The impact of catastrophic channel change on freshwater mussels in the Hunter River system, Australia: a conservation assessment

2009 ◽  
pp. n/a-n/a ◽  
Author(s):  
Hugh A. Jones ◽  
Maria Byrne
Keyword(s):  
Freshwater Mussels ◽  
River System ◽  
Conservation Assessment ◽  
Channel Change ◽  
The Impact

Decline and regional extirpation of freshwater mussels (Unionidae) in a small river system invaded by Dreissena polymorpha: the Rideau River, 1993–2000

2001 ◽  
Vol 79 (12) ◽  
pp. 2181-2191 ◽  
Author(s):  
André L Martel ◽  
Diane A Pathy ◽  
Jacqueline B Madill ◽  
Claude B Renaud ◽  
Stuart L Dean ◽  
...  
Keyword(s):  
Dreissena Polymorpha ◽  
Freshwater Mussels ◽  
Ecological Impact ◽  
Benthic Fauna ◽  
River System ◽  
Small River ◽  
River Systems ◽  
Long Term Study ◽  
The Impact ◽  
Rideau River

Data pertaining to the ecological impact of the exotic zebra mussel, Dreissena polymorpha, on benthic fauna in small river systems are scarce. We conducted a long-term study to assess the impacts of the D. polymorpha invasion in a small river system (100 km) in eastern Ontario during an 8-year period (1993–2000). A 30-km downstream section of the Rideau River was studied before and during rapid population growth of D. polymorpha in the area. During 1993–1995, D. polymorpha abundance on hard substrates increased by four to six orders of magnitude and remained high thereafter. A comparable temporal pattern of D. polymorpha abundance was observed on shells of live freshwater mussels (Unionidae). During peak fouling (1995–1997), mass ratios (mass of attached D. polymorpha / mass of live unionid host) ranged from 0.37 to 1.81. SCUBA-diving surveys (50-m transects) were conducted to examine the impact of D. polymorpha on native unionids in impounded river habitats. In 1993–1994, three unionid taxa were commonly found in 10-m2 quadrats sampled along transects: Elliptio complanata, Pyganodon grandis, and Lampsilis radiata. Overall, the mean density of unionids declined 5- to 8-fold from 1993 to 1997, coinciding with a rapid increase in D. polymorpha densities on unionids. By 1997, i.e., 4 years after fouling began, P. grandis and L. radiata had been extirpated from those sites, with only E. complanata remaining. By 2000, i.e., 7 years after fouling began, all three unionid taxa had been essentially extirpated from the 30-km section of the river, with only one live individual (E. complanata) collected during 10 extensive diving surveys (the total estimated area of riverbed surveyed was 4000 m2). This study indicates that heavy fouling by D. polymorpha causes the extirpation of unionids in small impounded river systems ([Formula: see text]100 km).

The impact of socioeconomic system on the river system in a heavily disturbed basin

2019 ◽  
Vol 660 ◽  
pp. 851-864 ◽  
Author(s):  
Zengliang Luo ◽  
Qiting Zuo ◽  
Quanxi Shao ◽  
Xiangyi Ding
Keyword(s):  
River System ◽  
Socioeconomic System ◽  
The Impact

scholarly journals Endemic Juniperus Montane Species Facing Extinction Risk under Climate Change in Southwest China: Integrative Approach for Conservation Assessment and Prioritization

Biology ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 63
Author(s):  
Mohammed A. Dakhil ◽  
Marwa Waseem A. Halmy ◽  
Walaa A. Hassan ◽  
Ali El-Keblawy ◽  
Kaiwen Pan ◽  
...  
Keyword(s):  
Climate Change ◽  
Potential Distribution ◽  
Extinction Risk ◽  
In Situ Conservation ◽  
Integrative Approach ◽  
Conservation Assessment ◽  
Distribution Models ◽  
Area Of Occupancy ◽  
Annual Range ◽  
The Impact

Climate change is an important driver of biodiversity loss and extinction of endemic montane species. In China, three endemic Juniperus spp. (Juniperuspingii var. pingii, J.tibetica, and J.komarovii) are threatened and subjected to the risk of extinction. This study aimed to predict the potential distribution of these three Juniperus species under climate change and dispersal scenarios, to identify critical drivers explaining their potential distributions, to assess the extinction risk by estimating the loss percentage in their area of occupancy (AOO), and to identify priority areas for their conservation in China. We used ensemble modeling to evaluate the impact of climate change and project AOO. Our results revealed that the projected AOOs followed a similar trend in the three Juniperus species, which predicted an entire loss of their suitable habitats under both climate and dispersal scenarios. Temperature annual range and isothermality were the most critical key variables explaining the potential distribution of these three Juniperus species; they contribute by 16–56.1% and 20.4–38.3%, respectively. Accounting for the use of different thresholds provides a balanced approach for species distribution models’ applications in conservation assessment when the goal is to assess potential climatic suitability in new geographical areas. Therefore, south Sichuan and north Yunnan could be considered important priority conservation areas for in situ conservation and search for unknown populations of these three Juniperus species.

scholarly journals Evaluating and Predicting the Effects of Land Use Changes on Hydrology in Wami River Basin, Tanzania

Hydrology ◽  
2020 ◽  
Vol 7 (1) ◽  
pp. 17 ◽  
Author(s):  
Sekela Twisa ◽  
Shija Kazumba ◽  
Mathew Kurian ◽  
Manfred F. Buchroithner
Keyword(s):  
Land Use ◽  
Water Resources ◽  
Assessment Tool ◽  
Swat Model ◽  
Land Use Changes ◽  
Management Strategies ◽  
River System ◽  
Least Squares Regression ◽  
Natural Forests ◽  
The Impact

Understanding the variation in the hydrological response of a basin associated with land use changes is essential for developing management strategies for water resources. The impact of hydrological changes caused by expected land use changes may be severe for the Wami river system, given its role as a crucial area for water, providing food and livelihoods. The objective of this study is to examine the influence of land use changes on various elements of the hydrological processes of the basin. Hybrid classification, which includes unsupervised and supervised classification techniques, is used to process the images (2000 and 2016), while CA–Markov chain analysis is used to forecast and simulate the 2032 land use state. In the current study, a combined approach—including a Soil and Water Assessment Tool (SWAT) model and Partial Least Squares Regression (PLSR)—is used to explore the influences of individual land use classes on fluctuations in the hydrological components. From the study, it is evident that land use has changed across the basin since 2000 (which is expected to continue in 2032), as well as that the hydrological effects caused by land use changes were observed. It has been found that the major land use changes that affected hydrology components in the basin were expansion of cultivation land, built-up area and grassland, and decline in natural forests and woodland during the study period. These findings provide baseline information for decision-makers and stakeholders concerning land and water resources for better planning and management decisions in the basin resources’ use.

scholarly journals Pronounced Impact of Salinity on Rapidly Intensifying Tropical Cyclones

2020 ◽  
Vol 101 (9) ◽  
pp. E1497-E1511 ◽  
Author(s):  
Karthik Balaguru ◽  
Gregory R. Foltz ◽  
L. Ruby Leung ◽  
John Kaplan ◽  
Wenwei Xu ◽  
...  
Keyword(s):  
Positive Impact ◽  
River System ◽  
Surface Salinity ◽  
Near Surface ◽  
Salinity Stratification ◽  
Sst Cooling ◽  
Prediction Scheme ◽  
Ocean Salinity ◽  
Global Coverage ◽  
The Impact

Abstract Tropical cyclone (TC) rapid intensification (RI) is difficult to predict and poses a formidable threat to coastal populations. A warm upper ocean is well known to favor RI, but the role of ocean salinity is less clear. This study shows a strong inverse relationship between salinity and TC RI in the eastern Caribbean and western tropical Atlantic due to near-surface freshening from the Amazon–Orinoco River system. In this region, rapidly intensifying TCs induce a much stronger surface enthalpy flux compared to more weakly intensifying storms, in part due to a reduction in SST cooling caused by salinity stratification. This reduction has a noticeable positive impact on TCs undergoing RI, but the impact of salinity on more weakly intensifying storms is insignificant. These statistical results are confirmed through experiments with an ocean mixed layer model, which show that the salinity-induced reduction in SST cold wakes increases significantly as the storm’s intensification rate increases. Currently, operational statistical–dynamical RI models do not use salinity as a predictor. Through experiments with a statistical RI prediction scheme, it is found that the inclusion of surface salinity significantly improves the RI detection skill, offering promise for improved operational RI prediction. Satellite surface salinity may be valuable for this purpose, given its global coverage and availability in near–real time.

scholarly journals Assessment of Siltation Processes of the Koronowski Reservoir in the Northern Polish Lowland Based on Bathymetry and Empirical Formulas

Water ◽  
2018 ◽  
Vol 10 (11) ◽  
pp. 1681 ◽  
Author(s):  
Dawid Szatten ◽  
Michał Habel ◽  
Luisa Pellegrini ◽  
Michael Maerker
Keyword(s):  
Flood Control ◽  
Field Measurements ◽  
Suspended Sediments ◽  
River System ◽  
Empirical Formulas ◽  
Filtration Method ◽  
Transport Dynamics ◽  
Sediment Budgets ◽  
The Impact ◽  
Artificial Reservoirs

Artificial reservoirs have an important role in water management of river systems in terms of flood control, water supply and sediment budgeting. Therefore, it is important to maximize the time of their effective functioning. Sediment budgeting mainly depends on sediment transport dynamics. This article illustrates the impact of the Koronowski Reservoir on suspended sediments transported by the Brda River. The river system and the reservoir represent a typical lowland river environment. Our research is based on hydrological and sedimentological investigations on the reservoir and the river system. Field measurements were used to create the respective hydrological and sediment budgets. Moreover, we carried out bathymetric measurements to generate present day bathymetry and to calculate the reservoir’s capacity. We assessed the silting of the reservoir following the approaches proposed by Goncarov and Stonawski. We show that the size and dynamics of suspended sediments are mainly determined by the hydrological conditions. Moreover, we illustrate that the suspended sediment measurements made with the filtration method correlate with the nephelometric results. Generally, we show that the Koronowski Reservoir is mainly filled up by suspended sediments. We further illustrate that the level of siltation estimated with the empirical formulas deviates significantly from calculations made by bathymetric measurements.

The impact of municipal wastewater effluent on field-deployed freshwater mussels in the Grand River (Ontario, Canada)

2013 ◽  
Vol 33 (1) ◽  
pp. 134-143 ◽  
Author(s):  
Patricia L. Gillis ◽  
François Gagné ◽  
Rodney McInnis ◽  
Tina M. Hooey ◽  
Emily S. Choy ◽  
...  
Keyword(s):  
Municipal Wastewater ◽  
Freshwater Mussels ◽  
Wastewater Effluent ◽  
Grand River ◽  
The Impact

scholarly journals The human impact on North American erosion, sediment transfer, and storage in a geologic context

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
David B. Kemp ◽  
Peter M. Sadler ◽  
Veerle Vanacker
Keyword(s):  
Mass Transfer ◽  
North American ◽  
Sediment Accumulation ◽  
River System ◽  
Rapid Expansion ◽  
Past Century ◽  
Spatial And Temporal Scales ◽  
Alluvial Sediment ◽  
European Colonization ◽  
The Impact

AbstractHumans are primary agents of geomorphic change, and rates of anthropogenic landscape change likely far exceed the pace of change expected from natural geologic processes. Nevertheless, our understanding of the impact of humans on the natural landscape is limited by difficulties in accurately comparing past and present rates of change across wide spatial and temporal scales. Here, we present a compilation of  >4000 rates of alluvial sediment accumulation that provide an indirect record of North American erosion, mass transfer and sediment storage from the late Pleistocene to the present day. Continent-wide rates of alluvium accumulation were broadly stable for ~40,000 years, but increased 10-fold during the rapid expansion of agriculture and river system modification associated with European colonization. Interpreted in terms of mass transfer, humans have moved as much sediment in North America in the past century as natural processes can transfer in 700–3000 years.

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