Regionalisation of freshwater fish assemblages in the Murray–Darling Basin, Australia

2017 ◽  
Vol 68 (4) ◽  
pp. 629 ◽  
Author(s):  
Serena H. Hamilton ◽  
Carmel A. Pollino ◽  
Keith F. Walker
Keyword(s):  
Native Species ◽  
Large Scale ◽  
Fish Assemblages ◽  
Multivariate Analyses ◽  
Ecological Communities ◽  
Early 19Th Century ◽  
The Past ◽  
Murray Darling Basin ◽  
Audit Data ◽  
Using Data

Regionalisations based on species assemblages are a useful framework for characterising ecological communities and revealing patterns in the environment. In the present study, multivariate analyses are used to discern large-scale patterns in fish assemblages in the Murray–Darling Basin, based on information from the Murray–Darling Basin Authority’s first Sustainable Rivers Audit (SRA), conducted in 2004–2007. The Basin is classified into nine regions with similar historical fish assemblages (i.e. without major human intervention), using data that combine expert opinion, museum collections and historical records. These regions are (1) Darling Basin Plains, (2) Northern Uplands, (3) Murray Basin Plains, (4) Northern Alps, (5) Central East, (6) Avoca Lowland, (7) Southern Slopes, (8) Southern Alps and (9) South-Western Slopes. Associations between assemblages and physical variables (catchment area, elevation, hydrology, precipitation, temperature) are identified and used to reinforce the definitions of regions. Sustainable Rivers Audit data are compared with the historical assemblages, highlighting species whose range and abundance have changed since the early 19th century. Notable changes include declines in native species such as silver perch, river blackfish, mountain galaxias, Macquarie perch, trout cod and freshwater catfish, and the advent of alien species including common carp, eastern gambusia, goldfish, redfin perch, brown trout and rainbow trout. Less significant declines are evident for native carp gudgeons, golden perch, two-spined blackfish, bony herring and flathead gudgeon. Changes are evident even in regions where habitats have been little disturbed in the past 200 years.

scholarly journals What is needed to restore native fishes in Australia’s Murray–Darling Basin?

2020 ◽  
Vol 71 (11) ◽  
pp. 1464
Author(s):  
John D. Koehn ◽  
Stephen R. Balcombe ◽  
Lee J. Baumgartner ◽  
Christopher M. Bice ◽  
Kate Burndred ◽  
...  
Keyword(s):  
First Nations ◽  
Native Species ◽  
Cultural Practices ◽  
Native Fish ◽  
The Past ◽  
Murray Darling Basin ◽  
Native Fishes ◽  
Conservation Concern ◽  
First Nations People

The Murray–Darling Basin (MDB) is Australia’s food bowl, contributing 40% of agricultural production and supporting a population of over 4 million people. Historically, the MDB supported a unique native fish community with significant cultural, subsistence, recreational, commercial and ecological values. Approximately one-quarter of the MDB’s native species are endemic. Changes to river flows and habitats have led to a >90% decline in native fish populations over the past 150 years, with almost half the species now of conservation concern. Commercial fisheries have collapsed, and important traditional cultural practices of First Nations People have been weakened. The past 20 years have seen significant advances in the scientific understanding of native fish ecology, the effects of human-related activities and the recovery measures needed. The science is well established, and some robust restoration-enabling policies have been initiated to underpin actions. What is now required is the political vision and commitment to support investment to drive long-term recovery. We present a summary of 30 priority activities urgently needed to restore MDB native fishes.

Are alien fish disadvantaged by extremely variable flow regimes in arid-zone rivers?

2010 ◽  
Vol 61 (8) ◽  
pp. 857 ◽  
Author(s):  
J. F. Costelloe ◽  
J. R. W. Reid ◽  
J. C. Pritchard ◽  
J. T. Puckridge ◽  
V. E. Bailey ◽  
...  
Keyword(s):  
Alien Species ◽  
Native Species ◽  
Fish Assemblages ◽  
Arid Zone ◽  
Flow Regimes ◽  
River Health ◽  
Alien Fish ◽  
Using Data ◽  
Large Floods ◽  
Dryland Rivers

The proliferation of alien fish in dryland rivers potentially obstructs the maintenance of river health. Modified flow regimes are hypothesised to facilitate invasions by alien fish but in unregulated dryland rivers, large floods provide a recruitment advantage for native over alien species whereas droughts favour alien species. We tested these hypotheses by using data from a 3-year study (2000–2003) of fish populations in the unmodified rivers of the Lake Eyre Basin (LEB) of Australia. Results from a lower reach of Cooper Creek were compared with those of an earlier study (1986–1992). During both periods, large floods occurred, with return periods ranging from >1 in 5 to >1 in 25 years. In the lower Cooper, decreases in the abundance of alien species relative to native species, and dramatic increases in recruitment of native species, were observed during a 1–3-year period following large floods. In two other rivers in 2000–2003, there was no statistically significant change in the already low abundances of alien species. We suggest that the naturally variable hydrological regimes and native-dominant fish assemblages of the unregulated LEB rivers afford some resistance to the establishment and proliferation of alien fish through flood and drought conditions.

scholarly journals Plant establishment and invasions: an increase in a seed disperser combined with land abandonment causes an invasion of the non-native walnut in Europe

2011 ◽  
Vol 279 (1733) ◽  
pp. 1491-1497 ◽  
Author(s):  
Magdalena Lenda ◽  
Piotr Skórka ◽  
Johannes M. H. Knops ◽  
Dawid Moroń ◽  
Stanisław Tworek ◽  
...  
Keyword(s):  
Central Europe ◽  
Native Species ◽  
Large Scale ◽  
Juglans Regia ◽  
Land Abandonment ◽  
Lag Phase ◽  
Suitable Habitat ◽  
Cascading Effects ◽  
Seed Disperser ◽  
The Past

Successful invasive species often are established for a long time period before increasing exponentially in abundance. This lag phase is one of the least understood phenomena of biological invasions. Plant invasions depend on three factors: a seed source, suitable habitat and a seed disperser. The non-native walnut, Juglans regia , has been planted for centuries in Central Europe but, until recently, has not spread beyond planted areas. However, in the past 20 years, we have observed a rapid increase in walnut abundance, specifically in abandoned agricultural fields. The dominant walnut disperser is the rook, Corvus frugilegus . During the past 50 years, rooks have increased in abundance and now commonly inhabit human settlements, where walnut trees are planted. Central Europe has, in the past few decades, experienced large-scale land abandonment. Walnut seeds dispersed into ploughed fields do not survive, but when cached into ploughed and then abandoned fields, they successfully establish. Rooks preferentially cache seeds in ploughed fields. Thus, land-use change combined with disperser changes can cause rapid increase of a non-native species, allowing it to become invasive. This may have cascading effects on the entire ecosystem. Thus, species that are non-native and not invasive can become invasive as habitats and dispersers change.

Stasis, biological disturbance, and community structure of a Holocene coral reef

Paleobiology ◽  
1997 ◽  
Vol 23 (3) ◽  
pp. 326-346 ◽  
Author(s):  
Richard B. Aronson ◽  
William F. Precht
Keyword(s):  
Large Scale ◽  
Coral Species ◽  
Community Integration ◽  
Percent Cover ◽  
Ecological Communities ◽  
Acropora Cervicornis ◽  
Point Counts ◽  
The Past ◽  
Community Transition ◽  
White Band Disease

Disturbances have drastically altered Caribbean coral reefs over the past two decades. Acropora cervicornis (staghorn coral), which predominated at intermediate depths (5—25 m) from the 1950s through the 1970s, has virtually disappeared from most reef environments. Other coral species have declined as well, and the cover of macroalgae has increased. In apparent contrast, fossil reef sequences suggest that the species composition and zonation of coral assemblages did not change during the Pleistocene and Holocene. One interpretation of these observations is that coral species persisted on Caribbean reefs for hundreds of thousands of years as components of tightly integrated communities, and that a rare or unique combination of disturbances led to the synchronous decline of A. cervicornis and other corals throughout the region. The hypotheses of (1) community integration and (2) a unique, recent community transition, were tested by ecological and paleoecological observations in the shelf lagoon of the Belizean Barrier Reef.The reef growing along the flanks of Channel Cay, a lagoonal shoal, was monitored by point counts along transects over a ten-year period (1986—95). This reef was covered primarily by A. cervicornis at 3—15 m depth until the late 1980s. After 1986, A. cervicornis experienced a mass mortality from White Band Disease, an epizootic of presumed bacterial origin. The cover of A. cervicornis dropped from ~70% in 1986 to nearly 0% in 1993. Agaricia spp. (lettuce corals) responded opportunistically to the availability of free space in the form of A. cervicornis skeletal rubble. Agaricia, which had been a minor constituent of the sessile biota (10% cover in 1986), replaced A. cervicornis as the most common occupant of space on the reef (56% cover in 1995). The percent cover of other coral species and macroalgae remained low throughout the ten-year period. Similar changes were observed on other reefs over an area of at least 250 km2.The Acropora-to-Agaricia transition left a clear signature in the sedimentary record. Trenches dug into the reef at Channel Cay revealed the accretion of a layer of Agaricia rubble with a mean thickness of 22 cm in the decade after 1986. Due to the unconsolidated, uncompacted nature of the reef sediments, evidence of previous Acropora-to-Agaricia transitions should have been visible in the fossil record as vertical accumulations of A. cervicornis branches interrupted by layers of imbricated Agaricia rubble. Coring studies at Channel Cay revealed that no other Agaricia layers were deposited during at least the past 3800 years; the recent transition was unique on a time scale of millennia. This result supports the contention that excursions from the Acropora-dominated situation are unusual in the history of Channel Cay and nearby reefs. However, the dynamics of the transition do not support the community integration hypothesis for the Channel Cay reef, indicating instead that different coral taxa in this assemblage responded differently, or not at all, to a large-scale biotic disturbance. The community transition also underscores the potential for biological factors in general, and disease in particular, to alter the composition of ecological communities and their sedimentary remains.

scholarly journals Adaptive management in action: using chemical marking to advance fish recovery programs in the Murray–Darling Basin

2016 ◽  
Vol 67 (10) ◽  
pp. i ◽  
Author(s):  
Lee Baumgartner
Keyword(s):  
Food Safety ◽  
Adaptive Management ◽  
Large Scale ◽  
Wild Fish ◽  
Inland Waters ◽  
The Past ◽  
Recovery Programs ◽  
Live Fish ◽  
Murray Darling Basin ◽  
The Difference

Being able to tell the difference between stocked and wild fish is essential to understand the overall success of hatchery programs. It is a substantial issue to address, especially considering that over 60 million fish have been stocked into Australian inland waters over the past 30 years. A trial into permanently marking live fish, with fluorescent chemicals, has demonstrated substantial promise. Having been cleared by food safety authorities, and validated by targeted research, it is presently being rolled out on a large scale in the Murray–Darling Basin.

scholarly journals Tropospheric NO2Trends over South Asia during the Last Decade (2004–2014) Using OMI Data

2015 ◽  
Vol 2015 ◽  
pp. 1-18 ◽  
Author(s):  
Zia ul-Haq ◽  
Salman Tariq ◽  
Muhammad Ali
Keyword(s):  
South Asia ◽  
Large Scale ◽  
Crop Residue ◽  
Meteorological Conditions ◽  
Spatiotemporal Variability ◽  
Motor Vehicles ◽  
Anthropogenic Emissions ◽  
Average Value ◽  
The Past ◽  
Using Data

The focus of this study is to assess spatiotemporal variability of tropospheric NO2over South Asia using data from spaceborne OMI during the past decade (2004–2015). We find an average value of NO21.0 ± 0.05 × 1015 molec/cm2and a significant decadal increase of 14%. The elevating NO2pollution over the region is linked to rise in motor vehicles and industrial and agricultural activities and increase in biomass fuel usage. The observed seasonality of NO2is associated with change in meteorological conditions and seasonal cycles of anthropogenic emissions. OMI data reveal a seasonal peak in spring followed by winter largely linked to metrological conditions and anthropogenic emissions from crop residue and biomass burning for heating purpose, and low concentration in summer is mostly attributed to meteorological conditions. Significant increase, up to 42%, in NO2concentrations over northwestern IGB, is observed connected to large scale postmonsoon crop residue events of 2010 and 2012. It is seen that NO2is mounting over all the hotspot locations and most of the cities. Dhaka shows the highest increase of 77% followed by Islamabad (69%), Kabul (68%), Korba (64%), Bardhaman (47%), and Lahore (40%). On the contrary, DG Khan has shown negative trend of −11%.

Siblings and Illness

2011 ◽  
Vol 7 ◽  
Author(s):  
Leah Sawyer Vanderwerp
Keyword(s):  
Depressive Symptoms ◽  
Birth Order ◽  
Family Size ◽  
Multivariate Analyses ◽  
Social Role ◽  
Chronically Ill ◽  
Demographic Variables ◽  
Future Research ◽  
Mother And Child ◽  
Using Data

Using data from the National Longitudinal Survey of Youth-Mother and Child samples, I investigated the relationships among child and adolescent depressive symptoms, having a chronically ill sibling, and other child and familial demographic variables. From research on social support and social role transitions, with the Stress Process as a theoretical model, I hypothesized that children with chronically ill siblings experience more depressive symptoms. Specifically, I looked at age, gender, birth order and family size as potentially reducing the effect size of having a chronically ill sibling. Findings showed that having a chronically ill sibling is associated with demonstrating more depressive symptoms both in the bivariate and multivariate analyses. Although age, gender, birth order and family size do not interact significantly with having a chronically ill sibling in predicting depressive symptoms, they do present interesting findings about childhood depressive symptoms in general. Thus, the results of this study suggest specific and meaningful paths for future research.

Molecular Epidemiology and Biomarkers in Etiologic Cancer Research: The New in Light of the Old

2020 ◽  
Author(s):  
Lungwani Muungo
Keyword(s):  
Gene Expression ◽  
Cancer Research ◽  
Molecular Epidemiology ◽  
Exposure Assessment ◽  
Large Scale ◽  
First Generation ◽  
Cancer Epidemiology ◽  
Policy Changes ◽  
The Past ◽  
New Generation

The purpose of this review is to evaluate progress inmolecular epidemiology over the past 24 years in canceretiology and prevention to draw lessons for futureresearch incorporating the new generation of biomarkers.Molecular epidemiology was introduced inthe study of cancer in the early 1980s, with theexpectation that it would help overcome some majorlimitations of epidemiology and facilitate cancerprevention. The expectation was that biomarkerswould improve exposure assessment, document earlychanges preceding disease, and identify subgroupsin the population with greater susceptibility to cancer,thereby increasing the ability of epidemiologic studiesto identify causes and elucidate mechanisms incarcinogenesis. The first generation of biomarkers hasindeed contributed to our understanding of riskandsusceptibility related largely to genotoxic carcinogens.Consequently, interventions and policy changes havebeen mounted to reduce riskfrom several importantenvironmental carcinogens. Several new and promisingbiomarkers are now becoming available for epidemiologicstudies, thanks to the development of highthroughputtechnologies and theoretical advances inbiology. These include toxicogenomics, alterations ingene methylation and gene expression, proteomics, andmetabonomics, which allow large-scale studies, includingdiscovery-oriented as well as hypothesis-testinginvestigations. However, most of these newer biomarkershave not been adequately validated, and theirrole in the causal paradigm is not clear. There is a needfor their systematic validation using principles andcriteria established over the past several decades inmolecular cancer epidemiology.

An Assessment of a Low-Cost Wastewater Disposal System after Twenty-Five Years of Operation

1987 ◽  
Vol 19 (5-6) ◽  
pp. 701-710 ◽  
Author(s):  
B. L. Reidy ◽  
G. W. Samson
Keyword(s):  
Large Scale ◽  
Low Cost ◽  
Wastewater Disposal ◽  
Industrial Base ◽  
Industrial Wastewaters ◽  
The Past ◽  
Gasification Process ◽  
Appropriate Treatment ◽  
Environmentally Safe ◽  
Coal Resource

A low-cost wastewater disposal system was commissioned in 1959 to treat domestic and industrial wastewaters generated in the Latrobe River valley in the province of Gippsland, within the State of Victoria, Australia (Figure 1). The Latrobe Valley is the centre for large-scale generation of electricity and for the production of pulp and paper. In addition other industries have utilized the brown coal resource of the region e.g. gasification process and char production. Consequently, industrial wastewaters have been dominant in the disposal system for the past twenty-five years. The mixed industrial-domestic wastewaters were to be transported some eighty kilometres to be treated and disposed of by irrigation to land. Several important lessons have been learnt during twenty-five years of operating this system. Firstly the composition of the mixed waste stream has varied significantly with the passage of time and the development of the industrial base in the Valley, so that what was appropriate treatment in 1959 is not necessarily acceptable in 1985. Secondly the magnitude of adverse environmental impacts engendered by this low-cost disposal procedure was not imagined when the proposal was implemented. As a consequence, clean-up procedures which could remedy the adverse effects of twenty-five years of impact are likely to be costly. The question then may be asked - when the total costs including rehabilitation are considered, is there really a low-cost solution for environmentally safe disposal of complex wastewater streams?

Recent Progress in Machine Learning-based Prediction of Peptide Activity for Drug Discovery

2019 ◽  
Vol 19 (1) ◽  
pp. 4-16 ◽  
Author(s):  
Qihui Wu ◽  
Hanzhong Ke ◽  
Dongli Li ◽  
Qi Wang ◽  
Jiansong Fang ◽  
...  
Keyword(s):  
Machine Learning ◽  
Drug Discovery ◽  
Large Scale ◽  
Recent Progress ◽  
High Specificity ◽  
Learning Approaches ◽  
Anticancer Peptides ◽  
The Past ◽  
Traditional Approaches ◽  
Large Scale Screening

Over the past decades, peptide as a therapeutic candidate has received increasing attention in drug discovery, especially for antimicrobial peptides (AMPs), anticancer peptides (ACPs) and antiinflammatory peptides (AIPs). It is considered that the peptides can regulate various complex diseases which are previously untouchable. In recent years, the critical problem of antimicrobial resistance drives the pharmaceutical industry to look for new therapeutic agents. Compared to organic small drugs, peptide- based therapy exhibits high specificity and minimal toxicity. Thus, peptides are widely recruited in the design and discovery of new potent drugs. Currently, large-scale screening of peptide activity with traditional approaches is costly, time-consuming and labor-intensive. Hence, in silico methods, mainly machine learning approaches, for their accuracy and effectiveness, have been introduced to predict the peptide activity. In this review, we document the recent progress in machine learning-based prediction of peptides which will be of great benefit to the discovery of potential active AMPs, ACPs and AIPs.

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