scholarly journals Suggested Sampling Methodology for Lake Benthic Macroinvertebrates under the Requirements of the European Water Framework Directive

Water ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 1353
Author(s):  
Chrysoula Ntislidou ◽  
Dimitra Bobori ◽  
Maria Lazaridou
Keyword(s):  
Benthic Macroinvertebrates ◽  
Temporal Variability ◽  
Sampling Design ◽  
Benthic Macroinvertebrate ◽  
Spatial And Temporal Variability ◽  
Sampling Effort ◽  
Taxa Richness ◽  
Natural Lakes ◽  
European Water ◽  
Precision Level

The estimation of the number of samples required for reliably monitoring lakes’ benthic macroinvertebrates is difficult due to the natural variability and cost and time constraints. To determine a statistically robust and effective sampling design, we collected benthic macroinvertebrate samples from 15 Greek natural lakes. We compared the spatial and temporal variability of the benthic macroinvertebrate community composition to identify differences among lakes, between lake zones (sublittoral and profundal) and sampling periods. Furthermore, we examined the sampling precision and determined the number of required samples to attain maximum taxa richness. The diminution of the sampling effort was estimated and the desired precision level, considering different benthic macroinvertebrate abundances, was modelled. No temporal or spatial variation between lake zones was observed in communities’ compositions. The precision of our sampling design was adequate, and rarefaction curves revealed an adequate taxa richness (>70%). The developed model could be applied to assess the required sampling effort in lakes within the Mediterranean ecoregion with similar benthic macroinvertebrate abundances.

scholarly journals Shale gas development has limited effects on stream biology and geochemistry in a gradient-based, multiparameter study in Pennsylvania

2020 ◽  
Vol 117 (7) ◽  
pp. 3670-3677 ◽  
Author(s):  
Adam C. Mumford ◽  
Kelly O. Maloney ◽  
Denise M. Akob ◽  
Sarah Nettemann ◽  
Arianne Proctor ◽  
...  
Keyword(s):  
Shale Gas ◽  
Temporal Variability ◽  
Oil And Gas ◽  
Headwater Streams ◽  
Stream Water ◽  
The United States ◽  
Benthic Macroinvertebrate ◽  
Spatial And Temporal Variability ◽  
Stream Chemistry ◽  
Geochemical Tracers

The number of horizontally drilled shale oil and gas wells in the United States has increased from nearly 28,000 in 2007 to nearly 127,000 in 2017, and research has suggested the potential for the development of shale resources to affect nearby stream ecosystems. However, the ability to generalize current studies is limited by the small geographic scope as well as limited breadth and integration of measured chemical and biological indicators parameters. This study tested the hypothesis that a quantifiable, significant relationship exists between the density of oil and gas (OG) development, increasing stream water concentrations of known geochemical tracers of OG extraction, and the composition of benthic macroinvertebrate and microbial communities. Twenty-five headwater streams that drain lands across a gradient of shale gas development intensity were sampled. Our strategy included comprehensive measurements across multiple seasons of sampling to account for temporal variability of geochemical parameters, including known shale OG geochemical tracers, and microbial and benthic macroinvertebrate communities. No significant relationships were found between the intensity of OG development, shale OG geochemical tracers, or benthic macroinvertebrate or microbial community composition, whereas significant seasonal differences in stream chemistry were observed. These results highlight the importance of considering spatial and temporal variability in stream chemistry and biota and not only the presence of anthropogenic activities in a watershed. This comprehensive, integrated study of geochemical and biological variability of headwater streams in watersheds undergoing OG development provides a robust framework for examining the effects of energy development at a regional scale.

scholarly journals Conservation unit and water quality: the influence of environmental integrity on benthic macroinvertebrate assemblages

2013 ◽  
Vol 25 (4) ◽  
pp. 442-450
Author(s):  
Jessé Renan Scapini Sobczak ◽  
Alice Teresa Valduga ◽  
Rozane Maria Restello ◽  
Rafael Imlau Cardoso
Keyword(s):  
Water Quality ◽  
Benthic Macroinvertebrates ◽  
Habitat Diversity ◽  
Benthic Macroinvertebrate ◽  
Conservation Unit ◽  
Macroinvertebrate Assemblages ◽  
Taxa Richness ◽  
Assessment Protocol ◽  
Shannon Diversity ◽  
Environmental Integrity

AIM: This study aimed to determine the effectiveness of a Conservation Unit (CU) in maintaining the quality of freshwater habitats and to evaluate the influence of environmental integrity on benthic macroinvertebrate assemblages. METHODS: The research was conducted at sampling sites located within and outside of the CU in the Alto Uruguai region, southern Brazil, and included two stages: (i) the collection of benthic macroinvertebrates and (ii) the application of a Rapid Assessment Protocol (RAP) to characterise the habitat quality. RESULTS: A total of 1,362 benthic macroinvertebrates were collected during the study, totalling 30 taxa. The densities within and outside the CU were significantly different (F= 160.08; p= 0.05), and the Shannon diversity and taxa richness followed the same pattern (F= 118.72, p= 0.05; and F= 176.33, p= 0.04, respectively). In contrast, the Pielou equitability did not differ within and outside the CU (F= 0.19, p= 0.74). The biotic index (Biological Monitoring Working Party) indicated that water quality was good or very good in the majority of cases. Most of the sampling sites were classified as ‘natural’ according to the RAP. The taxa richness was significantly related to habitat diversity (F= 7.24; p = 0.05), but no significant relationship was found between the habitat diversity and the Shannon diversity (F= 2.13, p = 0.22). CONCLUSION: The CU was effective for the conservation of water quality and the freshwater biodiversity of benthic macroinvertebrates. The results show that the environmental integrity was related to the distribution of benthic macroinvertebrates, primarily to the taxa richness. More detailed investigations need to be developed to better understand these relationships and to take into account the temporal scale. An analysis of the most significant sources of stress on the aquatic life outside the area is recommended.

scholarly journals Spatial and temporal variability of mobile macro-invertebrate assemblages associated to coralligenous habitat

2014 ◽  
Vol 15 (2) ◽  
pp. 302 ◽  
Author(s):  
R. BEDINI ◽  
L. BONECHI ◽  
L. PIAZZI
Keyword(s):  
Spatial Scale ◽  
Temporal Variability ◽  
Sampling Design ◽  
High Variability ◽  
Spatial And Temporal Variability ◽  
Macroinvertebrate Assemblages ◽  
Invertebrate Assemblages ◽  
One Year ◽  
Sessile Organisms

The study aimed to investigate patterns of spatial and temporal variability of mobile macroinvertebrate assemblages associated to coralligenous habitat. A multi-factorial sampling design was used to test the hypotheses that the structure of assemblages and their spatial and temporal variability changed in relation to substrate inclination. Moreover, macroalgae and sessile macro-invertebrates were also investigated in order to detect eventual relationship between sessile and mobile assemblages. A total of 236 mobile macro-invertebrate taxa were identified, among them 2 Platyhelminthes, 4 Sipuncula, 6 Nemertea, 27 Mollusca, 86 Annelida, 103 Arthropoda, 8 Echinodermata. Results of the study showed that mobile macro-invertebrate assemblages of coralligenous habitat were little influenced by the inclination of substrate and by the morphology of sessile organisms, as patterns of variation were different between the two assemblages. Mobile macro-invertebrate assemblages changed among sampling dates within one year period and they showed high variability at the spatial scale examined.

Response of Corn Grain Yield to Spatial and Temporal Variability in Emergence

Crop Science ◽  
2004 ◽  
Vol 44 (3) ◽  
pp. 847 ◽  
Author(s):  
Weidong Liu ◽  
Matthijs Tollenaar ◽  
Greg Stewart ◽  
William Deen
Keyword(s):  
Grain Yield ◽  
Temporal Variability ◽  
Spatial And Temporal Variability ◽  
Corn Grain ◽  
Corn Grain Yield
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