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

Unnamed Tributary to Floyd River Merrill

Fish Session #1665

Sample Date
8/4/2015
Timeframe
0930-1015  
Reach Size
530 ft
Method
Standard Wadeable
Sample Quality
Good
Last Update
1/19/2016 7:51:27 AM

Fish Health

# DELTs
0
# Non-DELTs
0

Equipment

Backpack Shockers
1
Blocknets
2
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
9
Warm Water
Poor
Session Comments

No comments recorded.

Collected Fish

Identity verification status for this species
Size Class: Typically only collected for sportfish
Taxa excluded from species count metrics.
Click on species name for more information about that species
Species Catch
Bigmouth Shiner
Latin: Ericymba dorsalis
Family: Leuciscidae
Tolerance: Tolerant
Trophic: Insectivore
Is Exotic: False
Is LithoSpawner: False
Is Hybrid: False
25
Creek Chub
Latin: Semotilus atromaculatus
Family: Leuciscidae
Tolerance: Tolerant
Trophic: Generalist
Is Exotic: False
Is LithoSpawner: False
Is Hybrid: False
12
Western Blacknose Dace
Latin: Rhinichthys obtusus
Family: Leuciscidae
Tolerance: Intermediate
Trophic: Insectivore
Is Exotic: False
Is LithoSpawner: False
Is Hybrid: False
11

FIBI Calculation Factors

Factor Value
Drainage area (mi2) 3.0680
Log(DA) 0.4869
Total Fish 48
Fish per 500 ft 45
Total Species 3
# Excluded Taxa 0
# Exotic Species 0
# LMB-BG 0
Calculation Last Updated 2/7/2025 2:33:26 PM

Fish Index of Biotic Integrity

Metric Name Value Score
Native Species 3 5.23
Sucker Species 0 0
Sensitive Species 0 0
Benthic Invertivore Species 0 0
Top 3 Abundance Percentage 100 0
Benthic Invertivore Percentage 0 0
Omnivore Percentage 0 2.5
Top Carnivore Percentage 0 0
Lithophilous Spawner Percentage 0 0
Tolerance Index 8.85 1.83
Adjusted Catch per Unit Effort 2.08 0.21
DELT Percentage Adjustment 0 0

FIBI Score Explained

Sites that score between 0 - 25 are considered poor. Fish abundance is usually lower than normal or, if fish are abundant, the collection is dominated by a few tolerant species. The number of native fish species present is low. Sensitive species and habitat specialists are absent or extremely rare. The population is dominated by just a few ubiquitous species that are tolerant of wide-ranging water quality and habitat conditions. Pioneering, introduced and/or short-lived fish species are typically the most abundant types of fish. Fish collected at poor sites often have a higher than normal occurrence of external physical anomalies.

This location has been classified as a Candidate Reference Site. Further study is required to determine if this site represents natural stream qualities that are least disturbed by human activities within the watershed.

EcoRegion Comparison

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

Northwest Iowa Loess Prairies

This site is in the Northwest Iowa Loess Prairies ecoregion.

Ecoregion Map
Max 63
75th Percentile 49
Median 44
25th Percentile 40
Min 35
This Session's Score 9
Total Reference Site Samples 25
Mean 45.36
Standard Deviation 7.15