Iowa DNR
BioNet
River & Stream Biological Monitoring
Fish and Benthic Macroinvertebrate Surveys
Physical Habitat Assessments

Unnamed tributary to Silver Creek N of Cresco (UI_SMC_02)

Fish Session #881

Sample Date
8/11/2023
Timeframe
39 min
Reach Size
935 ft
Method
Standard Wadeable
Sample Quality
Good
Last Update
1/23/2024 1:30:21 PM

Fish Health

# DELTs
0
# Non-DELTs
0

Equipment

Backpack Shockers
1
Blocknets
0
This sampling session was collected as part of the FishNet program.
Notice: This sampling session has not been through a Quality Assurance check and may contain errors. This notice will be removed once the QA has been completed.
Property Access Notice

This site is on privately-owned land. The DNR obtains permission from the landowner(s) prior to conducting any sampling surveys.

FIBI Score
49
Warm Water
Fair
Session Comments

Part of the Cold Water project. Water temperature 56 F, Conductivity 744 µS/cm. The fish survey was completed in 3 runs, these runs correspond to the same locations of the runs for the habitat survey. In run 1 we sampled 2 Brook Trout, 13 Western Blacknose Dace, 10 Brook Stickleback, and 41 0-6" White Suckers, run 2 included 23 Brook Trout, 8 Western Blacknose Dace, 17 0-6" White Suckers, and 3 Brook Stickleback, run 3 contained 8 Brook Trout, 3 Brook Stickleback, 13 0-6" White Suckers, and 1 Western Blacknose Dace. This survey represents the total from all of the runs combined.

Collected Fish

Identity verification status for this species
Morphometrics: Length/Weight measurements of individual specimens
Taxa excluded from species count metrics.
Click on species name for more information about that species
Species Catch
White Sucker
Latin: Catostomus commersonii
Family: Catostomidae
Tolerance: Intermediate
Trophic: Omnivore
Is Exotic: False
Is LithoSpawner: False
Is Hybrid: False
71
Brook Trout
Latin: Salvelinus fontinalis
Family: Salmonidae
Tolerance: Sensitive
Trophic: Top Carnivore
Is Exotic: False
Is LithoSpawner: False
Is Hybrid: False
33
Western Blacknose Dace
Latin: Rhinichthys obtusus
Family: Leuciscidae
Tolerance: Intermediate
Trophic: Insectivore
Is Exotic: False
Is LithoSpawner: False
Is Hybrid: False
22
Brook Stickleback
Latin: Culaea inconstans
Family: Gasterosteidae
Tolerance: Sensitive
Trophic: Insectivore
Is Exotic: False
Is LithoSpawner: False
Is Hybrid: False
16

FIBI Calculation Factors

Factor Value
Drainage area (mi2) 1.3200
Log(DA) 0.1206
Total Fish 142
Fish per 500 ft 76
Total Species 4
# Excluded Species 0
# Exotic Species 0
# LMB-BG 0
Calculation Last Updated 3/7/2025 2:49:52 PM

Fish Index of Biotic Integrity

Metric Name Value Score
Native Species 4 10
Sucker Species 1 10
Sensitive Species 2 10
Benthic Invertivore Species 0 0
Top 3 Abundance Percentage 88.73 7.5
Benthic Invertivore Percentage 0 0
Omnivore Percentage 50 7.5
Top Carnivore Percentage 23.24 0
Lithophilous Spawner Percentage 0 0
Tolerance Index 3.27 7.5
Adjusted Catch per Unit Effort 15.19 1.52
DELT Percentage Adjustment 0 0

FIBI Score Explained

Sites that score between 26 - 50 are considered fair. Fish abundance ranges from lower than average to very abundant. If fish are abundant, tolerant species are usually dominant. Native fish species usually equal ten or more species. The three most abundant species typically comprise two-thirds or more of the total number of fish. One or more sensitive species, long-lived fish species or benthic habitat specialists such as suckers (Catostomidae) are present. Top carnivore species are often, but not always present in low abundance. Species that are able to utilize a wide range of food items including plant, animal and detritus are usually more common than specialized feeders, such as benthic invertivore fish. Species that require silt-free, rock substrate for spawning or feeding are typically rare or absent. Fish condition is usually good; however, elevated levels of fish exhibiting external anomalies associated with disease or stress are not unusual.

This location has been classified as a survey site. Survey sites are compared to reference sites within the same ecoregion. A reference site represents natural stream qualities that are least disturbed by human activities within the watershed. Reference sites are grouped by ecoregion to establish a benchmark against which these survey streams are compared.

EcoRegion Comparison

Scores for a sampling session are compared against reference sites within the same ecoregion:

Iowan Surface

This site is in the Iowan Surface ecoregion.

Ecoregion Map
Max 92
75th Percentile 77
Median 70
25th Percentile 60
Min 27
This Session's Score 49
Total Reference Site Samples 140
Mean 67.94
Standard Deviation 13.97