Environmental Disturbance and Life Histories: Principles and Examples

1979 ◽  
Vol 36 (3) ◽  
pp. 329-334 ◽  
Author(s):  
D. M. Lehmkuhl
Keyword(s):  
Heavy Metals ◽  
Life Histories ◽  
Life Cycles ◽  
Detectable Effect ◽  
Toxic Substances ◽  
Short Term ◽  
Environmental Disturbances ◽  
Temperature Changes ◽  
Low Levels ◽  
Available Information

While many environmental disturbances have no readily detectable effect on aquatic invertebrates in the short term, they may prevent normal reproduction and cause eventual local extinction of a species. Small temperature changes may interfere with diapause signals and prevent completion of the life cycle. Heavy metals and toxic substances may drastically reduce reproduction rates in species exposed to sublethal levels. Dissolved salts and pH affect organisms at abnormally high or low levels but most mechanisms are unknown. It is concluded that relatively little information is available on the effects of environmental disturbances on life cycles. Available information, however, is sufficient to provide evidence of many problems that require attention. Key words: life histories, benthos, environmental disturbances, toxic substances, diapause, temperature, heavy metals

Bioremediation of Heavy Metals and Other Toxic Substances by Microorganisms

2021 ◽  
pp. 285-329
Author(s):  
Dhaneshwar Padhan ◽  
Pragyan Paramita Rout ◽  
Ritesh Kundu ◽  
Samrat Adhikary ◽  
Purbasha Priyadarshini Padhi
Keyword(s):  
Heavy Metals ◽  
Toxic Substances

Feeding rate and efficiency in an apex soil predator exposed to short-term temperature changes

2021 ◽  
Vol 50 ◽  
pp. 87-96
Author(s):  
Divya Ramachandran ◽  
Zoë Lindo ◽  
Matthew L. Meehan
Keyword(s):  
Feeding Rate ◽  
Short Term ◽  
Temperature Changes

scholarly journals Robustness of life histories to environmental variability in complex versus simple life cycles

2021 ◽  
Author(s):  
Annie Jonsson
Keyword(s):  
Growth Rate ◽  
Life Histories ◽  
Environmental Variability ◽  
Life Cycles ◽  
Relative Advantage ◽  
Complex Life Cycle ◽  
Life Stages ◽  
Vital Rates ◽  
Habitat Separation ◽  
Simple Life

AbstractMost animal species have a complex life cycle (CLC) with metamorphosis. It is thus of interest to examine possible benefits of such life histories. The prevailing view is that CLC represents an adaptation for genetic decoupling of juvenile and adult traits, thereby allowing life stages to respond independently to different selective forces. Here I propose an additional potential advantage of CLCs that is, decreased variance in population growth rate due to habitat separation of life stages. Habitat separation of pre- and post-metamorphic stages means that the stages will experience different regimes of environmental variability. This is in contrast to species with simple life cycles (SLC) whose life stages often occupy one and the same habitat. The correlation in the fluctuations of the vital rates of life stages is therefore likely to be weaker in complex than in simple life cycles. By a theoretical framework using an analytical approach, I have (1) derived the relative advantage, in terms of long-run growth rate, of CLC over SLC phenotypes for a broad spectrum of life histories, and (2) explored which life histories that benefit most by a CLC, that is avoid correlation in vital rates between life stages. The direction and magnitude of gain depended on life history type and fluctuating vital rate. One implication of our study is that species with CLCs should, on average, be more robust to increased environmental variability caused by global warming than species with SLCs.

scholarly journals Community structure, life histories and secondary production of stoneflies in two small mountain streams with different degree of forest cover

2015 ◽  
Author(s):  
Pavel Beracko ◽  
Andrea Kušnírová ◽  
Michaela Partlová ◽  
Jana Ciceková
Keyword(s):  
Community Structure ◽  
Secondary Production ◽  
Life Histories ◽  
Forest Cover ◽  
Adult Emergence ◽  
Life Cycles ◽  
Mountain Streams ◽  
Annual Life Cycle ◽  
Forested Stream ◽  
The Difference

<p>Our study examines community structure and nymphal biology (life cycles and secondary production) of stoneflies in two adjacent mountain streams with different degree of forest cover in the Prosiečanka River Basin (Chočské Vrchy Mts., West Carpathians). One of the streams has non-forested catchment, converted to meadows and pastures, while the other one has catchment with 60% covered by spruce forest. Differences in forest cover and in thermal regime of the streams were reflected by the difference of stonefly communities at their structural and functional level. Species <em>Nemoura cinerea and Leuctra aurita </em>created stonefly assemblage in non-forested stream, whereas <em>Nemoura cinerea</em> also occurred in naturally forested stream together with species <em>Leuctra armata, Leuctra nigra, Leuctra prima, Siphonoperla neglecta</em> and <em>Arcynopteryx dichroa</em>. All examined species had maximally annual life cycle and in eudominant species <em>Nemoura cinerea</em> one month shift was found in nymphal hatching and adult emergence between streams. Total secondary production of stoneflies in undisturbed stream (126.46 mg DW m<sup>-2</sup> y<sup>-1</sup>) was more than two times higher than the production in non-forested stream (47.39 mg DW m<sup>-2</sup> y<sup>-1</sup>). </p>

scholarly journals The effects of low-dose gamma-irradiation on the wholesomeness of mangoes (Mangifera indica) as determined by short-term feeding studies using rats

1976 ◽  
Vol 35 (1) ◽  
pp. 67-75
Author(s):  
G. M. J. Horton
Keyword(s):  
Mangifera Indica ◽  
Control Diet ◽  
Blood Chemistry ◽  
Female Rats ◽  
Toxic Substances ◽  
Weight Changes ◽  
Short Term ◽  
Dry Matter Digestibility ◽  
Daily Body Weight ◽  
Mango Pulp

1. A control diet and diets containing 150 g non-irradiated or 150 g irradiated mangopulp/kg were given to female rats from day 15 of the gestation period until weaning in trials 1 and 2, and from 40 d before mating until 28 d post weaning in trial 3.2. Food intake and dry-matter digestibility were similar with all diets.3. There were no significant differences between animals given the different dietary regimens in the daily body-weight changes of weanling males, pups, nursing females or females during the immediate postlactation period.4. No differences in haematological or blood chemistry values were found which could be attributed to the ingestion of irradiated mangoes. There was no evidence for the presence of any toxic substances in the irradiated-mango-pulp diet.5. Gross pathological observations revealed no aberrations which could be related to the ingestion of irradiated mangoes.6. It may be concluded that the wholesomeness of mangoes was not affected by gammairradiation at a dose of 75 krd.

scholarly journals ‘It isn't my area.’ Coaches’ awareness of concussion protocols in Scottish youth football

2021 ◽  
Vol 30 (1) ◽  
pp. 53-73
Author(s):  
David McArdle ◽  
Anne DeMartini ◽  
Sungwon Kim ◽  
Daniel Connaughton
Keyword(s):  
Short Term ◽  
Apparent Lack ◽  
Sports Concussion ◽  
Youth Football ◽  
Funded Project ◽  
Low Levels

This paper discusses an externally-funded project into Scottish coaches’ awareness of the sports concussion prevention initiative, If in Doubt, Sit Them Out. It explores the short-term risks of concussion to youth participants in particular before analysing the data from interviews with ten coaches of girls’ football. The coaches’ apparent lack of awareness of the policy are highlighted and the possibility that the different resources in girls’ and boys’ football, and between girls’ performance and girls’ recreational participation, might impact on injury recognition and treatment, are explored. The paper highlights the need for further research into those areas, and the need to immediately address the apparently low levels of awareness of If in Doubt. With that in mind, proposals for both immediate and longer-term reform for its dissemination are introduced.

scholarly journals HYGIENIC ASSESSMENT OF THE CONTENT OF CHEMICALS IN THE SOIL OF MINING AREAS OF THE TRANS-BAIKAL REGION

2019 ◽  
Vol 98 (4) ◽  
pp. 400-410 ◽  
Author(s):  
L. A. Mikhailova ◽  
M. A. Solodukhina ◽  
O. G. Alekseeva ◽  
N. M. Burlaka ◽  
S. E. Lapa
Keyword(s):  
Heavy Metals ◽  
Soil Contamination ◽  
Chemical Elements ◽  
Raw Materials ◽  
Atomic Absorption Spectrophotometry ◽  
Arsenic Content ◽  
Toxic Substances ◽  
Residential Areas ◽  
Entire Area ◽  
Mining Areas

Introduction. Intensive exploration and processing of mineral raw materials in the Trans-Baikal territory has caused the accumulation of considerable amount of industrial mining waste with high content of chemical elements of different classes of hazard. Currently 33 tailings storage facilities (TSF) accumulating approximately 3 milliard tons of different industrial waste are located in the territory of the region. The aim of the research is the hygienic assessment of soil contamination in the residential areas adjacent to TSFs. Material and methods. Atomic absorption spectrophotometry method was used for the determination of heavy metals. The study presents the results of analyses of 444 samples of gross content of lead, zinc, copper, mercury, arsenic, and cadmium in the soil of Khapcheranga, Sherlovaya Gora, Kadaya, Vershino-Darasunsky, and Vershino-Shakhtaminsky mining villages throughout the duration of 2012 - 2015. Results. During the period of the study the total value of soil contamination with Zc calculated by the median concentrations in Khapcheranga Village amounted to 4.7 6.9, in Vershino-Shakhtaminaky - to 6.7 8.8, which corresponds to the «allowable» level of the contamination. Zc calculation by maximum concentrations has shown the soil to be referred to the category from “moderately dangerous” to “extremely dangerous”; this value in Khapcheranga Village amounted to 48.7 - 235.3, in Vershino-Shakhtaminsky Village - to 23.76 - 164.8. Discussion. In the residential areas the allowable degree of soil contamination was determined to be predominantly observed; Khapcheranga and Vershino-Shakhtaminsky villages are the exceptions. The results of the assessment give the evidence of tge increased lead, cadmium and arsenic content throughout the entire area of the villages, while the highest levels of accumulated toxic substances are registered in the areas located near the TSF Conclusion. Thus, several zones of natural and anthropogenous contamination with increased concentrations of heavy metals and arsenic have been formed in the Trans-Baikal Territory. This dictates the need to study the influence of geochemical anomalies on the health of population.

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