196 research outputs found
First Record of Freckled Madtom (Noturus nocturnus) in Iowa
This is the first record of freckled madtom in Iowa and is one of the northern most records. On 30 August 1984, five freckled madtoms were collected from the English River, Washington County. The specimens ranged from 46 to 95mm in total length and mean weight of 3.3g. Estimate of standing stock was 0.807 Kg/ha with a density of 44 fish/ha
Food Habits of Largemouth Bass (Micropterus salmoides) at Big Creek Lake
Food habits of largemouth bass (Micropterus salmoides) were studied at Big Creek Lake, from 1974-76, to determine the utilization of various prey species, temporal food habits, size at which bass became piscivorous, and size of fish-food items in relation to size of bass. Stomach contents from 259 bass were examined and 75 were empty. Entomostraca and insects were important food items of young bass but a transition stage was noted at about 125 mm TL when fish became the prominent food item. Crayfish were important food items early in the spring. Bass fed mostly on 0-age Centrarchids, and particularly bluegill and Notropis sp. Fish provided 29 to 86% of the biomass consumed and 2 to 70% by number. Larger bass (300+ mm) tended to utilize larger but fewer fish-food items while smaller bass (200-299 mm) consumed smaller fish more frequently
Characteristics of Channel Catfish Populations in Streams and Rivers of Iowa with Varying Habitats
From 1983 co 1985, more than 1,000 channel catfish (Icatalurus punctatus) were sampled with rotenone from 50 streams and rivers in Iowa to assess differences in population densities, standing stocks, viral statistics, age and growth, and habitat use Catfish densities ranged from 5 fish/ha in sites on the South Skunk and Upper Iowa Rivers to more than 4,400 fish/ha at a site on the Thompson Fork of the Grand River. Standing stocks ranged from a low of 0.1 kg/ha on a site on the South Skunk River to a high of 467 kg/ha on the East Fork of the Des Moines River. In general, catfish in rivers grew at a slower rate than lake populations (taking about four years to reach 305 mm), but total annual morality was relatively low compared to one published lake population, usually between 20 and 35% for fish age III and older. Larger catfish were usually found in streams of larger watersheds, but headwater streams were important nursery areas for fish less than age III. Mean standing stocks of channel catfish were similar between landforms (P\u3e0.05), but both relative weight (W,) of channel catfish and PSD was higher (
Standing Stocks of Fish in Some Iowa Streams, with a Comparison of Channelized and Natural Stream Reaches in the Southern Iowa Drift Plain
Comparisons were made of fish populations inhabiting 11 channelized and natural stream reaches in the Southern Iowa Drift Plain and two drainage ditches in the Des Moines Lobe. Fish were sampled with rotenone, identified, enumerated, and weighed. Total densities of fish ranged from 483/ha at Cylinder Creek to 51,941/ha at Walnut Creek. Total standing stocks of fish ranged from 14 kg/ha at a channelized site on the Chariton River to 1,344 kg/ha at an unchannelized site on the same river. Number of fish species ranged from six sampled at Silver Creek to 16 sampled at Jack Creek. Channelized sites contained fewer fish and substantially lower standing stocks of fish than natural reaches; however the number of species sampled was often similar. The abundance of sport fish was significantly higher in the natural stream reaches, particularly channel catfish (lctalurus punctatus), flathead catfish (Pylodictis olivaris), bullhead (I. melas and natalis), and carp (Cyprinus carpio). The Index of Biotic Integrity average was higher at the natural stream reaches (x = 36) than channelized sites (x = 29. 7). The major differences in fish populations were due to habitat quality and diversity found in the natural sites as compared to the homogeneous habitat of channelized reaches. Iowa streams have insufficient protection from the inroads of man
Some Genetic Characteristics of Three Walleye Stocks in Iowa and the Impact of Fry Stockings in the Cedar River
Fry stockings of walleye Stizostedion v. vitreum into the Cedar River, Iowa began in the early 1950\u27s, and two studies of the success of these plants gave conflicting results. The objectives of my study were to identify some genetic characteristics in three stocks of walleye and to utilize these characteristics to assess the genetic impact of fry stockings in the Cedar River. Electrophoretic analysis of malate dehydrogenase (MDH) and isocitrate dehydrogenase (IDH) was completed for walleye stocks from the Mississippi and Cedar Rivers, and Big Spirit Lake, Iowa. Phenotypic frequencies of Mdh - B2 and Mdh - B3 were as follows: Mississippi River walleye, 83 and 17%, respectively; Cedar River walleye, 71 and 29%, respectively; and Spirit Lake walleye, 19 and 81%, respectively. Chi-Square testing of these frequencies demonstrated that Spirit Lake fish differed significantly from Mississippi (P\u3c0.001) and Cedar River fish (P\u3c0.05), but there was no difference in frequencies between the two river walleye populations. Phenotypic frequencies of Idh - B1 and B2 were 54 and 46% for Mississippi River fish; 65 and 35%, respectively, for Spirit Lake fish; and, 65 and 35 % for Cedar River walleye, respectively.
Chi-square testing indicated that these frequencies were similar (P\u3e0.05). My study indicated that there are some genetic differences between walleye stocks in the two Iowa rivers and Big Spirit Lake. It is probable that the native Cedar River and Mississippi River stocks are genetically similar, particularly since the former is a tributary to the latter. Also, fry stockings of Big Spirit Lake walleye, and their progeny, have contributed only about 19% to the Cedar River population. Fry stockings are less successful than was once thought, and a more refined stocking program is needed
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Kootenai River Fisheries Investigation[s]; Stock Status of Burbot, 2002-2003 Annual Report.
The Kootenai River Fisheries Investigation Project planned to monitor burbot Lota lota movement in the winter of 2002-2003 and test a hypothesis regarding the relationship of winter flow to upstream spawning migration success. The U.S. Army Corps of Engineers and the Bonneville Power Administration were unable to provide the consistent low winter flows needed to meet the experimental design criteria in that monitoring and evaluation plan (approximately 170 m{sup 3}/s from Libby Dam). Although conditions consistent with management for sustained minimum flows persisted throughout the winter, and stable low flows were maintained below Libby Dam from September 1 through November 24, 2002 (158 m{sup 3}/s average) and from January 1, 2003 until May 1 (144 m{sup 3}/s average), flows in the intervening 37 d period from November 25 to December 31 were increased significantly by the U.S. Army Corps of Engineers. During that important December spawning migration period for burbot, flows were well above those proposed in the monitoring and evaluation plan and peaked at 741 m{sup 3}/s on December 21, 2002. Furthermore, despite the low flow conditions for much of the winter, our capture of 10 burbot was the lowest since this investigation began in 1993, evidence that the stock is extremely depressed and the numbers of burbot are declining. We captured a single burbot in 2002-2003 that provided circumstantial evidence reproduction occurred during the winter of 2000-2001. This burbot of 352 mm TL was among the smallest captured since sampling began in 1993. Seven burbot were monitored with sonic telemetry; two of those were tagged the previous winter. The capture of a female burbot at Ambush Rock during the spawning period supports results of previous findings that low flows during winter enhances burbot migration and spawning. Sampling for larval burbot was conducted, but no larval burbot were captured
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Kootenai River Fisheries Investigation : Stock Status of Burbot : Project Progress Report 2008 Annual Report.
Objectives of this investigation were to (1) monitor the population status and recruitment of burbot Lota lota in the Kootenai River, Idaho and British Columbia, Canada during the winter of 2006-2007; (2) evaluate the selective withdrawal system in place at Libby Dam to maintain the river temperature near Bonners Ferry between 1-4 C (November-December) to improve burbot migration and spawning activity; and (3) determine if a hatching success of 10% of eyed burbot embryos could be achieved through extensive rearing and produce fingerlings averaging 9.8 cm in six months. Water temperature did not fall below the upper limit (4 C) until mid-January but was usually maintained between 1-4 C January through February and was acceptable. Snowpack was characterized by a 101% of normal January runoff forecast. Adult burbot were sampled with hoop nets and slat traps. Only three burbot were captured in hoop nets, all at Ambush Rock (rkm 244.5). No burbot were caught in either slat traps or juvenile sampling gear, indicating the population is nearly extirpated. Burbot catch per unit effort in hoop nets was 0.003 fish/net d. Extensive rearing was moved to a smaller private pond and will be reported in the 2008-2009 annual report
Seasonal movement of burbot in relation to temperature and discharge in the Kootenai
abstract.-Movements of 11 sonic tagged burbot Lota lota were examined in the Kootenai River, Idaho, USA and Kootenay River and Kootenay Lake, British Columbia, Canada through up to three spawning seasons. Our objectives were to determine seasonal movements, differences in behavior of individual burbot, and the role of temperature and discharge on prespawn movement. Burbot demonstrated multiple movement patterns: 3 burbot were very mobile, 3 appeared to be intermediate in activity, and 5 were sedentary in summer, while 2 of the 11 entered Kootenay Lake and returned to the river. Most burbot began in autumn what may have been prespawn migrations when river temperatures fell to a range of 3.0-4.9°C. Six burbot entered the Goat River during the spawning season, of which five showed a multiple-year pattern of fidelity, and four returned to an apparent home pool and then exhibited sedentary behavior until the following winter. Three of the 11 burbot demonstrated an apparent nonspawning or rest year, but this was thought to be habitat-related. Logistic regression analysis of three of the six fish entering the Goat River suggested their migration to be best correlated to decreasing temperature and discharge. If the logistic model were representative of the population, then predicted migrations of burbot to the Goat River during winter would have followed a consistent pattern in November preLibby Dam, while postLibby Dam showed migrations to be unpredictable. Results of this study suggest that burbot had multiple life history patterns and several spawning locations and that rehabilitation measures should promote cooler winter water temperatures less than 5°C and discharges less than 300 m 3 /s
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Kootenai River Fisheries Investigation; Stock Status of Burbot, 2004-2005 Annual Report.
The main objective of this investigation was to monitor movement and spawning activity of burbot Lota lota in the Kootenai River, Idaho and British Columbia, Canada during the winter of 2004-2005. As a secondary objective, we examined the literature to obtain inferential information on how changes in historic water temperature may affect burbot movement and spawning. Discharge from Libby Dam for October 2004 ranged from 133 to 272 m{sup 3}/s, was ramped up to 532 m{sup 3}/s early in November, then was brought down to about 283 m{sup 3}/s through the last 10 days of the month. In early December 2004, discharge was brought up to full powerhouse of about 762 m{sup 3}/s several times but remained above 436 m{sup 3}/s for most of the month. However, with the prospect of a below normal snowpack and a mild winter, discharge was brought down to 113 m{sup 3}/s, minimum flow, for the remainder of January through March 2005. Discharge did not meet the systems operation request as a burbot rehabilitation measure. Mean water temperature of the Kootenai River at Libby Dam from November 1, 2004 through April 5, 2005 was 5.3 C, ranging from 10.45 C on November 1, 2004 to 3.2 C on March 2, 2005. Tributary water temperatures were monitored in Deep, Smith, and Boundary creeks in Idaho and in the Goat River, Corn, and Summit creeks, British Columbia, Canada from November 1, 2004 to about April 18, 2005. Baited hoop nets of 25 and 19 mm bar mesh were fished from November 5, 2004 through April 4, 2005 for 2,046 net d (one net day is a single 24 h set). One hundred twenty-two fish were caught encompassing ten different species of fish. Eighteen burbot (14 different fish) were captured. Sixteen of the captures were at Ambush Rock (rkm 244.5), one was near Nicks Island (rkm 144.5), British Columbia, and the other was downstream of the Goat River (rkm 152.7). Of the 18 burbot captured, one fish escaped from the net overnight, four were recaptures from this year's study, six were recaptures from previous years, and seven were new fish. Of the recaptures, five were tagged the previous year with an external sonic transmitter (all tags were shed), and one recapture was a fish tagged in February of 2001 at the Goat River with an internal sonic transmitter. Hoop net catch per unit effort for burbot was 0.009 fish/net d or 111.1 net d/fish. Burbot total length ranged from 489 mm to 764 mm TL (mean = 615.7 mm, SD = 74.6 mm, n = 13). Burbot weight ranged from 867 g to 2,798 g (mean = 1695.8 g, SD = 555.5 g, n = 13). Our literature review indicated even subtle changes in temperature can cause a variety of changes in life history patterns and in some cases seriously alter the outcome of spawning and recruitment. Furthermore, results from a summary study of burbot from our investigations and this one indicated the effect of temperature on burbot behavior is modified by river discharge, but the two combined have probably altered the historic movement patterns of burbot, because temperatures are now warmer with higher river discharges
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