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Chinook Salmon genetic assignments for the Central Valley Project (CVP) and State Water Projects (SWP), Sacramento and San Joaquin Delta Waters, CA, 2024-25

Central Valley Chinook Salmon populations differ in their Endangered Species Act listing status. It is difficult to visually distinguish individuals from the different Evolutionarily Significant Units. As such, many of the salmon monitoring and evaluation efforts in the Central Valley and San Francisco Bay-Delta are hampered by uncertainty about population (stock) identification and proportional effects of management actions (Dekar et al. 2013; IEP 2019). Studies have identified that the current identification method (length-at-date models) of juvenile Chinook salmon (Fisher 1992) captured in the watershed vary in their accuracy, particularly for spring-run (NMFS 2013; Harvey et al. 2014; Merz et al. 2014). The inaccuracy of the size-based methods is likely due to differences in fish distribution during early rearing, habitat-specific growth rates, and inter-annual variability in temperatures and food availability that lead to overlap in size ranges among stocks. The primary objective of this project was the genetic classification (to genetic lineage; Evolutionary Significant Unit) of Chinook Salmon captured from State Water Project and Central Valley Project fish protection facilities and Interagency Ecological Program compliance monitoring programs. The genetic lineage was determined for sampled fish by comparing their genotypes to reference genetic baselines. Genetic methods, having less statistical uncertainty that size-based models for population identification, were intended to directly target (and reduce) one source of uncertainty in the estimation of loss (take) from water diversions (operations) and develop the information necessary for understanding stock-specific distribution, habitat utilization, abundance, and life history variation. This project supports recommendations from the Interagency Ecological Program’s Salmon and Sturgeon Assessment of Indicators by Life Stage and Interagency Ecological Program Science Agenda efforts to improve Central Valley

openCC (other)Sep 2020View details →

Metacommunity simulations for diatom assemblages residing in benthic cyanobacterial mats in Fryxell Basin in Taylor Valley in the McMurdo Dry Valleys, Antarctica

Here, we use MCSim, a spatially explicit metacommunity simulation package for R, to test alternative hypotheses about the roles of dispersal and species sorting in maintaining the biodiversity of diatom assemblages residing in black and orange mats in Fryxell Basin in Taylor Valley in the McMurdo Dry Valleys of Antarctica. The spatial distribution and patchiness of cyanobacterial mat habitats was characterized by remote imagery of the Lake Fryxell sub-catchment in Taylor Valley collected in January 2015. The available species pool for diatom metacommunity simulation scenarios was informed by the Antarctic Freshwater Diatoms Database, maintained by the McMurdo Dry Valleys Long Term Ecological Research program, representing samples collected between January 1994 and January 2013. We used simulation outcomes to test the plausibility of alternative community assembly hypotheses to explain empirically observed patterns of freshwater diatom biodiversity in the long-term record. The most plausible simulation scenarios suggest species sorting by environmental filters, alone, was not sufficient to maintain biodiversity in the Fryxell Basin diatom metacommunity. The most plausible scenarios included either (1) neutral models with different immigration rates for diatoms in orange and black mats or (2) species sorting by a relatively weak environmental filter, such that dispersal dynamics also influenced diatom community assembly, but there was not such a strong disparity in immigration rates between mat types. The results point to the importance of dispersal for understanding current and future biodiversity patterns for diatoms in this ecosystem, and more generally, provide further evidence that metacommunity theory is a useful framework for testing hypotheses about microbial community assembly. This dataset supports the paper: Sokol, E. Et al, 2020. Evaluating Alternative Metacommunity Hypotheses for Diatoms in the McMurdo Dry Valleys Using Simulations and Remote Sensing Data

openCC (other)Feb 2022View details →

Stream gage and outlet locations, McMurdo Dry Valleys, Antarctica (1993-2020, ongoing)

As part of the Long Term Ecological Research (LTER) project in the McMurdo Dry Valleys of Antarctica, a systematic sampling program has been undertaken to monitor the glacial meltwater streams in the region. Measurements are regularly made to examine water quality, quantity, and chemical properties. The stream gauge and outlet locations table serves as an index of the sampling points used to collect hydrological and stream chemistry data in the McMurdo Dry Valley network of streams. It documents the latitude, longitude and elevation of all the stream sample points used for hydrological and/or chemical analysis.

openCC (other)Feb 2025View details →

Ion concentrations in glacial meltwater streams, McMurdo Dry Valleys, Antarctica (1993-2023, ongoing)

As part of the Long Term Ecological Research (LTER) project in the McMurdo Dry Valleys of Antarctica, a systematic aqueous geochemical sampling program has been undertaken. A series of terrestrial water samples have been collected and analyzed for major ion chemistry by ion chromatography. The concentrations of ions cover a wide range of total dissolved solids from the stream waters. This dataset shows concentrations of lithium, sodium, potassium, magnesium, calcium, iron, chlorine, bromine, silicon, fluorine, sulfate, and hydrogen ions found in various streams of the McMurdo Dry Valleys.

Glacier stake locations, McMurdo Dry Valleys, Antarctica (1993-2023, ongoing)

As part of the Long Term Ecological Research (LTER) project in the McMurdo Dry Valleys of Antarctica, a systematic sampling program has been undertaken to monitor mass balance and meltwater flow from the Taylor Valley glaciers. This data set contains global positioning system (GPS) measurements of stakes on glaciers. The measurements include both low-quality estimates (+/- 100m) from hand-held GPS units and high precision measurements (+/- 2 cm) using Trimble (4000 SSE) geodetic receivers. The purpose of these measurements was to obtain rough stake locations for use in relocating stakes in the future and precise stake locations for use in calculating stake displacement. The measurements are made relative to the WGS84 ellipsoid.

Summarized glacier mass balance measurements, McMurdo Dry Valleys, Antarctica (1993-2023, ongoing)

As part of the Long Term Ecological Research (LTER) project in the McMurdo Dry Valleys of Antarctica, a systematic sampling program has been undertaken to monitor glacial mass balance and meltwater flow. This data package contains total mass balance changes at each stake measured on six glaciers (Canada, Commonwealth, Hughes, Suess, Howard, and Taylor) in Taylor Valley and one glacier (Adams) in Miers Valley, all of which are located in the McMurdo Dry Valleys region of Antarctica. These values are the result of an analysis of the raw data presented in other data files (glacier stake heights, snow depths, and snow densities). Included here for each stake is the total water equivalent mass change. The standard deviation or the range for each total is given. Most measurements began during the 93-94 field season. Adams measurements were established during the 14-15 field season. Measurements are ongoing except at Hughes and Suess Glaciers where monitoring ceased following the 08-09 field season. Monitoring the changes in these measurements over time provides a record of mass balance, and aids in determining the role of glaciers in the polar hydrologic cycle.

Snow, ice, and total glacier mass balance measurements, McMurdo Dry Valleys, Antarctica (1993-2023, ongoing)

As part of the Long Term Ecological Research (LTER) project in the McMurdo Dry Valleys of Antarctica, a systematic sampling program has been undertaken to monitor glacial mass balance and meltwater flow. This data package includes mass balance changes at each stake on six glaciers (Canada, Commonwealth, Hughes, Suess, Howard, and Taylor) in Taylor Valley and one glacier (Adams) in Miers Valley, all of which are located in the McMurdo Dry Valleys region of Antarctica. The values are the result of an analysis of the raw data presented in other data files (glacier stake heights, snow depths, and glacier snow densities). Included here for each stake are the change in ice and snow water equivalent (mass) values, and the total mass change. The standard deviation or the range for each total is also given. Most measurements began during the 93-94 field season. Adams measurements were established during the 14-15 field season. Measurements are ongoing except at Hughes and Suess Glaciers where monitoring ceased following the 08-09 field season. Monitoring the changes in these measurements over time provides a record of mass balance, and aids in determining the role of glaciers in the polar hydrologic cycle.

Glacier snow density measurements, McMurdo Dry Valleys, Antarctica (1993-2023, ongoing)

As part of the Long Term Ecological Research (LTER) project in the McMurdo Dry Valleys of Antarctica, a systematic sampling program has been undertaken to monitor glacial mass balance and meltwater flow. This data package includes snow density measurements determined at each stake with snow present on glaciers in Taylor Valley (Canada, Commonwealth, Howard, and Taylor) and Miers Valley (Adams), all of which are located in the McMurdo Dry Valleys of Antarctica. Included here for each stake are the snow thickness and density for each layer and the average density for each pit. Most measurements began during the 93-94 field season. Adams measurements were established during the 14-15 field season. Measurements are ongoing for Adams, Commonwealth, and Howard glaciers. Monitoring the changes in these measurements over time provides a record of mass balance, and aids in determining the role of glaciers in the polar hydrologic cycle.

Average glacier stake height and snow depth measurements, McMurdo Dry Valleys, Antarctica (1993-2023, ongoing)

As part of the Long Term Ecological Research (LTER) project in the McMurdo Dry Valleys of Antarctica, a systematic sampling program has been undertaken to monitor glacial mass balance and meltwater flow. This data package includes stake height and snow depth measurements to the surface of six glaciers (Canada, Commonwealth, Hughes, Suess, Howard, and Taylor) in Taylor Valley and one glacier (Adams) in Miers Valley, all of which are located in the McMurdo Dry Valleys of Antarctica. Most measurements began during the 93-94 field season. Adams measurements were established during the 14-15 field season. Measurements are ongoing except at Hughes and Suess Glaciers where monitoring ceased following the 08-09 field season. Monitoring the changes in these measurements over time provides a record of mass balance, and aids in determining the role of glaciers in the polar hydrologic cycle.

Glacier stake height measurements, McMurdo Dry Valleys, Antarctica (1993-2023, ongoing)

As part of the Long Term Ecological Research (LTER) project in the McMurdo Dry Valleys of Antarctica, a systematic sampling program has been undertaken to monitor glacial mass balance and meltwater flow. This data package includes stake height measurements to the surface of six glaciers (Canada, Commonwealth, Hughes, Suess, Howard, and Taylor) in Taylor Valley and one glacier (Adams) in Miers Valley, all of which are located in the McMurdo Dry Valleys of Antarctica. Most measurements began during the 93-94 field season. Adams measurements were established during the 14-15 field season. Measurements are ongoing except at Hughes and Suess Glaciers where monitoring ceased following the 08-09 field season. Monitoring the changes in these measurements over time provides a record of mass balance, and aids in determining the role of glaciers in the polar hydrologic cycle.

openCC (other)Feb 2025View details →

Nitrogen and phosphorus concentrations in glacial meltwater streams, McMurdo Dry Valleys, Antarctica (1993-2023, ongoing)

As part of the Long Term Ecological Research (LTER) project in the McMurdo Dry Valleys of Antarctica, a systematic sampling program has been undertaken to monitor the glacial meltwater streams in that region. This table contains macronutrient concentrations (nitrate, nitrite, ammonium, soluble reactive phosphorus) found at specific locations in McMurdo Dry Valley streams.

Integrated measurements of soil micro-invertebrate abundance and associated physicochemical properties from the McMurdo Dry Valleys, Antarctica (1993–2022)

This data package compiles three decades (1993–2022) of soil micro-invertebrate abundance data and associated physicochemical measurements collected as part of the McMurdo Dry Valleys Long Term Ecological Research (MCM LTER) project in Antarctica. Variables include soil micro-invertebrate counts and species richness, along with associated soil physicochemical properties, including gravimetric moisture content, pH, electrical conductivity, soil organic carbon, ammonium, and nitrate. Data originate from both long-term core monitoring efforts and targeted opportunistic sampling campaigns across multiple valleys, including Arena, Beacon, Pearse, Taylor, Victoria, and Wright Valleys. Sampling locations span a range of geomorphic and ecological settings, providing broad spatial and temporal coverage of soil conditions across the Dry Valleys ecosystem. Data were curated to represent the most comprehensive and spatially diverse records available while minimizing sampling bias across years and study types. These integrated measurements provide a valuable resource for understanding the drivers of soil micro-invertebrate abundance and habitat suitability and serve as a foundation for future analyses of long-term ecological change and species distribution modeling in polar desert soils.

Underwater Photosynthetically Active Radiation (PAR) from in-situ Lake Primary Production Experiments in the McMurdo Dry Valleys of Antarctica (1995-2024, ongoing)

As part of the Long Term Ecological Research (LTER) project in the McMurdo Dry Valleys of Antarctica, PAR is measured at one depth during primary production experiments in Dry Valley Lakes. This data set quantifies instantaneous underwater PAR at 10-meter depths in Lakes Bonney and Hoare, and at 7-meter depth in Lake Fryxell (depths vary after 2008, check data file for actual depth). Ambient PAR was also measured at the air-ice interface from each of these lakes.

openCC (other)Apr 2025View details →

Bathymetric model of Lake Joyce, McMurdo Dry Valleys, Antarctica

An updated bathymetric model was developed for Lake Joyce, located in the McMurdo Dry Valleys of Antarctica. The model integrates a published history of lake level rise from 1947 to 2014, historical lake depth soundings, digitized shoreline positions from both historical and modern aerial imagery, and subsurface bedrock topography from Taylor Glacier. The resulting dataset includes model-derived estimates of depth, map-projected area, lakebed surface area (factoring in slope), and water volume at 1-meter depth intervals.

openCC (other)Apr 2025View details →

Conductivity, temperature, and depth (CTD) vertical profiles from Lake Joyce, McMurdo Dry Valleys, Antarctica, November 2014

Vertical profiles of conductivity, temperature, and depth (CTD) were collected from Lake Joyce, a perennially ice-covered lake in the McMurdo Dry Valleys of Antarctica. Water column observations were made in November 2014 using a YSI 6600 multiparameter probe in the deepest region of the lake, as identified by Mackey et al. (2018). The water column was accessed by drilling a 10-inch wide hole through the perennial ice cover using a Jiffy drill. This data package includes CTD profiles, as well as measurements of salinity, total dissolved solids (TDS), dissolved oxygen (DO), pH, and pressure.

openCC (other)Aug 2025View details →

Soil Lake Inundation Moat Experiment (SLIME): Physical, chemical, and biological measurements from planktonic water columns, McMurdo Dry Valleys, Antarctica (2018-2020)

The Soil Lake Inundation Moat Experiment (SLIME) was developed by the McMurdo Dry Valleys Long Term Ecological Research (MCM LTER) project to investigate the ecological function of lake moats in Antarctica. These moats form during the austral summer when the margins of permanently ice-covered, closed-basin lakes melt, creating open-water zones, or ‘moats,’ between the shoreline and the thick (3-5 m) perennial ice cover. To study these habitats, sampling transects were established on the north and south shores of Lake Fryxell and the East Lobe of Lake Bonney. This data package includes three seasons of physical, chemical, and biological measurements from the planktonic water columns of these lakes, collected from SLIME transects between January 2018 and January 2020. Parameters include water temperature, conductivity, ion and nutrient concentrations, chlorophyll-a concentrations, as well as fluorescence and photochemical efficiencies for major algal classes. NCBI accession numbers are also provided for the microbial sequence data associated with each sample.

Thermistor chain measurements from West Lake Bonney, McMurdo Dry Valleys, Antarctica (2014-2019)

To capture year-round temperature variability in West Lake Bonney (WLB), Taylor Valley, Antarctica, we deployed two self-logging RBR Concerto T10 thermistor strings as part of the McMurdo Dry Valleys Long Term Ecological Research (MCM LTER) project. The thermistor strings were deployed beneath the permanent ice cover from December 2014 to November 2015 at two locations on the western side of the lake. In November 2015, both strings were relocated toward the centre of the glacier terminus to better capture potential subglacial inflows. Each thermistor string contained 10 sensors spaced at 1.44 m intervals. This data package includes 1-minute interval temperature measurements from all four deployment sites, along with daily averages compiled in a single file. Data from three thermistors were flagged as questionable based on comparisons with long-term MCM LTER CTD casts; these values remain in the dataset but are flagged to allow for adjustment during data processing.

openCC (other)Dec 2025View details →

Lake Fryxell under-ice conductivity, temperature, and depth (CTD) profiles, McMurdo Dry Valleys, Antarctica, January 2025

To characterize the upper ~2 m of the water column beneath the ~3 m ice cover in Lake Fryxell, located in the McMurdo Dry Valleys of Antarctica, 27 CTD (conductivity, temperature, depth) profiles were collected at ~5 m horizontal spacing along a transect spanning the dive hole to the shoreline. Measurements were made using a YSI Castaway CTD mounted on a 1 m mast atop a remotely operated vehicle (ROV), profiling upward from ~2 m below the ice-water interface. Using an ROV rather than drilling a hole through the ice was intended to minimize artifacts associated with ice openings. Sampling late in the austral summer targeted conditions during maximum seasonal ice melt.

openCC (other)Dec 2025View details →

Lake Fryxell continuous benthic dissolved oxygen and temperature measurements, McMurdo Dry Valleys, Antarctica, November 2023 to December 2024

To examine benthic dissolved oxygen (DO) dynamics in Lake Fryxell, located in the McMurdo Dry Valleys region of Antarctica, DO and temperature were continuously measured near the sediment–water interface at ~8.8 m depth from November 2023 to December 2024. A PME miniDOT® logger was deployed on the lake floor at 8.82 m depth, recording every 15 minutes from 9 November 2023 to 16 December 2024. An Onset HOBO® DO logger, buoyed slightly above the sediment at 8.80 m depth, recorded at the same 15-minute interval from 9 November 2023 to 6 August 2024. The shorter deployment period reflects the six-month lifespan of the HOBO optical sensor.