Effects of landscape-scale hypoxia on Salish sucker and salmonid habitat associations: implications for endangered species recovery and management

2021 ◽  
Author(s):  
Jordan S Rosenfeld ◽  
Michael P. Pearson ◽  
Jill Miners ◽  
Kaitlyn R Zinn
Keyword(s):  
Elevated Temperatures ◽  
Negative Relationship ◽  
Late Summer ◽  
Habitat Associations ◽  
Climate Projections ◽  
Nutrient Loads ◽  
Management Options ◽  
Strong Selection ◽  
Juvenile Salmonids ◽  
Low Do

To understand the effects of widespread urbanization and agricultural impacts on recovery of Salish sucker, a federally threatened Catostomid endemic to the lower Fraser Valley of British Columbia, we assessed i) the current extent and effects of hypoxia on the distribution of Salish sucker and juvenile salmonids, ii) potential drivers of hypoxia, and iii) management options for hypoxia mitigation. Over 40% of sucker critical habitat experiences hypoxia (dissolved oxygen (DO) < 4 mg·l-I) by late summer, indicating widespread non-compliance with water quality guidelines. The strong positive relationship between seasonal hypoxia and temperature (R2= 0.53) and negative relationship with streamflow (R2= 0.78) indicates that hypoxia is driven by a synergy between low summer flows, elevated temperatures, and high primary production associated with nutrient enrichment (eutrophication). Sucker show strong selection against high water temperatures and weaker negative selection against low DO; juvenile salmonids show very strong selection against both high temperatures and low DO. Climate projections for declining summer flows and elevated temperatures indicate worsening trends in DO without intensive watershed-scale management to reduce nutrient loads.

scholarly journals N Management of European Grasslands: Can the Exchange of Gaseous N Species Be Influenced at the Operational Level?

2001 ◽  
Vol 1 ◽  
pp. 652-657 ◽  
Author(s):  
P. Calanca ◽  
A. Neftel ◽  
J. Fuhrer
Keyword(s):  
Late Summer ◽  
Fertilizer Application ◽  
Effective Control ◽  
Management Options ◽  
Total N ◽  
Model Calculations ◽  
Weather Forecasts ◽  
Grassland Ecosystems ◽  
Order Of Magnitude ◽  
N Management

Grassland ecosystems can be regarded as biochemical reactors in which large amounts of organic nitrogen (N) are converted into inorganic N, and vice versa. If managed in a sustainable manner, grasslands should operate in a quasi steady state, characterized by an almost perfect balance between total N input and output. As a consequence, the exchange of gaseous N species (NH3, NO, NO2, N2O, and N2) between grasslands and the atmosphere is very small compared to the total N turnover. In this study, the effects of two management options (mowing and fertilization) on production and emission of nitrous oxide (N2O) from a grass/clover crop were examined on the basis of observations and model results referring to an experiment carried out on the Swiss Plateau in late summer of 2000. It was found that production and emission of N2O induced by mowing were of the same order of magnitude as those brought about by fertilization, suggesting a possible transfer of N from clover to the soil after defoliation. Emissions were strongly modulated by precipitation on time scales ranging from 1 day to 1 week. This indicates that effective control of N2O emissions through management on a day-to-day basis requires reliable medium-range weather forecasts. Model calculations were not able to reproduce essential characteristics of the emissions. The model slightly overestimated the background emissions, but severely underestimated the emission peaks following fertilizer application, and largely failed to reproduce emission induced by mowing. Shortfalls in the model used for this study were found in relation to the description of soil-water fluxes, soil organic matter, and the physiology of clover.

Sustainable grazing systems for the Central Tablelands of New South Wales. 1. Agronomic implications of vegetation - environment associations within a naturalised temperate perennial grassland

2006 ◽  
Vol 46 (4) ◽  
pp. 439 ◽  
Author(s):  
W. McG. King ◽  
P. M. Dowling ◽  
D. L. Michalk ◽  
D. R. Kemp ◽  
G. D. Millar ◽  
...  
Keyword(s):  
Perennial Grass ◽  
Acid Soils ◽  
Late Summer ◽  
Trifolium Subterraneum ◽  
Moisture Stress ◽  
Recent Change ◽  
Perennial Grasses ◽  
Management Options ◽  
Eastern Australia ◽  
Winter Annual

Temperate perennial grass-based pastures dominate the high rainfall zone of south-eastern Australia and support a major livestock production industry. This area has experienced a recent change in overall pasture condition, however, typified by a reduction in the abundance of perennial grasses and an increasingly prominent winter-annual grass weed component. Improving the condition and productivity of these pastures can be achieved by improved management but this requires better knowledge of the interactions between management options and pasture species composition and of the interaction between pasture vegetation and the complex effects of a heterogeneous landscape. This paper reports the results of an intensive survey of a 60-ha paddock that was designed to identify the species present, determine their patterns of distribution and examine the relationships between pasture vegetation and the environment. The survey of species present in late summer was supplemented by the identification of seedlings that later emerged from extracted soil cores and by soil physical and chemical analyses. Data were analysed using ordination and interpreted with GIS software so that topographic features could be considered. The most frequently identified taxa were Hypochaeris radicata, Austrodanthonia spp. and Bothriochloa spp. (in late summer) and Vulpia spp., Bromus molliformis and Trifolium subterraneum (winter-annual species). Austrodanthonia spp. were commonly found on the drier ridges and more acid soils with lower phosphate levels. These were also the areas dominated in spring by Vulpia spp. and were generally lower in plant species richness overall. The most species-rich areas occurred downslope where soil fertility was higher and less moisture stress was presumably experienced. The measured environmental factors explained a substantial proportion of the variation in the vegetation dataset, which underlined the importance of considering landscape effects in the management of typical tablelands pastures.

Effects of Water Temperature Under Projected Climate Change on the Development and Survival of Enallagma civile (Odonata: Coenagrionidae)

2019 ◽  
Vol 49 (1) ◽  
pp. 230-237
Author(s):  
S M Starr ◽  
N E McIntyre
Keyword(s):  
Body Size ◽  
Water Temperature ◽  
Great Plains ◽  
Elevated Temperatures ◽  
Model Organism ◽  
Common Species ◽  
Wildlife Habitat ◽  
Climate Projections ◽  
Continental Scale ◽  
Enallagma Civile

Abstract Current climate projections for the Great Plains of North America indicate markedly increased air temperatures by the end of the current century. Because the Great Plains contains &gt;80,000 intermittent wetlands that serve as irreplaceable wildlife habitat, this projected warming may have profound effects throughout a continental-scale trophic network. However, little research has been done to determine how projected warming may affect the growth, development, or survival of even common species in this region. We conducted laboratory warming experiments, using an abundant amphibious predatory insect, Enallagma civile (Hagen, 1861), as a model organism, to determine whether projected warming may affect development or survival. Eggs were collected and reared under four water temperature regimes representing current (26°C) and projected future conditions (32, 38, and 41°C). Nymph body size after each molt, development rate, and deaths were recorded. Elevated water temperatures were found to significantly affect the survivorship of E. civile eggs and nymphs as well as adult body size at emergence: an increase in temperature incurred a decrease in survival and size. Nymphs in the two hotter treatments were smaller and had low survivorship whereas individuals in the cooler temperatures generally survived to adulthood and were larger. Nymphs reared at 32°C experienced accelerated ontogenetic development compared with the other temperatures, going from egg to adult in 26 d. Projected elevated temperatures may, thus, be both advantageous and detrimental, causing concern for aquatic invertebrates in this region in the future.

scholarly journals The Impacts of Covid-19 Pandemic and Weather Conditions on Water Environment, a Case Study in Istanbul and London/South-east England

2021 ◽  
Author(s):  
FERHAT YILMAZ ◽  
Dan Osborn ◽  
Michel Tsamados
Keyword(s):  
Public Health ◽  
Climate Change ◽  
Water Use ◽  
Water Consumption ◽  
Water Levels ◽  
Additional Stress ◽  
Climate Projections ◽  
Management Options ◽  
Dpsir Framework ◽  
South East England

The Covid-19 Pandemic affects not only populations around the world but also the environment and natural resources. Lockdowns and restricted new lifestyles have had wide ranging impacts on the environment (e.g., on air quality in cities). Although hygiene and disinfection procedures and precautions are effective ways to protect people from Covid-19, they have important consequences for water usage and resources especially given the increasing impacts of climate change on rainfall patterns, water use and resources. Climate change and public health issues may compound one another and so we used a DPSIR Framework to scope the main factors that may interact to affect water use and resources (in the form of reservoirs) using evidence from Istanbul, Turkey with some discussion of the comparative situation in the UK and elsewhere. We modified initial views on the framework to account for the regional, city and community level experiences. We noted water consumption in Istanbul has been increasing over the last two decades (except, it appears, in times of very low rainfall/drought); that there were increases in water consumption in the early stages of the Covid-19 pandemic; and, despite some increase in rainfall, water levels in reservoirs appeared to decrease during lockdowns (for a range of reasons). We also noted, through a new simple way of visualising the data, that a low resource capacity might be recurring every 6 or 7 years in Istanbul. We made no attempt in this paper to quantify the relative contribution that climate change, population growth etc are making to water consumption and reservoir levels as we were focused here on scoping those social, environmental and economic factors that appear to play a role in potential water stress and on developing a DPSIR Framework that could aid both subsequent quantitative studies and the development of policy and adaptive management options for Istanbul and other large complex conurbations (such as London and south-east England). If there are periodic water resource issues and temperatures rise as expected in climate projections with an accompanying increase in the duration of hot spells the subsequent additional stress on water systems might make managing future public health emergencies, such as a pandemic, even more difficult.

scholarly journals Testing a river basin model with sensitivity analysis and autocalibration for an agricultural catchment in SW Finland

2009 ◽  
Vol 18 (3-4) ◽  
pp. 428-439 ◽  
Author(s):  
S. TATTARI ◽  
J. KOSKIAHO ◽  
I. BÄRLUND
Keyword(s):  
Sensitivity Analysis ◽  
River Basin ◽  
Swat Model ◽  
Protective Measure ◽  
Background Information ◽  
Cultivated Plants ◽  
Nutrient Loads ◽  
Management Options ◽  
Modeling Tools ◽  
Management Actions

Modeling tools are needed to assess (i) the amounts of loading from agricultural sources to water bodies as well as (ii) the alternative management options in varying climatic conditions. These days, the implementation of Water Framework Directive (WFD) has put totally new requirements also for modeling approaches. The physically based models are commonly not operational and thus the usability of these models is restricted for a few selected catchments. But the rewarding feature of these process-based models is an option to study the effect of protection measures on a catchment scale and, up to a certain point, a possibility to upscale the results. In this study, the parameterization of the SWAT model was developed in terms of discharge dynamics and nutrient loads, and a sensitivity analysis regarding discharge and sediment concentration was made. The SWAT modeling exercise was carried out for a 2nd order catchment (Yläneenjoki, 233 km2) of the Eurajoki river basin in southwestern Finland. The Yläneenjoki catchment has been intensively monitored during the last 14 years. Hence, there was enough background information available for both parameter setup and calibration. In addition to load estimates, SWAT also offers possibility to assess the effects of various agricultural management actions like fertilization, tillage practices, choice of cultivated plants, buffer strips, sedimentation ponds and constructed wetlands (CWs) on loading. Moreover, information on local agricultural practices and the implemented and planned protective measures were readily available thanks to aware farmers and active authorities. Here, we studied how CWs can reduce the nutrient load at the outlet of the Yläneenjoki river basin. The results suggested that sensitivity analysis and autocalibration tools incorporated in the model are useful by pointing out the most influential parameters, and that flow dynamics and annual loading values can be modeled with reasonable accuracy with SWAT. Sensitivity analysis thus showed the parameters which should be known better in order to result in more realistic parameter values. Moreover, the scenario runs for CWs made with SWAT revealed the high demand of land area for this protective measure to be substantially effective.;

scholarly journals Seasonal and Inter-Annual Variability of the Phytoplankton Dynamics in the Black Sea Inner Basin

Oceans ◽  
2020 ◽  
Vol 1 (4) ◽  
pp. 251-273
Author(s):  
Svetla Miladinova ◽  
Adolf Stips ◽  
Diego Macias Moy ◽  
Elisa Garcia-Gorriz
Keyword(s):  
Black Sea ◽  
Phytoplankton Bloom ◽  
Mesoscale Eddy ◽  
Late Summer ◽  
The Black Sea ◽  
Circulation System ◽  
Nutrient Loads ◽  
Geochemical Model ◽  
Annual Variability ◽  
Intermediate Layers

We explore the patterns of Black Sea phytoplankton growth as driven by the thermohaline structure and circulation system and the freshwater nutrient loads. Seasonal and inter-annual variability of the phytoplankton blooms is examined using hydrodynamic simulations that resolve mesoscale eddies and online coupled bio-geochemical model. This study suggests that the bloom seasonality is homogeneous across geographic locations of the Black Sea inner basin, with the strongest bloom occurring in winter (February–March), followed by weaker bloom in spring (April–May), summer deep biomass maximum (DBM) (June–September) and a final bloom in autumn (October–November). The winter phytoplankton bloom relies on vertical mixing of nitrate from the intermediate layers, where nitrate is abundant. The winter bloom is highly dependent on the strength of the cold intermediate layers (CIL), while spring/summer blooms take advantage of the CIL weakness. The maximum phytoplankton transport across the North Western Shelf (NWS) break occurs in September, prior to the basin interior autumn bloom. Bloom initiation in early autumn is associated with the spreading of NWS waters, which in turn is caused by an increase in mesoscale eddy activity in late summer months. In summary, the intrusion of low salinity and nitrate-rich water into the basin interior triggers erosion of the thermocline, resulting in vertical nitrate uplifting. The seasonal phytoplankton succession is strongly influenced by the recent CIL disintegration and amplification of the Black Sea circulation, which may alter the natural Black Sea nitrate dynamics, with subsequent effects on phytoplankton and in turn on all marine life.

Simulation-based indices for a climate-resilient agriculture - insights from ADAPTER

2021 ◽  
Author(s):  
Sebastian Bathiany ◽  
Diana Rechid ◽  
Susanne Pfeifer ◽  
Juliane El Zohbi ◽  
Klaus Goergen ◽  
...  
Keyword(s):  
Climate Change ◽  
Elevated Temperatures ◽  
Climate Model ◽  
Regional Climate ◽  
Weather Conditions ◽  
Climate Projections ◽  
Public Attention ◽  
Compound Events ◽  
Climate Model Simulations ◽  
The Individual

&lt;p&gt;Agriculture is among the sectors that are most vulnerable to extreme weather conditions and climate change. In Germany, the subsequent dry and hot summers 2018, 2019, and 2020 have brought this into the focus of public attention. Agricultural actors like farmers, advisors or companies are concerned with such interannual variability and extremes. Yet, it often remains unclear what long-term adaptation options are most suitable in the context of climate change, mainly because climate projections have uncertainties and are usually not tailored to meet requirements, measures and scales of the individual practicioners.&amp;#160;In the ADAPTER project, we explore regional and local change&amp;#160;on the weather- and climate-related time scales and together with stakeholders (administration, plant breeders, educators, agricultural advisors), we co-design&amp;#160;tailored climate change indices and usable products.&lt;/p&gt;&lt;p&gt;In this contribution, we provide a snapshot view of our stakeholders' requirements regarding information about climate change over the next decades. We then focus on the analysis of three groups of indices based on 85 regional climate model simulations from Coordinated Downscaling Experiments over Europe - EURO-CORDEX: (i) changes in daily temperature variability, (ii) occurrence of agricultural droughts in summer, (iii) compound events of combined dryness and elevated temperatures during the same events. We show that these user-oriented, newly constructed indices can capture relevant changes during important phenological development states of typical crops. Finally, we discuss first implications of our findings for different adaptation strategies in Mid-Europe, such as alternating crop rotations, irrigation strategies or plant breeding. The analysis products presented are interactively and publicly available through a product platform (www.adapter-projekt.de) for agricultural stakeholders.&lt;/p&gt;

scholarly journals Expected declines in recruitment of walleye pollock (Theragra chalcogramma) in the eastern Bering Sea under future climate change

2011 ◽  
Vol 68 (6) ◽  
pp. 1284-1296 ◽  
Author(s):  
Franz J. Mueter ◽  
Nicholas A. Bond ◽  
James N. Ianelli ◽  
Anne B. Hollowed
Keyword(s):  
Climate Change ◽  
Bering Sea ◽  
Late Summer ◽  
Walleye Pollock ◽  
Future Climate ◽  
Future Climate Change ◽  
Theragra Chalcogramma ◽  
Climate Projections ◽  
Eastern Bering Sea ◽  
Walleye Pollock Theragra Chalcogramma

Abstract Mueter, F. J., Bond, N. A., Ianelli, J. N., and Hollowed, A. B. 2011. Expected declines in recruitment of walleye pollock (Theragra chalcogramma) in the eastern Bering Sea under future climate change. – ICES Journal of Marine Science, 68: 1284–1296. A statistical model is developed to link recruitment of eastern Bering Sea walleye pollock (Theragra chalcogramma) to variability in late summer sea surface temperatures and to the biomass of major predators. The model is based on recent advances in the understanding of pollock recruitment, which suggest that warm spring conditions enhance the survival of early larvae, but high temperatures in late summer and autumn are associated with poor feeding conditions for young-of-year pollock and reduced recruitment in the following year. A statistical downscaling approach is used to generate an ensemble of late summer temperature forecasts through 2050, based on a range of IPCC climate projections. These forecasts are used to simulate future recruitment within an age-structured stock projection model that accounts for density-dependent effects (stock–recruitment relationship), the estimated effects of temperature and predation, and associated uncertainties. On average, recruitment in 2040–2050 should expectedly decline by 32–58% relative to a random recruitment scenario, depending on assumptions about the temperature relationship, the magnitude of density-dependence, and future changes in predator biomass. The approach illustrated here can be used to evaluate the performance of different management strategies and provide long-term strategic advice to managers confronted with a rapidly changing climate.

Combined consideration for decentralised non-potable water supply from local groundwater and nutrient load reduction in urban drainage

2011 ◽  
Vol 63 (6) ◽  
pp. 1289-1297 ◽  
Author(s):  
O. Barron ◽  
A. Barr ◽  
M. Donn ◽  
D. Pollock
Keyword(s):  
Water Balance ◽  
Water Supply ◽  
Environmental Impacts ◽  
Potable Water ◽  
Groundwater Resources ◽  
Shallow Groundwater ◽  
Integrated Analysis ◽  
Nutrient Loads ◽  
Management Options ◽  
Potable Water Supply

Integrated analysis of land use change and its effect on catchment water balance allows the selection of appropriate water and land management options for new urban developments to minimise the environmental impacts of urbanisation. A process-based coupled surface water-groundwater model was developed for Southern River catchment (Perth, Western Australia) to investigate the effect of urban development on catchment water balance. It was shown that urbanisation of highly permeable flat catchments with shallow groundwater resulted in significant increase in net groundwater recharge. The increased recharge creates the opportunity to use local groundwater resources for non-potable water supply with the added advantage of reducing the total discharge from new urban developments. This minimises the environmental impacts of increased urbanisation, as higher discharge is often associated with greater nutrient loads to receiving environments. Through the used of water balance modelling it was demonstrated that there are both water and nutrient benefits from local groundwater use in terms of reduced nutrient exports to receiving waters and additional water resources for non-potable water supply.

scholarly journals Threshold values and management options for nutrients in a catchment of a temperate estuary with poor ecological status

2012 ◽  
Vol 16 (8) ◽  
pp. 2663-2683 ◽  
Author(s):  
K. Hinsby ◽  
S. Markager ◽  
B. Kronvang ◽  
J. Windolf ◽  
T. O. Sonnenborg ◽  
...  
Keyword(s):  
Algal Blooms ◽  
Climate Models ◽  
Regional Climate ◽  
Ecological Status ◽  
Water Clarity ◽  
Nutrient Loads ◽  
Threshold Values ◽  
Management Options ◽  
Total N ◽  
Good Ecological Status

Abstract. Intensive farming has severe impacts on the chemical status of groundwater and streams and consequently on the ecological status of dependent ecosystems. Eutrophication is a widespread problem in lakes and marine waters. Common problems are hypoxia, algal blooms, fish kills, and loss of water clarity, underwater vegetation, biodiversity and recreational value. In this paper we evaluate the nitrogen (N) and phosphorus (P) concentrations of groundwater and surface water in a coastal catchment, the loadings and sources of N and P, and their effect on the ecological status of an estuary. We calculate the necessary reductions in N and P loadings to the estuary for obtaining a good ecological status, which we define based on the number of days with N and P limitation, and the corresponding stream and groundwater threshold values assuming two different management options. The calculations are performed by the combined use of empirical models and a physically based 3-D integrated hydrological model of the whole catchment. The assessment of the ecological status indicates that the N and P loads to the investigated estuary should be reduced to levels corresponding to 52 and 56% of the current loads, respectively, to restore good ecological status. Model estimates show that threshold total N (TN) concentrations should be in the range of 2.9 to 3.1 mg l−1 in inlet freshwater (streams) to Horsens estuary and 6.0 to 9.3 mg l−1 in shallow aerobic groundwater (∼ 27–41 mg l−1 of nitrate), depending on the management measures implemented in the catchment. The situation for total P (TP) is more complex, but data indicate that groundwater threshold values are not needed. The stream threshold value for TP to Horsens estuary for the selected management options is 0.084 mg l−1. Regional climate models project increasing winter precipitation and runoff in the investigated region resulting in increasing runoff and nutrient loads to the Horsens estuary and many other coastal waters if present land use and farming practices continue. Hence, lower threshold values are required in many coastal catchments in the future to ensure good status of water bodies and ecosystems.

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