Intervention Analysis of Power Plant Impact on Fish Populations

1986 ◽  
Vol 43 (4) ◽  
pp. 819-829 ◽  
Author(s):  
Charles P. Madenjian ◽  
David J. Jude ◽  
Frank J. Tesar
Keyword(s):  
Power Plant ◽  
Nuclear Power ◽  
Yellow Perch ◽  
Lake Michigan ◽  
Type I Error ◽  
Intervention Analysis ◽  
Type I ◽  
Alosa Pseudoharengus ◽  
First Order ◽  
Plant Effect

Alewife (Alosa pseudoharengus) and yellow perch (Perca flavescens) abundances, estimated from monthly gillnet and trawl catches at two transects, were monitored before (1973–74) and during (1975–82) operation of the D. C. Cook Nuclear Power Plant, southeastern Lake Michigan. Intervention analysis, a technique which accounts for autocorrelated observations, and analysis of variance (ANOVA) were applied to the monitoring data to assess any plant impact beginning in 1975. Both analyses disclosed no significant power plant impacts except for gillnetted yellow perch adults. The ANOVA indicated a significant decrease in abundance at the plant-discharge transect relative to the reference transect as plant operation began, which established a plant effect; intervention analysis showed no change. When April and May catches (months of low abundance) were deleted, this plant effect was insignificant. Monte Carlo simulation showed that as the first-order autoregressive coefficient increased positively, type I error of the ANOVA F-test increased. However, ANOVA was more powerful than intervention analysis when a first-order autoregressive component was included. Impact assessment based only on ANOVA can result in detection of impact when actually there was no effect (type I error) when observations are serially correlated (lack independence).

Robustness of Yao’s, James’, and Johansen’s Tests Under Variance-Covariance Heteroscedasticity and Nonnormality

1991 ◽  
Vol 16 (2) ◽  
pp. 125-139 ◽  
Author(s):  
James Algina ◽  
Takako C. Oshima ◽  
K. Linda Tang
Keyword(s):  
Type I Error ◽  
Error Rates ◽  
Second Order ◽  
Type I ◽  
Lognormal Distributions ◽  
First Order ◽  
Type I Error Rates ◽  
Mean Vectors ◽  
Equality Of Mean Vectors

Type I error rates for Yao’s, James’ first order, James’ second order, and Johansen’s tests of equality of mean vectors for two independent samples were estimated for various conditions defined by the degree of heteroscedasticity and nonnormality (uniform, Laplace, t(5), beta (5, 1.5), exponential, and lognormal distributions). For these alternatives to Hotelling’s T2, variance-covariance homogeneity is not an assumption. Although the four procedures can be seriously nonrobust with exponential and lognormal distributions, they were fairly robust with the rest of the distributions. The performance of Yao’s test, James’ second order test, and Johansen’s test was slightly superior to the performance of James’ first order test.

Cyclopoid Predation on Lake Michigan Fish Larvae

1982 ◽  
Vol 39 (12) ◽  
pp. 1563-1568 ◽  
Author(s):  
John H. Hartig ◽  
David J. Jude ◽  
Marlene S. Evans
Keyword(s):  
Yellow Perch ◽  
Lake Michigan ◽  
Fish Larvae ◽  
Spatial Proximity ◽  
Osmerus Mordax ◽  
Alosa Pseudoharengus ◽  
Rainbow Smelt ◽  
Common Carp Cyprinus Carpio ◽  
Diacyclops Thomasi ◽  
Temporal And Spatial

Cyclopoid predation on fish larvae, as evidenced by copepods attached to larvae in field collections, was quantitatively investigated during 1975–76 in southeastern Lake Michigan. Although six species of fish larvae were collected, predation occurred primarily (98%) on alewife (Alosa pseudoharengus); 2% of the predators were attached to spottail shiner (Notropis hudsonius) larvae. No cyclopoids were observed on rainbow smelt (Osmerus mordax), yellow perch (Perca flavescens), common carp (Cyprinus carpio), or sculpin (Cottus spp.) larvae. Most alewife larvae attacked were 3–8 mm long; older larvae and larvae of more robust species, such as yellow perch and spottail shiner, are apparently immune to such predation. Most predation (99%) occurred in July when alewife larvae were numerous and cyclopoids abundant. Fish larvae with attached copepods were found only in night collections. Most cyclopoid predators (99%) were adult female Diacyclops thomasi and Acanthocyclops vernalis. Other predaceous species of zooplankton, that occurred in close temporal and spatial proximity to fish larvae, apparently were not predaceous on these organisms.Key words: Alosa pseudoharengus larvae, Notropis hudsonius larvae, Diacyclops thomasi, Acanthocyclops vernalis, cyclopoid predation, Lake Michigan

scholarly journals Dynamics of the Lake Michigan food web, 1970–2000

2002 ◽  
Vol 59 (4) ◽  
pp. 736-753 ◽  
Author(s):  
Charles P Madenjian ◽  
Gary L Fahnenstiel ◽  
Thomas H Johengen ◽  
Thomas F Nalepa ◽  
Henry A Vanderploeg ◽  
...  
Keyword(s):  
Food Web ◽  
Zebra Mussel ◽  
Dreissena Polymorpha ◽  
Yellow Perch ◽  
Lake Michigan ◽  
Petromyzon Marinus ◽  
Perca Flavescens ◽  
Sea Lamprey ◽  
Alosa Pseudoharengus ◽  
Coregonus Clupeaformis

Herein, we document changes in the Lake Michigan food web between 1970 and 2000 and identify the factors responsible for these changes. Control of sea lamprey (Petromyzon marinus) and alewife (Alosa pseudoharengus) populations in Lake Michigan, beginning in the 1950s and 1960s, had profound effects on the food web. Recoveries of lake whitefish (Coregonus clupeaformis) and burbot (Lota lota) populations, as well as the buildup of salmonine populations, were attributable, at least in part, to sea lamprey control. Based on our analyses, predation by salmonines was primarily responsible for the reduction in alewife abundance during the 1970s and early 1980s. In turn, the decrease in alewife abundance likely contributed to recoveries of deepwater sculpin (Myoxocephalus thompsoni), yellow perch (Perca flavescens), and burbot populations during the 1970s and 1980s. Decrease in the abundance of all three dominant benthic macroinvertebrate groups, including Diporeia, oligochaetes, and sphaeriids, during the 1980s in nearshore waters ([Formula: see text]50 m deep) of Lake Michigan, was attributable to a decrease in primary production linked to a decline in phosphorus loadings. Continued decrease in Diporeia abundance during the 1990s was associated with the zebra mussel (Dreissena polymorpha) invasion, but specific mechanisms for zebra mussels affecting Diporeia abundance remain unidentified.

Recent Changes in Lake Michigan's Fish Community and Their Probable Causes, With Emphasis on the Role of the Alewife (Alosa pseudoharengus)

1987 ◽  
Vol 44 (S2) ◽  
pp. s53-s60 ◽  
Author(s):  
Gary W. Eck ◽  
Larue Wells
Keyword(s):  
Native Species ◽  
Yellow Perch ◽  
Gasterosteus Aculeatus ◽  
Lake Michigan ◽  
Lake Trout ◽  
Pink Salmon ◽  
Oncorhynchus Gorbuscha ◽  
Alosa Pseudoharengus ◽  
Poor Recruitment ◽  
Emerald Shiner

Major changes in fish populations occurred in Lake Michigan between the early 1970s and 1984. The abundance of lake trout (Salvelinus namaycush) and several nonnative species of salmonines increased greatly as a result of intensive stocking. The exotic alewife (Alosa pseudoharengus), which had proliferated to extremely high levels of abundance in the mid-1960s, declined, particularly in the early 1980s. We believe that the sharp decline in alewives in the 1980s was caused primarily by poor recruitment during the colder than normal years of 1976–82. Several of Lake Michigan's endemic species of fish appeared to be adversely affected by alewives: bloater (Coregonus hoyi), lake herring (C. artedii), emerald shiner (Notropis atherinoides), yellow perch (Perca flavescens), and deepwater sculpin (Myoxocephalus thompsoni), and possibly spoonhead sculpin (Cottus ricei). All declined when alewives were abundant, and those that did not become rare, i.e. the bloater, perch, and deepwater sculpin recovered when alewives declined. We present evidence suggesting that the mechanism by which alewives affect native species is not by competition for food, as has often been hypothesized, and discuss the possibility that it is predation on early life stages. Despite the decreased availability of alewives in the early 1980s, salmonines continued to eat mainly alewives. The highly abundant alternate prey species were eaten only sparingly, but alewives still may have been abundant enough to meet the forage requirements of salmonines. Two new exotics, the pink salmon (Oncorhynchus gorbuscha) and threespine stickleback (Gasterosteus aculeatus), increased in abundance in the 1980s, and could become detrimental (particularly the salmon) to other species.

Recent Major Declines in Zooplankton Populations in the Inshore Region of Lake Michigan: Probable Causes and Implications

1986 ◽  
Vol 43 (1) ◽  
pp. 154-159 ◽  
Author(s):  
Marlene S. Evans
Keyword(s):  
Yellow Perch ◽  
Lake Michigan ◽  
Food Limitation ◽  
Fish Predation ◽  
Alosa Pseudoharengus ◽  
Population Decrease ◽  
Probable Consequence ◽  
Major Increase ◽  
Standing Stocks ◽  
Zooplankton Communities

Summer Zooplankton communities in the inshore region of southeastern Lake Michigan were dominated by small species during the 1970s, suggesting that size-selective fish predation pressures were intense. Abundances of alewife (Alosa pseudoharengus), the dominant planktivore in the 1970s, declined in recent years, especially over 1982–84. Despite decreased alewife predation, small zooplankton taxa continued to predominate. Moreover, zooplankton standing stocks declined 10-fold during 1982–84, suggesting that predatory pressures had intensified. Concurrent with the alewife population decrease was a major increase in yellow perch (Perca flavescens) abundances. As a probable consequence of intense predation pressures exerted by abundant yellow perch, zooplankton standing stocks were severely reduced. Yellow perch populations may have been adversely affected by food limitation, especially in summer 1984 when zooplankton standing stocks were only 3% of their average level over 1975–81.

Reliability Analysis of the Automatic Control System of Reactor Power in Nuclear Power Plant Based on DFM

2016 ◽  
Author(s):  
Wang Hao ◽  
Tian Cong ◽  
Zhou Shiliang ◽  
Liu Yu Yuan ◽  
Shahroze Ahmad
Keyword(s):  
Control System ◽  
Power Plant ◽  
Nuclear Power Plant ◽  
Reliability Analysis ◽  
Nuclear Power ◽  
Boolean Logic ◽  
Type I ◽  
Type Ii ◽  
Sensor Failure ◽  
Sequence Of Events

Instrumentation and control (I&C) system is central nervous system of nuclear power plant (NPP), so its reliability is very important for the safety of NPP. Now Digital I&C system (DICS) is widely used in NPP, its reliability should be analyzed more carefully due to the more complex interaction among its components than analog I&C system. The interaction among DICS can be divided into type I and type II. The former is the interaction among sensor failure, controller failure and actuator failure, the latter is the interaction among hardware\software components of DICS. Limited by static Boolean logic, traditional fault tree is hard to model the dynamic interaction among DICS, so dynamic modelling method is required. In this paper, Dynamic flowgraph methodology (DFM) is used for reliability analysis of a subsystem of NPP DICS, namely APC (Automatic Power Control System). The proposed dynamic flowgraph modelled type I and type II interaction among APC and reliability of APC is assessed via inductive and deductive analysis. In the inductive analysis, three basic events (user defined combination of states) are considered, which includes sensor failure, SRB failure and master\checker processor failure, and the sequence of events caused by these basic events are tracked. In the deductive analysis, top event (combinations of possible system parameters and/or component states) is defined as actual control rod position is lower than demanded, and four combinations of basic events are tracked according to occurrence probability of their corresponding event.

Complementarity in the Use of Food and Thermal Habitat by Lake Michigan Fishes

1981 ◽  
Vol 38 (6) ◽  
pp. 662-668 ◽  
Author(s):  
Larry B. Crowder ◽  
John J. Magnuson ◽  
Stephen B. Brandt
Keyword(s):  
Native Species ◽  
Yellow Perch ◽  
Lake Michigan ◽  
Perca Flavescens ◽  
Common Species ◽  
Osmerus Mordax ◽  
Alosa Pseudoharengus ◽  
Rainbow Smelt ◽  
Thermal Habitat ◽  
Young Of The Year

The potential for ecological segregation of Lake Michigan fishes was examined by comparing diets and thermal habitat use of common species. Samples were collected by bottom trawling (N = 68) off Grand Haven, Michigan, September 7–13, 1977. Five common species exhibited complementarity in the use of food and thermal habitat resources. During the day, adult alewife (Alosa pseudoharengus), and rainbow smelt (Osmerus mordax) had similar diets but occupied somewhat different thermal habitats. Young-of-the-year (YOY) alewives segregated from adult alewife and rainbow smelt on both habitat and food. Spottail shiner (Notropis hudsonius), YOY alewives, and yellow perch (Perca flavescens) used similar thermal habitats but fed on different prey. Trout-perch (Percopsis osmiscomaycus) tended to segregate from the others based on both food and thermal habitat but may experience diffuse competition. Adults of the three native species consume entirely different prey than exotic alewife and rainbow smelt. The native species which declined during the invasion of alewife and rainbow smelt were those with apparently similar habitat and food requirements to the exotics. These data suggest that competition is important in maintaining the structure of the Lake Michigan fish community.Key words: competition, fishes, food, habitat, Lake Michigan, predation, temperature

scholarly journals A Study on the Development of Concrete Specimens for Nuclear Power Plant Using Type I Cement

2018 ◽  
Vol 18 (5) ◽  
pp. 165-170
Author(s):  
Namjin Cho ◽  
Sujin Hwang ◽  
Hyunwook Bang ◽  
Teayeon Cho ◽  
Junglim Lee
Keyword(s):  
Power Plant ◽  
Nuclear Power Plant ◽  
Nuclear Power ◽  
Type I
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