Are Current Tissue‐Based Selenium Guidelines and Criteria Overly Protective of Freshwater Fish Populations? A Critical Review with Recommendations

2021 ◽  
Author(s):  
Guy Gilron ◽  
Graham Matheson ◽  
Reid Garrett ◽  
William J. Adams
Keyword(s):  
Freshwater Fish ◽  
Critical Review ◽  
Fish Populations

scholarly journals Effects of multigenerational exposure and phenotypic variation on a freshwater fish species exposed to elevated carbon dioxide (CO2)

2021 ◽  
Author(s):  
◽  
Jenna Laurel Fleet
Keyword(s):  
Carbon Dioxide ◽  
Freshwater Fish ◽  
Elevated Co2 ◽  
Phenotypic Variation ◽  
Mrna Abundance ◽  
Fish Populations ◽  
High Co2 ◽  
Filial Generation ◽  
Behavioural Phenotypes ◽  
Carbon Dioxide Co2

The amount of dissolved carbon dioxide (CO2) and the acidity of aquatic ecosystems is increasing as atmospheric CO2 concentrations increase due to human activities. Changes in pH and dissolved CO2 can have considerable aversive effects on fish physiology and behaviour, which can result in negative effects on fish populations. Multigenerational studies have found that the conditions experienced by parents can have significant effects on the performance of their offspring and understanding these effects can help to predict how fish populations will cope in future conditions. Additionally, repeatable behavioural phenotypes are good predictors of trends in behaviour, can be useful predictors of other physiological and life history traits, and can be subject to selection pressures. Unfortunately, the effects of elevated CO2 on freshwater fishes over multiple generations, and the effects of behavioural phenotypes, are poorly understood. In my thesis, freshwater Japanese Medaka (Oryzias latipes) were used to investigate the influence of phenotypic variation and differences in time of exposure (generational) on biological responses to elevated CO2. Lab-reared medaka were divided into ‘responsive’ and ‘non-responsive’ groups based on behavioural differences from the population mean during acute exposure to high CO2 in a common shuttling and novel tank behavioural assay. Responsive and non-responsive fish in parental generation (P) were subdivided and exposed to either control (~480 ppm) or high CO2 (~1250 ppm) conditions over a 6-week period. Following this time, eggs from this generation were collected and randomly selected into either high or control conditions, where they were hatched and reared until maturation (filial generation one (F1), 18 weeks). Eggs from F1 were collected and hatched and reared in the same conditions as their parents until adulthood (filial generation two (F2), 24 weeks). Body condition (size, weight and length), behaviour (total distance moved, time spent in the outer zone of the behavioural arena, and swimming direction), reproductive (number of eggs, size of eggs, and survival to hatch) performance, and the relative abundance of various mRNA transcripts in whole brain tissue of fish was measured across these three generations. Behavioural phenotypes influenced reproduction for P and F2 generation fish, and growth for F1 and F2 fish; suggesting that intraspecific variation in behavioural phenotypes may influence how medaka respond to elevated CO2. However, behavioural phenotypes did not have a significant effect on mRNA abundance on genes targeted in my study. Multigenerational exposure to elevated CO2 were shown to improve the performance of offspring in some measures and resulted in changes of mRNA abundance of several genes. Transgenerational exposure, where a parent or grandparent was exposed to elevated CO2 but the offspring were not exposed to elevated CO2, resulted in some deleterious effects suggesting that, generally, exposure to environmental conditions that differ from that of their parents may put fish especially at risk. In my thesis, current CO2 exposure appeared to be the best predictor of overall condition, where fish exposed to elevated CO2 were worse off than fish exposed to control CO2 conditions. The results of this research contribute to filling a current gap of knowledge in understanding how freshwater fish will respond to future conditions over an ecologically-relevant time scale. Importantly, this information will contribute to generating more informed decisions on freshwater ecosystem management and future research directions. Marine and freshwater environments offer food and water security and are of high importance to the economy and the health of our planet, making my research relevant to our broader society.

Genetic introgression on freshwater fish populations caused by restocking programmes

2005 ◽  
pp. 117-125
Author(s):  
María José Madeira ◽  
Benjamín J. Gómez-Moliner ◽  
Annie Machordom Barbe
Keyword(s):  
Freshwater Fish ◽  
Fish Populations ◽  
Genetic Introgression

Impacts of mesomycetozoean parasites on amphibian and freshwater fish populations

2013 ◽  
Vol 27 (3-4) ◽  
pp. 100-111 ◽  
Author(s):  
Jodi J.L. Rowley ◽  
Frank H. Gleason ◽  
Demetra Andreou ◽  
Wyth L. Marshall ◽  
Osu Lilje ◽  
...  
Keyword(s):  
Freshwater Fish ◽  
Fish Populations

The effects of acidification on Scandinavian freshwater fish fauna

1984 ◽  
Vol 305 (1124) ◽  
pp. 517-528 ◽  
Keyword(s):  
Freshwater Fish ◽  
Surface Area ◽  
Aquatic Ecosystems ◽  
Fish Fauna ◽  
Fish Populations ◽  
Lake Surface ◽  
Southwest Coast ◽  
Freshwater Fish Fauna ◽  
Lake Surface Area ◽  
Southern Norway

Acidification of freshwaters have inflicted a m ajor perturbation on Scandinavian aquatic ecosystems as indicated by severe regional loss of fish populations. This decline was first noted in the early 1920s but became particularly severe after W orld W ar II in the 1950s and 1960s. In southern Norway regional dam age is now docum ented in an area of 33000 km 2 , 13000 km 2 of which are devoid offish. Several m ajor southern salmon rivers are now barren. In Sweden more than 2500 lakes are docum ented to be affected. This corresponds to 3 -4 % of the total lake surface area. An additional 6000 lakes are assumed to be affected by acidification. Population losses are also found in thousands of kilometres of running w ater as well as in salmon and seatrout rivers on the southwest coast. This paper describes the early observations, chronology of this decline and reviews possible causes and mechanisms. The acidification and the associated loss of fishstocks over vast areas is apparently the most devastating change recorded for the fish fauna of Scandinavia

scholarly journals A moving target—incorporating knowledge of the spatial ecology of fish into the assessment and management of freshwater fish populations

2016 ◽  
Vol 188 (4) ◽  
Author(s):  
Steven J. Cooke ◽  
Eduardo G. Martins ◽  
Daniel P. Struthers ◽  
Lee F. G. Gutowsky ◽  
Michael Power ◽  
...  
Keyword(s):  
Freshwater Fish ◽  
Spatial Ecology ◽  
Fish Populations ◽  
Moving Target

Interspecific Competition and Population Control in Freshwater Fish

1956 ◽  
Vol 13 (3) ◽  
pp. 327-342 ◽  
Author(s):  
P. A. Larkin
Keyword(s):  
Interspecific Competition ◽  
Freshwater Fish ◽  
Quantitative Data ◽  
Population Control ◽  
Feeding Habits ◽  
Reproductive Potential ◽  
Habitat Type ◽  
Fish Populations ◽  
Population Interaction

Interspecific competition is defined as the demand of more than one organism for the same resource of the environment in excess of immediate supply. When two species are "competing for a niche" the term competition has been used to include phenomena such as predation of the two species on each other, competition to avoid a parasite, etc. Making this distinction in natural situations is unrealistic. In the limited sense in which interspecific competition is defined above, it is a discrete phenomenon, which with other phenomena such as predation, can be measured as a factor involved in interaction between species.Freshwater environments offer comparatively few opportunities for specialization in fishes. In consequence many species have a relatively wide tolerance of habitat type, a flexibility of feeding habits and in general share many resources of their environment with several other species of fish. Cannibalism and mutual predation are common complications of competitive relationships between species. The organization of freshwater fish communities is thus characterized by breadth at each level of the food chain rather than by a height of a pyramid of numbers. Flexible growth rate and high reproductive potential permit fish populations to tide over unfavorable periods of competition. In these circumstances it is difficult to separate the role of interspecific competition from other phenomena as a factor of population control. As a subordinate factor, predisposing fish to loss from other causes, interspecific competition may act to influence population levels. There is need for quantitative data and mathematical models for study of the types of population interaction typical in freshwater fish associations.

scholarly journals Morphological plasticity in a wild freshwater fish, Systomus sarana (Cyprinidae) from India: a glimpse through advanced morphometric toolkits 

2020 ◽  
Author(s):  
Deepmala Gupta ◽  
Arvind Kumar Dwivedi ◽  
Madhu Tripathi
Keyword(s):  
Geometric Morphometrics ◽  
Freshwater Fish ◽  
Function Analysis ◽  
Morphological Plasticity ◽  
Partial Least Square ◽  
Least Square ◽  
Fish Populations ◽  
Network System ◽  
Morphometric Characters ◽  
Truss Network System

Abstract Background: Body morphology supposed to underpin wide differences in animal performance that can be used to understand the diversification of characters. Further, identifying the fish population with unique shape due to variations in their morphometric characters enable better management of these subunits. Advanced statistical toolkits of morphometry called truss network system and geometric morphometrics have been increasingly used for detecting variations in morphological traits between subunits of fish populations. The present study was therefore carried out with the objective of determining phenotypically distinct units of freshwater fish Systomus sarana collected from geographically isolated locations.Methods: In the present study, 154 specimens of olive barb, S. sarana were collected from four distantly located rivers covering the northern (Ganga), southern (Godavari), central (Narmada), and eastern (Mahanadi) regions of India. Truss-network system and geometric morphometrics have been utilized. Fourteen landmarks were digitized uniformly on each specimen. In the present study, the truss network system yielded size-corrected morphometric characters that were subjected to univariate and multivariate statistical assessment. Results: Analysis of variance (ANOVA) presented significant differences among 63 out of 90 variables (p<0.05). Truss approach includes principal component analysis (PCA) and discriminant function analysis (DFA) while the geometric approach includes PCA, DFA, canonical variate analysis (CVA), partial least square (PLS), the relative warp (RW), and wireframes. CVA extracted Mahalanobis and Procrustes distances among groups found to be highly significant (p<0.0001). In linear DFA, the overall assignment of correctly classified individuals into their original groups was 86.2% for Ganga, 86.1% for the Godavari, 93.9% for the Narmada, and 92.9% for the Mahanadi population. Conclusions: The results revealed significant variations in the morphometric characters which were reflected in the shape of different body features of the studied populations. Both methods revealed analogous results and significant differences among groups in examined features. Our results suggest that S. sarana shows morphological plasticity across different rivers in India. This study supports the concept that geographical isolation among fish populations can lead to morphological variations.

The Effect of Synthetic Estrogens on Fathead Minnow Populations

2018 ◽  
Author(s):  
Shannon Brent ◽  
Reem Abaza ◽  
Walid Aoude ◽  
Rebecca Arcieri ◽  
Olivia Bruce
Keyword(s):  
Freshwater Fish ◽  
Fathead Minnow ◽  
Pimephales Promelas ◽  
Sewage Treatment ◽  
Treatment Plant ◽  
Wide Distribution ◽  
Fish Populations ◽  
Model Organisms ◽  
Canadian Association ◽  
Synthetic Estrogens

The fathead minnow (Pimephales promelas) is a freshwater fish with a wide distribution in lakes, streams, and ponds across North America, including Ontario. This species has been recognized as one of the most useful model organisms for freshwater toxicology monitoring, due to its tolerance of its range for aquatic conditions. Synthetic estrogens are excreted as a metabolic product in the urinary waste of women using oral contraceptives. Estrogens are not effectively filtered out by sewage treatment plants and are subsequently released into water effluents, affecting aquatic wildlife. In response to experimentally heightened estrogen concentrations, male and female fathead minnows have shown increases in vitellogenin protein, and females have displayed delayed ovarian development and increased numbers of underdeveloped ovarian follicles. Males also experienced lowered gonadosmatic indices, and some males had primary stage oocytes in their testes. As would be expected, synthetic estrogen additions influenced fathead minnow reproductive success, leading to a collapse of the experimental fish population. By taking a multi-disciplinary approach, this study looks to identify how synthetic estrogens are threatening local fish populations, and how this may eventually disrupt the freshwater food chain. Collaboration with The Canadian Association on Water Quality (Kingston), Ravensview Wastewater Treatment Plant, and the Catarqui Region Conservation Authority will provide a greater understanding of the hormonal content in Kingston’s wastewaters. Ultimately, this study will provide more insight on the level of risk faced by freshwater fish populations on a local scale, and propose a method to reduce estrogen deposition in freshwater environments.

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