Realm: Freshwater
Climate: Temperate
Biome: Multiple
Central latitude: 42.091610
Central longitude: -93.295140
Duration: 29 years, from 1994 to 2022

18329 records

129 distinct species

Across the time series Semotilus atromaculatus is the most frequently occurring species

Methods

GENERAL:Since 1994, the Iowa Department of Natural Resources and the State Hygienic Laboratory (SHL) have sampled fish and benthic macroinvertebrates across the state to assess the biological integrity of Iowa's streams and rivers.” Since the program began in 1994, biological assessments have been performed at 1364 locations throughout the state. Over half a million fish and nearly as many bugs were collected and identified during this time. Sites within the biological monitoring program are divided into three major types- Wadeable, Non-wadeable, and Headwater streams. Wadeable streams make up the vast majority of all sites sampled within the program. These are sites that are easily sampled with standardized sampling gear by staff members wading into the stream and collecting the data. Because this is the most common stream type, all Fish and Benthic Macroinvertebrate Indicies of Biotic Integrity (IBI) are calibrated to streams this size. Non-wadeable streams are much larger streams and rivers that are too deep and wide to sample with backpack electroshockers, and require the use of a specially equipped boat with electroshocking gear and large dip-nets. Fish sampling is not as effective, due to the difficulty in capturing smaller fish and minnows in the deeper water and stronger current. Benthic macroinvertebrate sampling is extremely difficult in these types of streams as well. Headwater streams are found at the upper reaches (headwaters) of streams. These are very small streams, and can often be sampled with just one backpack shocker, rather than the 2-3 typically used in wadeable streams. Because the fish and benthic macroinvertebrate communities are much different in the upper reaches, a separate IBI is currently under development.” There are two main statuses assigned to invdividual sites- Reference and Survey sites. All other statuses are derived from these two categories. Reference sites represent stream conditions that are least disturbed by human activities, and are used to set biological criteria for measuring the health of other streams within the same ecoregion. To maintain a baseline for biological quality, twenty different reference sites are monitored each year, and each individual site is sampled on a 5-year schedule. Survey sites are sampled to determine if the stream's biological health is impacted by disturbances such as channelization, livestock grazing, manure spills, wastewater discharges, point and non-point source pollution, and urban runoff. Currently, the biological assessment program is able to monitor approximately 40 different survey sites per year.” Stream biological sampling is completed from July 1 - October 15 while stream flow levels are relatively stable. The length of stream segment sampled ranges from 5001150 feet, depending on the stream width and how frequently stream habitat features are repeated. Sampling frequency ensures that important habitat niches utilized by benthic macroinvertebrates and fish are adequately represented.” FISH SAMPLING:Fish are sampled using electrofishing gear. Battery-powered, backpack shockers are used in small streams and a generator-powered, barge shocker is used in larger streams. Sampling is accomplished in one pass (downstream to upstream) through the sampling area. The electrical current in the water temporarily stuns fish swimming near the shocker electrodes. The fish are netted and transferred to a holding bucket or live well for processing. The fish are identified, counted, and examined for diseases and parasites and then released to the stream.” [Extracted from: https://programs.iowadnr.gov/bionet/Docs/About] Fish community sampling requires the use of direct current electricity supplied by the electrofishing equipment. One backpack shocker is used for approximately every 15 feet of average stream width. However, in deeper streams or streams with complex habitat that have an average stream width of <15, two backpack shockers should be used. It is important to use as many backpack shockers as needed to obtain a representative sample. A barge electrofishing unit, consisting of generator, electrical control box, retractable electrodes, and a live well, is used in relatively deep or wide wadeable streams which cannot be effectively sampled with backpack shockers.” Fish sampling is normally conducted by a crew ranging from 2-7 people depending on stream size and sampling gear used. The number of crew members required is based on the number and type of electrofishing equipment used. Optimally, for every crew member operating a backpack shocker or barge probe, there should be one crew member netting the fish.” Fish community sampling requires the use of direct current electricity supplied by the electrofishing equipment. One backpack shocker is used for approximately every 15 feet of average stream width. However, in deeper streams or streams with complex habitat that have an average stream width of <15, two backpack shockers should be used. It is important to use as many backpack shockers as needed to obtain a representative sample. A barge electrofishing unit, consisting of generator, electrical control box, retractable electrodes, and a live well, is used in relatively deep or wide wadeable streams which cannot be effectively sampled with backpack shockers.” [Extracted from: Biological Sampling and Physical Habitat Assessment Standard Operating Procedure for Iowa Wadeable Streams and Rivers, July 24, 2015. See: https://publications.iowa.gov/20274/] See this source for more detail. NOTES: The dataset in BioTIME includes data from sites sampled at least two different years. All sites are standard wadeable. Grain size is the average area sampled across sites & sampling events in m2. Abundance units are ind/100m2.

Citation(s)

@Online{BioTIME_cit682, Study_id = {821}, Citation_id = {682}, Author = {{Iowa Dept. of Natural Resources}}, Title = {BioNet Biological Assessment Database}, Year = {2023}, Url = {https://programs.iowadnr.gov/bionet/}, Language = {English} }<br/>@Online{BioTIME_cit683, Study_id = {821}, Citation_id = {683}, Author = {{Iowa Dept. of Natural Resources}}, Pages = {70}, Title = {Biological Sampling and Physical Habitat Assessment Standard Operating Procedure for Iowa Wadeable Streams and Rivers, July 24, 2015}, Year = {2015}, Url = {https://publications.iowa.gov/20274/}, Language = {English} }