Effect of sampling effort and sampling frequency on the composition of the planktonic crustacean assemblage: a case study of the river Danube

Abstract

Although numerous studies have focused on the seasonal dynamics of riverine zooplankton, little is known about its short-term variation. In order to examine the effects of sampling frequency and sampling effort, microcrustacean samples were collected at daily intervals between 13 June and 21 July of 2007 in a parapotamal side arm of the river Danube, Hungary. Samples were also taken at biweekly intervals from November 2006 to May 2008. After presenting the community dynamics, the effect of sampling effort was evaluated with two different methods; the minimal sample size was also estimated. We introduced a single index (potential dynamic information loss; to determine the potential loss of information when sampling frequency is reduced. The formula was calculated for the total abundance, densities of the dominant taxa, adult/larva ratios of copepods and for two different diversity measures. Results suggest that abundances may experience notable fluctuations even within 1 week, as do diversities and adult/ larva ratios.

Spatial Variation of Structural and Functional Indicators in a Large New Zealand River

“…Vadadi‐Fülöp et al . () reported marked short‐term variations over weekly timescales in the abundance and diversity of planktonic crustaceans in the Danube River, suggesting that temporal variation can be high and frequent sampling may be required to represent site conditions. Zooplankton abundances tend to be less variable in main channel habitats compared with backwaters (Burdis and Hoxmeier, ), and Dickerson et al .…”

“…In our study, plankton groups showed variable responses to local habitat conditions and reach-scale differences in water quality. Vadadi-Fülöp et al (2010) reported marked short-term variations over weekly timescales in the abundance and diversity of planktonic crustaceans in the Danube River, suggesting that temporal variation can be high and frequent sampling may be required to represent site conditions. Zooplankton abundances tend to be less variable in main channel habitats compared with backwaters (Burdis andHoxmeier, 2011), andDickerson et al (2010) concluded that hydrology must be accounted for before zooplankton can be used as indicators of environmental stress because they respond to flow characteristics as well as local environmental conditions such as water temperature.…”

Climate change and plankton phenology in freshwater: current trends and future commitments

“…Much of the selected papers derived their findings from samples collected at weekly and fortnightly intervals at least during the growing season, which is a common and recognised method in limnology, although significant variation in community dynamics of zooplankton may remain hidden at fortnightly sampling (Vadadi-Fülöp et al, 2010).…”