1-50% of total objects

Jackson and Checkley, 2011in Monterey Bay, zooplankton 1-60% of all objects

200 profils of the UVP4 (6 years of sampling) 50-1000m, no size measurments

Stemmann et al., 2008a and b

Sarcodines : an important component of macrozooplankton community (<40%). Definition of 9 provinces that fits Longhurst biogeochemical regions

Stemmann et al., 2008

• to assess the vertical distribution of particles/zooplankton

• to assess the relative importance of crustacean/sarcodine

• impact of the nature of the trophic state, or of the geographical position on the observed patterns

Sampling and Hardware (UVP6)Sampling and Hardware (UVP6)

1060 profiles (0-2000m, 50m3) 4 years of sampling

Mediterranean Sea: BOUM, TARA2009Atlantic: LOHAFEX, TARA 2010, TARA2012Arctic sea: MALINAPacific Ocean: OPEREX,GATEKEEPER, TARA 2011Indian Ocean: TARA 2010S. Indian Ocean: KEOPS2

Picheral et al., 2010

(Please see the HydroptiC stand for details)

Computer assisted recognition and morphologyComputer assisted recognition and morphology

Vertical profiles of vignettes >500µm

TRAINING SET

Defining groups 1Cross-validation

2

Prediction by the model

Accuracy (confusion matrix)

PREDICTION in 5-10 groups

3 Manual validation in 15 taxa

Vandromme et al., 2012

How accurate are the abundance and size estimates of zooplankton ?How accurate are the abundance and size estimates of zooplankton ?

Lab calibration

in situ validation MALINA (Forest et al., 2012)

Mean concentration of main zooplankton taxa during all cruisesMean concentration of main zooplankton taxa during all cruises

0-200mParticles >80%Among livingSarcodines 45%Crustacean 30%Gelatinous carn. 10%Gelatinous filt. 5%Other 10%

Zooplankton and particles abundances (0-200 m, ind m-3)Zooplankton and particles abundances (0-200 m, ind m-3)

Mean vertical profiles of main zooplankton taxa during all cruisesMean vertical profiles of main zooplankton taxa during all cruises

ResultsResults

0-200 m

200-1000 m

Conclusion - PerspectivesConclusion - Perspectives

1. Imaging sensors are now available for global monitoring

2. Globally 80% of all objects >500µm are non living (marine snow+pellets)

3. Among living 40% are sarcodines, 30% crustaceans, but sarcodines mainly populate tropical waters (that were mainly visited)

1. Differentiate among groups

2. Relate zooplankton and particle size distributions to investigate the trophic and vertical couplings

3. Miniaturization of the UVP5 to equipped profiling floats

Thank you

By the way, do you know what they are ???

System Where Technology Size-spectra Reference

LISST Lab/in situ Laser 1.25 – 500 μm

Karp-Boss et al. 2007

LOPC lab/in situ Laser beams 100 – 3000 Herman et al. 2004

HoloMar in situ Holography 5 – 250 μm Katz et al. 1999

SIPPER in situ Linescan-Camera >100 µm Samson et al. 2001

UVP in situ Camera CCD 100 – few cm Picheral et al. 2010

Par Cam in situ Camera Wefer and Ratmeyer, 1996; Iversen et al., 2001

VPR in situ Camera 100 – 1 cm Davis et al. 1992

ISIIS in situ Line scanning camera

100-few cm Cowen and Guigand, 2008

Non exhaustive review of instruments sizing particles used in marine systems Non exhaustive review of instruments sizing particles used in marine systems

0-200mSarcodines 45%Crustacean 30%Gelatinous carn. 10%Gelatinous filt. 5%Other 10%

200-1000mSarcodines xx%Crustacean xx%Gelatinous carn. xx%Gelatinous filt. x%Other xx%