14 research outputs found
Knuckey Lagoons management plan
No full textMade available by the Northern Territory Library via the Publications (Legal Deposit) Act 2004 (NT).1. INTRODUCTION TO THE PLAN -- 1.1 BACKGROUND -- 1.2 Values of the Reserve -- 1.3 Concept of the Reserve and its Purposes -- 1.4 Regional Context -- 1.5 Management of Knuckey Lagoons -- 1.5 Intent of the Plan -- 2. ZONING SCHEME -- 2.1 Outline of the Zoning Scheme -- 2.2 Special Purpose Zone -- 2.3 Dispersed Use Zone -- 3. MANAGEMENT OF THE RESERVE?S RESOURCES -- 3.1 Objectives -- 3.2 Geology, Landforms and Soils -- 3.3 Water Resources -- 3.4 Native Vegetation -- 3.5 Weed Control -- 3.6 Fauna -- 3.7 Feral animals, Animal Pests and Domestic Animal Control -- 3.8 Fire Management -- 3.9 Aboriginal Cultural Resources -- 3.10 Historical Resources -- 4. MANAGEMENT FOR VISITOR USE -- 4.1 Objectives -- 4.2 Access -- 4.3 Visitor Facilities and Developments -- 4.4 Communication, Interpretation and Information -- 4.5 Visitor Monitoring -- 4.6 Visitor Safety -- 5. RESERVE ADMINISTRATION AND RESEARCH -- 5.1 Objectives -- 5.2 Management Facilities and Staffing -- 5.3 Research and Monitoring -- 5.4 External Relations -- 5.5 Law Enforcement -- 6. MANAGEMENT PROGRAMS.Date:2000-09Bibliography: p. 31-33
Assessment of Climate Change Impacts on the Dynamics of Sandy Nearshore Inlet Systems: A case study: Katama Bay, and Santa Lucia Estuary
No full textSandy barriers comprise 12% of coastlines around the world, and most of these barriers enclose tidal bays and lagoons. These systems accommodate human settlements vulnerable to climate change, which offer enough economic, social, and environmental utility to require further research on the impact of climate change and subsequent best management practices.The present work aims to analyze how climate change impacts the hydrodynamics and morphodynamics of two barrier inlet systems: Katama Bay (United States of America), and the Santa Lucia Estuary (South Africa). The goal is to estimate future changes in forcing variables (e.g., sea level rise, wave climate, river discharge, tides), implement them in process-based models (coupled SWAN and Delft3D), and identify changes in the dynamics of both systems by comparing present and future state simulations.This thesis develops a replicable and flexible methodology that can be used as a systematic tool to assess the impacts of climate change on the overall dynamics of tidal inlet systems. A novel approach (copula analysis) was used to derive the wave climate implemented in Delft3D, which was then qualitatively validated for both sites. Model results were used to compare changes to inlet stability, inlet geometry, and sediment pathways for present and future hydrodynamic conditions.Results show that sea level rise is the primary contributor to the overall morphodynamics at both sites, whereas changes in wave direction strongly impact the rate of inlet migration. Other changes (e.g., significant wave height, wave period, and river discharge) play a secondary role in the dynamics of both systems. Comparisons with previous studies suggest that wave direction impacts each system differently. These impacts must be specifically addressed for each tidal inlet, as the results from one site should not be used to determine a general behavior for the assessment of CC impacts in tidal inlet systems.Coastal and Marine Engineering and Management (CoMEM
Prediction of the closure of an artificial lagoon at the Dutch Coast: A case study on the lagoon at the Hondsbossche Dunes
No full textTo protect the coastal system, nourishment of the coast is nowadays being applied more frequently. Within these coastal systems new elements are often implemented to add value to the design without compromising on the function of the design of the nourishment. One of these possible purposes is the creation of an artificial lagoon. However, to be effectively applied a deeper understanding of the behaviour of these lagoons is required. In 2015 the Hondsbosse Dunes (HD) were realized at the Dutch coast at the former “Hondsbosse en Pettermer Zeewering” near Camperduin, and an artificial lagoon was created for nature and recreation purposes within this design. The lagoon provides a boost for both the beach itself as well as the surrounding region. However, the lagoon’s inlet is not stable and continuous maintenance is needed. The objective of this study is to explore the behaviour and longevity of this artificial lagoon, considering the frequency and moments of closure of the lagoon’s inlet. This is achieved by assessing and studying offshore hydrodynamic conditions, satellite imagery, geographical measurements, dredging activity, and water level measurements inside the lagoon. Whether the lagoon is stable or not depends on the inlet stability. Key factors that affect the inlet stability are the tidal prism and the annual littoral drift. The lagoon at the HD can be characterized as an intermittently closed estuary, which is a water body that become isolated from the open coast for a period of time. This system can be divided in a perched or a non-perched system. A perched system has a high berm that closes of the system, where a non-perched system does not necessarily have a berm but has a lack of channel surface area. To get a better understanding on how local hydrodynamic conditions can cause the lagoon’s closure, the hydrodynamic conditions and available data were analysed. The significant wave height for storm events and the total water level at the shore, which includes the tide, the surge and the runup, are considered for the hydrodynamic conditions. Geographical measurements, satellite imagery and dredging moments are used to achieve a better insight of the system. The lagoon surface area is examined above 2.03 m NAP, to establish the behaviour of the lagoon basin and its inlet in time. The result of the data analysis performed in this thesis suggest that the lagoon surface area does not move spatially in time. However, due to the lack of bathymetric measurements the lagoon could not be studied in further detail. Closure of the system occurs due to its highly dynamic channel, which is supported by an analysis of the cross-sections of the channel area in combinations with satellite imagery. A detailed view on the water level inside the lagoon and the exchange between the open coast resulted in four stages that were indicated visually: 1.Closed stage, resulting in a closed channel. The water level can only increase when the water level at the open coast overflows the berm. It leads to a stepwise increasement of the water level, referred to as a perched system. .Open stage. The channel is open and water exchange is possible with the open coast. The effect of the tide can be observed clearly in the water level of the lagoon. 3.Dredging stage. The water level decreases rapidly from a level above high tide at the open coast, to a value near or below high tide level. Afterwards water exchange with the open coast may occur, but this is not always the case. 4.Episodic event. The water level fluctuates, for which the cause cannot be stated beforehand. It depends among others on the type of system, hydrodynamic conditions and on the shape of the channel. The system is called non-perched when a high-water level overwashes the berm in the channel. It seems that the system is open, but water exchange does not occur and the water level in the lagoon increases Analysis of these stages indicates that the system is closed almost 70% of the time. The system is most often closed between October and April, when the channel is dredged again leading to an open system. An open system occurs after dredging in spring, where the results shows that the water level inside the lagoon follows the tide. The data indicate that the system is open for 10-17% of the time. Storm events highly influence closure of the channel. Although storm events on the North Sea are indicated by a significant wave height larger than 400 cm, the results demonstrate that storm events with a significant wave height of 300 cm provoke closure of the channel. This is the result of the small catchment of the lagoon. These storm events increase in winter periods, whereas summer storms appear two to three times a year. The impression that storm events lead to closure of the channel is therefore confirmed. The results show that the lagoon remains the same over a timespan of three years, which suggests that the frequency of closure and opening is not time dependent. This leads to different dredging strategies that are possible for the near future. To create an open lagoon all year round, dredging frequency needs to increase, as it is implied that storm events lead to closure. This increases the dredging costs. If the preference lies in low dredging costs, the system will be closed during certain periods of the year. Since the lagoon is created for recreation purposes closure during the winter season and dredging during the recreation season is proposed as a strategy. These findings correspond to the currently considered strategy for the HD. The data suggest that artificial lagoons, like the investigated case at the Hondsbosse Dunes, never stay open or open without human intervention. This indicates that active management is needed to keep these lagoons open.Civil Engineering | Hydraulic Engineerin
Trends and challenges for sustainable marine resource management for rural Solomon Islanders
No full textMuch has been claimed about the positive benefits of the customary marine tenure (CMT) system in the South Pacific and its implications for resource management. In Solomon Islands the premise of effective community-based resource management (CBRM) as a contemporary management tool, rests to a great degree on CMT, but does CMT still provide a sufficiently strong foundation to support this premise?
This research examines the social and environmental characteristics of two rural Solomon Islands coastal communities that have a long history in customary marine tenure; one with a strong chiefly system and the other one with a weaker chiefly system. The research gains insight into and an understanding of the experiences and lives of the villagers, given current debates on the need to address and move forward with the concept of CBRM with regards to the sustainability issues that they are currently confronting.
Using primarily qualitative methodologies the study focused on how marine resources are perceived and valued by different members of the community. The findings suggest that in communities where a common agreement on CMT no longer exists there is a significant challenge to stakeholders in attaining the goal of sustainably managed coastal marine resources through community based approaches. This challenge needs to be accounted for on a case by case basis as part of CBRM facilitation processes.
While this research may true for much of Solomon Islands, the case studies have revealed that although the villages are made up of families who are closely related they are not unified as a whole. Study findings suggest that the people retain a lingering vision of a small, integrated community but have failed to grasp how their differences as a community have affected their resource management outcomes.
The present day communities are affected by many outside factors that did not exist when traditional management systems were evolving. These factors bring management challenges for which traditional arrangements were not designed to cope and thus many have severely destabilising effects on the performance of traditional systems
Micrometeorological studies of a beef feedlot, dairy, and grassland: measurements of ammonia, methane, and energy balance closure
No full text2018 Spring.Includes bibliographical references.Ammonia emissions from concentrated animal feeding operations (CAFOs; most of which are beef feedlots) near the Colorado Front Range are suspected to be a large regional input of reactive nitrogen which has been found to accumulate and cause deleterious effects in nearby downwind Class I areas like Rocky Mountain National Park. Methane (CH4) is a strong greenhouse gas (GHG) emitted in large amounts from dairy anaerobic lagoons used for liquid manure management. Lagoon systems account for over half of the manure management-based CH4 emissions from agriculture in the US. There is a strong need for more emissions measurements from CAFOs like feedlots and dairies. For these data to be trusted, well-developed techniques must be utilized at emissions measurement sites and such techniques should be validated in ideal scenarios. Three micrometeorological studies were performed involving measurement of emissions using micrometeorological methods in the surface layer. The first study involved estimating summertime NH3 emissions from a 25,000-head beef feedlot in Northern Colorado. Two different NH3 sensors were used: a cavity ring down spectroscopy analyzer collected data at a single point while a long-path FTIR collected data along a 226-m long transect, both deployed along the same fenceline. Concentration data from these systems were used with two inverse dispersion models (FIDES, an inverse solution to the advection dispersion equation; and WindTrax, a backward Lagrangian stochastic model). Point sensor concentrations of NH3 were similar to line-integrated sensor concentrations suggesting some spatial uniformity in emissions. Emissions had a diurnal pattern (i.e., afternoon peak with minimum in early morning) that was driven by temperature. Emissions predicted by WindTrax were 25.2% higher than those from FIDES. Point vs. long-path measurements of NH3 had minimal effect on predicted emissions. The mean NH3 emission factor (EF) was 80 ± 39 g NH3 hd−1 d−1, with 40.0% of dietary-N emitted as NH3. The second study involved using eddy covariance and WindTrax to quantify CH4 emissions from a 3.9-ha anaerobic lagoon serving a 1400-head dairy in northern Colorado. Methane emissions followed a strong seasonal pattern correlated with temperature of the organic sludge layer on the bottom of the lagoon. Fluxes started increasing in late spring (May; ~10°C), increased rapidly in Jun (10-15°C) peaked in the summer (Jul/Aug; ~18-20°C) and remained high until mid-autumn (late Oct/early Nov; ~10°C). Fluxes then decreased and remained consistently low (up to 10 times less than peak emissions) until microbial activity ramped up again in May. The EC signal was very dependent on wind direction, with highest concentrations and fluxes associated with the direction of the lagoon. Gap-filled data showed a slight diurnal pattern to all seasons, with tenfold increases in diurnal values for summer over winter. Additionally, EFs for the lagoon varied by season with lows in the winter and highs in the summer with an annual mean of 819 ± 774 g CH4 hd-1 d-1. WindTrax overestimated EC for the lagoon (1163 ± 1049 g CH4 hd-1 d-1 versus 819 ± 774 g CH4 hd-1 d-1), but this difference may be attributable to differences in the sampling footprint and stability conditions. IPCC Tier 2-calculated EFs were extremely close to EC-based measurements and WT-based estimates. The third study involved using eddy covariance in an ideal environment (tallgrass prairie in Kansas) to test the reasons behind the "energy balance (EB) closure problem" at two landscape positions. This problem can cast uncertainty on flux measurements made by EC. One upland and one lowland EC tower each were used to measure EB components (i.e., net radiation, Rn; soil heat flux, G; total change in heat storage, deltaS; and sensible and latent heat fluxes, H and λE) during the summers of 2007 and 2008. To maximize closure, special attention was given to reduce all forms of instrumentation error and account for heat storage and photosynthesis between the soil and the reference height. Landscape position had little effect on G, H, and Rn; differences were ≤ 2% between sites. Lowland λE was 8% higher than upland λE because of greater biomass and soil moisture. On average, EB closure (i.e., Σ[λE+H] / Σ[Rn–G–ΔS]) was 0.88 and 0.94 at the upland and lowland sites, respectively. Closure was not correlated with friction velocity or the stability of the surface boundary layer. Given high confidence in Rn, G, and ΔS, turbulent fluxes depend directly on vertical velocity (w), and the fact that a systematic underestimation of w was recently found in literature, lack of closure may have resulted largely from anemometer-based underestimates of w
Impact of Antibiotic Use on Resistance in Beef Feedlot and Dairy Cattle
No full textIn recent years, consumer demand for natural and organic foods has increased, partly due to concerns about the use of antimicrobials in food producing animals. The aim of this study was to evaluate antimicrobial resistance (AMR) in beef feedlot and dairy cattle raised without use of antibiotics compared to cattle raised in conventional (CONV) production. Three research projects were conducted to accomplish that general goal. In the first study, a conventional feedlot, natural feedlot, conventional dairy and organic dairy were visited to collect cattle feces, wastewater from lagoons and soil where the wastewater was applied. After DNA extraction, sequencing, and processing, metagenomic reads were aligned to reference databases for identification of antibiotic resistance genes (ARGs; i.e. the resistome) and bacteria (microbiome). Resistome composition was influenced by rearing method, cattle type, and type of sample. Most mechanisms of resistance affected by rearing method were enriched (P < 0.05) in conventional samples. Resistome differences were greatest for wastewater samples by rearing method but with contradictory results that suggested an impact of effluent management on wastewater resistome. Resistance to tetracycline and macrolide-lincosamide-streptogramin classes were more abundant in feces of feedlot cattle than in dairy cattle (P < 0.05); whereas resistance to beta-lactams was greatest in feces of dairy cattle ( P < 0.05). Resistome and microbiome of feces differed ( P < 0.05) between wastewater and soil samples. Results indicated that ARGs are widespread in beef feedlot and dairy cattle farms even in those with restricted antibiotic use. In the second study, feces from RWA (n=36) and CONV (n=36) cattle lots were recovered from colons at a commercial beef processing plant. Samples were equally distributed by month and production protocol over one year (3 samples/production protocol/month). After extracting DNA from individual samples, composite samples were prepared by mixing DNA from each lot into a single composite sample (N = 72) and sequencing the composites on an Illumina platform. Metagenomic reads were processed similarly to those in experiment 1for identification of ARGs and bacteria. Resistomes of CONV and RWA cattle were significantly different by season. In general, mechanisms conferring resistance to beta-lactams, tetracyclines, multi-drug and macrolides were more prevalent (P < 0.05) in feces from CONV colons than in RWA colons. In the third study, a systematic review and meta-analysis was performed to assess the relationship between antimicrobial use (AMU) and antimicrobial resistance (AMR) in feedlot cattle. After conducting a literature search and screening reported studies, 32 studies were selected for use that addressed AMR in Escherichia coli, Enterococcus, Salmonella, Campylobacter, and Mannheimia haemolytica. Overall, 60% (95% CI: 26% to 88%) of the observational studies and 50% (95% CI: 30% to 70%) of the controlled trials reported a positive association between AMU and AMR. Meta-analysis provided evidence for an increase in average relative risk (RR) associated with antibiotic use. Isolates recovered from treated cattle were 2.5 times (95% confidence interval: 1.7 – 3.5) as likely to display antibiotic resistance compared to isolates recovered from unexposed animals. Risk of resistance increases with animal defined daily doses (DDDs). More comprehensive studies that consider the relationship between antibiotic use in cattle and antibiotic resistant bacteria in humans are needed as a part of a farm to fork approach to tackle antimicrobial resistance
Evaluation of cow peat as a plant growth media
No full text2018 Summer.Includes bibliographical references.Almost 63% of non-CO2 greenhouse gases, mostly methane and nitrous oxide, are produced by the agricultural industry. As Livestock waste lagoons are designed to prevent the nutrient transport and treat manure, they are major contributors to the release of these non-CO2 greenhouse gases. They have to be controlled and one such way is to harness these gases by implementing anaerobic digestion. Anaerobic digestion of livestock waste has shown very good potential but, handling of digested solid end products require extensive management. One potential option is to recover fiber from the solid digestate to make a cow peat plant growth material. Peatlands are one of the most important natural ecosystems in the world which have key values for biodiversity conservation, climate regulation and support welfare, water regulation in drylands, acts as an enormous carbon sink and also an agricultural land. But overexploitation of peatlands has led to adverse effects on the environment. Peat mosses have well defined lignified cell structure as a soil material which makes them perfect media for plant growth. All these degradations and its effects have made peat extraction unsustainable and so search for alternatives have begun over the last decade. The fiber components of digested dairy manure (Cow Peat) have been evaluated by researchers as a suitable substitute for peat moss along with many other products such as biochar, rice husk, wheat straw, sewage waste, potato waste etc. Results have shown that the cow peat has similar physicochemical properties to peat moss and so, they have been widely used in the horticulture and floriculture industries as a replacement for peat moss. In this study, we assessed the potential to recover cow peat from a novel multi-stage anaerobic digester that processes high solids content manure. Edible crops were grown in the digestate and cow peat for the first time, as they have been already proven in the other industry such as the growth of perennial plants, strawberries, bedding plants etc. The study has been carried out in two trails without nutrient amendment. The first experiment was conducted with bean plants and 6 soil mixes with digested manure. The performance was compared with commercially available soil mixes including peat moss. The best performing soil mixes were utilized in a second experiment assessing two more plant types, beet, and lettuce. The results of both the experiments have revealed that digested manure (well composted digested manure solids) and fiber (component separated from manure solids by fractionation) component has produced plants with significantly similar (p > 0.05) shoot dry mass and root structure as commercially available plant media. The digested dairy fiber contains a significant amount of nutrients for the plant to germinate. Carbon/Nitrogen ratio was higher than recommended range and so may have had an adverse effect on pH and reducing the availability of micronutrients. Results demonstrate the potential for anaerobically digested fiber to replace peat moss as plant growth media providing growers with a local, renewable substitute for peat and a supplemental income for animal farm operators
Coral reef fish and the aquarium trade: ecological impacts and socio-cultural influences in southern Sri Lanka
No full textThe chronic degradation of coral reefs globally and its negative impact on coastal communities such as those in southern Sri Lanka dependent on the marine ornamental trade for their livelihood forms the focus of this study. Attempts to improve the conservation status of Sri Lanka's coral reefs and their associated fauna have failed because they omit to address the social circumstances of local people. Such social-ecological systems require an integrated approach, which provides holistic reasons for the degradation of natural ecosystems and livelihoods of coastal people. The aim of this study was therefore to ascertain the current sustainability of the marine ornamental trade in southern Sri Lanka through an interdisciplinary study employing a participatory bottom-up approach, and derive from findings alternative pathways to restore and maintain the health of the reef and thus provide better livelihoods for the fishing communities.
Findings confirm both the fragile state of nearshore coral reefs, their fish populations and the precarious nature of local communities’ livelihoods. Historical and recent environmental and anthropogenic impacts reduced resilience in all trade sectors and current fishing practices and the unjust supply chain compound these effects. Therefore, a holistic co-management framework is recommended that recognises local ecological knowledge and involves fishing communities as citizen scientists to improve monitoring and also provides communication channels to facilitate interaction within and across all groups of the ornamental trade. In this way, all actors are involved in making decisions and taking responsibility for the management of the supply chain at their particular level. This single, coherent framework would thus employ diverse groups and ways of doing as a resilience strategy to halt the degradation and reinvigorate the reef for more sustainable utilisation whilst simultaneously developing highly acceptable alternative income generating livelihoods, such as the community-based aquaculture experiment undertaken during this study
The biology and conservation of the Damara Tern in Namibia
No full textThe globally Near-threatened Damara Tern Sterna balaenarum is little known and faces several conservation issues. The aim of this study was to provide a description of the ecology and numbers of the species and discuss conservation management plans that will effectively ensure its survival
Physical and geochemical characterisation of canal sediments in the Black Country, West Midlands.
No full textA thesis submitted in fulfilment of the requirements of the University of
Wolverhampton for the award of the degree of Doctor of Philosophy (Ph.D.)Potentially harmful elements (PHEs) have been researched in a wide variety of disciplines, including pedology, chemistry, pollution science and medicine. Within the scientific community, emphasis has usually been placed on the toxic elements, such as cadmium, chromium, lead and arsenic, but rarely has there been consideration of interactions between PHEs, the sediment matrix and processes occurring in the sediments. Dredging of canals is needed for navigability purposes and consequently testing of dredged sediments (to assess whether sediments are hazardous) and landfilling can be costly for British Waterways facing constantly changing regulations and reduction in government grants. PHE mobility and availability in canal sediments can be affected by oxygen availability, pH and Redox. Remediation is thus becoming a priority for British Waterways to limit their operational costs. Zeolites, a type of remediation tool, have been widely studied in the past 30 years due to their attractive properties, such as molecular-sieving, high cation exchange capacities and their affinity for PHEs. The pilot study to investigate the efficiency of the clinoptilolite showed that there was a concentration difference between PHEs adsorbed by the clinoptilolite and the PHE concentration lost from the sediments from three sites in the West Midlands. Thorough characterisation of the sediments was needed to understand the speciation of the PHEs and the secondary processes occurring in the sediments. The different components of the sediments were analysed using various analytical methods, such as X-Ray Fluorescence spectroscopy (XRF), particle size and X-ray Diffraction (XRD) for the solid-inorganic phase, Ion Chromatography (IC) and Inductively Coupled Plasma-Optical Emissions Spectroscopy (ICP-OES) for the liquid phase (pore water), Gas Chromatography-Mass Spectrometry (GC-MS) and organic loss on ignition for the organic phase, pH and Redox for the electrochemistry of the sediments and Scanning Electron Microscope with Energy Dispersive X-Ray analysis (SEM-EDX) for microscopy and imaging. The British Geological Survey (BGS) sequential extraction method was used to investigate the different phases in the sediments. pH remained near neutral for all three sites and Redox remained anoxic. Organic contents for all three sites were around 30% and contained most of the polycyclic aromatic hydrocarbons considered hazardous. Pore water showed only high concentrations of sulphates but low concentrations of PHEs, suggesting PHEs were not mobile. Sequential extraction confirmed the other results showing that PHEs were mainly associated with stable phases, such as iron and manganese oxides or sulphides. The results have been taken into consideration to design a new remediation strategy to maximise efficiency of the zeolite
