7/25/2019 Comparison Sampling Methods Zooplakcton Riverine
2011
1/1
2011 E. Schweizerbartsche Verlagsbuchhandlung, Stuttgart,
Germany
DOI: 10.1127/1868-5749/2011/0048
www.schweizerbart.de
1868-5749/2011/0048 $ 5.40
A comparison of sampling methods for riverine zooplankton
Tamara D. Sluss1, Jeffrey D. Jack* and James H. Thorp2
with 5 figures and 1 table
Abstract:Research of zooplankton in large rivers is more recent
and less common than lentic and marine studies
and over ten different sampling devices have been used to sample
riverine zooplankton around the world to date.
The objectives of this study were to (i) demonstrate the need
for standardizing collection methods for riverine zoo-
plankton; (ii) report the results of field tests on the relative
effectiveness of three sampling devices (alpha bottle,
Schindler trap, and manual bilge pump) in collecting copepods,
cladocerans, and rotifers from a large river during
low and high flow periods at two depths in the Ohio River; and
(iii) discuss advantages and disadvantages of sam-
pling devices and provide sampling suggestions based on this
field study and experience sampling riverine zoo-
plankton. Our results indicate that there is great variability
in the densities of zooplankton captured by different
sampling devices and variability between replicate measurements
of the same sampling device. The alpha bottle and
the pump collected significantly different densities of every
taxa (excepting Bosmina) with significant differences
due to sampling device. All other taxa showed no significant
differences between devices indicating that the Schind-
ler may be the least effective of the three devices. The
Schindler captured less total zooplankton than the other de-
vices and those differences were driven by the capture of fewer
Bosmina and Keratellaby the Schindler device.
Additionally, during the three sampling events, there were only
significant differences between samples taken from
different depths for cyclopoid copepods indicating a relatively
well-mixed sampling region both vertically and later-
ally, from shore to channel. Although this study was conducted
in only one large river and across two sampling
seasons, the differences due to sampling device makes it clear
that conclusions drawn from cross-study comparisons
when different sampling devices were used are precarious. It may
be proper for river researchers to standardize col-
lection methods while also becoming aware of the consequences of
using different methods in various riverine
habitats and during disparate seasonal and hydrologic
conditions.
Keywords:Riverine zooplankton, sampling, comparative methods
River Systems Vol. 19/4, p. 315326published online November
2011
Addresses of the authors:1Division of Math and Sciences,
Kentucky State University, Frankfort, KY 40601
([email protected])2Kansas Biological Survey and Department of
Ecology and Evolutionary Biology, University of Kansas, Lawrence,
KS 66047-3759
USA ([email protected])
*Deceased
Article
Introduction
The need for standardized collection methodsfor riverine
zooplankton
Zooplankton are important consumers in many aquatichabitats
(Williamson 1987) and can be vital conduits forenergy and material
transfers from suspended algae anddetritus to higher trophic levels
(Mallin & Paerl 1994).
Their crucial role in riverine food webs have only just re-
ceived attention in fundamental ecological research (e.g.,Thorp
et al. 1994, Kobayashi 1997, Gosselain et al. 1998,Jack & Thorp
2002, Thorp & Mantovani 2005). Zoo-
plankton occur along the longitudinal dimension of
rivers(headwaters to the mouth) in two broad areas: higher
flow,main channel habitats and lower to zero flow,
slackwaterhabitats (side channels, bays, near shore, etc.)
(Lair,2006). Densities and growth rates are considerably greaterin
slackwaters, probably primarily because of low turbu-
lence and greater water retention which affect recruit-
