Indicators Of Anthropogenic Stress Research Articles

Ecological and economic assessment of the ecological situation transformation in the Republic of Kazakhstan regions in 1990–2020

The article is devoted to problems of stating the complex index of anthropogenic impact (IAI) formation estimating the ecological stress level in regions of Kazakhstan. A system of indicators of anthropogenic stress for ecological monitoring is justified as different methods of normalization and aggregation of indices. Results of various estimations are provided. Factors of transformation of territorial structure of pollution are revealed. IAI shows that in the post-Soviet period, inherited ecological problems and new sources of impact determined the anthropogenic impact spatial shift at the regional level from the North and East to the South and West. Industry is losing its status as the main source of anthropogenic impact (AI), so densely populated areas and the increase in associated impact indicators have caught up with industry. The population outflow in Northern Kazakhstan has a positive effect on the AI level and increases AI in Southern Kazakhstan. The entire variety of scenarios for the dynamics of the impact of material production on the environment can be reduced to four types: ecological degradation, when an economic downturn is accompanied by increased environmental pollution; depressive development, when an economic downturn is accompanied by decreased pollution; extensive ecological development, where economic growth is accompanied by increased pollution; balanced development, when economic growth is accompanied by decreased pollution. During crisis years, there was a decrease in industrial pollution, the volume of atmospheric emissions and polluted wastewater, and, to a lesser extent, water consumption; conversely, vehicle emissions, the volume of toxic waste, the area of disturbed lands, and forest fires do not depend on the change in GRP. Despite the fact that for the country as a whole, the dependence of the level of pollution on the level and dynamics of economic development is weakening, with each new crisis, there is an increasing number of regions where the environmental state continues to deteriorate despite the economic downturn.

Responses of different facets of aquatic plant diversity along environmental gradients in Mediterranean streams: Results from rivers of Greece

Aquatic and riparian plants play a crucial role in the functioning of riverine ecosystems. Hence, analyzing multiple facets of plant diversity could be extremely useful for assessing the ecological integrity of lotic ecosystems. The main objective of this study was to investigate the response of multiple facets of aquatic plant diversity, such as species richness, taxonomic distinctness and compositional dissimilarity, to environmental factors (i.e. nutrient pollution and hydromorphological alteration) in 72 stream reaches of mainland Greece.We employed Generalized Additive Models to identify the variables with the highest influence and examine the response of species richness and taxonomic distinctness to environmental gradients. The relationship between compositional dissimilarity and the environment was examined with Generalized Dissimilarity Modelling. Our results supported our hypothesis that human disturbances play a considerable role in shaping macrophyte assemblages. In particular, phosphates and hydromorphological modification were significant predictors of species richness, whereas taxonomic distinctness was unaffected by indicators of anthropogenic stress but it was influenced mostly by elevation, water temperature and pH. Concerning the compositional dissimilarity, geographic distance, elevation, temperature and total inorganic nitrogen were the most important environmental parameters. Our findings suggest that human stressors, such as hydromorphological modification and nutrient enrichment, affect the plant species richness at stream reach scale, but when considering community composition or taxonomic distinctness, environmental factors associated with the natural variability (e.g. elevation, temperature and geographic distance) are of higher importance. Overall, our results emphasize the advantage of examining multiple aspects of diversity when designing conservation schemes and management plans for riparian areas.

Macroinvertebrate and Fish Community Metrics: Confounding Effects and Consistency over Time

Macroinvertebrate and fish metrics are an essential tool in freshwater biomonitoring. Yet, many well-known stream metrics do not perform well as indicators of anthropogenic stress in lakes and wetlands, and there is a need to better understand the role of potential confounding factors such as latitude or environmental variables acting at regional scales. We attempt to untangle the relationships among metrics and watershed stressors while accounting for potential confounding factors using hierarchical partitioning, and test metric consistency across time, focusing on the Laurentian Great Lakes wetland monitoring programs conducted 10 years apart. Our results show that many frequently used metrics have high temporal variability and are significantly affected by spatial factors, most notably richness-type metrics used in numerous regional monitoring studies. Only a few metrics (invasive fish species richness and relative abundance, mayfly family richness and the relative abundance of Ephemeroptera, Trichoptera, Sphaeriidae and Odonata) had slightly better and more consistent correlations with watershed land use. We suggest that explicit consideration of confounding factors is essential in the context of large-scale monitoring programs, and focus on the less general (such as habitat-specific) metrics may be a more promising approach.

Brown Hare\u2019s (Lepus europaeus) Histone H1 Variant H1.2 as an Indicator of Anthropogenic Stress

From the liver tissues of brown hare individuals that lived in two various habitats, i.e., the agricultural region with the predominant farms and the industrial area near a metallurgical plant, histones H1 were analyzed to compare their within and between population variability. Furthermore, because agricultural production emits mainly organic pollutants and metallurgical industry is a primarily source of inorganic contaminations, we wanted to check how the brown hare individuals are sensitive for both agents. Among brown hare H1 histones, the histone H1.2 was determined as heterogeneous due to its varied mobility in two-dimensional SDS–polyacrylamide gel. The obtained electrophoretic patterns contained differently moving single spots of histone H1.2 and also its double spots have a similar rate of electrophoretic mobility. Based on this, two homozygous phenotypes (slowly migrating 2a and faster moving 2b) and a heterozygous phenotype (2a2b) was distinguished. The relatively low variable (CV < 0.25) and comparably abundant (p > 0.05) histone H1.2 homozygous phenotypes form a heterozygous phenotype in a similar proportion, at a ratio approximating 0.5. Although the brown hare population originating from agricultural area displayed a slight excess of heterozygous individuals 2a2b (F = − 0.04), it was conformed to the Hardy–Weinberg assumption (χ2 = 0.035, p = 0.853). Compared with this population, a sevenfold reduced frequency of the phenotype 2b and above tenfold increase of a heterozygosity (F = − 0.53) was observed in the brown hare population inhabiting the vicinity of metallurgical plant. Therefore, this population did not fit to the Hardy–Weinberg law (χ2 = 5.65, p = 0.017). Despite the negligible genetic differentiation (FST = 0.026) between brown hare populations inhabiting areas with different anthropogenic pressure, a statistically significant difference in the distribution of their phenotypes (χ2 = 6.01, p = 0.049) and alleles (χ2 = 6.50, p = 0.013) was noted. The collected data confirm that the brown hare species is sensitive for environmental quality and may serve as a good indicator of habitat conditions related to both organic pollution emitted by agricultural activities (PIC = 0.48) and inorganic contamination originating from metallurgical processes (PIC = 0.49). These difference in the environmental quality might be assessed by estimation of genetic variability among the brown hare populations, based on the phenotypes distribution of histone H1 variant H1.2, the protein that was not so far employed as a molecular marker of anthropogenic stress.

Longitudinal variation and response to anthropogenic stress in diatom assemblages of the Lower Mississippi River, USA

We evaluated diatom assemblages as indicators of anthropogenic stress from fi fty-four sites, distributed across 1,350 river kms of the Lower Mississippi River (LMR), as part of the National Rivers and Streams Assess- ment. We used multivariate analyses, as well as European- and regionally-derived stressor models, to examine vari- ation in assemblages relative to land-cover (e.g., agriculture) and water quality (e.g., ions, nutrients) stressors. Longitudinal changes in both periphytic and planktonic diatom assemblage structures, as species composition and assemblage diversity, were signifi cantly different for sites with greater watershed alterations, notably agriculture and development, and total ion (metals and anions) concentrations. The scale of land-cover delineation (e.g., sub- or entire watershed) was important in relation to diatom assemblage structure as land-cover classes were unrelated to assemblage structure at too fi ne or coarse a scale. European indices, from the OMNIDIA program, of trophic class and ecological condition classifi ed the LMR as eutrophic and polluted, but indices were not well correlated with land-cover or water quality variables. A diatom-based stressor response model developed for the Upper Mississippi River (UMR) basin corroborated the LMR as being highly eutrophic and infl uenced by agriculture and develop- ment. However, condition scores were constrained relative to the UMR suggesting few reaches of low anthropo- genic impact exist on the LMR. Our study showed that diatom assemblages are effective indicators of physico- chemical stress in a great river.

Using emergence from soil propagule banks as indicators of ecological integrity in wetlands: advantages and limitations

Wetland soils contain a reservoir of dormant plant seeds and invertebrate eggs, collectively termed the seed or propagule bank, which integrate spatiotemporal variation at various levels of biology (genetic, phenotypic, species, and community). Several recent studies suggest that anthropogenic physical or chemical stressors may disrupt the process of emergence from propagule banks. This process is often the single most important colonization process in wetlands isolated geographically from other water bodies. The potential for disruption of emergence can be exploited as a useful indicator of anthropogenic stress. The aim of our paper is to provide a conceptual framework that shows the advantages and limitations of wetland propagule banks as indicators of anthropogenic stress or ecological integrity. This framework describes mechanistic responses of propagule banks to stressors and makes recommendations on experimental approaches for the evaluation of cause–effect relationships between stressors and propagule bank responses. This indicator could help bridge the current gap between basic and applied wetland ecology and could find application in future wetland management and restoration strategies.

Baseline Incidence of Mouthpart Deformities in Chironomidae (Diptera) From The Laurentian Great Lakes, Canada

Larval chironomid mouthpart deformities are used as indicators of anthropogenic stress. However, there are limited data on the incidence of naturally occurring deformities. Chironomid larvae were collected from 252 reference sites throughout the Great Lakes by Environment Canada from 1991 through 1993. Overall incidence of mentum deformities was 2.27% for Procladius (SE = 0.46, n = 1055), 2.15% for Chironomus (SE = 0.51, n = 839), 1.27% for Heterotrissocladius (SE = 0.57, n = 393), 1.38% for Tanytarsus (SE = 0.61, n = 363), and 3.25% for Polypedilum (SE = 1.07, n = 277). The most common deformity was one missing tooth in the mentum. Deformity frequency was highest in Northern Channel and Georgian Bay of Lake Huron. However, incidences were homogeneous among regions (G-test, p > 0.05). In examining contaminated conditions, a result greater than one 95% confidence interval above these reference deformity frequencies should be considered significantly elevated from baseline levels.

A dyin delta? A case study of a wetland paradigm

The Peace-Athabasca Delta, Canada, a RAMSAR Wetland of International Significance, has since the 1970s been viewed as an ecosystem in decline. The putative reason for its decline has been the regulation of the Peace River by the W.A.C. Bennett Dam in British Columbia. The dying delta paradigm has its origin in a short-term study that coincided with a transient drawdown of the open drainage lakes in the delta. The paradigm has circumscribed all subsequent studies of the delta in its a priori assumption that all detected changes are due to the dam and are negative. As a result, the growth of scientific understanding has been stifled. Factors that contribute to the lack of ecological understanding unclude problems of data quality, quantity, and scale, ecological complexity, media marketing, failure to consult or analyze older/historical datasets, over-reliance on gray literature, too few wetland ecologists, and too little interdisciplinary thinking. Factors that may be involved in the recent changes, or lack of changes, include climatic variation and change. normal wetland dynamism, stochasticity, flow regulation, weirs, dredging, avulsions and their prevention, influxes of weeds and contaminants, delta evolution, and cultural change. The assessment of health in a delta is problematic since deltas are naturally stressed, dynamic ecosystems. Indicators of anthropogenic stress, such as declines in diversity and abundance, changes in biomass and primary production, or retrogressive succession may be difficult to apply in deltas. Long-term datasets are required that allow differentiation of normal from anthropogenic changes. Critique of the ‘dying delta’ view reveals little scientific support. The often-stated decline in flood frequency seems to have no statistical basis. The ecological health of the Peace-Athabasca Delta was assessed based on 26 attributes; 18 attributes indicated health, 3 indicated stress/disease, and 5 attributes were either neutral or required study. When compared to other major deltas in North America, the Peace-Athabasca Delta stands out as a paragon of ecosystem health. This study presents a cautionary lesson in the power of unchallenged paradigms in shaping scientific and popular opinion. A new paradigm views the delta as predominantly healthy, driven by large-scale natural processes, complex, and dynamically varying.

Is the ‘microbial loop’ an early warning indicator of anthropogenic stress?

Various components of the ‘Microbial loop’ such as bacteria, heterotrophic nanoflagellates and autotrophic picoplankton were analyzed, for the first time across the Great Lakes, during a cruise in the summer of 1988. In addition, the size fractionated primary productivity using carbon-14 techniques was also determined. The statistical analysis indicated that bacteria, autotrophic picoplankton and ultraplankton/picoplankton productivity were significantly higher in Lakes Ontario and Erie than Lakes Huron and Michigan. The autotrophic picoplankton and ultraplankton/picoplankton productivity was higher in Lake Erie compared to Lake Ontario. The autotrophic picoplankton showed sensitivity to nutrients and contaminants in various types of environments. A dramatic decrease of autotrophic picoplankton in eutrophic-contaminated areas, such as Ashbridges Bay, Hamilton Harbour and western Lake Erie was observed. Conversely, in Saginaw Bay, another eutrophic environment, the autotrophic picoplankton were significantly higher than in Lake Huron. The sensitivity of autotrophic picoplankton to nutrients/contaminants might have implications to trophic interactions. Our results suggest that structural and functional characteristics of the ‘microbial loop’ may be operating differently in stressed versus unstressed ecosystems. The possibility of using autotrophic picoplankton as an early warning indicator of environmental perturbation is proposed.