Realm: Freshwater
Climate: Temperate
Biome: Small river ecosystems
Central latitude: 38.073730
Central longitude: -121.822900
Duration: 50 years, from 1972 to 2021

29079 records

16 distinct species

Across the time series Neomysis mercedis is the most frequently occurring species

Methods

Curators note: The original IEP zooplankton dataset has been split by the different survey programmes due to methodological differences. The Interagency Ecological Program (IEP) is a consortium of State and federal agencies that has been conducting cooperative ecological investigations since the 1970s. The IEP runs over twenty long-term monitoring surveys on biological components of the Upper San Francisco Estuary. Surveys monitor phytoplankton, zooplankton, benthic invertebrates, water quality, and many types of fish. Several fish surveys sample zooplankton concurrently, and information on zooplankton species composition and abundance can be coupled with fish diet studies. The IEP long-term surveys that monitor zooplankton are the Environmental Monitoring Program (EMP; also known as the IEP zooplankton study), 20-mm Survey (20mm), Fall Midwater Trawl (FMWT), Summer Townet Survey (STN), the Yolo Bypass Fisheries Monitoring Survey (not included in this integrated dataset), and the Fish Restoration Program (FRP). An overview of these programs is provided in study_metadata.csv. Locations of fixed sampling locations for surveys with fixed sampling designs are provided in stations.csv, and coordinates for every sample are provided in environment.csv. Zooplankton surveys sample 3 different size classes of zooplankton, by towing nets with different sized mesh (or in one case a pump that pumps water into a microzooplankton net). Every IEP survey that collects zooplankton samples with a mesozooplankton net, which targets adult copepods and cladocerans, because these taxa are believed to comprise the majority of zooplankton in juvenile and adult planktivorous fish diets. Some surveys also sample with micro- or macro-zooplankton nets. Three size classes of zooplankton are targeted by these sampling programs with different net mesh sizes: micro zooplankton (copepods and rotifers) are targeted with a 43 µm mesh net, meso zooplankton (copepods and cladocerans) are targeted with 150 - 160 µm mesh nets, and macro zooplankton (mysids and amphipods) are targeted with 500-505 µm mesh nets. EMP Zooplankton for EMP are sampled in 3 different size ranges: microzooplankton are sampled using a pump, mesozooplankton are sampled using a modified Clarke-Bumpus net, and macrozooplankton are sampled using a mysid net. All EMP zooplankton are collected monthly at fixed stations year-round in open channels at high slack tide and preserved in 10% formalin dyed with rose bengal. Macrozooplankton and Mesozooplankton are collected using 10-minute oblique tows with a 124 cm long net with 505 µm mesh, and a 73 cm long net with 160 µm mesh, respectively. Prior to 1974, macrozooplankton were sampled with a 930 µm mesh net. Microzooplankton are collected with a Teel marine pump while the intake hose is raised through the water column and pumped into a net with 43 µm mesh. Pump samples collected approximately 1.5 - 1.9 L from 1972 2007, and 75 L from 2008 - present, measured by a digital flowmeter connected to the hose. Microzooplankton samples are passed through a 154 µm mesh sieve nested on top of a 43 µm mesh sieve in the lab, and only the smaller size fraction that passes through the larger sieve and is retained on the smaller sieve is counted. Lengths are recorded for macrozooplankton (but not included in this dataset), and biomass is estimated by length-weight equations for macrozooplankton and by average values for mesozooplankton and microzooplankton (biomass_mesomicro.csv).

Citation(s)

@Dataset{BioTIME_cit332, Study_id = {558}, Citation_id = {332}, Author = {Bashevkin, S.M. and Hartman, R. and Thomas, M. and Barros, A. and Burdi, C.E. and Hennessy, A. and Tempel, T. and Kayfetz, K. and Alstad, K. and Pien, C.}, Publisher = {Environmental Data Initiative}, Title = {Interagency Ecological Program: Zooplankton abundance in the Upper San Francisco Estuary from 1972-2021, an integration of 7 long-term monitoring programs ver 4}, Year = {2023}, Doi = {10.6073/pasta/8b646dfbeb625e308212a39f1e46f69b}, Url = {https://doi.org/10.6073/pasta/8b646dfbeb625e308212a39f1e46f69b}, Language = {English}, Version = {4} }