Interspecies differences in biochemical, histopathological, and population responses in four wild fish species exposed to ethynylestradiol added to a whole lakeThis paper is part of the series “Forty Years of Aquatic Research at the Experimental Lakes Area”.

2009 ◽  
Vol 66 (11) ◽  
pp. 1920-1935 ◽  
Author(s):  
V. P. Palace ◽  
R. E. Evans ◽  
K. G. Wautier ◽  
K. H. Mills ◽  
P. J. Blanchfield ◽  
...  
Keyword(s):  
Lake Trout ◽  
Population Decline ◽  
Pimephales Promelas ◽  
Population Level ◽  
Experimental Lakes Area ◽  
Population Responses ◽  
Species Population ◽  
Second Year ◽  
Histopathological Effects ◽  
Histopathological Evidence

Efforts to understand the effects of environmental estrogens on fish have shifted away from biochemical indicators towards population-level impacts. Ethynylestradiol (EE2) was added to a whole lake at environmentally relevant concentrations for 3 consecutive years to examine links between vitellogenin (VTG) induction, histopathological impacts, and population decline in four species of fish. VTG induction and histopathological effects in tissues were most severe in fathead minnow ( Pimephales promelas ) and pearl dace ( Margariscus margarita ). VTG was induced to a similar extent in lake trout ( Salvelinus namaycush ) but less so in white sucker ( Catostomus commersonii ). There were no histopathological effects in tissues of the two latter species. Population decline occurred in fathead minnows in the second year of EE2 additions and there were some indications of population decline in pearl dace during the third year. White suckers were not affected but lake trout declined in year 3. Habitat selection probably altered EE2 exposure and the different effects in each species likely also reflect differing sensitivities. It appears that VTG induction is not sufficient to predict effects of xenoestrogens on fish populations. However, stronger predictions can be made when VTG induction is assessed in conjunction with histopathological evidence of liver, kidney, and gonad tissue damage.

scholarly journals Environmental oestrogens cause predation-induced population decline in a freshwater fish

2018 ◽  
Vol 5 (10) ◽  
pp. 181065 ◽  
Author(s):  
Daniel C. Rearick ◽  
Jessica Ward ◽  
Paul Venturelli ◽  
Heiko Schoenfuss
Keyword(s):  
Freshwater Fish ◽  
Species Interactions ◽  
Population Decline ◽  
Pimephales Promelas ◽  
Lepomis Macrochirus ◽  
Population Level ◽  
Delayed Response ◽  
Escape Performance ◽  
Population Declines ◽  
Structured Population Model

Understanding population-level effects of environmental stressors on aquatic biota requires knowledge of the direct adverse effects of pollutants on individuals and species interactions that relate to survival and reproduction. Here, we connect behavioural assays with survival trials and a modelling approach to quantify changes in antipredator escape performance of a larval freshwater fish following exposure to an environmental oestrogen, and predict changes in population abundance. We quantified the effects of short-term (21 days) exposure to 17β-oestradiol (E2) on the antipredator escape performance of larval fathead minnows ( Pimephales promelas ) and the probability of predation by a natural predator, the bluegill sunfish ( Lepomis macrochirus ). Compared with unexposed minnows, minnows exposed to environmentally relevant concentrations of E2 that approach total oestrogenic activity of wastewater-dominated environments (38 and 103 ng l −1 ) had delayed response times and slower escape speeds, and were more susceptible to predation. Incorporating these data into a stage-structured population model demonstrated that enhanced predation mortality at the larval stage can result in population declines. These results indicate that subtle, sub-lethal shifts in the behaviour of individuals due to human-mediated environmental change can impact species interactions with measurable population-level effects. Such changes have the potential to alter higher-order trophic interactions and disrupt aquatic communities.

Responses of Fish Populations in Lake 223 to 8 Years of Experimental Acidification

1987 ◽  
Vol 44 (S1) ◽  
pp. s114-s125 ◽  
Author(s):  
K. H. Mills ◽  
S. M. Chalanchuk ◽  
L. C. Mohr ◽  
I. J. Davies
Keyword(s):  
Fathead Minnow ◽  
Lake Trout ◽  
Pimephales Promelas ◽  
Salvelinus Namaycush ◽  
Early Years ◽  
White Sucker ◽  
Experimental Lakes Area ◽  
Northwestern Ontario ◽  
Slimy Sculpin ◽  
Experimental Acidification

Lake 223 in the Experimental Lakes Area, northwestern Ontario, was experimentally acidified with sulfuric acid from 1976 (initial average pH 6.49) to 1981 (average pH 5.02), and then maintained at pH 5.02 to 5.13 from 1981 to 1983. Lake trout (Salvelinus namaycush), white sucker (Catostomus commersoni), fathead minnow (Pimephales promelas), and slimy sculpin (Cottus cognatus) were abundant at the onset of acidification. A decline in the abundance of fathead minnow began in 1979 (pH 5.64), and was followed first by a rapid increase in number of pearl dace (Semotilus margarita) in 1980 (pH 5.59) and then a rapid decrease in 1982 (pH 5.09). The abundance of slimy sculpin decreased rapidly in 1979. Abundances of lake trout and white sucker increased during the early years of acidification, but declined following consecutive recruitment failures starting in 1980 for trout and in 1981 for white suckers. By 1982 recruitment had ceased for all Lake 223 fishes. Survival of lake trout [Formula: see text] age 1 decreased in 1982 and 1983, but no other changes in survival of fish [Formula: see text] age 1 were detected for lake trout or white sucker. By spring 1983 many lake trout were emaciated due to losses of the lake trout food organisms. No changes in growth of lake trout and white suckers occurred during the initial years of acidification, but growth of lake trout slowed in 1982 and growth of white sucker increased in 1979.

Induction of Vitellogenin and Histological Effects in Wild Fathead Minnows from a Lake Experimentally Treated with the Synthetic Estrogen, Ethynylestradiol

2002 ◽  
Vol 37 (3) ◽  
pp. 637-650 ◽  
Author(s):  
Vince P. Palace ◽  
Robert E. Evans ◽  
Kerry Wautier ◽  
Christopher Baron ◽  
Lenore Vandenbyllardt ◽  
...  
Keyword(s):  
Estrogenic Activity ◽  
Pimephales Promelas ◽  
Population Level ◽  
Egg Yolk ◽  
Testicular Development ◽  
Fathead Minnows ◽  
Experimental Lakes Area ◽  
Northwestern Ontario ◽  
Synthetic Estrogen ◽  
Tubule Lumen

Abstract Potential effects of exposure to contaminants with estrogenic activity are currently being examined in fish from a lake experimentally treated with the synthetic estrogen, ethynylestradiol (EE2). EE2 was added to Lake 260, a small Precambrian shield lake in the Experimental Lakes Area (ELA) of northwestern Ontario, from late May to October 2001. Concentrations of EE2 in epilimnetic waters ranged between 4.0 and 8.1 ng/L, with a mean (±SD) of 6.0 ± 2.8 ng/L. Male fathead minnows (Pimephales promelas) captured from Lake 260 after EE2 additions began contained 9000-fold higher concentrations of the egg yolk precursor vitellogenin (VTG), than were detected in fish captured from the same lake prior to the EE2 additions, or when compared to fatheads from reference lakes during the same sample period. VTG in females was induced 8- to 80-fold and was sustained beyond the normal window of vitellogenesis in Lake 260. Histological examination of tissues from EE2-exposed male fatheads in Lake 260 showed widespread fibrosis and inhibition of testicular development. Enlargement of liver cells, edema in the interstitium between kidney tubules, and eosinophilic deposits in the kidney tubule lumen were also evident in male fatheads from Lake 260. Further studies will examine the relationships between biochemical and histological alterations and population level effects.

Geochemical Pathways and Biological Uptake of Radium in Small Canadian Shield Lakes

1984 ◽  
Vol 41 (3) ◽  
pp. 459-468 ◽  
Author(s):  
R. H. Hesslein ◽  
E. Slavicek
Keyword(s):  
Lake Trout ◽  
Pimephales Promelas ◽  
Canadian Shield ◽  
Coregonus Clupeaformis ◽  
Experimental Lakes Area ◽  
Biological Uptake ◽  
Single Addition ◽  
Shield Lakes ◽  
Large Adult

The sediment–water interactions and biological uptake of 226Ra are described for four small Canadian Shield lakes at the Experimental Lakes Area, Kenora, Ont. A single addition of 226Ra was made to each lake between 1970 and 1976. Approximately 90% of the added 226Ra initially sorbed to the sediments. Outflow from the lakes showed losses of only 5–11% 226Ra per year. Models are proposed for adsorption and outflow of 226Ra from lakes. Biological uptake and long-term 226Ra concentrations were measured in three species of macrophytes, crayfish, and five species of fish. Bioaccumulation ranged from 1100 to 5000 in macrophytes, 750 in crayfish, from 30 to 80 in large adult lake trout (Salvelinus namaycush), white sucker (Catostomus commersoni), and lake whitefish (Coregonus clupeaformis), and from 230 to 1200 in fathead minnows (Pimephales promelas), pearl dace (Semotilus margarita), and northern redbelly dace (Chrosomus eos). The concept of Ra/Ca ratio in organisms versus water and food is used to explain the differences in bioaccumulation. 226Ra is discriminated against versus calcium by fish but favored by macrophytes and crayfish.

scholarly journals Direct and indirect responses of a freshwater food web to a potent synthetic oestrogen

2014 ◽  
Vol 369 (1656) ◽  
pp. 20130578 ◽  
Author(s):  
Karen A. Kidd ◽  
Michael J. Paterson ◽  
Michael D. Rennie ◽  
Cheryl L. Podemski ◽  
Dave L. Findlay ◽  
...  
Keyword(s):  
Indirect Effects ◽  
Fathead Minnow ◽  
Lake Trout ◽  
Prey Availability ◽  
Pimephales Promelas ◽  
Endocrine Disrupting Chemicals ◽  
Benthic Invertebrate ◽  
Small Scale ◽  
Direct Effects ◽  
Experimental Lakes Area

Endocrine-disrupting chemicals (EDCs) in municipal effluents directly affect the sexual development and reproductive success of fishes, but indirect effects on invertebrate prey or fish predators through reduced predation or prey availability, respectively, are unknown. At the Experimental Lakes Area in northwestern Ontario, Canada, a long-term, whole-lake experiment was conducted using a before-after-control-impact design to determine both direct and indirect effects of the synthetic oestrogen used in the birth control pill, 17α-ethynyloestradiol (EE2). Algal, microbial, zooplankton and benthic invertebrate communities showed no declines in abundance during three summers of EE2 additions (5–6 ng l −1 ), indicating no direct toxic effects. Recruitment of fathead minnow ( Pimephales promelas ) failed, leading to a near-extirpation of this species both 2 years during (young-of-year, YOY) and 2 years following (adults and YOY) EE2 additions. Body condition of male lake trout ( Salvelinus namaycush ) and male and female white sucker ( Catostomus commersonii ) declined before changes in prey abundance, suggesting direct effects of EE2 on this endpoint. Evidence of indirect effects of EE2 was also observed. Increases in zooplankton, Chaoborus , and emerging insects were observed after 2 or 3 years of EE2 additions, strongly suggesting indirect effects mediated through the reduced abundance of several small-bodied fishes. Biomass of top predator lake trout declined by 23–42% during and after EE2 additions, most probably an indirect effect from the loss of its prey species, the fathead minnow and slimy sculpin ( Cottus cognatus ). Our results demonstrate that small-scale studies focusing solely on direct effects are likely to underestimate the true environmental impacts of oestrogens in municipal wastewaters and provide further evidence of the value of whole-ecosystem experiments for understanding indirect effects of EDCs and other aquatic stressors.

Land water linkages: influences of riparian deforestation on lake thermocline depth and possible consequences for cold stenotherms

1997 ◽  
Vol 54 (6) ◽  
pp. 1299-1305 ◽  
Author(s):  
Robert France
Keyword(s):  
Thermal Stratification ◽  
Lake Trout ◽  
Salvelinus Namaycush ◽  
Thermocline Depth ◽  
Experimental Lakes Area ◽  
Northwestern Ontario ◽  
Riparian Trees ◽  
Tree Removal ◽  
Riparian Tree ◽  
Land Water

The purpose of the present study was to determine if riparian deforestation would expose lake surfaces to stronger winds and therefore bring about deepening of thermoclines and resulting habitat losses for cold stenotherms such as lake trout (Salvelinus namaycush). Removal of protective riparian trees through wind blowdown and two wildfires was found to triple the overwater windspeeds and produce thermocline deepening in two lakes at the Experimental Lakes Area. A survey of thermal stratification patterns in 63 northwestern Ontario lakes showed that lakes around which riparian trees had been removed a decade before through either clearcutting or by a wildfire were found to have thermocline depths over 2 m deeper per unit fetch length compared with lakes surrounded by mature forests. Riparian tree removal will therefore exacerbate hypolimnion habitat losses for cold stenotherms that have already been documented to be occurring as a result of lake acidification, eutrophication, and climate warming.

Lack of relationship between simulated fish population responses and their life history traits: inadequate models, incorrect analysis, or site-specific factors?

2005 ◽  
Vol 62 (4) ◽  
pp. 886-902 ◽  
Author(s):  
Kenneth A Rose
Keyword(s):  
Life History ◽  
Life History Traits ◽  
Lake Trout ◽  
Fish Population ◽  
Population Models ◽  
Site Specific ◽  
Density Dependent ◽  
Population Responses ◽  
Adult Growth ◽  
Specific Factors

Relationships between fish population responses to changes in their vital rates and commonly available life history traits would be a powerful screening tool to guide management about species vulnerability, to focus future data collection on species and life stages of concern, and to aid in designing effective habitat enhancements. As an extension of previous analyses by others, I analyzed the responses to changes in fecundity and yearling survival of age-structured matrix and individual-based population models of 17 populations comprising 10 species. Simulations of the matrix models showed that the magnitude of population responses, but not the relative order of species sensitivity, depended on the state (sustainable or undergoing excessive removals) of the population. Matrix and individual-based models predicted population responses that appeared to be unrelated to their species-level life history traits when responses were plotted on a three-end-point life history surface. Density-dependent adult growth was added to the lake trout (Salvelinus namaycush) matrix model, and simulations demonstrated the potential importance to predicted responses of density-dependent processes outside the usual spawner–recruit relationship. Four reasons for the lack of relationship between population responses and life history traits related to inadequate population models, incorrect analysis, inappropriate life history model, and important site-specific factors are discussed.

scholarly journals Characteristics of Recipients of Red Blood Cell Concentrates in a German Federal State

2020 ◽  
Vol 47 (5) ◽  
pp. 370-378
Author(s):  
Linda Schönborn ◽  
Kerstin Weitmann ◽  
Andreas Greinacher ◽  
Wolfgang Hoffmann
Keyword(s):  
Blood Cell ◽  
Red Blood Cell ◽  
Population Decline ◽  
Population Level ◽  
Practice Change ◽  
Federal State ◽  
Treatment Practices ◽  
Study Results ◽  
Related Group ◽  
German Federal State

Background: Annual transfusion rates in many European countries range between 25 and 35 red blood cell concentrates (RBCs)/1,000 population.It is unclear why transfusion rates in Germany are considerably higher (approx. 50–55 RBCs/1,000 population). Methods: We assessed the characteristics of transfusion recipients at all hospitals of the German federal state Mecklenburg-Western Pomerania during a 10-year longitudinal study. Results: Although 75% of patients received ≤4 RBCs/patient in 2015 (1 RBC: 11.3%; 2 RBCs: 42.6%; 3 RBCs: 6.3%; 4 RBCs: 15.0%), the mean transfusion index was 4.6 RBCs due to a minority of patients with a high transfusion demand. Two thirds of all RBCs were transfused to only 25% of RBC recipients. Consistently, male patients received a higher number of RBCs (2005: 54.2%; 2015: 56.8%) and had a higher mean transfusion index than female patients (mean 5.1 ± 7.2; median 2; inter-quartile range [IQR] 2–4 vs. mean 4.0 ± 5.8; median 2; IQR 2–4). The absolute transfusion demand decreased between 2005 and 2015 by 13.5% due to a composite of active reduction (clinical practice change) and population decline in the 65- to 75-year age group (lower birth rate cohort 1940–1950); however, with major differences between hospitals (range from –61.0 to +41.4%). Conclusion: Transfusion demand in a population could largely be driven by patients with high transfusion demand. Different treatment practices in this group of patients probably add to the major differences in transfusion demand per 1,000 individuals between countries. The available data cannot prove this hypothesis. Implementation of a diagnosis-related group-based monitoring system is urgently needed to allow informative monitoring on the population level and meaningful comparisons between transfusion practices.

scholarly journals Direct evidence of poison-driven widespread population decline in a wild vertebrate

2020 ◽  
Vol 117 (28) ◽  
pp. 16418-16423 ◽  
Author(s):  
Patricia Mateo-Tomás ◽  
Pedro P. Olea ◽  
Eva Mínguez ◽  
Rafael Mateo ◽  
Javier Viñuela
Keyword(s):  
Large Scale ◽  
Population Decline ◽  
Population Level ◽  
Breeding Population ◽  
Time Frame ◽  
Regulatory Control ◽  
Individual Level ◽  
Lead Ammunition ◽  
Organochlorine Insecticides ◽  
Local Extinctions

Toxicants such as organochlorine insecticides, lead ammunition, and veterinary drugs have caused severe wildlife poisoning, pushing the populations of several apex species to the edge of extinction. These prime cases epitomize the serious threat that wildlife poisoning poses to biodiversity. Much of the evidence on population effects of wildlife poisoning rests on assessments conducted at an individual level, from which population-level effects are inferred. Contrastingly, we demonstrate a straightforward relationship between poison-induced individual mortality and population changes in the threatened red kite (Milvus milvus). By linking field data of 1,075 poisoned red kites to changes in occupancy and abundance across 274 sites (10 × 10-km squares) over a 20-y time frame, we show a clear relationship between red kite poisoning and the decline of its breeding population in Spain, including local extinctions. Our results further support the species listing as endangered, after a breeding population decline of 31% to 43% in two decades of this once-abundant raptor. Given that poisoning threatens the global populations of more than 2,600 animal species worldwide, a greater understanding of its population-level effects may aid biodiversity conservation through increased regulatory control of chemical substances. Our results illustrate the great potential of long-term and large-scale on-ground monitoring to assist in this task.

scholarly journals Predicting how populations decline to extinction

2011 ◽  
Vol 366 (1577) ◽  
pp. 2577-2586 ◽  
Author(s):  
Ben Collen ◽  
Louise McRae ◽  
Stefanie Deinet ◽  
Adriana De Palma ◽  
Tharsila Carranza ◽  
...  
Keyword(s):  
At Risk ◽  
Extinction Risk ◽  
Mammalian Species ◽  
Local Population ◽  
Population Decline ◽  
Scale Up ◽  
Population Level ◽  
Biological Traits ◽  
Population Declines ◽  
Trend Data

Global species extinction typically represents the endpoint in a long sequence of population declines and local extinctions. In comparative studies of extinction risk of contemporary mammalian species, there appear to be some universal traits that may predispose taxa to an elevated risk of extinction. In local population-level studies, there are limited insights into the process of population decline and extinction. Moreover, there is still little appreciation of how local processes scale up to global patterns. Advancing the understanding of factors which predispose populations to rapid declines will benefit proactive conservation and may allow us to target at-risk populations as well as at-risk species. Here, we take mammalian population trend data from the largest repository of population abundance trends, and combine it with the PanTHERIA database on mammal traits to answer the question: what factors can be used to predict decline in mammalian abundance? We find in general that environmental variables are better determinants of cross-species population-level decline than intrinsic biological traits. For effective conservation, we must not only describe which species are at risk and why, but also prescribe ways to counteract this.

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