Sedimentation effects on the benthos of streams and estuaries: a cross-ecosystem comparison

2011 ◽  
Vol 62 (10) ◽  
pp. 1201 ◽  
Author(s):  
David J. Reid ◽  
Luca D. Chiaroni ◽  
Judi E. Hewitt ◽  
Drew M. Lohrer ◽  
Christoph D. Matthaei ◽  
...  
Keyword(s):  
Community Structure ◽  
Land Use Changes ◽  
Species Traits ◽  
Biological Traits ◽  
Taxon Richness ◽  
Macroinvertebrate Communities ◽  
Sediment Addition ◽  
Estuarine Condition ◽  
The Common ◽  
Ecosystem Comparison

Connected ecosystems can be detrimentally affected by the same stressor, such as occurs when excess fine sediment moves from streams into estuaries. However, no previous study has directly compared sedimentation effects across these ecosystems. Responses of benthic macroinvertebrate communities to sedimentation were predicted to vary between streams and estuaries, because of intersystem differences in the physical environment and representation of species traits. To compare these responses, fine terrigenous sediment was added simultaneously to replicated plots in stream-run habitats and the adjacent estuary. Although sediment addition to streams caused reduced invertebrate densities after 1 week, no changes in taxon richness or consistent changes in community structure were detected, and densities had recovered another week later. In contrast, sediment addition to estuarine sites caused large declines in invertebrate densities and changes in community structure, which remained evident at the innermost sites 16 days after addition. Across both systems, sedimentation effects were detectable only for some of the common taxa, and biological traits were not predictive of effects. The potential for more severe effects in estuaries should be considered when predicting the implications of land-use changes that may increase sedimentation, and when setting guidelines for maintaining stream and estuarine condition.

scholarly journals Monitoring of Neotropical Streams Using Macroinvertebrate Communities: Evidence from Honduras

Environments ◽  
2021 ◽  
Vol 8 (4) ◽  
pp. 27
Author(s):  
Stefano Fenoglio ◽  
Alberto Doretto
Keyword(s):  
Water Quality ◽  
Working Party ◽  
Biological Indicators ◽  
Environmental Conservation ◽  
Taxon Richness ◽  
Macroinvertebrate Communities ◽  
Class A ◽  
Neotropical Streams ◽  
Local Contribution ◽  
Level Identification

Assessing the water quality by using biological indicators is a reliable and economically feasible way to promote environmental conservation in developing tropical countries. Here, we report one of the few examples of river biomonitoring in Honduras. In June 2005, benthic macroinvertebrates were collected from six sites in the Río Cangrejal basin. An adapted version of the Biological Monitoring Working Party index (BMWP) was used to assess the water quality because it is simple, consolidated, relatively easy to use, and needs a family-level identification. Moreover, two other community metrics were calculated, namely the total taxon richness and local contribution to beta diversity (LCBD). Differences in the biomonitoring and diversity metrics among sites and their correlations were statistically tested. Thirty-nine macroinvertebrate taxa were collected and, despite significant differences in the BMWP score, all sampling sites were classified in the high environmental quality class. A very strong and positive correlation between the BMPW and taxon richness was found, while LCBD did not vary significantly and did not correlate with the other metrics. Our results suggest that taxon richness could be used as a surrogate indicator to assess the water quality when consolidate biomonitoring methods are not available.

Comparison of mayfly (Ephemeroptera) taxocenes of permanent and intermittent Central European small streams via species traits

Biologia ◽  
2010 ◽  
Vol 65 (4) ◽  
Author(s):  
Pavla Řezníčková ◽  
Tomáš Soldán ◽  
Petr Pařil ◽  
Světlana Zahrádková
Keyword(s):  
Global Climate ◽  
Extreme Temperature ◽  
Oxygen Demand ◽  
Hydrological Regime ◽  
Species Traits ◽  
Individual Species ◽  
Biological Traits ◽  
Small Streams ◽  
High Oxygen Demand ◽  
The Impact

AbstractThe recurrent drying out of small streams in past decades has shown an urgent need to pay attention to the impact of global climate change. The objectives of this study were to describe the effect of drying out on the composition of the mayfly taxocene and evaluate the relevance of individual species traits for survival of mayflies to drying out. The mayfly taxocenes of two model localities, one at an intermittent and one at a permanent brook, were investigated in 2002, 2003 and 2005. Compared with the permanent stream, the taxocene of the intermittent stream was short of nine species, foremost rheobionts and high oxygen demand species. To explain further differences between both stream types in survival and recolonisation ability, 15 species traits were evaluated. These included so-called “ecological traits” (e.g., habitat and substrate range, density, distribution, current velocity adaptation) and “biological traits” connected with life cycle and larval/adult adaptations. Species showing the highest number of advantageous traits (with only exception of Electrogena sp. cf. ujhelyii — species of taxonomically unclear status) were able to successfully survive under the unfavourable conditions of the intermittent brook. Biological traits considered more important in many respects seem to be good predictors for assessing sensitivity to extreme temperature changes, hydrological regime fluctuations and the survival/recolonisation ability of species in exposed habitats.

Detecting communities from networks based on their intrinsic properties

2019 ◽  
Vol 30 (12) ◽  
pp. 1950104 ◽  
Author(s):  
Haijuan Yang ◽  
Jianjun Cheng ◽  
Mingwei Leng ◽  
Xing Su ◽  
Wenbo Zhang ◽  
...  
Keyword(s):  
Community Structure ◽  
Intrinsic Properties ◽  
Structure Quality ◽  
Novel Method ◽  
The Common ◽  
Influential Nodes ◽  
High Quality Result ◽  
Full Utilization ◽  
Entire Procedure

Communities in networks expose some intrinsic properties, each of them involves some influential nodes as its cores, around which the entire community grows gradually; the more the common neighbors that exist between a pair of nodes, the larger the possibility of belonging to the same community; the more the neighbors of any one node belong to a community, the larger the possibility that node belongs to that community too. In this paper, we present a novel method, which makes full utilization of these intrinsic properties to detect communities from networks. We iteratively select the node with the largest degree from the remainder of the network as the first seed of a community, then consider its first- and second-order neighbors to identify other seeds of the community, then expand the community by attracting nodes whose large proportion of neighbors have been in the community to join. In this way, we obtain a series of communities. However, some of them might be too small to make sense. Therefore, we merge some of the initial communities into larger ones to acquire the final community structure. In the entire procedure, we try to keep nodes in every community to be consistent with the properties as possible as we can, this leads to a high-quality result. Moreover, the proposed method works with a higher efficiency, it does not need any prior knowledge about communities (such as the number or the size of communities), and does not need to optimize any objective function either. We carry out extensive experiments on both some artificial networks and some real-world networks to testify the proposed method, the experimental results demonstrate that both the efficiency and the community-structure quality of the proposed method are promising, our method outperforms the competitors significantly.

scholarly journals Assessing macroinvertebrate communities in relation to environmental variables: the case of Sambandou wetlands, Vhembe Biosphere Reserve

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Tatenda Dalu ◽  
Rivoningo Chauke
Keyword(s):  
Community Structure ◽  
Water Depth ◽  
Environmental Variables ◽  
Anthropogenic Activities ◽  
Biosphere Reserve ◽  
High Water ◽  
Macroinvertebrate Community ◽  
Macroinvertebrate Communities ◽  
Negative Effect ◽  
Macrophyte Cover

AbstractThe Vhembe Biosphere Reserve, South Africa, contains many wetlands that serve as wildlife habitats and provide vital ecosystem services. Some of the wetlands are continuously being degraded or destroyed by anthropogenic activities causing them to disappear at an alarming rate. Benthic macroinvertebrates are known as good water quality bioindicators and are used to assess aquatic ecosystem health. The current study investigated habitat quality using macroinvertebrate community structure and other biotic variables (i.e. phytoplankton, macrophytes) in relation to environmental variables in the Sambandou wetlands using canonical correspondence analysis (CCA). A total of fifteen macroinvertebrate families were identified over two seasons. The CCA highlighted seven variables, i.e. pH, phosphate concentration, temperature, ammonium, macrophyte cover, conductivity and water depth, which were significant in structuring macroinvertebrate community. Picophytoplankton and microphytoplankton concentrations decreased from winter to summer, whereas nanophytoplankton concentration increased from winter to summer. Thus, the dominance of small-sized phytoplankton indicated nutrient limitation and decreased productivity, whereas winter sites 2 and 3 were dominated by large-celled phytoplankton, highlighting increased productivity. Winter sites were mostly negatively associated with CCA axis 1 and were characterised by high temperature, phosphate and ammonium concentrations, macrophyte cover, pH and conductivity. Summer sites were positively associated with axis 1, being characterised by high water depth and pH levels. The results obtained highlighted that agricultural activities such as cattle grazing and crop farming and sand mining/poaching had a negative effect on macroinvertebrate community structure.

scholarly journals The response of sward-dwelling arthropod communities to reduced grassland management intensity in pastures

2015 ◽  
Vol 54 (2) ◽  
pp. 107-120 ◽  
Author(s):  
Alvin J. Helden ◽  
Annette Anderson ◽  
John Finn ◽  
Gordon Purvis
Keyword(s):  
Community Structure ◽  
Grassland Management ◽  
Taxon Richness ◽  
Arthropod Communities ◽  
Pitfall Trapping ◽  
Management Intensity ◽  
Arthropod Biodiversity ◽  
Stocking Rates ◽  
Univariate Analyses ◽  
Suction Sampling

AbstractWe compared arthropod taxon richness, diversity and community structure of two replicated grassland husbandry experiments to investigate effects of reduced management intensity, as measured by nutrient input levels (390, 224 and 0 kg/ha per year N in one experiment, and 225 and 88 kg/ha per year N in another). Suction sampling was used to collect Araneae, Coleoptera, Hemiptera and Hymenoptera, with Araneae and Coleoptera also sampled with pitfall trapping. Univariate analyses found no significant differences in abundance and species density between treatments. However, with multivariate analysis, there were significant differences in arthropod community structure between treatments in both experiments.Reducing N input and associated stocking rates, as targeted by agri-environment schemes, can significantly alter arthropod communities but without increasing the number of species present. Other approaches that may be necessary to achieve substantial enhancement of sward arthropod biodiversity are suggested.

Species traits and resilience of meiofauna to floods and drought in a Mediterranean stream

2010 ◽  
Vol 61 (11) ◽  
pp. 1336 ◽  
Author(s):  
Ainhoa Gaudes ◽  
Joan Artigas ◽  
Isabel Muñoz
Keyword(s):  
Species Traits ◽  
Life Cycles ◽  
Biological Traits ◽  
Mediterranean Stream ◽  
Migratory Capacity ◽  
The Face ◽  
Droughts And Floods ◽  
Downstream Communities ◽  
Density And Biomass ◽  
Low Order

In Mediterranean streams, droughts and floods are mainly seasonal and predictable, occurring twice or three times a year. Under these conditions, multivoltinism and short life-cycles would be favoured, particularly for organisms with low migratory capacity. The meiofaunal community is therefore hypothesised to have species traits adapted to these hydrological perturbations. However, meiofauna have been neglected in many lotic studies. The present study examined the temporal variability of meiofaunal density and biomass over a 2-year period in three reaches of a low-order Mediterranean stream. Relationships between biological traits and hydrological and environmental characteristics were investigated. Resilience of meiofauna to floods was quantified using regression. Small differences in basin drainage resulted in different responses. The abundance and resilience of the meiofauna were higher in the upstream reach than those in the downstream communities. A small, worm-shaped body and active locomotor structures conferred higher resilience in the face of natural hydrological disturbances. Low-order reaches are refugia for functionally important meiofauna that can eventually repopulate downstream reaches.

Macroinvertebrate Communities and Environment in a Southern African Mountain Stream

1988 ◽  
Vol 45 (12) ◽  
pp. 2168-2181 ◽  
Author(s):  
J. M. King ◽  
J. A. Day ◽  
P. R. Hurly ◽  
M-P. Henshall-Howard ◽  
B. R. Davies
Keyword(s):  
Community Structure ◽  
Environmental Variables ◽  
Mediterranean Ecosystems ◽  
Mountain Stream ◽  
Functional Feeding Groups ◽  
Stepwise Discriminant Analysis ◽  
Macroinvertebrate Communities ◽  
Strong Correlations ◽  
Stream Community ◽  
Community Changes

In a study of a second-order southern African stream, complementary classification and multidimensional scaling (MDS) techniques revealed longitudinal changes in macroinvertebrate community structure, but no temporal changes. Stepwise discriminant analysis and multiple linear regression were used to identify environmental variables correlated with the community changes but produced conflicting results depending on the information used, possibly because of strong correlations between some of the variables. The MDS plot of biotic samples illustrated that potassium levels correlated most strongly with community distribution. Because of the large number of variables now shown worldwide to correlate with faunal distributions, we suggest ways to choose the variables to suit the kind of study to be undertaken. Attempts to assign the invertebrates to functional feeding groups (FFGs) were unsatisfactory as the relevant categories are poorly defined and often inadequate for classifying the fauna. We suggest that until these categories are more clearly defined, and more uniformly applied, concepts relating to FFGs cannot be tested satisfactorily. The stream community in Langrivier is more similar to communities found in two other mediterranean ecosystems than to those in other southern African rivers, probably because of the greater predictability of flow in the former.

scholarly journals Lophius in the world: a synthesis on the common features and life strategies

2008 ◽  
Vol 65 (7) ◽  
pp. 1272-1280 ◽  
Author(s):  
A. C. Fariña ◽  
M. Azevedo ◽  
J. Landa ◽  
R. Duarte ◽  
P. Sampedro ◽  
...  
Keyword(s):  
Life Histories ◽  
Current Knowledge ◽  
Northwest Pacific ◽  
Biological Traits ◽  
Life Strategies ◽  
Common Features ◽  
Genetic Structure Of Populations ◽  
The World ◽  
Adaptive Processes ◽  
The Common

Abstract Fariña, A. C., Azevedo, M., Landa, J., Duarte, R., Sampedro, P., Costas, G., Torres, M. A., and Cañás, L. 2008. Lophius in the world: a synthesis on the common features and life strategies. – ICES Journal of Marine Science, 65: 1272–1280. Seven species of Lophius are known worldwide, six in the Atlantic Ocean and just one in the Northwest Pacific. The genus supports valuable fisheries (except for Lophius vaillanti), most for a long time, though the exploitation of Lophiusgastrophysus along the coast of Brazil is relatively recent. The manuscript reviews the current knowledge of phylogeographic and biological traits of Lophius species, pointing out common aspects in the life histories. Within the Lophiidae, the genus Lophius is phylogenetically the most derived, vicariance and dispersal having played a significant role in driving speciation. Life histories seem to have followed similar adaptive processes from a common ancestor along with similar environmental characteristics. The genetic structure of populations is poorly known, and usually, genetic differentiation is limited. Life-history aspects (age, growth, reproductive cycle, early stages, and feeding ecology) are addressed, and fisheries are reviewed. However, knowledge of many aspects of the biology and ecology (e.g. validation of the growth pattern, maturation processes, spawning areas and periodicity, recruitment processes, mortality, stock identification, and habitat needs) remains limited.

scholarly journals Structure of aquatic macroinvertebrate communities in streams of a sub-basin in the Pampa Biome, Southern Brazil

2021 ◽  
Vol 16 (2) ◽  
pp. 249-271
Author(s):  
Sirlei Maria Hentges ◽  
Tieli Cláudia Menzel ◽  
Cristiane Maria Loebens ◽  
Samuel Elias Siveris ◽  
David Augusto Reynalte-Tataje ◽  
...  
Keyword(s):  
Correspondence Analysis ◽  
Canonical Correspondence Analysis ◽  
Riparian Forest ◽  
Trophic Group ◽  
Temporal Variations ◽  
Macroinvertebrate Community ◽  
Taxon Richness ◽  
Macroinvertebrate Communities ◽  
Aquatic Macroinvertebrate ◽  
Environmental Integrity

The Piratinim River is located in the northwest of Rio Grande do Sul, and represents an important effluent from the Uruguay River, with streams located far from urbanized areas, in conditions similar to those of environmental integrity, but under the influence of agricultural activities. In this study, we aim at investigating the structure of the aquatic macroinvertebrate community in streams of the Piratinim river basin by observing both spatial and local scales. The sampling was carried out in six streams distributed in three regions (upper, middle and lower) of the basin, thus exploring its upstream, intermediate and downstream stretches, during spring and autumn. Macroinvertebrates were collected using aquatic dipnets and were identified at the family level; trophic-functional categories were established according to the classification adapted to the state of Paraná. The spatial and temporal variations of the groups and of the biotic attributes (density, richness, diversity and equitability) were subjected to Kruskal-Wallis non-parametric tests and a posteriori Dunn’s tests. The abiotic variables were obtained to verify possible influence on the composition of the macroinvertebrate community, evaluated through a Canonical Correspondence Analysis. We sampled 11,564 macroinvertebrate individuals from 72 taxa, and found a predominance of the collector-filter trophic group. Abundance and richness were different between streams; the highest densities were found in the streams located in the upper region of the watershed (Chuní and Itú). The highest taxon richness was found in the lower region of the watershed (Guaracapa stream), and the lowest richness was found in the two streams for the intermediate region (Santana and Ximbocu). Diversity and equitability did not vary; temporal variations were not found. Canonical correspondence analysis explained 31.7% of the data variability. The main environmental variables that influenced macroinvertebrates distribution were temperature, electrical conductivity, dissolved oxygen, altitude and extension of the riparian forest. Seasonality and the longitudinal gradient along the basin represented determining factors for the structure and distribution of the macroinvertebrate community in the tributary streams of the Piratinim River.

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