LISST‐100 measurements of phytoplankton size distribution: evaluation of the effects of cell shape

Information on cell size is central to studies of phytoplankton ecology, yet in situ measurements of particle size distribution remain a challenge. The LISST-100 (Laser In Situ Scattering and Transmissometry; Sequoia Scientific, Inc.) is one of few commercially available instruments that provide autonomous measurements of size distributions of suspended particles in situ. Its capability to size phytoplankton needs to be evaluated, however, for two reasons. First, size is not measured directly; rather, information on size is obtained from near-forward scattering measurements that are inverted to obtain size distributions. The inversion assumes that particles are homogeneous spheres. Phytoplankton, however, display a wide range of cell shapes and their scattering behavior is likely to be different from that of spheres. Second, the LISST-100 was originally designed for sediments and its inversion assumes an index of refraction typical of inorganic particles. We compared size and volume concentration distributions obtained by the LISST-100 to those derived via microscopy for phytoplankton cultures of different cell sizes and shapes. Results demonstrate the success of the LISST-100 in measuring size and volume concentrations of cells with a cell aspect ratio that is close to 1 and illustrate its limitations when nonspherical cells are present in the sample. Uses of the LISST-100 in laboratory and field studies are discussed in light of the results from this study.

[1]  B. C. Booth.  The Use of Autofluorescence for Analyzing Oceanic Phytoplankton Communities , 1987 .

[2]  T. Kiørboe.  Small-scale turbulence, marine snow formation, and planktivorous feeding , 1997 .

[3]  G. Dubelaar,et al.  CytoBuoy: a step forward towards using flow cytometry in operational oceanography* , 2000 .

[4]  D. Kamykowski,et al.  The temperature acclimatized swimming speed of selected marine dinoflagellates , 1986 .

[5]  T. Serra,et al.  The role of advection and turbulent mixing in the vertical distribution of phytoplankton , 2003 .

[6]  Colin S. Reynolds,et al.  The ecology of freshwater phytoplankton , 1984 .

[7]  U. Sommer.  Some size relationships in phytoflagellate motility , 1988, Hydrobiologia.

[8]  Michael S. Twardowski,et al.  Particulate backscattering ratio at LEO 15 and its use to study particle composition and distribution , 2004 .

[9]  Marcel J. W. Veldhuis,et al.  Phaeocystis blooms and nutrient enrichment in the continental coastal zones of the North sea , 1987 .

[10]  S. Chisholm,et al.  PATTERNS OF CELL SIZE CHANGE IN A MARINE CENTRIC DIATOM: VARIABILITY EVOLVING FROM CLONAL ISOLATES 1 , 1992 .

[11]  Robert J. Olson,et al.  An automated submersible flow cytometer for analyzing pico- and nanophytoplankton: FlowCytobot , 2003 .

[12]  Iain Maccallum,et al.  The measurement and modelling of light scattering by phytoplankton cells at narrow forward angles , 2004 .

[13]  Helmut Hillebrand,et al.  BIOVOLUME CALCULATION FOR PELAGIC AND BENTHIC MICROALGAE , 1999 .

[14]  Y. C. Agrawal,et al.  Instruments for particle size and settling velocity observations in sediment transport , 2000 .

[15]  D. Mann,et al.  Experimental studies on sexual reproduction in diatoms. , 2004, International review of cytology.

[16]  Augustin-Louis Cauchy.  Oeuvres complètes: Mémoire sur la rectification des courbes et la quadrature des surfaces courbes , 2009 .

[17]  A. Bricaud,et al.  Theoretical results concerning light absorption in a discrete medium, and application to specific absorption of phytoplankton , 1981 .

[18]  T. Christensen,et al.  The Diatoms. Biology and Morphology of the Genera , 1991 .

[19]  B. R. Jennings,et al.  Particle size measurement: the equivalent spherical diameter , 1988, Proceedings of the Royal Society of London. A. Mathematical and Physical Sciences.

[20]  H. V. Hulst.  Light Scattering by Small Particles , 1957 .

[21]  A. Basset,et al.  Body size–abundance distributions of nano- and micro-phytoplankton guilds in coastal marine ecosystems , 2005 .

[22]  C. Lancelot,et al.  Autoecology of the Marine Haptophyte Phaeocystis sp. , 1998 .

[23]  J. Colomera,et al.  The role of advection and turbulent mixing in the vertical distribution of phytoplankton , 2003 .

[24]  C. Goldman,et al.  A Freshwater “Red Tide” on Clear Lake, California1 , 1971 .

[25]  S. Menden‐Deuer,et al.  Effect of preservation on dinoflagellate and diatom cell volume, and consequences for carbon biomass predictions , 2001 .

[26]  Francisco Pedocchi,et al.  Evaluation of the LISST-ST instrument for suspended particle size distribution and settling velocity measurements , 2006 .

[27]  Lee Karp-Boss,et al.  INHERENT OPTICAL PROPERTIES OF NON-SPHERICAL MARINE-LIKE PARTICLES — FROM THEORY TO OBSERVATION , 2007 .

[28]  U. Pollingher.  Phytoplankton periodicity in a subtropical lake (Lake Kinneret, Israel) , 1984, Hydrobiologia.

[29]  James D. Irish,et al.  A laboratory evaluation of the laser in situ scattering and transmissometery instrument using natural sediments , 1999 .

[30]  T. Smayda.  The suspension and sinking of phytoplankton in the sea , 1970 .

[31]  L. E. Paramonov.  Optical equivalence of the randomly oriented ellipsoidal and polydisperse spherical particles: extinction, scattering, and absorption cross sections , 1994, Remote Sensing.

[32]  Miroslaw Jonasz,et al.  Nonsphericity of suspended marine particles and its influence on light scattering1 , 1987 .

[33]  E. Boss,et al.  Calibrated near-forward volume scattering function obtained from the LISST particle sizer. , 2006, Optics express.

[34]  T. Serra,et al.  Evaluation of Laser In Situ Scattering Instrument for Measuring Concentration of Phytoplankton, Purple Sulfur Bacteria, and Suspended Inorganic Sediments in Lakes , 2001 .

[35]  W. Steen.  Absorption and Scattering of Light by Small Particles , 1999 .

[36]  Andrea Rinaldo,et al.  Microbial size spectra from natural and nutrient enriched ecosystems , 2001 .

[37]  T. Serra,et al.  Spatio-temporal heterogeneity in a planktonic Thiocystis minor population, studied by laser in situ particle analysis , 2003 .

[38]  D. H. Jewson,et al.  Size reduction, reproductive strategy and the life cycle of a centric diatom , 1992 .

[39]  S. Grant,et al.  Size distribution, sources, and seasonality of suspended particles in southern California marine bathing waters. , 2007, Environmental science & technology.

[40]  Eyvind Aas,et al.  Refractive index of phytoplankton derived from its metabolite composition , 1996 .

[41]  R. Crawford.  The role of sex in the sedimentation of a marine diatom bloom , 1995 .

[42]  B. Osborne,et al.  Light and Photosynthesis in Aquatic Ecosystems. , 1985 .

[43]  V. Chepurnov,et al.  RELATIONSHIPS BETWEEN GROWTH RATE, CELL SIZE, AND INDUCTION OF SPERMATOGENESIS IN THE CENTRIC DIATOM THALASSIOSIRA WEISSFLOGII (BACILLARIOPHYTA) 1 , 2006 .

[44]  V. Bricelj,et al.  Aureococcus anophagefferens: Causes and ecological consequences of brown tides in U.S. mid‐Atlantic coastal waters , 1997 .