scholarly journals Environmental Flow Requirements of Estuaries: Providing Resilience to Current and Future Climate and Direct Anthropogenic Changes

2021 ◽  
Vol 9 ◽  
Author(s):  
Daniel Chilton ◽  
David P. Hamilton ◽  
Ivan Nagelkerken ◽  
Perran Cook ◽  
Matthew R. Hipsey ◽  
...  
Keyword(s):  
Habitat Restoration ◽  
Environmental Flows ◽  
Economic Value ◽  
Flow Regimes ◽  
Mitigation Strategies ◽  
Rainfall Runoff ◽  
Freshwater Flow ◽  
Ecological Processes ◽  
Degraded Ecosystems ◽  
Natural Characteristics

Estuaries host unique biodiversity and deliver a range of ecosystem services at the interface between catchment and the ocean. They are also among the most degraded ecosystems on Earth. Freshwater flow regimes drive ecological processes contributing to their biodiversity and economic value, but have been modified extensively in many systems by upstream water use. Knowledge of freshwater flow requirements for estuaries (environmental flows or E-flows) lags behind that of rivers and their floodplains. Generalising estuarine E-flows is further complicated by responses that appear to be specific to each system. Here we critically review the E-flow requirements of estuaries to 1) identify the key ecosystem processes (hydrodynamics, salinity regulation, sediment dynamics, nutrient cycling and trophic transfer, and connectivity) modulated by freshwater flow regimes, 2) identify key drivers (rainfall, runoff, temperature, sea level rise and direct anthropogenic) that generate changes to the magnitude, quality and timing of flows, and 3) propose mitigation strategies (e.g., modification of dam operations and habitat restoration) to buffer against the risks of altered freshwater flows and build resilience to direct and indirect anthropogenic disturbances. These strategies support re-establishment of the natural characteristics of freshwater flow regimes which are foundational to healthy estuarine ecosystems.

scholarly journals Effective framework for Environmental-flows estimation for data deficient Indian rivers

2019 ◽  
Vol 11 (2) ◽  
pp. 545-555 ◽  
Author(s):  
Urvashi Sharma
Keyword(s):  
Indigenous Population ◽  
Environmental Flows ◽  
Flow Regimes ◽  
Ecological Analysis ◽  
Fluvial Morphology ◽  
The World ◽  
Data Deficient ◽  
Inland Water Body ◽  
Degraded Ecosystems ◽  
Take All

Data deficiency is a major problem in recommending appropriate environmental flows (e-flows) requirements for rivers in many parts of the world. Several studies have been done using a variety of e-flows assessment methodologies. Large dams and hydropower projects are major manipulators of the flow regimes resulting in degraded ecosystems ubiquitously. In India attempts have been made to develop e-flows requirements of rivers to maintain a good riverine ecosystem. Most of the studies are based on hydrological methods, which do not take all the variables affecting flow-regimes into consideration. This paper highlights the problems in assessment of e-flows and their on-ground implications in India. In this study, probable solutions to these problems are suggested a conceptual framework for data deficient areas is proposed. This framework is based upon extensive baseline surveys of fluvial morphology, ecology and of indigenous population. Framework has six steps namely: monitoring the baseline conditions, setting up objectives, hydrological analysis, ecological analysis, climatic anomalies incorporation and recommendations. Finally, e-flows recommendations are made based on hydrological studies, habitat suitability curves and area of inland water body which should be maintained in the river basin. All these recommendations are compared and suitable e-flows recommendations are made based on studied variables. The review also suggests for bottom-up approach for e-flows assessment i.e. e-flows assessment and application should be done on small tributaries of rivers in initial phase of projects and those methods which deliver satisfactory results should only be applied to larger rivers. 

scholarly journals The Value and Services of Urban Stream Polygnotou, Thessaloniki

Proceedings ◽  
2018 ◽  
Vol 2 (11) ◽  
pp. 576
Author(s):  
Eleni A. Athanasiadou ◽  
Maria Tratsela ◽  
Eleni Gkrimpa
Keyword(s):  
Green Infrastructure ◽  
Large Scale ◽  
Economic Value ◽  
Urban Streams ◽  
Urban Stream ◽  
Riparian Ecosystems ◽  
Runoff Water ◽  
Ecological Processes ◽  
Urban Stream Syndrome ◽  
Mental Map

Grey, blue and green infrastructure supports socio-ecological processes the city undergoes. Yet, procedures of constructing anthropogenic habitats often undermine the value of natural landscape elements such as urban streams. Thessaloniki’s backbone comprises of urban streams that run from the suburban forest of ‘Seih-Sou’ to the Thermaikos Gulf acting as corridors of the natural urban matrix. Policies of the past have dealt with urban streams through extensive engineering drainage methods, eliminating the risk of flooding, yet resulting in rapid stormwater runoff, water quality problems, disturbed riparian ecosystems, leading to the urban stream syndrome. Furthermore, they have failed to address urban streams as an inseparable part of the landscape and thus to incorporate them in people’s mental map and everyday activities. The paper discusses the case of ‘Polygnotou stream’ which forms the beginning of the large scale engineered peripheral moat of Thessaloniki, constructed in the 60’s, and playing the role of the water recipient for six urban streams in total. It falls unknown to the majority of people living in the area, yet its services as an ecosystem ought to be acknowledged, helping inform decision makers of its socio-ecologic, perceptual and economic value. In addition, Polygnotou stream, adjacent streams and the peripheral moat overall, could be considered as a touristic product of great importance.

How can grass-based dairy farmers reduce the carbon footprint of milk?

2016 ◽  
Vol 56 (3) ◽  
pp. 495 ◽  
Author(s):  
D. O'Brien ◽  
A. Geoghegan ◽  
K. McNamara ◽  
L. Shalloo
Keyword(s):  
Milk Production ◽  
Carbon Footprint ◽  
Economic Value ◽  
Ghg Emissions ◽  
Mitigation Strategies ◽  
Quota System ◽  
Dairy Farmers ◽  
Increase Milk Production ◽  
Fertiliser Use ◽  
Milk Solids

The Irish dairy industry aims to increase milk production from grass-based farms following the removal of the EU milk-quota system, but is also required to minimise greenhouse gas (GHG) emissions to meet European reduction targets. Consequently, the sector is under increasing pressure to reduce GHG emissions per unit of milk, or carbon footprint (CF). Therefore, the goal of the present study was to determine the main sources of the CF of grass-based milk production and to identify mitigation strategies that can be applied to reduce farm footprints. In total, the CF of milk was estimated for 62 grass-based dairy farms in 2014. The method used to quantify GHG emissions was a life cycle assessment (LCA), independently certified to comply with the British standard for LCA (PAS 2050). The LCA method was applied to calculate annual on- and off-farm GHG emissions associated with dairy production until milk was sold from the farm in CO2-equivalent (CO2-eq). Annual GHG emissions computed using LCA were allocated to milk on the basis of the economic value of dairy products and expressed per kilogram of fat- and protein-corrected milk to estimate CF. Enteric methane was the main source of the CF of milk (46%), followed by emissions from inorganic N fertilisers (16%), manure (16%) and concentrate feedstuffs (8%). The mean CF of milk from the 62 farms was 1.26 kg of CO2-eq per kilogram of fat- and protein-corrected milk, but varied from 0.98 kg to 1.67 kg as measured using the 95% confidence interval. The CF of milk was correlated with numerous farm attributes, particularly N-fertiliser, the percentage of grazed grass in the diet, and production of milk solids. Grass-based dairy farmers can significantly improve these farm attributes by increasing herd genetic merit, extending the length of the grazing season and optimising N fertiliser use and, thereby, reduce the CF of milk.

Population genetic structure of the snow crab (Chionoecetes opilio) at the Northwest Atlantic scale

2008 ◽  
Vol 65 (3) ◽  
pp. 425-436 ◽  
Author(s):  
Oscar Puebla ◽  
Jean-Marie Sévigny ◽  
Bernard Sainte-Marie ◽  
Jean-Claude Brêthes ◽  
AnnDorte Burmeister ◽  
...  
Keyword(s):  
Genetic Structure ◽  
Population Genetic Structure ◽  
Population Genetic ◽  
Economic Value ◽  
Snow Crab ◽  
Atlantic Canada ◽  
Ecological Processes ◽  
Northwest Atlantic ◽  
Larval Phase ◽  
Chionoecetes Opilio

Marine species with planktonic larval durations of several months (teleplanic larvae) can potentially maintain demographic connectivity across large geographical distances. This perspective has important fundamental and applied implications, notably for the understanding of evolutionary and ecological processes in the marine realm, the implementation of marine protected areas, and fisheries management. Here we present, at the scale of the Northwest Atlantic, a spatial analysis of snow crab (Chionoecetes opilio, Majoidea) population genetic structure, a species that has a planktonic larval phase of 3 to 5 months. Eight microsatellite markers analysed on 847 C. opilio samples from 13 locations revealed an absence of significant genetic structure along the west coast of Greenland and within Atlantic Canada from southern Labrador to Nova Scotia. These results are consistent with a scenario of extensive demographic connectivity among C. opilio populations and have implications for the management of this species, which supports one of the most important Canadian and Greenlandic fisheries in terms of economic value. A genetic break is nevertheless identified between Greenland and Atlantic Canada, showing that genetic structure can develop within seas (the Labrador Sea in this case) despite the occurrence of very long planktonic larval stages.

scholarly journals Temporal and spatial scales of lake processes. Part 1: physical and ecological scales, non-dimensional parameters and flow regimes

2013 ◽  
Vol 13 (4) ◽  
pp. 339-353
Keyword(s):  
Spatial Scales ◽  
Flow Regimes ◽  
Turbulence Structure ◽  
Dimensionless Time ◽  
Dimensionless Numbers ◽  
Ecological Processes ◽  
Mixing Processes ◽  
Lake Ecosystems ◽  
Dimensional Parameters ◽  
Prandtl Numbers

Scaling concepts, related to basic physical transport and mixing processes and other ecological aspects in lakes, are reviewed in an ecohydrodynamic perspective; the length and time scales as well as the non-dimensional parameters governing the various flow regimes and relevant to these processes are also presented, emphasizing the influence they have on lake ecosystems. The hierarchy of length scales is very important in determining both the turbulence structure, and in affecting the ecological processes occurring in lakes. Most of these scales are defined in terms of several basic parameters which, when combined properly, yield important dimensionless numbers, as: Rf, Ri, Pr, T, Ret, Frt, Grt, and Prt, the flux and gradient Richardson numbers, the Prandtl number, a dimensionless time, and the turbulent Reynolds, Froude, Grasshof and Prandtl numbers, respectively. A few more dimensionless numbers (as the Lake and Wedderburn numbers, LΝ, W, etc.) are also useful in characterizing the general dynamic behavior of lakes. Ratios of length or time scales may also provide similar useful parameters.

Cultural and Recreational Values for Environmental Flows in Mexico's Colorado River Delta

2017 ◽  
Vol 03 (02) ◽  
pp. 1650035 ◽  
Author(s):  
Ashley Kerna ◽  
Bonnie Colby ◽  
Francisco Zamora
Keyword(s):  
Aquatic Ecosystems ◽  
Colorado River ◽  
Environmental Flows ◽  
Economic Value ◽  
Strong Support ◽  
Local Area ◽  
River Delta ◽  
Colorado River Delta ◽  
Total Economic Value ◽  
High Level

Worldwide, aquatic ecosystems subsist on water leftover from agricultural, industrial, and municipal water uses. While bi-national agreements have temporarily provided water for the Colorado River Delta (Delta) in Mexico, dedication of water to support aquatic ecosystems is rare. High-level U.S. – Mexico negotiations are underway to consider whether and how to provide water for the Delta once the current pilot program ends in 2017. Better understanding of the value of aquatic ecosystems can be useful in securing water to sustain them. This paper reports research findings on values held by visitors from nearby Mexican communities for environmental flows in the Delta. Based on surveys conducted at five recreation locations, this contingent valuation methodology (CVM) study assesses visitors' willingness-to-pay (WTP) for an assured source of water to sustain the Delta's ecosystem and the recreational opportunities it provides. Results indicate strong support for Delta restoration, with the majority of respondents indicating positive WTP to ensure adequate amounts of water to sustain a healthy and vibrant Delta ecosystem. Econometric model results indicate a median WTP ranging from $97 to $168 MXN (approximately $7–$13 USD at the time of analysis) per car per entry. These values represent only a subset of recreational users, and recreation values are only one of many components of the ecosystem services provided by the Delta. While only a fraction of recreation value and total economic value, it is important to understand values held by local recreation visitors. These values gauge support for preserving aquatic ecosystems in nearby communities. Furthermore, values held in the local area affect water management and policy decisions regarding restoration of this unique aquatic ecosystem.

The ecology of rivers with contrasting flow regimes: identifying indicators for setting environmental flows

2014 ◽  
Vol 59 (10) ◽  
pp. 2064-2080 ◽  
Author(s):  
Danielle M. Warfe ◽  
Scott A. Hardie ◽  
Adam R. Uytendaal ◽  
Chris J. Bobbi ◽  
Leon A. Barmuta
Keyword(s):  
Environmental Flows ◽  
Flow Regimes
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