Geology topics

Kevin S. Irons

Publications and source records attributed to Kevin S. Irons.

4 recordsLinked to original sources

USGS2021

Demographic rate variability of Bighead and Silver Carps along an invasion gradient

Invasive Bighead Carp Hypophthalmichthys nobilis and Silver Carp H. molitrix have infested and caused largescale ecological and economic damage to the Illinois, Mississippi, and Ohio rivers. We compiled demographic data from 42,995 fish from 23 pools in the Illinois, Mississippi, and Ohio rivers, which universities and management agencies previously collected as part of management, monitoring, and research activities. We used this data set to test whether demographic rates (length–weight relations including body condition, mortality, growth curves, and female maturity curves) varied among subpopulations across a gradient of invasion status. We found that length–weight relations and growth curves varied among subpopulations, whereas maturity curves did not. Our findings demonstrated spatial variability in demographic rates for Bighead and Silver carp across a broad geographic area in relation to invasion status and river conditions. Herein, we provide general subpopulation management options and present different hypotheses to explain the observed spatial variability in demographic rates.

Illinois, Indiana, Iowa, Kentucky, West Virginia↗

USGS2009

Nonnative Fishes in the Upper Mississippi River System

The introduction, spread, and establishment of nonnative species is widely regarded as a leading threat to aquatic biodiversity and consequently is ranked among the most serious environmental problems facing the United States today. This report presents information on nonnative fish species observed by the Long Term Resource Monitoring Program on the Upper Mississippi River System a nexus of North American freshwater fish diversity for the Nation. The Long Term Resource Monitoring Program, as part of the U.S. Army Corps of Engineers' Environmental Management Plan, is the Nation's largest river monitoring program and stands as the primary source of standardized ecological information on the Upper Mississippi River System. The Long Term Resource Monitoring Program has been monitoring fish communities in six study areas on the Upper Mississippi River System since 1989. During this period, more than 3.5 million individual fish, consisting of 139 species, have been collected. Although fish monitoring activities of the Long Term Resource Monitoring Program focus principally on entire fish communities, data collected by the Program are useful for detecting and monitoring the establishment and spread of nonnative fish species within the Upper Mississippi River System Basin. Sixteen taxa of nonnative fishes, or hybrids thereof, have been observed by the Long Term Resource Monitoring Program since 1989, and several species are presently expanding their distribution and increasing in abundance. For example, in one of the six study areas monitored by the Long Term Resource Monitoring Program, the number of established nonnative species has increased from two to eight species in less than 10 years. Furthermore, contributions of those eight species can account for up to 60 percent of the total annual catch and greater than 80 percent of the observed biomass. These observations are critical because the Upper Mississippi River System stands as a nationally significant pathway for nonnative species expansion between the Mississippi River and the Great Lakes Basin. This report presents a synthesis of data on nonnative fish species observed during Long Term Resource Monitoring Program monitoring activities.

Scientific Investigations Report↗

USGS1997

1994 annual status report: a summary of fish data in six reaches of the upper Mississippi River system

The Long Term Resource Monitoring Program (LTRMP) completed 2,653 collections of fishes from stratified random and permanently fixed sampling locations in six study reaches of the Upper Mississippi River System during 1994. Collection methods included day and night electrofishing, hoop netting, fyke netting (two net sizes), gill netting, seining, and trawling in select aquatic area classes. The six LTRMP study areas are Pools 4 (excluding Lake Pepin), 8, 13, and 26 of the Upper Mississippi River, and unimpounded reach of the Mississippi River near Cape Girardeau, Missouri, and the La Grange Pool of the Illinois River. A total of 61-79 fish species were detected in each study area. For each of the six LTRMP study areas, this report contains summaries of (1) sampling efforts in each combination of gear type and aquatic area class, (2) total catches of each species from each gear type, (3) mean catch-per-unit of gear effort statistics and standard errors for common species from each combination of aquatic area class and selected gear type, and (4) length distributions of common species from selected gear types.

Long Term Resource Monitoring Program↗

USGS1997

1993 annual status report: a summary of fish data in six reaches of the upper Mississippi River system

The Long Term Resource Monitoring Program (LTRMP) completed 1,994 collections of fishes from stratified random and permanently fixed sampling locations in six study reaches of the Upper Mississippi River System during 1993. Collection methods included day and night electrofishing, hoop netting, fyke netting (two net sizes), gill netting, seining, and trawling in select aquatic area classes. The six LTRMP study reaches are Pools 4 (excluding Lake Pepin), 8, 13, and 26 of the Upper Mississippi River, an unimpounded reach of the Mississippi River near Cape Girardeau, Missouri, and the La Grange Pool of the Illinois River. A total of 62-78 fish species were detected in each study reach. For each of the six LTRMP study reaches, this report contains summaries of: (1) sampling efforts in each combination of gear type and aquatic area class, (2) total catches of each species from each gear type, (3) mean catch-per-unit of gear effort statistics and standard errors for common species from each combination of aquatic area class and selected gear type, and (4) length distributions of common species from selected gear types.

Long Term Resource Monitoring Program↗