scholarly journals Experimental tests of water chemistry response to ornithological eutrophication: biological implications in Arctic freshwaters

2019 ◽  
Vol 16 (23) ◽  
pp. 4719-4730
Author(s):  
Heather L. Mariash ◽  
Milla Rautio ◽  
Mark Mallory ◽  
Paul A. Smith
Keyword(s):  
Water Chemistry ◽  
Nutrient Loading ◽  
Experimental Tests ◽  
Freshwater Ecosystems ◽  
Nitrogen And Phosphorus ◽  
Cascading Effects ◽  
Chen Caerulescens ◽  
Dissolved Nitrogen ◽  
Terrestrial Habitats ◽  
Chen Rossii

Abstract. Many populations of Arctic-breeding geese have increased in abundance in recent decades, and in the Canadian Arctic, snow geese (Chen caerulescens) and Ross's geese (Chen rossii) are formally considered overabundant by wildlife managers. The impacts of these overabundant geese on terrestrial habitats are well documented, and, more recently, studies have suggested impacts on freshwater ecosystems as well. The direct contribution of nutrients from goose faeces to water chemistry could have cascading effects on biological functioning, through changes in phytoplankton biovolumes and community composition. We demonstrated previously that goose faeces can enrich ponds with nutrients at a landscape scale. Here, we show experimentally that goose droppings rapidly released nitrogen and phosphorus when submerged in freshwater, increasing the dissolved nitrogen and phosphorus in the water. This resulted in both a decrease in the nitrogen:phosphorus ratio and an increase in cyanobacteria in the goose dropping treatment. In contrast, this pattern was not found when we submerged cut sedge (Carex sp.) leaves. These results demonstrate that geese act as bio-vectors, causing terrestrial nutrients to be bioavailable in freshwater systems. Collectively, the results demonstrate the direct ecological consequences of ornithological nutrient loading from hyper-abundant geese in Arctic freshwater ecosystems.

scholarly journals Experimental tests of phytoplankton response to ornithological eutrophication in Arctic freshwaters

2019 ◽  
Author(s):  
Heather L. Mariash ◽  
Milla Rauito ◽  
Mark Mallory ◽  
Paul A. Smith
Keyword(s):  
Nutrient Loading ◽  
Experimental Tests ◽  
Freshwater Ecosystems ◽  
Nitrogen And Phosphorus ◽  
Phytoplankton Productivity ◽  
Cascading Effects ◽  
Chen Caerulescens ◽  
Dissolved Nitrogen ◽  
Terrestrial Habitats ◽  
Chen Rossii

Abstract. Many populations of Arctic-breeding geese have increased in abundance in recent decades, and in the Canadian Arctic, Snow (Chen caerulescens) and Ross’ Geese (Chen rossii) are formally considered overabundant by wildlife managers. The impacts of these overabundant geese on terrestrial habitats are well documented, and more recently, studies have suggested impacts to freshwater ecosystems as well. The direct contribution of nutrients from goose faeces to water chemistry could have cascading effects on biological functioning, through changes in phytoplankton productivity and community composition. We demonstrated previously that goose faeces can enrich ponds with nutrients at a landscape scale. Here, we show experimentally that goose droppings rapidly released nitrogen and phosphorus when submerged in freshwater, increasing the dissolved nitrogen and phosphorus in the water. This resulted in both a decrease in the nitrogen:phosphorus ratio and an increase in cyanobacteria in the goose dropping treatment. In contrast, this pattern was not found when we submerged cut sedge (Carex sp.) leaves. These results demonstrate that geese act as biovectors, causing terrestrial nutrients to be bioavailable in freshwater systems. Collectively, the results demonstrate the direct ecological consequences of ornithological nutrient loading from hyperabundant geese in Arctic freshwater ecosystems.

scholarly journals Calcium interacts with temperature to influence Daphnia movement rates

2016 ◽  
Vol 3 (12) ◽  
pp. 160537 ◽  
Author(s):  
Gustavo S. Betini ◽  
Jordan Roszell ◽  
Andreas Heyland ◽  
John M. Fryxell
Keyword(s):  
Water Chemistry ◽  
Calcium Concentration ◽  
Synergistic Effects ◽  
Thermal Conditions ◽  
Aquatic Organisms ◽  
Freshwater Ecosystems ◽  
Environmental Stressors ◽  
Ecosystem Dynamics ◽  
Movement Rates ◽  
Projected Changes

Predicting the ecological responses to climate change is particularly challenging, because organisms might be affected simultaneously by the synergistic effects of multiple environmental stressors. Global warming is often accompanied by declining calcium concentration in many freshwater ecosystems. Although there is growing evidence that these changes in water chemistry and thermal conditions can influence ecosystem dynamics, little information is currently available about how these synergistic environmental stressors could influence the behaviour of aquatic organisms. Here, we tested whether the combined effects of calcium and temperature affect movement parameters (average speed, mean turning frequency and mean-squared displacement) of the planktonic Daphnia magna , using a full factorial design and exposing Daphnia individuals to a range of realistic levels of temperature and calcium concentration. We found that movement increased with both temperature and calcium concentration, but temperature effects became considerably weaker when individuals were exposed to calcium levels close to survival limits documented for several Daphnia species, signalling a strong interaction effect. These results support the notion that changes in water chemistry might have as strong an effect as projected changes in temperature on movement rates of Daphnia , suggesting that even sublethal levels of calcium decline could have a considerable impact on the dynamics of freshwater ecosystems.

scholarly journals Photosynthetic response to nitrogen source and different ratios of nitrogen and phosphorus in toxic cyanobacteria, Microcystis aeruginosa FACHB-905

2016 ◽  
Author(s):  
Guotao Peng ◽  
Zhengqiu Fan ◽  
Xiangrong Wang ◽  
Chen Chen
Keyword(s):  
Chlorophyll Fluorescence ◽  
Algal Blooms ◽  
Freshwater Ecosystems ◽  
Cyanobacterial Blooms ◽  
Photosynthetic Response ◽  
Nitrogen And Phosphorus ◽  
Ammonium Toxicity ◽  
Chlorophyll Fluorescence Parameters ◽  
Fluorescence Parameters ◽  
N Assimilation

<p>The frequent outbreak of cyanobacterial blooms has become a worldwide phenomenon in freshwater ecosystems. Studies have elucidated the close relationship between harmful algal blooms and nutrient contents, including the loading of nitrogen and the ratios of nitrogen (N) and phosphorus (P). In this study, the effect of inorganic (nitrate and ammonium) and organic (urea) nitrogen at varied N/P ratios on the <em>Microcystis</em> <em>aeruginosa</em> FACHB-905 accumulation and photosynthesis was investigated.  The optimal NO<sub>3</sub>/P in this study were 30~50 indicated by the cell abundance (4.1×10<sup>6</sup>/mL), pigment concentration (chlorophyll a 3.1 mg/L,  phycocyanin 8.3mg/L), and chlorophyll fluorescence parameters (<em>rETR</em>, <em>E<sub>k</sub>, α, φPSII</em> and <em>F<sub>v</sub>/F<sub>m</sub> </em>values), while too high NO<sub>3</sub>-N (N/P=100:1) would cause an intracellular nitrate inhibition, leading to a decrease of photosynthetic activity. In addition, low concentration of NH<sub>4</sub>-N (N/P=4:1) would favor the <em>M. aeruginosa </em>growth and photosynthesis, and high NH<sub>4</sub>/P ratio (&gt;16) would rise the ammonium toxicity of algal cells and affect the N assimilation. In urea treatments, <em>M. aeruginosa </em>responded similarly to the NH<sub>4</sub>-N treatments both in growth curves and pigment contents, and the favorable N/P ratio was between 16~30, suggested by the chlorophyll fluorescence parameters. The results demonstrated that the various chemical forms of N and N/P ratios have a significant impact on <em>Microcystis</em> abundance and photosynthesis. More work is needed to figure out the mechanism of nitrogen utilization by <em>Microcystis</em> and  the photosynthetic response to nutrient stress at the molecular level.</p>

scholarly journals Qanuq ukua kanguit sunialiqpitigu? (What should we do with all of these geese?) Collaborative research to support wildlife co-management and Inuit self-determination

2020 ◽  
Vol 6 (3) ◽  
pp. 173-207 ◽  
Author(s):  
Dominique A. Henri ◽  
Natalie A. Carter ◽  
Aupaa Irkok ◽  
Shelton Nipisar ◽  
Lenny Emiktaut ◽  
...  
Keyword(s):  
Collaborative Research ◽  
Canadian Arctic ◽  
Self Determination ◽  
Habitat Alteration ◽  
Management Options ◽  
Chen Caerulescens ◽  
Chen Rossii ◽  
Inuit Knowledge ◽  
Management Recommendations ◽  
Participatory Research Methods

Inuit living in Nunavut have harvested light geese and lived near goose colonies for generations. Inuit knowledge includes important information about light goose ecology and management that can inform co-management and enhance scientific research and monitoring. Since the 1970s, populations of light geese (Snow and Ross’ Geese; kanguit and kangunnait in Inuktut; Chen caerulescens (Linnaeus, 1758) and Chen rossii (Cassin, 1861)) have experienced significant increases in abundance which led to habitat alteration in some portions of the central and eastern Canadian Arctic. In response to concerns expressed by Inuit and wildlife managers about light goose abundance, we conducted a collaborative research project in Arviat and Salliq (Coral Harbour), Nunavut, aiming to mobilize and document Inuit knowledge about light goose ecology and management in the Kivalliq region. Here, we explore the potential of collaborative research for mobilizing Inuit knowledge to support informed and inclusive decision-making about wildlife resources. First, we describe the participatory research methods employed to explore Inuit-identified management recommendations for light geese and engage co-management partners and research contributors to explore select management options. Then, we present these light goose management recommendations and options. Lastly, we discuss opportunities and challenges around the use of collaborative research to support wildlife co-management and Inuit self-determination. Inuit nunaqaqtut Nunavuumi angunasuksimalirmata kanguqpangnik kangurniglu nunaqarvingita sanianni araagunik unuqtunnik. Inuit qaujimaningat ilaqaqpuq aturnilingnik kanguit niqinginnik mianirijauninginniklu tusaumatitaulutik qaujisarningit mianiriyaunigillu. Taimangat 1970s atuqtilugit, kanguit unirningit (kanguit amma kanguaryuit Inuktut; Chen caerulescens (Linnaeus, 1758) amma Chen rossii (Cassin, 1861)) ayunganaqtukut pisimangmata unulialiqlutik amma niqiqatiarungnauqlutik Kanataup uqiuktaqtunngani. Tamana piblugu Inuit uumayuliriyillu isumaalulirmata kanguit unulualirninginnik, taima qaujisarnirmik pigialauqpugut Arvianni and Sallim (Coral Harbour), Nunavuumi, aulataulutik amma qaujisagaulutik Inuit kaujimajagit kangurnik Kivallirmi. Tavani atuqtuuluaqtunik qaujisarnirmut mianiqsinirmullu pitaqaqpuq Inuit nagminiq isumaliurlutik nirjutinut atugaksanullu. Sivullirmik, qaujisarniup qanuinninga isumagilugu kanguit mianirijauninginut. Amma suli, uqausirilirlugu kanguit mianirijauningat atugaujuuluaqtullu. Kingulirmik, uqausirilugu atuinnaujut amma ajurutaujut qaujisarniup iluanni nirjutinik amma Inuit nagminiq aulatuulualirninginnik.

scholarly journals Critical loads of sulphur and nitrogen for freshwaters in Great Britain and assessment of deposition reduction requirements with the First-order Acidity Balance (FAB) model

2000 ◽  
Vol 4 (1) ◽  
pp. 125-140 ◽  
Author(s):  
C. Curtis ◽  
T. Allott ◽  
J. Hall ◽  
R. Harriman ◽  
R. Helliwell ◽  
...  
Keyword(s):  
Great Britain ◽  
Water Chemistry ◽  
Critical Load ◽  
Acid Deposition ◽  
Critical Loads ◽  
Freshwater Ecosystems ◽  
Acid Neutralizing Capacity ◽  
First Order ◽  
Fab Model ◽  
S Deposition

Abstract. The critical loads approach is widely used within Europe to assess the impacts of acid deposition on terrestrial and freshwater ecosystems. Recent work in Great Britain has focused on the national application of the First-order Acidity Balance (FAB) model to a freshwaters dataset of 1470 lake and stream water chemistry samples from sites across Britain which were selected to represent the most sensitive water bodies in their corresponding 10 km grid square. A ``Critical Load Function" generated for each site is compared with the deposition load of S and N at the time of water chemistry sampling. The model predicts that when catchment processes reach steady-state with these deposition levels, increases in nitrate leaching will depress acid neutralizing capacity (ANC) below the critical threshold of 0 μeql-1 at more than a quarter of the sites sampled, i.e. the critical load of acid deposition is exceeded at these sites. The critical load exceedances are generally found in upland regions of high deposition where acidification has been previously recognised, but critical loads in large areas of western Scotland are also exceeded where little biological evidence of acidification has yet been found. There is a regional variation in the deposition reduction requirements for protection of the sampled sites. The FAB model indicates that in Scotland, most of the sampled sites could be protected by sufficiently large reductions in S deposition alone. In the English and Welsh uplands, both S and N deposition must be reduced to protect the sites. Current international commitments to reduce S deposition throughout Europe will therefore be insufficient to protect the most sensitive freshwaters in England and Wales. Keywords: critical loads; acidification; nitrate; FAB model; acid deposition

Global implementation of two shared socioeconomic pathways for future sanitation and wastewater flows

2014 ◽  
Vol 71 (2) ◽  
pp. 227-233 ◽  
Author(s):  
P. J. T. M. van Puijenbroek ◽  
A. F. Bouwman ◽  
A. H. W. Beusen ◽  
P. L. Lucas
Keyword(s):  
Wastewater Treatment ◽  
Surface Water ◽  
Population Growth ◽  
Nutrient Loading ◽  
Wastewater Treatment Plants ◽  
Developed Countries ◽  
Emission Model ◽  
Nitrogen And Phosphorus ◽  
Nutrient Emissions ◽  
Sewage Systems

Households are an important source of nutrient loading to surface water. Sewage systems without or with only primary wastewater treatment are major polluters of surface water. Future emission levels will depend on population growth, urbanisation, increases in income and investments in sanitation, sewage systems and wastewater treatment plants. This study presents the results for two possible shared socioeconomic pathways (SSPs). SSP1 is a scenario that includes improvement of wastewater treatment and SSP3 does not include such improvement, with fewer investments and a higher population growth. The main drivers for the nutrient emission model are population growth, income growth and urbanisation. Under the SSP1 scenario, 5.7 billion people will be connected to a sewage system and for SSP3 this is 5 billion. Nitrogen and phosphorus emissions increase by about 70% under both SSP scenarios, with the largest increase in SSP1. South Asia and Africa have the largest emission increases, in the developed countries decrease the nutrient emissions. The higher emission level poses a risk to ecosystem services.

scholarly journals Distributions and stoichiometry of dissolved nitrogen and phosphorus in the iron-fertilized region near Kerguelen (Southern Ocean)

2015 ◽  
Vol 12 (2) ◽  
pp. 623-635 ◽  
Author(s):  
S. Blain ◽  
J. Capparos ◽  
A. Guéneuguès ◽  
I. Obernosterer ◽  
L. Oriol
Keyword(s):  
Southern Ocean ◽  
Organic Nitrogen ◽  
Organic Phosphorus ◽  
Polar Front ◽  
Nitrogen And Phosphorus ◽  
Phosphorus Species ◽  
Dissolved Phosphorus ◽  
Dissolved Nitrogen ◽  
Total Dissolved Nitrogen ◽  
Preferential Uptake

Abstract. During KEOPS2 (Kerguelen Ocean and Plateau Compared Study 2), we determined dissolved inorganic and organic nitrogen and phosphorus species in the naturally fertilized region of Kerguelen Island (Southern Ocean). Above 150 m, stations were clearly separated by the polar front (PF), with concentrations of NO3-, NO2- and PO43- overall lower north of the PF than south. Though less pronounced, a similar trend was detectable for dissolved organic nitrogen (DON) and dissolved organic phosphorus (DOP). At all stations offshore and above the plateau, a subsurface maximum of NH4+ was observed between 50 and 150 m. We examined nutrient stoichiometry by calculating the linear combination N* = [NO3-]-16 [PO43-]. The majority of stations and depths revealed N* close to −3 μM; however, for surface waters north of the PF, N* increased up to 6 μM. This suggests a preferential uptake of PO43- versus NO3- by fast-growing diatoms. Using the tracer TNxs = [TDN]-16[TDP] (TDN, total dissolved nitrogen; TDP, total dissolved phosphorus) revealed that the dissolved organic fraction significantly contributed to changes in TNxs. TNxs values were negative for most stations and depths, and relatively constant in the 0–500 m layer. As for N*, the stations north of the PF had higher TNxs in the 0–100 m layer. We discuss this stoichiometric anomaly with respect to possible external sources and sinks of N and P. Additional data collected in February 2013 at two sites revealed the occurrence of a subsurface minimum of N* located just below the pycnocline, which denotes a layer where remineralization of particulate organic matter with low N : P ratio P, possibly associated with preferential remineralization of P versus N, persists throughout the season.

scholarly journals Efficiency of aquatic macrophytes to treat Nile tilapia pond effluents

2006 ◽  
Vol 63 (5) ◽  
pp. 433-438 ◽  
Author(s):  
Gustavo Gonzaga Henry-Silva ◽  
Antonio Fernando Monteiro Camargo
Keyword(s):  
Total Nitrogen ◽  
Total Phosphorus ◽  
Nile Tilapia ◽  
Aquatic Macrophytes ◽  
Fish Farming ◽  
Pistia Stratiotes ◽  
Fish Pond ◽  
Nitrogen And Phosphorus ◽  
Dissolved Phosphorus ◽  
Dissolved Nitrogen

The effluents from fish farming can increase the quantity of suspended solids and promote the enrichment of nitrogen and phosphorus in aquatic ecosystems. In this context, the aim of this work was to evaluate the efficiency of three species of floating aquatic macrophytes (Eichhornia crassipes, Pistia stratiotes and Salvinia molesta) to treat effluents from Nile tilapia culture ponds. The effluent originated from a 1,000-m² pond stocked with 2,000 male Nile tilapia Oreochromis niloticus. The treatment systems consisted of 12 experimental tanks, three tanks for each macrophyte species, and three control tanks (without plants). Water samples were collected from the: (i) fish pond source water, (ii) effluent from fish pond and (iii) effluents from the treatment tanks. The following water variables were evaluated: turbidity, total and dissolved nitrogen, ammoniacal-N, nitrate-N, nitrite-N, total phosphorus and dissolved phosphorus. E. crassipes and P. stratiotes were more efficient in total phosphorus removal (82.0% and 83.3%, respectively) and total nitrogen removal (46.1% and 43.9%, respectively) than the S. molesta (72.1% total phosphorus and 42.7% total nitrogen) and the control (50.3% total phosphorus and 22.8% total nitrogen), indicating that the treated effluents may be reused in the aquaculture activity.

An ecosystem-based approach to support water quality assessment and management under climate and land-use condition

2020 ◽  
Author(s):  
Andrea Critto ◽  
Hung Vuong Pham ◽  
Anna Sperotto ◽  
Silvia Torresan ◽  
Elisa Furlan ◽  
...  
Keyword(s):  
Land Use ◽  
Ecosystem Services ◽  
Best Management Practices ◽  
Water Demand ◽  
Management Practices ◽  
Freshwater Ecosystems ◽  
Water Yield ◽  
Management Scenarios ◽  
Nitrogen And Phosphorus ◽  
Change Models

&lt;p&gt;Freshwater ecosystems can be negatively affected by climate change and human interventions through the alteration of water supply and demand. There is an urgent need to protect the ecosystems, and the services they provide, to maintain their essential contribution to human wellbeing and economic prosperity, especially in a rapid and unpredictable global change context. In this work, we developed an integrated approach, coupling the outputs of ecosystem services (InVEST), climate (COSMO-CLM) and land use (LUISA) change models utilizing Bayesian Networks (BNs), to map freshwater-related Ecosystem Services (ESs), namely, water yield, nitrogen and phosphorus retention, and to assess their changes until 2050 under different management scenarios. First, InVEST was calibrated and validated with climate and land-use data to map and quantify ESs. Second, outputs of the ES model were integrated into the BN and the changes induced by different learning techniques and input settings were investigated. Finally, thousands of different scenarios were simulated testing multiple input variables configurations, thus allowing to describe the uncertainty of climate conditions, land-use change and water demand. Two types of inferences were conducted, namely, diagnostic and prognostic inference. The former permitted to find the best combination of the key drivers (i.e. &amp;#160;precipitation, land-use, and water demand) so that ESs are maximized while the latter concentrated on the quantification of ESs under different scenarios. This approach was applied and validated in the Taro River basin in Italy. The results show that the values of all the three types of ESs would decline in the medium-term period under most scenarios. Moreover, there would be a limit of space to improve those values, especially for nutrient retention services. The obtained results provide valuable support to identify and prioritize the best management practices for sustainable water use, balancing the tradeoffs among services. This analysis allows decision-makers to pick up one scenario with a specific configuration of land-use and water demand to optimize relevant ESs within their basin. Finally, these decisions are transformed into a &amp;#8220;decision space&amp;#8221; where the values of selected services are plotted in the space of ES to represent the gain/loss of each decision.&lt;/p&gt;

The Effects of Estuary Dredging on Removing Nitrogen and Phosphorus in Dianchi Lake, China

2012 ◽  
Vol 518-523 ◽  
pp. 2895-2899 ◽  
Author(s):  
Ju Hong Zhan ◽  
Sha Deng ◽  
Zhao Xin Li ◽  
Yu Luo ◽  
Ting Ting Zhao ◽  
...  
Keyword(s):  
Total Nitrogen ◽  
Total Phosphorus ◽  
Nutrient Loading ◽  
Nutrient Content ◽  
Dianchi Lake ◽  
Nitrogen And Phosphorus ◽  
Eutrophic Lakes ◽  
Available Nitrogen ◽  
Sediment Dredging ◽  
Internal Nutrient Loading

Sediment dredging is currently the most commonly selected option for getting rid of contaminated sediments. In this study, the effects of estuary dredging on removing nitrogen and phosphorus were investigated by comparing the different vertical nutrient content between the dredged and un-dredged areas in Dianchi Lake. The results showed that the contents of total nitrogen and total phosphorus in the un-dredged areas were relatively higher than that in dredged areas. Besides, the contents of bio-available nitrogen and phosphorus represented the similar results, only a few dredged spots showed a higher potential releasing capacity. Therefore, with the reduction of internal nutrient loading, it indicated that sediment dredging might be an effective and reliable way to improve such eutrophic lakes.

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