Mike D Yard
20200708
Rainbow trout growth data and growth covariate data downstream of Glen Canyon Dam in the Colorado River, Arizona, 2012 - 2016
comma-separated values
Flagstaff, AZ
U.S. Geological Survey
https://doi.org/10.5066/P90ODKZ3
Josh Korman
Michael D. Yard
Maria C. Dzul
Charles B. Yackulic
Michael J. Dodrill
Bridget R. Deemer
Theodore A. Kennedy
20200827
Changes in prey, turbidity, and competition reduce somatic growth and cause the collapse of a fish population
publication
n/a
Wiley
https://doi.org/10.1002/ecm.1427
These data are the primary data used to estimate rainbow trout abundance and survival in the Colorado River, Glen and Grand Canyons. Refer to the analyses as per the associated journal manuscript (see Larger Work Citation). Prey availability, feeding efficiency, and competition reduce somatic growth and cause the collapse of a fish population" Nighttime boat electrofishing was used to sample rainbow trout four times per year in April, July, September, and January, from April 2012 through September 2016. A total of five reaches were sampled between Glen Canyon Dam (river kilometer [rkm] 0) to below the confluence with the Little Colorado River (located at rkm 130). Reaches ranged from two to six km in length. A total of 47,056 individual rainbow trout were tagged with passive integrated transponders (PIT) over the first 18 trips across the five study reaches. and 7,733 of these individuals were recaptured one or more trips after they were released. A total of 1,477 individuals (19%) were recaptured more than once (i.e., on two or more trips after release). In total, 9,542 across-trip recaptures with length and weight measurements on release and recapture events were obtained. Very few tagged fish were recaptured in reaches other than the ones they were released in, and these fish were excluded from the analysis. Provided are tabulated data for fish capture (158,324 records), size-stratified abundance estimates by reach and sampling trip, and the upper and lower confidence intervals for total abundance. We evaluated the effects of discharge, water temperature, solar insolation, turbidity-driven reactive distance (feeding efficiency), intraspecific competition, and prey availability on growth rates of rainbow trout. These six covariates were selected based on hypotheses of how they affect the rate of prey delivery, metabolic and foraging costs, foraging efficiency, and prey availability. Covariates are compiled as tabulated mean values for each reach and sampling trip and corresponding data sources.
The purpose of these datasets is to quantify the effects of abiotic and biotic factors on somatic growth of rainbow trout (Oncorhynchus mykiss) in the Colorado River below Glen Canyon Dam and demonstrate the resulting effect on maturation and survival rates and abundance. Rainbow trout is a freshwater salmonid that supports many recreational fisheries but is also included in the global list of the top 100 worst invasive species (Global Invasive Species Database 2018). Improved understanding of factors that affect somatic growth rates, abundance, and distribution of this species would help manage fisheries and the impacts of numerous introductions on native fish; particularly endangered species. Some rainbow trout from this tailwater population disperse downstream where they can have negative effects on endangered Humpback Chub (Gila cypha). Understanding the factors which control the vital rates of rainbow trout below Glen Canyon Dam is therefore critical for managing both the tailwater sport fishery and Humpback Chub. These datasets were developed to identify the factors that control somatic growth and to determine the causes of change in rainbow trout population abundance and distribution. Somatic growth is a potentially important process controlling fish populations since it can affect survival, sexual maturity, and reproductive success. This large field effort provided approximately 10,000 direct observations of growth at 3-month intervals over five years. Prey availability and competition were quantified as were a suite of abiotic covariates. The objectives of this research were to determine the effects of discharge, water temperature, solar insolation, turbidity-driven reactive distance (feeding efficiency), intraspecific competition, and prey availability on growth rates of rainbow trout. These six covariates were selected based on hypotheses of how they affect the rate of prey delivery, metabolic and foraging costs, foraging efficiency, and prey availability. This study is one of few that links abiotic factors, prey availability, and competition, to fish growth, vital rates, and population abundance. Making these research datasets accessible to the broader public and research community potentially benefits future research by allowing for reanalysis and alternative analysis yet explored. Hopefully, by presenting these original data will facilitate the development of collaborative efforts and provide data sources for educational research and analytical training.
These data were collected and compiled for the purposes of quantify the effects of abiotic and biotic factors on somatic growth of rainbow trout in the Colorado River below Glen Canyon Dam and demonstrate the resulting effect on maturation and survival rates and abundance. These data are likely to have secondary research value beyond the scope that was originally envisioned by these researchers. We are pleased and required to make these data sets publicly available; however, request that future users use these data appropriately. Although considerable attention was directed at reducing errors in the data sets (refer to ‘Data Limitations’ Steps 3-5) there likely remains some degree of inaccuracy for some units of measure; particularly for length and weight measurements. Future users should recognize this uncertainty when using these data. Users should review the 'Cross References' worksheets for a full list of all citations and references used in developing this dataset. Additionally, compiled data in the ‘Data - Physical Covariate’ and ‘Data - SRP Table’ worksheets contain mean values; therefore, if users want the unit values these can be obtained from the original source identified in the ‘Secondary Data Sources’ worksheet. Data users should read the entire metadata record and acquire the manuscript identified as the ‘Larger Work Citation’ to have a complete understanding of how these data were created and used. The data are specific to the uses identified above, as described in the ‘Larger Work Citation’, and any other use of these data would be inappropriate. See 'Distribution liability' statements for more information.
20120419
20160924
ground condition
None planned
-114.02379
-111.476798
36.965854
35.740126
USGS Thesaurus
biogeography
field inventory and monitoring
field sampling
fish
freshwater ecosystems
river ecosystems
river reaches
time series datasets
USGS Biocomplexity Thesaurus
abiotic
biotic
fish
freshwater
rainbow trout
None
95% confidence intervals
covariate data
date
electrofishing
field data
fish capture
fish distribution
fish length
fish recapture
fish weight
fork length
freshwater salmonid
growth modelling
mark-recapture study
measurements
passive integrated transponders (PIT)
rainbow trout abundance
shoreline sites
somatic growth
tailwater
time
trip interval
USGS Metadata Identifier
USGS:5e46bda1e4b0ff554f66395e
Geographic Names Information System (GNIS)
Arizona
Buck Farm
Colorado River
Glen Canyon Dam
Glen Canyon
Grand Canyon
House Rock
Lees Ferry
Little Colorado River
Marble Canyon
Paria River
Marble Canyon
None
lower Colorado River
lower Colorado River confluence
lower Marble Canyon
middle Marble Canyon
upper Marble Canyon
none
none
Mike D Yard
U.S. Geological Survey
Fishery Biologist
mailing and physical
Mail Stop 9395, 2255 North Gemini Drive
Flagstaff
AZ
86001
US
928-556-7377
myard@usgs.gov
This research was funded by the U.S. Bureau of Reclamation through the Glen Canyon Dam Adaptive Management Program.
Wyatt F. Cross
Colden V. Baxter
Emma J. Rosi-Marshall
Robert O. Hall, Jr.
Theodore A. Kennedy
Kevin C. Donner
Holly A. Wellard Kelly
Sarah E. Z. Seegert
Kathrine E. Behn
Michael D. Yard
2013
Foodweb dynamics in a large river discontinuum
Wiley Online Library
Ecological Monographs
https://esajournals.onlinelibrary.wiley.com/doi/pdf/10.1890/12-1727.1
Invasive Species Specialist Group
2015
The Global Invasive Species Database, Version 2015.1 (accessed 4 May 2018)
Invasive Species Specialist Group (online)
Invasive Species Specialist Group (ISSG)
http://www.issg.org/database
Theodore A. Kennedy
Charles B. Yackulic
Wyatt F. Cross
Paul E. Grams
Michael D. Yard
Adam J. Copp
2013
The relation between invertebrate drift and two primary controls, discharge and benthic densities, in a large regulated river
Wiley Online Library
Freshwater Biology
https://doi.org/10.1111/fwb.12285
Josh Korman
Michael D. Yard
2017
Effects of environmental covariates and density on the catchability of fish populations and the interpretation of catch per unit effort trends
ScienceDirect (online)
Fisheries Research
https://doi.org/10.1016/j.fishres.2017.01.005
David J. Topping
David M. Rubin
DL. E. Vierra Jr.
2000
Colorado River sediment transport 1. Natural sediment supply limitation and the influence of Glen Canyon Dam
AGU Publications (online)
Water Resources Research
https://doi.org/10.1029/1999WR900285
Carl J. Walters
John R. Post
1993
Density-dependent growth and competitive asymetries in size-structured fish populations: a theoretical model and recommendations for field experiments (Published online: 09 Jan 2011)
American Fisheries Society (online)
Transactions of the American Fisheries Society
https://doi.org/10.1577/1548-8659(1993)122<0034:DDGACA>2.3.CO;2
No formal attribute accuracy tests were conducted
No formal logical accuracy tests were conducted
Data set is considered complete for the information presented, as described in the abstract. Users are advised to read the rest of the metadata record carefully for additional details.
No formal positional accuracy tests were conducted
No formal positional accuracy tests were conducted
General Sampling Description: Five reaches were sampled between Glen Canyon Dam (river kilometer [rkm] 0) to below the confluence with the LCR (located at rkm 130). Reaches ranged from two to six km in length. Reach I, represents conditions in Glen Canyon, which extends from the dam to the confluence with the Paria River (rkm 27.0). This reach is a clear, low-gradient tailwater that is wide and shallow. Marble Canyon is 100 km long and is located between the Paria and LCR confluences. Reaches II, III, and IVa represent conditions in upper, middle, and lower Marble canyon, respectively. Large inputs of fine sediment from the Paria River, which generally occur during the summer monsoon season (July-September, Topping 2000), result in elevated turbidity in these reaches, in contrast to Glen Canyon, which is perennially clear. Reach IVb represents conditions downstream of the LCR and is more frequently turbid because it is affected by sediment inputs from both the Paria and the LCR. The five sampling reaches cover 17% of the 130 km-long study area (refer to Table called Study Reach). Nighttime boat electrofishing was used to sample rainbow trout four times per year in April, July, September, and January, from April 2012 through September 2016 (19 trips). All five study reaches were divided into 250-m long shoreline sites on each bank and were identified in the field by reflective markers, GPS, and high-resolution air photographs. River-left and river-right sites were sampled by separate boat electofishing crews consisting of a boatman and netter.
2019
Field data collection: As part of a mark-recapture study, electrofishing was conducted over a two night effort using two separate boats. The electrofishing effort on the first two passes for all reaches was completed at a pace of approximately 3 seconds per meter of shoreline. The single netter per boat captured stunned fish with a long-handled dipnet and fish were held in aerated 40-L buckets. On average, 12 minutes of electrofishing effort were needed to sample a 250-m site. A tender boat retrieved labelled buckets from electrofishing boats and transported them to a central processing location.
2019
Sample Processing: At the central processing location, which was typically located near the center of each reach, buckets of incoming fish were kept on the beach and aerated and flushed with water to maintain adequate water quality. Groups of 10-15 fish were anesthetized with clove oil. Fork length and weight were recorded to the nearest mm and gram for fish > 150 mm, and 1/10th of a gram for smaller fish. All fish >=75 mm were scanned for a passive integrated transponder (PIT) tag. Following processing, fish were held in aerated 40-L buckets for a minimum of 30 minutes prior to their return to the center of the original 250-m site of capture. Tagged fish that did not look healthy after the holding period were euthanized. The tag IDs for fish that were not released were recorded so they could be removed from the list of live releases. Total time from capture to release typically ranged from 1-2 h. Following measurements fish were revived and returned to site of capture.
2019
Development of the Growth Data tables - Data entry: All data fields for each processed fish were electronically recorded on-the-fly using custom software which included the capability to capture the PIT tag ID from the scanner, eliminating potential transcription errors. The data structure was designed having a flat file construction (no relational data structure). Sampling dates and times, reach, sites, boat operators and effort were recorded in advance of processing fish caught for each sample. Once completed all sampled fish were processed. The time involved to process an individual fish from start to finish ranged from nine to twelve seconds per record. Multiple people handled the same fish during processing to eliminate incorrect data calls and problems with verbally reversing numeric order (lengths and weights). This protocol reduced species misidentification, and incorrect lengths and weights. Scanning and tagging errors were avoided by multiple scans data entry reconfirmation. Error trapping subroutines were used to catch data entry errors, which included pull down lists with specific species ID codes, length-to-weight relationships that established bounds (1±STD). Recaptures were confirmed using a set of PIT-tag lookup files (binary structure containing 500K unique records) that matched PIT tag ID to prior capture history for each recaptured fish. A secondary PIT-tag look-up file was used for fish new records collected during the current trip. This file was nonvolatile and records were appended with each new PIT-tag and recaptured PIT-tag record. Errors from previous trips or the current trip were detected by automatically comparing current field entries to past field entries before the record was saved. When differences between records occurred, confirmation was required before that record was saved. Compared fields were Species, Date, Reach, MarkType, PIT-TAG, Recap, TL, FL, and Wt. Acceptable bounds were assigned to length (>2 mm) and weight (allometrically scaled). Data recorder was alerted when differences in measurements were encountered within that trip that were in excess of the established value. Each sample record was independently saved to four multiple drives (hard-drive and secondary jump drives) to avoid power outages or hardware failure. Multiple redundant data entry computers were also available on each trip to avoid problems with hardware and software failure. Updates to the software were made prior to each trip. Since this is a mark-recapture study that had two or more nights of electrofishing all incidental mortalities were collected over the night by the Tender boat. At the end of the night all incidental mortalities were scanned for the presence of a PIT-tag. If a tag was present, disposition of fish was recorded; and if the recaptured tag ID was for a newly processed fish the ID number for the cull was purged from the active list (i.e., a newly tagged fish is a fish that had received a tag that night).
2019
Data Quality Assessment and Quality Control (QAQC) - Data processing: In the field, raw data were retrieved and imported into a spreadsheet on the following day. Data records were then assessed for errors. Errors were corrected, however, if unresolvable the mistakes were identified and latter reconciled following completion of field work. Each nightly effort was compiled into a single trip file. Following each trip, the entire trip file was reassessed for errors in an office setting. Trip data sets were then compiled for a total of 19 trips. These data represent the cumulative effort from April-2012 to September-2016. The associated process year assigned to this data set is 2019.
2019
Data Quality Assessment and Quality Control (QAQC) - Data storage and maintenanc: The final data set herein (refer to Data - Fish Capture Table) is a compilation of 19 fish surveys over five years. These data are specific to rainbow trout, and have gone through a series of rigorous QA/QC protocols both in the field and in the office. These data are currently maintained by USGS Data Acquisition Storage and Analysis (DASA) program as part of the Southwest Biological Science Center, Flagstaff, AZ.
2019
Finalize Data for Dissemination: Data sent to the Southwest Biological Science Center Data Steward for dissemination and preservation per USGS Data Management Policies SM 502.6, SM 502.7, SM 502.8 and SM 502.9 (1 October 2016).
2020
Abundance Confidence Int Data
These data represent 95% confidence intervals of rainbow trout abundance by reach and trip.
Producer defined
Interval
Lower and upper limit of 95% confidence intervals
Producer defined
Lower
Lower confidence intervals on total abundance (across size classes) per trip
Producer defined
Upper
Upper confidence intervals on total abundance (across size classes) per trip
Producer defined
Reach
General location of sampling effort
Producer defined
1
Lees Ferry, 48 sampling units (250 meters), river mile -6.04 to -2.12)
Producer defined
2
House Rock, 48 sampling units (250 meters), river mile 17.22 to 20.58)
Producer defined
3
Buck Farm, 48 sampling units (250 meters), river mile 38.2 to 41.63)
Producer defined
4
Upstream of the Little Colorado River, 16 sampling units (250 meters), river mile 60.2 to 61.28)
Producer defined
5
Downstream of the Little Colorado River, 18 sampling units (250 meters), river mile 63.44 to 65.02)
Producer defined
1 to 19
Numeric code used to represent an individual trip; Numeric value, first trip 1, last trip 19
Producer defined
-0.402901245
57.0988
decimal number
Fish Capture Data
These data represent individual fish capture records which include the date and time of capture, the location of capture (reach), the PIT tag ID for tagged fish, whether the fish was a recapture, total length, fork length, and weight.
Producer defined
Date
Capture "date/time" field is the time used to distinguish the end point in the sampling period. The gear used for sampling was electrofishing and the catch per unit effort is based on shoreline length (250 m), not time. All five study reaches were divided into a series of sampling sites that were 250-m shoreline length.
Producer defined
04/19/2012 20:40:00
09/24/2016 20:51:00
24-hour clock
Reach
General location of sampling effort
Producer defined
1
Lees Ferry, 48 sampling units (250 meters), river mile -6.04 to -2.12)
Producer defined
2
House Rock, 48 sampling units (250 meters), river mile 17.22 to 20.58)
Producer defined
3
Buck Farm, 48 sampling units (250 meters), river mile 38.2 to 41.63)
Producer defined
4A
Above Little Colorado River, 16 sampling units (250 meters), river mile 60.2 to 61.28)
Producer defined
4B
Below Little Colorado River, 18 sampling units (250 meters), river mile 63.44 to 65.02)
Producer defined
Mark Type
Used to distinguish between what type of mark was given or later detected upon recapture.
Producer defined
AD
Adipose Clip
Producer defined
AN
Anal Clip
Producer defined
LC
Lower Caudal Clip
Producer defined
UC
Upper Caudal Clip
Producer defined
None
No Mark Type
Producer defined
FL
Floy Tag
Producer defined
PIT
PIT-tag (alphanumeric code)
Producer defined
PITCLIP
Pit-tag (alphanumeric code) + Adipose Clip
Producer defined
TNS
PIT-tag detected, but not recorded
Producer defined
PIT-TAG
Unique alphanumeric code
Producer defined
Rainbow trout ≥ 75 mm were tagged with passive integrated transponders (PIT) tags. PIT tags are glass encapsulated 134.2 kHz, 12 mm long by 2.1 mm in diameter that have a unique radio frequency identification (RFID) alfphanumeric code. All PIT tags are ISO (International Organization for Standardization) 11784/11785 compliant and ICAR (International Committee of Animal Recording) approved.
Recap
Represents whether a trout has been recaptured previously on one or more trips after it was initially tagged and released. (refer to CaptureData Table for recapture data)
Producer defined
NO
a trout has not been recaptured previously on one or more trips after it was initially tagged and released
Producer defined
YES
a trout has been recaptured previously on one or more trips after it was initially tagged and release
Producer defined
TL
Total length of captured fish, NA (Not applicable)
Producer defined
28
551
millimeters
FL
Fork length of captured fish, NA (Not applicable)
Producer defined
20
927
millimeters
Wt
Weight of captured fish,NA (Not applicable)
Producer defined
0.1
1972
grams
Fish Condition Factor Data
These data represent the condition factor calculated for each rainbow trout that was captured by dividing its weight by the expected weight based on its fork length and a weight-length relationship (see Fish Capture Data), whose parameters were estimated from all trout that were captured and measured during this study (W=e-10.7+2.855·log(L), n=144,322). As condition factor varied among size classes, averages by reach and trip interval were computed for each of five size classes (75-124 mm, 125-174 mm, 175-224 mm, 225-274 mm, and >=275 mm).
Producer defined
Reach
General location of sampling effort
Producer defined
1
Lees Ferry, 48 sampling units (250 meters), river mile -6.04 to -2.12)
Producer defined
2
House Rock, 48 sampling units (250 meters), river mile 17.22 to 20.58)
Producer defined
3
Buck Farm, 48 sampling units (250 meters), river mile 38.2 to 41.63)
Producer defined
4
Upstream of the Little Colorado River, 16 sampling units (250 meters), river mile 60.2 to 61.28)
Producer defined
5
Downstream of the Little Colorado River, 18 sampling units (250 meters), river mile 63.44 to 65.02)
Producer defined
1 to 18
Numeric code used to represent an individual trip; Numeric value, first trip 1, last trip 18. -99 indicates no data.
Producer defined
0.77
1.26
decimal number for relative condition factor
Physical Covariate Data 1
These data represent reach and trip interval values of covariate data used in the growth modelling.
Producer defined
Reach
General location of sampling effort
Producer defined
1
Lees Ferry, 48 sampling units (250 meters), river mile -6.04 to -2.12)
Producer defined
2
House Rock, 48 sampling units (250 meters), river mile 17.22 to 20.58)
Producer defined
3
Buck Farm, 48 sampling units (250 meters), river mile 38.2 to 41.63)
Producer defined
4
Upstream of the Little Colorado River, 16 sampling units (250 meters), river mile 60.2 to 61.28)
Producer defined
5
Downstream of the Little Colorado River, 18 sampling units (250 meters), river mile 63.44 to 65.02)
Producer defined
TripInt
Numeric value used to represent Trip Intervals between April 2012 and September 2016.
Producer defined
Numeric value, first Interval 1, last interval 18
Q
The average discharge (cubic meters per second) for each trip interval and reach was used as a covariate in the growth model.
Producer defined
250.3515941
438.7406425
Cubic meters per second (m-3 s-1)
Wtemp
The average water temperature for each trip interval and reach was used as a covariate in the growth model.
Producer defined
7.848221987
14.5873865
degrees Celcius
lgPMR
Log-transformed datab (base 10) for percentage of maximum reactive distance (PMR)
Producer defined
2.429288627
4.559194579
Log Percentage of maximum reactive distance
Light
Solar insolation levels were calculated along the shoreline at 50 m lengths for both left and right banks for the entire length of the sampling reach. Data represents mean daily solar insolation levels (mol m−1 d−1) across the visible light spectrum (400–700 nm).
Producer defined
14.06793
53.64837
mol m−1 d−1
lgSSL2
SSL2 = Sum(N[i]*L[i]^2); Where N is the density of trout in size class ‘i’ (one of our five size classes, e.g. 75-124 mm), and L is the midpoint of each length size class. This is briefly explained in supplement of growth manuscript. It is our index of competition. The notion is that 10 big fish will result in a greater competitive effect than 10 small fish. The L^2 comes from bioenergetic arguments. lgSSL2 is simply the natural log of SSL2.
Producer defined
-6.069179354
0.59106388
dimensionless
Dtot
Average drift concentration (mg m-3) are weight based estimates derived from measured lengths and taxa-specific length-weight relationships for three taxa (which are chironomids [midges], Simuliium articum [a blackfly], and Gammarus lacustris [an amphipod]). The average drift concentration for each trip interval and reach was used as a covariate in the growth model.
Producer defined
0.018662329
0.624198938
mg m-3
Physical Covariate Data 2
These data represent time series data for selected covariates in reaches I (Glen Canyon), III (middle Marble Canyon), and IVb (downstream of Little Colorado River) used for Figure S2.
Producer defined
Trip Interval
The duration of time in days between two sequential sampling trips, concatenated text refers to the month and year of each trip. Example Apr12-Jul12 is the time interval between April 2012 and July 2012. Trips were four times per year in April, July, September, and January from April 2012 through September 2016 (19 trips leading to 18 trip intervals).
Producer defined
Apr12-Jul12 to Sep15-Jan16
Reach
General location of sampling effort
Producer defined
I
Lees Ferry, 48 sampling units (250 meters), river mile -6.04 to -2.12)
Producer defined
III
Buck Farm, 48 sampling units (250 meters), river mile 38.2 to 41.63)
Producer defined
IVb
Below Little Colorado River, 18 sampling units (250 meters), river mile 63.44 to 65.02)
Producer defined
Wtemp
The average water temperature for each trip interval and reach was used as a covariate in the growth model, (see Physical Covariate Data 1 for water temperature data).
Producer defined
7.848221987
15.55444008
degrees Celcius
PMR
A log of the average PMR (percentage of maximum reactive distance) values was used from each reach and trip interval as a covariate in the growth model, (see Physical Covariate Data 1 for PMR data). The PMR for each trip interval and reach was used as a covariate in the growth model.
Producer defined
11.35080455
95.50652585
percentage of maximum reactive distance
Comp
Competition was quantified based on population estimates for each of five size classes (75-124 mm, 125-174 mm,175-224 mm, 225-274 mm, and >275 mm) in each reach and trip over the study period (Korman and Yard 2017). Estimates of abundance were transformed to densities by dividing by reach length. To translate population density into an index of competition, the density of each size class was multiplied by the square of the midpoint length for the size class, and then summed across the five size classes (Refer to Walters and Post 1993).
Producer defined
0.002313071
1.805908664
dimensionless
Drift
Average drift concentration (mg m-3) are weight based estimates. Average drift concentration (#∙m-3) were computed per reach and trip from all samples for three taxa commonly consumed by rainbow trout in Grand Canyon (Cross et al. 2013, Kennedy et al. 2014) which are chironomids (midges), Simuliium articum (a blackfly), and Gammarus lacustris (an amphipod). The average weight of these taxa, determined from measured lengths and taxa-specific length-weight relationships, was multiplied by drift concentration to calculate total edible drift mass.
Producer defined
0.018662329
0.624198938
mg m-3
Size-structure Abundance Data
These data represent most likely estimates of rainbow trout abundance by reach and trip.
Producer defined
Reach
General location of sampling effort
Producer defined
I
Lees Ferry, 48 sampling units (250 meters), river mile -6.04 to -2.12)
Producer defined
II
House Rock, 48 sampling units (250 meters), river mile 17.22 to 20.58)
Producer defined
III
Buck Farm, 48 sampling units (250 meters), river mile 38.2 to 41.63)
Producer defined
Iva
Above Little Colorado River, 16 sampling units (250 meters), river mile 60.2 to 61.28)
Producer defined
Ivb
Below Little Colorado River, 18 sampling units (250 meters), river mile 63.44 to 65.02)
Producer defined
Trip
Numeric code used to represent an individual trip
Producer defined
Numeric value, first trip 1, last trip 19
(N) 75-124
Size Class 75-124mm, fork length
Producer defined
0
18.51165
millimeters
(N) 125-174
Size Class 125-174mm, fork length
Producer defined
0.000720062
17.5077
millimeters
(N) 175-224
Size Class 175-224mm, fork length
Producer defined
0.006704896
7.2478
millimeters
(N) 225-274
Size Class 225-274mm, fork length
Producer defined
0.00624195
13.94855
millimeters
(N) >=275
Size Class >=275mm, fork length
Producer defined
0.005954108
13.41415
millimeters
U.S. Geological Survey - ScienceBase
U.S. Geological Survey
mailing and physical
Denver Federal Center, Building 810, Mail Stop 302
Denver
CO
80225
United States
1-888-275-8747
sciencebase@usgs.gov
The author(s) of these data request that data users contact them regarding intended use and to assist with understanding limitations and interpretation. Unless otherwise stated, all data, metadata and related materials are considered to satisfy the quality standards relative to the purpose for which the data were collected. Although these data and associated metadata have been reviewed for accuracy and completeness and approved for release by the U.S. Geological Survey (USGS), no warranty expressed or implied is made regarding the display or utility of the data for other purposes, nor on all computer systems, nor shall the act of distribution constitute any such warranty.
This zip file contains data available in comma-separated values (csv). The user must have software capable of uncompressing the zip file and displaying the tabular data.
20200827
Mike D Yard
U.S. Geological Survey
Fishery Biologist
mailing and physical
Mail Stop 9395, 2255 North Gemini Drive
Flagstaff
AZ
86001
US
928-556-7377
myard@usgs.gov
Content Standard for Digital Geospatial Metadata
FGDC-STD-001-1998