Realm: Freshwater
Climate: Temperate
Biome: Small lake ecosystems
Central latitude: 43.196619
Central longitude: -75.919813
Duration: 32 years, from 1975 to 2006
30307 records
31 distinct species
Across the time series Diaptomus minutus is the most frequently occurring species
Methods
Zooplankton samples were collected at variable intervals throughout the year from 1964 to 1974 at the Shackelton Point site and atweekly intervals from 1975 to the end of the data series during May - October. and from November - April as weather permitted. at 1to 6 sites. The main site used was Shackelton Point. Because one site (Billington Bay) was only sampled some years. it is notincluded in the weekly average table. This table averages data taken from five sites (Shackelton Point. Buoy 109. 117 and 125. andThree Mile Bay) collected during the same sampling week. Sampling week is identified with a number that in most cases is the sameas the week number of the year. On a small number of occasions. a sampling was conducted on a Friday to Sunday for the followingweek. The net used was a 153-um mesh nylon net (0.5 m diameter) towed vertically from 0.5 m off the sediment surface to the watersurface. The efficiency of the net was measured with flow meters from 1999 to present. If flow meter readings indicate a malfunctionor human error (efficiencies below 50% and above 125%) and when no flow meter was used. we assumed an efficiency of 87.4%(average of the 1999 to 2010 sampling period 87.4% SD 9.5%. N=1655). Flow meters were calibrated each year. When flow meterswere not available. volume strained was calculated as[Vol Strained] = [Tow Depth] * pi()*0.25^2*0.874Samples were preserved in 8 % sugar-formalin solution (1964-1996) or 70 % ethyl alcohol (1997-present). Samples are stored at theCornell Biological Field Station.Crustacean zooplankton were counted (1964-1974) and counted and measured (1975-end of data series) using a dissectingmicroscope (1964-1982). a touch screen-caliper setup with computer-assisted plankton analysis system (1983-1997) (WSAM.Hambright and Fridman 1994) or a digitizing tablet and microscope (1998-end of the data series). For each sample. a 1-mLsub-sample was drawn with a calibrated Hensen-Stempel pipette or large-bore calibrated automatic pipette and all crustaceanscounted and measured (since 1975). Additional sub-samples were drawn until a minimum of 100 animals were counted andmeasured from each sample. From 1964 to 1979. three such subsamples were counted and averaged. Gamble et al. (2006)compiled the data from 1975 to 1997 for a study on biomass size spectrum and re-measured historic samples from 1975 when onlyDaphnia were measured. Unrealistic length measurements sometimes substantially (for small cladocerans) outside acceptedmaximum lengths occurred on a small number of occasions and were assumed to be in error. They were replaced by the modallength for small cladocerans and the maximum accepted length for other species [25 of 39398 Bosmina. 146 of 28882 Chydorus. 16of 7035 Diaphanosoma. 8 of 22767 Eubosmina. 4 of 77932 Diacyclops and 82 of 61208 nauplii] Biomass for individual species wascalculated using length-weight regressions based mainly on Bottrell et al. (1976) and summarized in Watkins et al. (2011).Length-weight parameters are included in the taxa table. For years without length measurements (1964 to 1974 and 1978). thebiomass is estimated from the average weight of the species or species group calculated for the time period 1975 to 1981 and givenin the taxa table. Taxonomic detail varies over time. For the period 1964 to 1974 all crustacean were categorized in 10 speciesgroups: Bosmina. Ceriodaphnia. Chydorus. Daphnia pulicaria. D. mendotae. D. retrocurva. Leptodora. Diaphanosoma. calanoidcopepods and cyclopoid copepods. Nauplii were excluded in 1964-74. Information on the taxonomic details is in the taxa table.Copepod nauplii were counted since 1975 but not identified to group. Nauplii are underestimated due to the large mesh size (153_m).Rotifers and zebra mussel veligers are not included in this data set. More information regarding specifics of data collection isavailable from the data package contact. Individual length data can be requested from the data package contact for the post 1998time period. Unit of abundance = CountPerSqM, Unit of biomass = DryBiomass
Citation(s)
Rudstam, L. (2008) “Zooplankton survey of Oneida Lake, New York, 1964 – 2012”, KNB Data Repository. Available at: https://knb.ecoinformatics.org/#view/kgordon.17.56, accessed 2016.