A data-driven method for selecting candidate reference sites for stream bioassessment programs using generalised dissimilarity models

2016 ◽  
Vol 67 (4) ◽  
pp. 440 ◽  
Author(s):  
P. M. Rose ◽  
M. J. Kennard ◽  
F. Sheldon ◽  
D. B. Moffatt ◽  
G. L. Butler
Keyword(s):  
Site Selection ◽  
Fish Assemblages ◽  
Reference Conditions ◽  
Monitoring Program ◽  
Specific Reference ◽  
Reference Sites ◽  
Probabilistic Sampling ◽  
Β Diversity ◽  
Biogeographic History ◽  
Stream Bioassessment

Key issues with defining reference condition for stream bioassessment are (1) equivocal definitions of ‘minimally disturbed’ pressure criteria and wide-ranging approaches to site selection, (2) highly modified regions where near-pristine areas do not exist, leading to management decisions based on inconsistent and unquantified benchmarks and (3) costly field campaigns associated with ‘extensive spatial survey’ approaches. We used generalised dissimilarity modelling (GDM) to classify stream segments into ecotypes, and transparently and efficiently define candidate reference conditions for the Ecosystem Health Monitoring Program (EHMP) assessment area in south-eastern Queensland, a highly modified region with a complex biogeographic history. We modelled fish presence–absence data from 396 sites with GIS-based natural and anthropogenic predictors. Stream segments were classified into ecotypes using the GDM-transformed natural variables so that (1) reference-site selection adequately covered the β-diversity of the study area and (2) we could evaluate the validity of incorporating sites from neighbouring catchments outside of the EHMP assessment area. Relationships between selected anthropogenic variables (the river disturbance index and %stream connectivity) and fish assemblages were used to define pressure criteria and map candidate reference conditions. We conclude by describing a new framework that can be used to select indicator-specific reference sites by GDM and a stratified, probabilistic sampling design.

Type-specific reference conditions of fluvial landscapes: A search in the past by 3D-reconstruction

CATENA ◽  
2008 ◽  
Vol 75 (2) ◽  
pp. 200-215 ◽  
Author(s):  
Severin Hohensinner ◽  
Mathew Herrnegger ◽  
Alfred P. Blaschke ◽  
Christine Habereder ◽  
Gertrud Haidvogl ◽  
...  
Keyword(s):  
3D Reconstruction ◽  
Reference Conditions ◽  
Specific Reference ◽  
The Past

scholarly journals INFORMATION SYSTEM AND PRODUCTION PROCESS CONTROL

2019 ◽  
Author(s):  
Angelo Zanella ◽  
Egidio Cascini
Keyword(s):  
Information System ◽  
Quality Control ◽  
Process Control ◽  
Production Control ◽  
Reference Conditions ◽  
Specific Reference ◽  
Theoretic Model ◽  
Perishable Goods ◽  
Control Production ◽  
Accounting Control

We start with the definition of experimental data. First place we consider the controllable variables, whose levels are established by technical production experts with regard to a theoretic “model” defining the production components, their connections and working rules in sight of the envisaged achievements. Then, the responses or results of production activities, which typically show random variability. The controllable variables are used to regulate the means of their distributions and aspects of variability (Taguchi approach). An information system represents a data collection, which is directed to specific purposes like: financial control, accounting control, personnel control, business control, production control, framed around production programs, control of production lines and related maintenance, quality control, framed around control of nonconformities regarding some specification limits and ensuring product good quality over time. Qualitative guidelines for choosing the data for a quality control information system are that it must be as near as possible to a sufficient system which means that it is capable of explaining any nonconformity in a product characteristic, as well as being complete, that is, such that it is also capable of suggesting how to remove them. In a natural way quality control implies a dynamic approach based on a systematic improvement of production activities, starting from specific reference conditions. We consider two examples appropriated to explain the fundamentals of a methodology useful to cope with this complex subject. The first example refers to a real industrial application regarding the process control of polyvinyl chloride production, found in literature [9]. The second example concerns the distribution process of perishable goods, which is considered to be an innovation. In this case we suppose that there is a finite set of operating situations (points of sale) and that we can define an indicator Q=Q1 /c = Quality of a reference product/a corresponding economic quantity (cost or earning). In the case considered, by means of the ordering of the ratios total cost/total earning, we come to the most profitable situation.

No detrimental effects of desalination waste on temperate fish assemblages

2020 ◽  
Author(s):  
Sasha K Whitmarsh ◽  
Greg M Barbara ◽  
James Brook ◽  
Dimitri Colella ◽  
Peter G Fairweather ◽  
...  
Keyword(s):  
Species Diversity ◽  
Fish Assemblages ◽  
Waste Product ◽  
Ecological Impacts ◽  
Global Changes ◽  
Reference Sites ◽  
Desalination Plant ◽  
Saline Waste ◽  
Temperate Fish ◽  
The Impact

Abstract Water resources are becoming increasingly scarce due to population growth and global changes in weather patterns. Desalination plants that extract freshwater from brackish or seawater are already being used worldwide, with many new plants being developed and built. The waste product from the extraction processes has an elevated salt concentration and can potentially cause substantial impacts to local marine flora and fauna. The present study assesses the impact of saline waste from a 100 GL/year desalination plant on southern Australian temperate fish assemblages, using baited remote underwater video. The study compared four reference sites to the impact site (desalination outfall) and found no evidence that the saline waste was having a detrimental effect on fish assemblages in proximity to the outfall, with species diversity and abundance comparable to those observed at reference sites. However, species diversity and abundance varied across geographical location, protection from fishing pressure, and reef type. Our study is one of the few assessing the ecological impacts of saline waste discharged from a large desalination plant and shows no decrease in fish diversity or abundance, which is the response typically associated with the negative impacts of anthropogenic activities on fish assemblages.

scholarly journals Can fishways restore river connectivity? A case study using β diversity as a method of assessment

2018 ◽  
Vol 30 (0) ◽  
Author(s):  
Hugo Marques ◽  
João Henrique Pinheiro Dias ◽  
Igor Paiva Ramos
Keyword(s):  
Multidimensional Scaling ◽  
Fish Assemblages ◽  
Neotropical Fish ◽  
Whitney Test ◽  
Β Diversity ◽  
Mantel Tests ◽  
Before And After ◽  
Method Of Assessment ◽  
Sørensen Index

Abstract Aim β diversity was used as an indicator to test the hypothesis that a fishway can increase river connectivity, as a reduction in the value of this metric indicates greater similarity among fish assemblages. Methods Quarterly sampling was performed with gillnets upstream and downstream of the Porto Primavera dam, Upper Paraná Basin, before the opening of the fishway between February 1999 and May 2001, and between February 2003 and May 2005 with the fishway in operation (10 samples per period/site). The correlation between the fish assemblages and sites was verified by applying two Mantel tests (downstream versus upstream before and one equivalent after the fishway) using the distance matrices generated by the Bray‐Curtis index. The β diversity between downstream and upstream was calculated using the Sørensen index for each sample for the comparison of such values before and after the operation of the fishway, which were tested with Asymptotic Wilcoxon-Mann-Whitney Test. To summarize changes in the structure of the fish assemblages between the sites and periods nonmetric multidimensional scaling (NMDS) was applied based on Bray-Curtis dissimilarities, using multi-response permutation procedures (MRPP). Results The Mantel tests showed no correlation between the upstream and downstream assemblages before the operation of the fishway but greater correlation after. β diversity was lower after than before the fishway, representing an increase in similarity between downstream and upstream with the fishway. MRPP analysis indicated that the fish assemblages between the sites differed more than was expected by chance, with smaller divergence between the sampling sites after the fishway (A = 0.08) than before it opened (A = 0.09). Conclusions Although fishways remain an incipient and controversial theme for neotropical fish, the Porto Primavera fishway appears to be effective in terms of the restoration of connectivity.

Role of environmental and spatial processes structuring fish assemblages in streams of the eastern Amazon

2018 ◽  
Vol 69 (2) ◽  
pp. 243 ◽  
Author(s):  
N. L. Benone ◽  
R. Ligeiro ◽  
L. Juen ◽  
L. F. A. Montag
Keyword(s):  
Environmental Factors ◽  
Environmental Variables ◽  
Fish Assemblages ◽  
Flood Plain ◽  
Habitat Isolation ◽  
Flood Plains ◽  
Β Diversity ◽  
Flood Period ◽  
Stream Fish Assemblages ◽  
Stream Biota

Considering the increasing importance of analysing spatial structure in ecological studies, the aims of the present study were to test whether fluvial distances and environmental factors are important drivers of the β-diversity of stream fish assemblages, and whether β-diversity is different in distinct hydrological periods. Specimens were sampled at 33 stream sites in the eastern Amazon. Eight environmental variables were measured at each site and fluvial distances between pairs of stream sites were determined. Environmental variables were the main factors structuring fish assemblages in both periods. However, fluvial distances were important only during the flood period. This can be related to the formation of extensive flood plains in this period, which increases connectivity between streams, breaking habitat isolation and increasing the regional signal for fish species. The higher correlation of β-diversity with environmental variables during the flood period may be related to decreased dispersal limitations and intermediate dispersal. Finally, β-diversity was higher during the flood period, highlighting the importance of the heterogeneity of the flood plain to stream biota. The results of the present study indicate that spatial and environmental factors play complementary roles in structuring fish assemblages in Amazon streams, and that β-diversity was affected by changes in the habitat connectivity experienced in different hydrological periods.

scholarly journals Predicting New Zealand riverine fish reference assemblages

2018 ◽  
Author(s):  
Adam D Canning
Keyword(s):  
New Zealand ◽  
Freshwater Fish ◽  
Riparian Vegetation ◽  
Fish Assemblages ◽  
Reference Conditions ◽  
Native Fish ◽  
River Reach ◽  
Riverine Fish ◽  
Insight Into

Biomonitoring is a common method to monitor environmental change in river ecosystems, a key advantage of biomonitoring over snap-shot physicochemical monitoring is that it provides a more stable, long-term. insight into change that is also effects-based. In New Zealand, the main biomonitoring method is a macroinvertebrate sensitivity scoring index, with little established methods available for biomonitoring of fish. This study models the contemporary distribution of common freshwater fish and then uses those models to predict freshwater fish assemblages for each river reach under reference conditions. Comparison of current fish assemblages with those predicted in reference conditions (as observed/expected ratios) may provide a suitable option for freshwater fish biomonitoring. Most of the fish communities throughout the central North Island and lower reaches show substantial deviation from the modelled reference community. Most of this deviation is explained by nutrient enrichment, followed by downstream barriers (i.e., dams) and loss of riparian vegetation. The presence of modelled introduced species had relatively little on the presence of the modelled native fish. The maps of observed/expected fish assemblage may provide a rapid way to identify potential restoration sites.

scholarly journals Species-Richness Responses to Water-Withdrawal Scenarios and Minimum Flow Levels: Evaluating Presumptive Standards in the Tennessee and Cumberland River Basins

Water ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 1334
Author(s):  
Lucas J. Driver ◽  
Jennifer M. Cartwright ◽  
Rodney R. Knight ◽  
William J. Wolfe
Keyword(s):  
Species Richness ◽  
Fish Assemblages ◽  
Reference Conditions ◽  
River Basins ◽  
Water Withdrawal ◽  
Management Decisions ◽  
Site Specific ◽  
Minimum Flow ◽  
Resource Managers ◽  
Cumberland River

Water-resource managers are challenged to balance growing water demand with protecting aquatic ecosystems and biodiversity. Management decisions can benefit from improved understanding of water-withdrawal impacts on hydrologic regimes and ecological assemblages. This study used ecological limit functions for fish groups within the Tennessee and Cumberland River basins to predict species richness responses under simulated constant-rate (CR) and percent-of-flow (POF) withdrawals and for different minimum flow level protections. Streamflow characteristics (SFC) and richness were generally less sensitive to POF withdrawals than CR withdrawals among sites, fish groups, and ecoregions. Species richness generally declined with increasing withdrawals, but responses were variable depending on site-specific departures of SFCs from reference conditions, drainage area, fish group, ecoregion, and minimum flow level. Under POF withdrawals, 10% and 20% daily flow reductions often resulted in loss of <1 species and/or ≤5% richness among fish groups. Median ecological withdrawal thresholds ranged from 3.5–31% for POF withdrawals and from 0.01–0.92 m3/s for CR withdrawals across fish groups and ecoregions. Application of minimum flow level cutoffs often resulted in damping effects on SFC and richness responses, indicating that protection of low streamflows may mitigate hydrologic alteration and fish species richness loss related to water withdrawals. Site-specific and regionally summarized responses of flow regimes and fish assemblages under alternative withdrawal strategies in this study may be useful in informing water-management decisions regarding streamflow allocation and maintaining ecological flows.

Advances in Understanding Landscape Influences on Freshwater Habitats and Biological Assemblages

2019 ◽  
Keyword(s):  
Large Scale ◽  
River Flow ◽  
Fish Assemblages ◽  
Generalized Additive Models ◽  
Sampling Site ◽  
Monitoring Program ◽  
Additive Models ◽  
Species Lists ◽  
Freshwater Habitats ◽  
Eastern Mosquitofish

<i>Abstract.</i>—We document a simple electrofishing-only monitoring program for assessing fish assemblages across large spatial extents. First, we demonstrate the justification for using only electrofishing for the monitoring. Second, we demonstrate the usefulness of having a well-designed surveillance-monitoring program in place to demonstrate the effect of landscape disturbances. Implementing electrofishing alone means that multiple sites can be sampled in a single day and there is no need to return to clear nets or traps within a sampling site. Whereas electrofishing alone does not return full species lists within sampled sites, we demonstrate that when data are aggregated up to the watershed or catchment extent, more than 90% of species are included. Analyses that do not require a census of species, such as bioassessment of river health can be readily carried out using electrofishing data. The Murray–Darling basin, Australia, was sampled with the recommended large-extent electrofishing program between 2004 and 2012, a period that saw the region subjected to large-scale variations in river flow levels spatially and temporally. We fit generalized additive models to the electrofishing data in conjunction with river flow data to document large-extent relationships between fish species occurrence and relative flow levels for the previous 3 d, 3 months, or 3 years. We found that several small-bodied species, Eastern Mosquitofish <i>Gambusia holbrooki</i>, Flathead Gudgeon <i>Philypnodon grandiceps</i>, and Australian Smelt <i>Retropinna semoni</i>, were more likely to be collected when conditions were drier in the past 3 d to 3 months, whereas common medium and large-bodied species were less likely to be collected when flow was lower over the previous 3 months to 3 years.

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