Hydrological connection links zooplankton communities and improves juvenile Chinook salmon growth in intertidal wetlands

Corline, Nicholas 1 ; Levinson, Marissa2; Christe, Noah3; Peek, Ryan1; Jeffres, Carson1

Published Nov 14, 2025 on Dryad. https://doi.org/10.5061/dryad.6hdr7srdn

Data files

Nov 14, 2025 version files 282.95 KB

fish_data.csv

6.75 KB
fish_gut_contents.csv

134.29 KB
README.md

3.15 KB
wq.csv

16.53 KB
zoop_raw.csv

112.12 KB
zoop_wq.csv

10.11 KB

Abstract

Many once coupled habitats are now disconnected due to human infrastructure that prevents not only the transfer of organisms but also fundamental ecosystem processes. Here we investigate the importance of hydrologic connectivity between remnant floodplain and freshwater intertidal marsh habitats for zooplankton metacommunity dynamics and juvenile Chinook salmon growth in the Sacramento-San Joaquin Delta, California, U.S.A. Hydrological connection led to highly similar zooplankton communities between habitats. Further, we found that connected intertidal marsh habitats had approximately twice the total abundance of zooplankton of upstream floodplains and, in some cases, 15 times greater abundance than during disconnection. Gut content analysis demonstrated that salmon in our study utilized these abundant and high-value zooplankton food resources which likely contributed to elevated juvenile salmon growth rates in connected intertidal marsh habitats, where salmon had 25% greater growth rates (mm day-1) than those reared in disconnected marsh habitats. Additionally, salmon growth rates and condition factors were, in some instances, greater in connected intertidal habitats than upstream floodplains. These results provide strong evidence for the importance of connectivity for meta-community dynamics as well as productivity in historically coupled ecosystems and provide important information for future management and restoration.

https://doi.org/10.5061/dryad.c866t1gh1

Description of the data and file structure

This data was collected from 2019 -2020 in the California Delta; specifically in the Yolo Bypass, a restored intertidal marsh in Liberty Island, the Cosumnes River floodplain, and a intertidal marsh downstream of the Cosumnes River floodplains. Data includes water quality, zooplankton, and juvenile Chinook salmon growth data.

wq.csv - water quality data. NAs refer to when samples were not taken due to equipment malfunction, or in the case of time when collection times were not recorded. Site = location of collection, zooplankton at generic and family level, Temp_C = temperature degrees Celsius, EC = electrical conductivity uS/cm, SPC = specific electrical conductivity uS/cm, TDS = total dissolved solids mg/L, Sal=salinity PSU, DO_prcnt = dissolved oxygen percent, DO_mg_L = dissolved oxygen mg/L, Turb = turbidity NTUs, BGA = blue green algea chlorophyl a, Ave_POC = average POC mg/L, Chl_ug_L = chlorophyll a concentration micrograms/L, Ch_C = chlorophyl carbon mg/L, c_chlaC= ratio of POC to Chl.a carbon.

zoop_wq.csv - average zooplankton abundance and water quality data for each site visit. NAs refer to when samples were not taken due to equipment malfunction. Site = location of collection, zooplankton at generic and family level, Temp_C = temperature degrees Celsius, EC = electrical conductivity uS/cm, SPC = specific electrical conductivity uS/cm, TDS = total dissolved solids mg/L, Sal=salinity PSU, DO_prcnt = dissolved oxygen percent, DO_mg_L = dissolved oxygen mg/L, Turb = turbidity NTUs, BGA = blue green algea chlorophyl a, Ave_POC = average POC mg/L, Ch_C = chlorophyl carbon mg/L, c_chlaC= ratio of POC to Chl.a carbon.

zoop_raw.csv - raw zooplankton collection, abundance, and taxonomic information. Site = Location of collection, Date = date mm/dd/Y, FlowMeterBegin = initial flow meter rotation number (note 0 was used for throwing method), FlowMeterEnd = end flow meter rotation number (note 744.24 was used for throws to account for distance of 4 throws at 5 meters), RingSize_cm = size of zooplankton net ring, SplitFraction = fraction of sample used for subsampling, TotalVolume_ml = total volume in beaker used for subsampling, Volumesubsampled = total volume subsampled to reach 250 total individuals, Phylum - Species = taxonomic information, LifeStage = life stage, abundance = number of individuals counted per sub sample.

fish_data.csv - Cage = fish cage assignment per site, Ave_t0_FL = average initial fork length (mm), FL_mm = finale fork length (mm), wt_g = final weight (g), Days = days reared in cage, Growth_Rate_mmper_Day = calculated growth rate, NA = missing data

fish_gut_contents.csv - fish stomach contents. Site - location of collection, Fork Length (mm) - fish fork length, Phylum - Species = taxonomic information, LifeStage = life stage of invertebrate, Abundance = number of individual counted from stomach.

Hydrological connection links zooplankton communities and improves juvenile Chinook salmon growth in intertidal wetlands

Data files

Abstract

README: Hydrological connection links zooplankton communities and improves juvenile Chinook salmon growth in intertidal wetlands

Description of the data and file structure