Evaluating the Ecological Benefits of Management Actions to Complement Environmental Flows in River Systems

2021 ◽  
Author(s):  
Sam Nicol ◽  
J. Angus Webb ◽  
Rebecca E. Lester ◽  
Marcus Cooling ◽  
Paul Brown ◽  
...  
Keyword(s):  
Environmental Flows ◽  
River Systems ◽  
Ecological Benefits ◽  
Management Actions

Monitoring Crocodylus porosus populations in the Northern Territory of Australia: a retrospective power analysis

2001 ◽  
Vol 28 (6) ◽  
pp. 547 ◽  
Author(s):  
S. C. Stirrat ◽  
D. Lawson ◽  
W. J. Freeland ◽  
R. Morton
Keyword(s):  
Power Analysis ◽  
Northern Territory ◽  
Management Program ◽  
Survey Method ◽  
Management Information ◽  
River Systems ◽  
Pooled Data ◽  
Management Actions ◽  
Sampling Program ◽  
Crocodylus Porosus

In the Northern Territory of Australia, populations of the estuarine crocodile (Crocodylus porosus) have been subject to an annual egg harvest since the early 1980s. Since 1997, adult and juvenile crocodiles have also been harvested in some catchments. Annual surveys of crocodile populations are conducted in order to ensure that the harvest is sustainable. Boat surveys commenced in 1975 and helicopter surveys commenced in 1989. Retrospective power analysis was used to determine whether the sampling program meets the objectives of the Crocodile Management Program for the Northern Territory. Data collected during boat surveys vary in quality between river systems. The analysis of pooled data from 7 river systems with a residual standard deviation of 0.11 indicates that the power of the current spotlight survey method to detect a decline of 10% per annum in around 4 years is about 0.9. In this time the population would decline by around 33% and would fully recover in 8 years following the removal of the factor causing the decline. This allows detection of a decline within one-third, and recovery within two-thirds, of the estimated generation time of the saltwater crocodile and will allow management actions to be implemented before the impacts on populations are serious. The data from helicopter and boat surveys from a 10-year period were compared. Helicopter surveys did not provide useful management information.

An Assessment of Stream Flow Modelling Combined with The Montana Method as a Basis for Developing Optimal Environmental Flows Below a Proposed Dam.

1998 ◽  
Vol 20 (2) ◽  
pp. 303
Author(s):  
D Goldney ◽  
L. Gilbert
Keyword(s):  
Environmental Flows ◽  
Flow Conditions ◽  
River Systems ◽  
Order Stream ◽  
Ecosystem Integrity ◽  
Freshwater Organisms ◽  
Freshwater Biota ◽  
Species Specific ◽  
Management Flow ◽  
Australian Freshwater

Little research has been carried out in Australia to determine the riparian and environmental flows needed to maintain riverine ecosystem integrity. Given the range of organisms present in the Australian freshwater biota, each with its own optimal requirements, it is probable that management flow conditions arrived at from species-specific studies, may not necessarily benefit all organisms. We also have inadequate understanding of how freshwater organisms interact with dynamic changes that occur in river systems (drought and flood), and the generally degraded nature of these streams. Hence formulating management outcomes in regard to flow conditions must be viewed as a particularly complex issue. In this paper a case history study is described for a tableland stream in the central west of New South Wales, where a major dam is being built on a first order stream. Comparisons are made with three other creek/river systems in the central tablelands and some implications for platypus conservation are identified.

scholarly journals Advancing the Science of Environmental Flow Management for Protection of Temporarily Closed Estuaries and Coastal Lagoons

Water ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 595
Author(s):  
Eric D. Stein ◽  
Eleanor M. Gee ◽  
Janine B. Adams ◽  
Katie Irving ◽  
Lara Van Niekerk
Keyword(s):  
Climate Change ◽  
Cultural Values ◽  
Environmental Flows ◽  
Coastal Lagoons ◽  
Regional Scale ◽  
Environmental Flow ◽  
Hydrologic Alteration ◽  
Tight Coupling ◽  
Flow Management ◽  
Management Actions

The science needed to inform management of environmental flows to temporarily closed estuaries and coastal lagoons is decades behind the state of knowledge for rivers and large embayments. These globally ubiquitous small systems, which are often seasonally closed to the ocean’s influence, are under particular threat associated with hydrologic alteration because of changes in atershed land use, water use practices, and climate change. Managing environmental flows in these systems is complicated by their tight coupling with watershed processes, variable states because of intermittently closing mouths, and reliance on regional scale sediment transport and littoral processes. Here we synthesize our current understanding of ecohydrology in temporarily closed estuaries (TCEs) and coastal lagoons and propose a prioritized research agenda aimed at advancing understanding of ecological responses to altered flow regimes in TCEs. Key research needs include agreeing on a consistent typology, improving models that couple watershed and ocean forcing at appropriate spatial and temporal scales, quantifying stress–response relationships associated with hydrologic alteration, improving tools to establish desired conditions that account for climate change and consider cultural/indigenous objectives, improving tools to measure ecosystem function and social/cultural values, and developing monitoring and adaptive management programs that can inform environmental flow management in consideration of other stressors and across different habitat types. Coordinated global efforts to address the identified research gaps can help guide management actions aimed at reducing or mitigating potential impacts of hydrologic alteration and climate change through informed management of freshwater inflows.

scholarly journals Review of trap-and-haul for managing Pacific salmonids (Oncorhynchus spp.) in impounded river systems

2020 ◽  
Author(s):  
Tobias J. Kock ◽  
John W. Ferguson ◽  
Matthew L. Keefer ◽  
Carl B. Schreck
Keyword(s):  
Pacific Salmon ◽  
Biological Effects ◽  
Management Tool ◽  
Management Approach ◽  
Facility Design ◽  
River Systems ◽  
Management Actions ◽  
High Head ◽  
Pacific Salmonids

AbstractHigh-head dams are migration barriers for Pacific salmon Oncorhynchus spp. in many river systems and recovery measures for impacted stocks are limited. Trap-and-haul has been widely used in attempts to facilitate recovery but information from existing programs has not been synthesized to inform improvements to aid recovery of salmonids in systems with high-head dams. We reviewed 17 trap-and-haul programs regarding Pacific salmon to: (1) summarize information about facility design, operation and biological effects; (2) identify critical knowledge gaps; and (3) evaluate trap-and-haul as a current and future management tool. Existing programs are operated to address a range of management goals including restoring access to historical habitats, temporarily reducing exposure to dangerous in-river conditions, and reintroducing ecological processes upstream from dams. Information gathered from decades of operation on facility design criteria and fish handling protocols, and robust literature on fish collection and passage are available. While many aspects of trap-and-haul have been evaluated, effects on population productivity and sustainability remain poorly understood. Long-term and systematic studies of trap-and-haul outcomes are rare, and assessments can be confounded by concurrent management actions and broad ecological and climatic effects. Existing data suggest that performance and effectiveness vary among programs and over various time scales within programs. Although critical information gaps exist, trap-and-haul is an important management and conservation tool for providing Pacific salmonids access to historical habitats. Successful application of trap-and-haul programs requires long-term commitment and an adaptive management approach by dam owners and stakeholders, and careful planning of new programs.

Australia's Environmental Flow Initiative: filling some knowledge gaps and exposing others

2001 ◽  
Vol 43 (9) ◽  
pp. 73-88 ◽  
Author(s):  
C. J. Gippel
Keyword(s):  
Environmental Flows ◽  
Rapid Assessment ◽  
Environmental Values ◽  
River Systems ◽  
Knowledge Gaps ◽  
Management Options ◽  
Lack Of Information ◽  
Assessment Techniques ◽  
Development And Validation ◽  
Ecologically Sustainable

Many of Australia's river systems have been seriously degraded by inappropriate management of regulated flows. Other systems are facing threats from future water resources developments. There is a lack of information available to aid in allocation of environmental flows to rivers in order that they are managed in an ecologically sustainable manner. The Environmental Flows Initiative (EFI) is a major Australia-wide R&D program into environmental flows, funded through the Natural Heritage Trust (NHT), and administered by Environment Australia (EA). The program aims to identify environmental values, undertake targeted research to identify risks to river systems and flow requirements to sustain environmental values, to trial flow management options, and to evaluate these trials. The NHT relies on matching funding provided by the State and Territory authorities, and supports integrative approaches with emphasis on works on-the-ground where possible. While the EFI will close significant knowledge gaps, other gaps remain. Some of these relate to development and validation of rapid assessment techniques, understanding the importance of flow variability and how to define it, manipulation of flows to control alien species, developing a system of prioritising rivers for environmental flows, and enhancing flows with other catchment, channel and floodplain rehabilitation measures.

scholarly journals Combining Tools from Edge-of-Field to In-Stream to Attenuate Reactive Nitrogen along Small Agricultural Waterways

Water ◽  
2020 ◽  
Vol 12 (2) ◽  
pp. 383 ◽  
Author(s):  
Brandon C. Goeller ◽  
Catherine M. Febria ◽  
Lucy A. McKergow ◽  
Jon S. Harding ◽  
Fleur E. Matheson ◽  
...  
Keyword(s):  
Contaminant Transport ◽  
Water Retention ◽  
Reactive Nitrogen ◽  
Organic Soils ◽  
Ecological Benefits ◽  
Transport Pathways ◽  
Cold Temperatures ◽  
Management Actions ◽  
Novel Applications ◽  
Productive Landscapes

Reducing excessive reactive nitrogen (N) in agricultural waterways is a major challenge for freshwater managers and landowners. Effective solutions require the use of multiple and combined N attenuation tools, targeted along small ditches and streams. We present a visual framework to guide novel applications of ‘tool stacking’ that include edge-of-field and waterway-based options targeting N delivery pathways, timing, and impacts in the receiving environment (i.e., changes in concentration or load). Implementing tools at multiple locations and scales using a ‘toolbox’ approach will better leverage key hydrological and biogeochemical processes for N attenuation (e.g., water retention, infiltration and filtering, contact with organic soils and microbes, and denitrification), in addition to enhancing ecological benefits to waterways. Our framework applies primarily to temperate or warmer climates, since cold temperatures and freeze–thaw-related processes limit biologically mediated N attenuation in cold climates. Moreover, we encourage scientists and managers to codevelop N attenuation toolboxes with farmers, since implementation will require tailored fits to local hydrological, social, and productive landscapes. Generating further knowledge around N attenuation tool stacking in different climates and landscape contexts will advance management actions to attenuate agricultural catchment N. Understanding how different tools can be best combined to target key contaminant transport pathways and create activated zones of attenuation along and within small agricultural waterways will be essential.

scholarly journals Silvopastoral System in Morocco: Focus on Their Importance, Strategic Functions, and Recent Changes in the Mediterranean Side

2021 ◽  
Vol 13 (19) ◽  
pp. 10744
Author(s):  
Youssef Chebli ◽  
Samira El Otmani ◽  
Fouad Elame ◽  
Nassim Moula ◽  
Mouad Chentouf ◽  
...  
Keyword(s):  
Mediterranean Region ◽  
Forest Degradation ◽  
Silvopastoral Systems ◽  
Silvopastoral System ◽  
Ecological Benefits ◽  
Management Actions ◽  
Southern Mediterranean ◽  
Change Impact ◽  
Animal Feeding ◽  
The Mediterranean

In the Mediterranean basin, the silvopastoral system has always been part of the regional economy. Silvopastoral areas contribute significantly to the development of the ecological and socio-economic factors of territorial sustainability. However, little attention has been paid to reviewing the importance, historical evolution, socio-economic conditions, and climate change impact of the southern Mediterranean region of northern Morocco. This review casts light on research on the silvopastoral systems in Morocco with a focus on the Mediterranean side. Sixty-nine peer-reviewed publications were selected for this systematic review. The findings revealed that silvopastoral areas play a very important role in animal feeding in Morocco. Animals are managed traditionally on these woodlands where they graze throughout the year. The silvopastoral system has undergone several changes over recent decades. These changes have had a direct impact on ecosystems, causing a decline in biodiversity, forest degradation, and an increase in land use at the expense of silvopastoral areas, mainly in the Mediterranean region of northern Morocco. Consequently, the sustainability of the silvopastoral systems would undoubtedly be negatively affected. The review finishes with some crucial strategies and propositions that could be encouraged to support sustainable management actions of silvopastoral resources. In the conclusion, we outline the need to assess the realistic socio-economic and ecological benefits of silvopastoral systems to promote their sustainable development.

Why life history information matters: drought refuges and macroinvertebrate persistence in non-perennial streams subject to a drier climate

2011 ◽  
Vol 62 (7) ◽  
pp. 801 ◽  
Author(s):  
B. J. Robson ◽  
E. T. Chester ◽  
C. M. Austin
Keyword(s):  
Life Histories ◽  
Environmental Flows ◽  
Species Traits ◽  
Biological Traits ◽  
Stream Drying ◽  
Management Actions ◽  
Ecological Concepts ◽  
History Information ◽  
Habitat Templet

In some arid, semi-arid or Mediterranean climate regions, increased water extraction combined with climate change will prolong periods of drought in non-perennial streams, but the effects on macroinvertebrate populations are poorly understood. Drought refuges allow species to survive drying but their use depends on species’ traits, and refuge availability depends on landscape structure. This review evaluates the utility of existing ecological concepts for predicting the role of drought refuges for sustaining biodiversity in non-perennial streams. We also suggest traits that may determine invertebrate species’ resistance or resilience to prolonged drying. Parts of the likely responses by populations to increased stream drying are described by existing ecological concepts, such as the biological traits of species and their interaction with the habitat templet, barriers to dispersal and metapopulation dynamics, the use of drought refuges, habitat fragmentation and population and landscape genetics. However, the limited knowledge of invertebrate life histories in non-perennial streams restricts our ability to use these concepts in a predictive manner. In particular, reach or pool occupancy by species cannot be accurately predicted, but such predictions are necessary for evaluating potential management actions such as the use of environmental flows to sustain drought refuges during dry periods.

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