scholarly journals Dams Alter Nutrient Flows to Coasts

Eos ◽  
2020 ◽  
Vol 101 ◽  
Author(s):  
Elizabeth Thompson
Keyword(s):  
River Water ◽  
Coastal Ecosystems ◽  
Nutrient Loads ◽  
Nutrient Flows ◽  
New Models

New models indicate how dams worldwide influence the mix of nutrients in river water reaching the ocean. As more dams are built, changing nutrient loads may adversely affect coastal ecosystems.

Climate change and recovery from eutrophication reduce benthic fauna and carbon processing in a coastal sea

2020 ◽  
Author(s):  
Eva Ehrnsten ◽  
Alf Norkko ◽  
Bärbel Müller-Karulis ◽  
Erik Gustafsson ◽  
Bo Gustafsson
Keyword(s):  
Climate Change ◽  
Baltic Sea ◽  
Coastal Ecosystems ◽  
Benthic Macrofauna ◽  
Combined Effects ◽  
Nutrient Loads ◽  
The Baltic Sea ◽  
The Future ◽  
The Baltic ◽  
Carbon Processing

<p>Nutrient loading and climate change affect coastal ecosystems worldwide. Unravelling the combined effects of these pressures on benthic macrofauna is essential for understanding the future functioning of coastal ecosystems, as it is an important component linking the benthic and pelagic realms. In this study, we extended an existing model of benthic macrofauna coupled with the physical-biogeochemical BALTSEM model of the Baltic Sea to study the combined effects of changing nutrient loads and climate on biomass and metabolism of benthic macrofauna historically and in scenarios for the future. Based on a statistical comparison with a large validation dataset of measured biomasses, the model showed good or reasonable performance across the different basins and depth strata in the model area. In scenarios with decreasing nutrient loads according to the Baltic Sea Action Plan, but also with continued recent loads (mean loads 2012-2014), overall macrofaunal biomass and carbon processing were projected to decrease significantly by the end of the century despite improved oxygen conditions at the seafloor. Climate change led to intensified pelagic recycling of primary production and reduced export of particulate organic carbon to the seafloor with negative effects on macrofaunal biomass. In the high nutrient load scenario, representing the highest recorded historical loads, climate change counteracted the effects of increased productivity leading to a hyperbolic response: biomass and carbon processing increased up to mid-21<sup>st</sup> century but then decreased, giving almost no net change by the end of the 21<sup>st</sup> century compared to present. The study shows that benthic responses to environmental change are nonlinear and partly decoupled from pelagic responses and indicates that benthic-pelagic coupling might be weaker in a warmer and less eutrophic sea.</p>

scholarly journals Modelling nitrogen and phosphorus loads in a Mediterranean river catchment (La Tordera, NE Spain)

2011 ◽  
Vol 8 (4) ◽  
pp. 7555-7594 ◽  
Author(s):  
F. Caille ◽  
J. L. Riera ◽  
A. Rosell-Melé
Keyword(s):  
Input Data ◽  
Point Sources ◽  
Good Representation ◽  
Nutrient Loads ◽  
Management Options ◽  
Nitrogen Emissions ◽  
Nutrient Flows ◽  
North East ◽  
Nutrient Emissions ◽  
Nutrient Emission

Abstract. Human activities have resulted in increased nutrient levels in many rivers all over Europe. Sustainable management of river basins demands an assessment of the causes and consequences of human alteration of nutrient flows, together with an evaluation of management options. In the context of an integrated and interdisciplinary environmental assessment (IEA) of nutrient flows, we present and discuss the application of the nutrient emission model MONERIS (MOdelling Nutrient Emissions into River Systems) to the Catalan river basin, La Tordera (North-East of Spain), for the period 1996-2002. After a successful calibration and verification process (Nash-Sutcliffe efficiencies E = 0.85 for phosphorus, and E = 0.86 for nitrogen), the application of the model MONERIS proved to be useful to estimate nutrient loads. Crucial for model calibration, in-stream retention (mainly affected by variability in precipitation) was estimated to be about 50 % of nutrient emissions on an annual basis. Through this process, we identified the importance of point sources for phosphorus emissions (about 94 % for 1996–2002), and diffuse sources, especially inputs via groundwater, for nitrogen emissions (about 31 % for 1996–2002). Despite potential hurdles related to model structure, observed loads, and input data encountered during the modelling process, MONERIS provided a good representation of the major interannual and spatial patterns in nutrient emissions. An analysis of the model uncertainty and sensitivity to input data indicates that the model MONERIS, even in data-starved Mediterranean catchments, may be profitably used for evaluating quantitative nutrient emission scenarios that may help catchment managers and planners to develop effective policy and management measures to reduce nutrient loads.

scholarly journals Modelling nitrogen and phosphorus loads in a Mediterranean river catchment (La Tordera, NE Spain)

2012 ◽  
Vol 16 (8) ◽  
pp. 2417-2435 ◽  
Author(s):  
F. Caille ◽  
J. L. Riera ◽  
A. Rosell-Melé
Keyword(s):  
Input Data ◽  
River Basins ◽  
Point Sources ◽  
Good Representation ◽  
Nutrient Loads ◽  
Management Options ◽  
Nutrient Flows ◽  
North East ◽  
Nutrient Emissions ◽  
Nutrient Emission

Abstract. Human activities have resulted in increased nutrient levels in many rivers all over Europe. Sustainable management of river basins demands an assessment of the causes and consequences of human alteration of nutrient flows, together with an evaluation of management options. In the context of an integrated and interdisciplinary environmental assessment (IEA) of nutrient flows, we present and discuss the application of the nutrient emission model MONERIS (MOdelling Nutrient Emissions into River Systems) to the Catalan river basin, La Tordera (north-east Spain), for the period 1996–2002. After a successful calibration and verification process (Nash-Sutcliffe efficiencies E=0.85 for phosphorus and E=0.86 for nitrogen), the application of the model MONERIS proved to be useful in estimating nutrient loads. Crucial for model calibration, in-stream retention was estimated to be about 50 % of nutrient emissions on an annual basis. Through this process, we identified the importance of point sources for phosphorus emissions (about 94% for 1996–2002), and diffuse sources, especially inputs via groundwater, for nitrogen emissions (about 31% for 1996–2002). Despite hurdles related to model structure, observed loads, and input data encountered during the modelling process, MONERIS provided a good representation of the major interannual and spatial patterns in nutrient emissions. An analysis of the model uncertainty and sensitivity to input data indicates that the model MONERIS, even in data-starved Mediterranean catchments, may be profitably used by water managers for evaluating quantitative nutrient emission scenarios for the purpose of managing river basins. As an example of scenario modelling, an analysis of the changes in nutrient emissions through two different future scenarios allowed the identification of a set of relevant measures to reduce nutrient loads.

scholarly journals Impacts of Climate Change and Population Growth on River Nutrient Loads in a Data Scarce Region: The Upper Awash River (Ethiopia)

2021 ◽  
Vol 13 (3) ◽  
pp. 1254
Author(s):  
Gianbattista Bussi ◽  
Paul G. Whitehead ◽  
Li Jin ◽  
Meron T. Taye ◽  
Ellen Dyer ◽  
...  
Keyword(s):  
Climate Change ◽  
Water Pollution ◽  
Water Quality ◽  
Population Growth ◽  
River Water ◽  
Addis Ababa ◽  
River Water Quality ◽  
Nutrient Concentrations ◽  
Nutrient Loads ◽  
The Impact

Assessing the impact of climate change and population growth on river water quality is a key issue for many developing countries, where multiple and often conflicting river water uses (water supply, irrigation, wastewater disposal) are placing increasing pressure on limited water resources. However, comprehensive water quality datasets are often lacking, thus impeding a full-scale data-based river water quality assessment. Here we propose a model-based approach, using both global datasets and local data to build an evaluation of the potential impact of climate changes and population growth, as well as to verify the efficiency of mitigation measures to curb river water pollution. The upper Awash River catchment in Ethiopia, which drains the city of Addis Ababa as well as many agricultural areas, is used as a case-study. The results show that while decreases in runoff and increases in temperature due to climate change are expected to result in slightly decreased nutrient concentrations, the largest threat to the water quality of the Awash River is population growth, which is expected to increase nutrient loads by 15 to 20% (nitrate) and 30 to 40% (phosphorus) in the river by the second half of the 21st century. Even larger increases are to be expected downstream of large urban areas, such as Addis Ababa. However, improved wastewater treatment options are shown to be efficient in counteracting the negative impact of population growth and returning water pollution to acceptable levels.

Silicon Substitution for Calcium in the Shell of the Fingernail Clam, Musculium Transversum Studied By X-Ray Analysis

1980 ◽  
Vol 38 ◽  
pp. 560-561
Author(s):  
Judith A. Murphy ◽  
Anthony Paparo ◽  
Richard Sparks
Keyword(s):  
Carbonic Anhydrase ◽  
River Water ◽  
Food Chains ◽  
Well Water ◽  
Shell Formation ◽  
X Ray ◽  
Molluscan Shell ◽  
Fingernail Clams

Fingernail clams (Muscu1ium transversum) are dominant bottom-dwelling animals in some waters of the midwest U.S. These organisms are key links in food chains leading from nutrients in water and mud to fish and ducks which are utilized by man. In the mid-1950’s, fingernail clams disappeared from a 100-mile section of the Illinois R., a tributary of the Mississippi R. Some factor(s) in the river and/or sediment currently prevent clams from recolonizing areas where they were formerly abundant. Recently, clams developed shell deformities and died without reproducing. The greatest mortality and highest incidence of shell deformities appeared in test chambers containing the highest proportion of river water to well water. The molluscan shell consists of CaCO3, and the tissue concerned in its secretion is the mantle. The source of the carbonate is probably from metabolic CO2 and the maintenance of ionized Ca concentration in the mantle is controlled by carbonic anhydrase. The Ca is stored in extracellular concentric spherical granules(0.6-5.5μm) which represent a large amount of inertCa in the mantle. The purpose of this investigation was to examine the role of raw river water and well water on shell formation in the fingernail clam.

Review of New models for mass communication research.

1975 ◽  
Vol 20 (5) ◽  
pp. 431-432
Author(s):  
ANTHONY G. GREENWALD
Keyword(s):  
Mass Communication ◽  
Communication Research ◽  
New Models

Educational Psychology Texts: Two New Models

1969 ◽  
Vol 14 (8) ◽  
pp. 421-423 ◽  
Author(s):  
W. ROBERT DIXON
Keyword(s):  
Educational Psychology ◽  
New Models

Anti-crisis measures or structural reforms: Russia’s economic policy in 2015

2016 ◽  
pp. 5-33 ◽  
Author(s):  
V. Mau
Keyword(s):  
Economic Growth ◽  
Economic Policy ◽  
Structural Transformation ◽  
Growth Model ◽  
Emerging Economies ◽  
Social Issues ◽  
Import Substitution ◽  
Structural Reforms ◽  
Energy Prices ◽  
New Models

The paper deals with 2015 trends and challenges for social and economic policy in the nearest future. The analysis of global crisis includes: uneven developments in the leading advanced and emerging economies; new models of economic growth which look differently in different countries; prospects of globalization and challenges of ‘regional globalization’; currency configurations of the future; energy prices dynamics and its influence on political and economic prospects of particular states. Current challenges are discussed in the context of previous 30 years. Among the main topics on Russia, there are approaches to a new growth model, structural transformation (including import substitution issues), economic dynamics, budget and monetary outlines, social issues. The priorities of economic policy are also considered.

Emerging patterns of artistic organizations in Portugal: A three case studies analysis

2020 ◽  
pp. 84-107
Author(s):  
Vera Borges ◽  
Luísa Veloso
Keyword(s):  
Labour Market ◽  
Economic Crisis ◽  
Performing Arts ◽  
Work Organization ◽  
The Arts ◽  
Emerging Patterns ◽  
New Models ◽  
Organizational Patterns ◽  
New Forms Of Work ◽  
Anal Yses

In the wake of the 2008 global financial and economic crisis, new forms of work organization emerged in Europe. Following this trend, Portugal has undergone a reconfiguration of its artistic organizations. In the performing arts, some organiza-tions seem to have crystalized and others are reinventing their artistic mission. They follow a plurality of organizational patterns and resilient profiles framed by cyclical, structural and occupational changes. Artistic organizations have had to adopt new models of work and seek new opportunities to try out alternatives in order to deal, namely, with the constraints of the labour market. The article anal-yses some of the restructuring processes taking place in three Portuguese artistic organizations, focusing on their contexts, individual trajectories and collective missions for adapting to contemporary challenges of work in the arts. We conclude that organizations are a key domain for understanding the changes taking place.

Sign in / Sign up

Export Citation Format

Share Document