Intercomparison of zooplankton (net) sampling systems: Results from the ICES/GLOBEC sea-going workshop

Abstract An inter-comparison and evaluation of methods for sampling and determination of zooplankton distribution and biomass was conducted in a fjord environment (Storfjorden at More, Norway) from 2 to 13 June 1993. The inter-comparison was carried out with the German R/V “ A. v. Humboldt ” and the Norwegian R/V “ Johan Hjort ” and involved a total number of 38 scientific personnel from 8 countries. The inter-comparisons included the MOCNESS, BIONESS, MultiNet, LHPR, OPC, CPR, Gulf-V, CalCOFI 1-m Ring Net, and WP-2 net. In addition, acoustics data were collected with a Simrad EK500 echosounder operating on 4 frequencies (18, 38, 120, 200 kHz) and hydrographic, nutrient, phytoplankton, and meteorological data were collected to characterize the environment in which the comparisons were made; environmental changes were minor during the study. The results of this study corroborate the results of earlier studies. Mesh size of the net had a major influence on the biomass and species composition of the zooplankton community. There is a consistent relationship between retention (or escapement through the mesh) and the width of the organisms; about 50% of the organisms escape through the mesh at a width equal to the mesh size. The effect of towing speed on the extrusion of smaller organisms through the net can be substantial and adds to the loss due to escapement. Active avoidance of the sampler is only important for the larger macrozooplankton and not a significant problem for the mesozooplankton. Different vertical, oblique, and multiple opening/closing net systems produced similar estimates of zooplankton when operated with comparable mesh-sized nets and a sufficiently high mesh open area to mouth opening ratio. The choice of mesh size is important and 150 μm mesh is possibly an optimal mesh size for use in coastal waters with neritic zooplankton communities. Replicate tow variability was also consistent with earlier studies and reflects the need to understand the interplay between the underlying patchiness of the zooplankton distributions and the method of sampling. No single net is suitable to sample across the wide size range of zooplankton from small mesozooplankton to macrozooplankton. Recent large interdisciplinary programs to assess marine ecosystem structure and dynamics have recognized this through the use of nets designed to sample particular size fractions in combination with video and acoustic remote sensing techniques.

[1]  V. Hensen.  Methodik der Untersuchungen , 1895 .

[2]  M. Heath,et al.  Field calibration of the Optical Plankton Counter with respect to Calanus finmarchicus , 1999 .

[3]  T. Kiørboe.  A Mechanistic Approach to Plankton Ecology , 2008 .

[4]  J. H. Nichols,et al.  Flume tank experiments to estimate the volume filtered by highspeed plankton samplers and to assess the effect of net clogging , 1993 .

[5]  A. Saville.  Mesh Selection in Plankton Nets , 1958 .

[6]  K. Brander,et al.  Diel differences in avoidance of three vertical profile sampling gears by herring larvae , 1989 .

[7]  P. Dalpadado,et al.  Abundance, maturity and growth of the krill species Thysanoessa inermis and T. longicaudata in the Barents Sea , 1996 .

[8]  Maria Stehle,et al.  Comparison of zooplankton sampling performance of Longhurst-Hardy Plankton Recorder and Bongo nets , 2007 .

[9]  M. W. Johnson,et al.  A statistical analysis of the performance of the folsom plankton sample splitter, based upon test observations , 1954 .

[10]  A. Bradley,et al.  Assessing the distribution and abundance of zooplankton: a comparison of acoustic and net-sampling methods with D-BAD MOCNESS , 1998 .

[11]  J. Colton,et al.  Bongo Net Retention Rates as Effected by Towing Speed and Mesh Size , 1980 .

[12]  P. Wiebe.  A Field Investigation of the Relationship Between Length of Tow, Size of Net and Sampling Error , 1972 .

[13]  K. Foote,et al.  Sampling and experimental design , 2000 .

[14]  R. Williams,et al.  The double LHPR system, a high speed micro- and macroplankton sampler , 1983 .

[15]  D. Robins,et al.  Is Oithona the most important copepod in the world's oceans? , 2001 .

[16]  R. Marak,et al.  The MARMAP Bongo Zooplankton Samplers , 1980 .

[17]  Peter H. Wiebe,et al.  PLANKTON PATCHINESS: EFFECTS ON REPEATED NET TOWS1 , 1968 .

[18]  Richard D. Methot.  Frame trawl for sampling pelagic juvenile fish , 1986 .

[19]  V. Siegel,et al.  Distribution and demography of Antarctic krill in the Southeast Atlantic sector of the Southern Ocean during the austral summer 2008 , 2010, Polar Biology.

[20]  Peter H. Wiebe,et al.  Video plankton recorder estimates of copepod, pteropod and larvacean distributions from a stratified region of Georges Bank with comparative measurements from a MOCNESS sampler , 1996 .

[21]  P. Wiebe,et al.  Longhurst-hardy Plankton recorders: their design and use to minimize bias , 1976 .

[22]  M. Evans,et al.  Mesh size and collection characteristics of 50-cm diameter conical plankton nets , 1985, Hydrobiologia.

[23]  R Iturriaga,et al.  Temporal and spatial variability of chroococcoid cyanobacteria Synechococcus spp. specific growth rates and their contribution to primary production in the Sargasso Sea , 1988 .

[24]  H. Weikert,et al.  Experiences with a modified Bé multiple opening-closing plankton net , 1981 .

[25]  D. Slagstad,et al.  Habitat selection of overwintering Calanus finmarchicus in the NE Norwegian Sea and shelf waters off Northern Norway in 2000–02 , 2003 .

[26]  K. R. Clarke,et al.  Change in marine communities : an approach to statistical analysis and interpretation , 2001 .

[27]  Mark Dickey-Collas,et al.  Descriptions of the Gulf VH/PRO-NET and MAFF/Guildline unencased high-speed plankton samplers , 1998 .

[28]  W. Melle,et al.  Zooplankton reproduction in the Barents Sea vertical distribution of eggs and nauplii of Calanus finmarchicus in relation to spring phytoplankton development , 1989 .

[29]  S. Motoda.  Devices of Simple Plankton Apparatus , 1959 .

[30]  J. Downing,et al.  A Manual on Methods for the Assessment of Secondary Productivity in Fresh Waters , 1984 .

[31]  P. Wiebe.  A COMPUTER MODEL STUDY OF ZOOPLANKTON PATCHINESS AND ITS EFFECTS ON SAMPLING ERROR1 , 1971 .

[32]  N. Halliday,et al.  A comparison of morphometric and geometric methods for the estimation of individual zooplankton volumes , 2001 .

[33]  J. H. Nichols,et al.  Mesh selection of copepodite and nauplius stages of four calanoid copepod species , 1991 .

[34]  W. Hagen,et al.  Biomass and abundance , 2000 .

[35]  M. Ewing,et al.  A Quantitative Multiple Opening-and-Closing Plankton Sampler for Vertical Towing , 1959 .

[36]  L. Hernroth.  Sampling and filtration efficiency of two commonly used plankton nets. A comparative study of the Nansen net and the Unesco WP 2 net , 1987 .

[37]  W. Melle,et al.  Reproduction and development of Calanus finmarchicus, C. glacialis and C. hyperboreus in the Barents Sea , 1998 .

[38]  J. Gamble,et al.  The Early Life History of Fish , 1974, Springer Berlin Heidelberg.

[39]  W. Gurney,et al.  Comparative ecology of over-wintering Calanus finmarchicus in the northern North Atlantic, and implications for life-cycle patterns , 2004 .

[40]  M. Bernhard,et al.  Influence of pore size of plankton nets and towing speed on the sampling performance of two high-speed samplers (Delfino I and II) and its consequences for the assessment of plankton populations , 1973 .

[41]  Paul Harris,et al.  Sampling and Statistics , 1993 .

[42]  P. Wiebe,et al.  From the Hensen net toward four-dimensional biological oceanography , 2003 .

[43]  Alex W. Herman,et al.  Design and calibration of a new optical plankton counter capable of sizing small zooplankton , 1992 .

[44]  Carl Smith,et al.  A comparison of LHPR and OPC data from vertical distribution sampling of zooplankton in a Norwegian fjord , 2001 .

[45]  An analysis of a zooplankton sampling-gear change in the CalCOFI long-term monitoring program, with implications for copepod population abundance trends , 2002 .

[46]  E. Hagen,et al.  Large-Scale and Mesoscale Distribution of Plankton Biomass and Metabolic Activity in the Northeastern Central Atlantic , 1999 .

[47]  E. Durbin,et al.  Abundance and spatial distribution of copepods on Georges Bank during the winter/spring period , 2006 .

[48]  Pierre Pepin,et al.  Variability and capture efficiency of bongo and Tucker trawl samplers in the collection of ichthyoplankton and other macrozooplankton , 1997 .

[49]  John A. McGowan,et al.  A NEW OPENING - CLOSING PAIRED ZOOPLANKTON NET, , 1966 .

[50]  H. Bjørke,et al.  Efficiency Test on Four High-Speed Plankton Samplers , 1974 .

[51]  Mark D. Ohman,et al.  A COMPARISON OF ZOOPLANKTON SAMPLING METHODS IN THE CALCOFI TIME SERIES , 1995 .

[52]  A. Bradley,et al.  New development in the MOCNESS, an apparatus for sampling zooplankton and micronekton , 1985 .

[53]  D. Markle,et al.  An evaluation of accuracy, precision, and speed of several zooplankton subsampling techniques , 1982 .

[54]  Estimates of zooplankton abundance and size distribution with the Optical Plankton Counter (OPC) , 1997 .

[55]  Robin A. Clark,et al.  A critical comparison of two long-term zooplankton time series from the central-west North Sea , 2001 .

[56]  A. Remsen,et al.  What you see is not what you catch: a comparison of concurrently collected net, Optical Plankton Counter, and Shadowed Image Particle Profiling Evaluation Recorder data from the northeast Gulf of Mexico , 2004 .

[57]  K. Bailey,et al.  Comparative analysis of ichthyoplankton sampling gear for early life stages of walleye pollock (Theragra chalcogramma) , 1994 .

[58]  C. A. Kofoid.  ON SOME IMPORTANT SOURCES OF ERROR IN THE PLANKTON METHOD. , 1897, Science.

[59]  P. Wiebe,et al.  Patterns and Processes in the Time-Space Scales of Plankton Distributions , 1978 .

[60]  Mark F. Baumgartner,et al.  Comparisons of Calanus finmarchicus fifth copepodite abundance estimates from nets and an optical plankton counter , 2003 .

[61]  M. Anraku.  SOME EXPERIMENTS ON THE VARIABILITY OF HORIZONTAL PLANKTON HAULS AND ON THE HORIZONTAL DISTRIBUTION OF PLANKTON IN A LIMITED AREA , 1956 .

[62]  D. Caron,et al.  Video plankton recorder reveals high abundances of colonial Radiolaria in surface waters of the central North Pacific , 2002 .

[63]  A. Longhurst,et al.  A new system for the collection of multiple serial plankton samples , 1966 .

[64]  D. Hartline,et al.  Escape behavior of planktonic copepods in response to hydrodynamic disturbances: high speed video analysis , 2002 .

[65]  Improved agreement of net and acoustical methods for surveying euphausiids by mitigating avoidance using a net-based LED strobe light system , 2013 .

[66]  Paul E. Smith,et al.  Changes in Filtering Efficiency of Plankton Nets Due to Clogging Under Tow , 1968 .

[67]  J. Blaxter.  The Early life history of fish : the proceedings of an international symposium held at the Dunstaffnage Marine Research Laboratory of the Scottish Marine Biological Association at Oban, Scotland, from May 17-23, 1973 , 1974 .

[68]  W. G. Warren,et al.  Comparison of Catch Rates among Small and Large Bongo Sampler for Calanus finmarchicus Copepodite Stages , 1991 .

[69]  H. Gjøsæter,et al.  Impact of grazing from capelin (Mallotus villosus) on zooplankton: a case study in the northern Barents Sea in August 1985 , 1991 .

[70]  G. Hays.  Mesh selection and filtration efficiency of the Continuous Plankton Recorder , 1994 .

[71]  S. Batten,et al.  Mesozooplankton biomass in the Celtic Sea: a first approach to comparing and combining CPR and LHPR data , 1999, Journal of the Marine Biological Association of the United Kingdom.

[72]  V. Mohrholz,et al.  Zooplankton biomass variability off Angola and Namibia investigated by a lowered ADCP and net sampling , 2007 .

[73]  R. Lough,et al.  A direct comparison of MOCNESS and Video Plankton Recorder zooplankton abundance estimates : Possible applications for augmenting net sampling with video systems , 2006 .

[74]  D. D. Sameoto,et al.  BIONESS, a New Design in Multiple Net Zooplankton Samplers , 1980 .

[75]  H. Gjøsæter,et al.  A comparison of performance of WP2 and MOCNESS , 2000 .

[76]  D. Sameoto,et al.  Convergence of Acoustic, Optical, and Net-Catch Estimates of Euphausiid Abundance: Use of Artificial Light to Reduce Net , 1993 .

[77]  S. M. Marshall,et al.  On the variability of replicate plankton samples and some applications of ‘contagious’ series to the statistical distribution of catches over restricted periods , 1951, Journal of the Marine Biological Association of the United Kingdom.

[78]  Ph Wiebe,et al.  A multiple opening/Closing net and environment sensing system for sampling zooplankton , 1976 .

[79]  O. Godø,et al.  Catchability of pelagic trawls for sampling deep-living nekton in the mid-North Atlantic , 2011 .

[80]  G. Hays,et al.  Comparison of the epipelagic zooplankton samples from a U-Tow and the traditional WP2 net , 2001 .

[81]  C. Davis,et al.  Using a high-powered strobe light to increase the catch of Antarctic krill , 2004 .