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mosquitoes. What is the impact of such ecological change and what will it look like in the future? 9.6.2 Mosquito or aquatic plant control? The options for control of aquatic plants such as Hydrilla are mechanical, biological, chemical, or a combination of these methods. The objective of aquatic weed control should be to control growth sufficiently to permit the water to be used in the desired way but without a change in the balance of species (Bill 1977). Aquatic plants are only weeds if they pose a major nuisance or hazard. Clearly there is a case as mentioned previously for clearing buffer zones to mitigate against swimmer’s itch or to facilitate boating and safe swimming. Aquatic plant growth generally relies upon nutrient availability, light availability, adequate physicochemical characteristics and habitat stability. Nutrient availability relies upon substrate type and the presence of dissolved organic and inorganic matter. Light intensity decreases with depth to the point where the energy acquired by photosynthesis cannot meet the energy requirement of vegetation and plant growth ceases. The interrelationships of key factors such as depth, wave exposure, littoral slope and sediment characteristics are complex (Duarte and Kalff 1990), although slopes of greater than 15° are regarded as the first limit to plant growth and the second is depth. The Ross River reservior is shallow with an average depth of less than 3 m, which explains why Hydrilla beds sometimes cover up to 37 per cent of the surface area of the lake. Bill (1977) discussed a protocol for deciding the best and most effective control measures to be used and outlined a checklist of questions. • To what extent is plant growth responsible for the particular problem, e.g. reduction of channel capacity, interference with recreational use? • Are chemical methods of control more suitable than mechanical or biological methods, or could more than one method be used? • What is the most economical long-term approach? • What degree of control is required to provide adequate relief from the particular problem? • If chemical methods are most appropriate, which material is likely to be most effective and how should it be used? Are residues of chemicals in the water following a treatment likely to be detrimental to human health or to fish, wildlife or irrigated crops? • Is it desirable to retain some plants for the benefits of fish and waterbirds? Biological control is not the universal solution to all pest problems, but it may be applied to a vast array of problems and when effective it is the most satisfactory and economical form
DOI link for mosquitoes. What is the impact of such ecological change and what will it look like in the future? 9.6.2 Mosquito or aquatic plant control? The options for control of aquatic plants such as Hydrilla are mechanical, biological, chemical, or a combination of these methods. The objective of aquatic weed control should be to control growth sufficiently to permit the water to be used in the desired way but without a change in the balance of species (Bill 1977). Aquatic plants are only weeds if they pose a major nuisance or hazard. Clearly there is a case as mentioned previously for clearing buffer zones to mitigate against swimmer’s itch or to facilitate boating and safe swimming. Aquatic plant growth generally relies upon nutrient availability, light availability, adequate physicochemical characteristics and habitat stability. Nutrient availability relies upon substrate type and the presence of dissolved organic and inorganic matter. Light intensity decreases with depth to the point where the energy acquired by photosynthesis cannot meet the energy requirement of vegetation and plant growth ceases. The interrelationships of key factors such as depth, wave exposure, littoral slope and sediment characteristics are complex (Duarte and Kalff 1990), although slopes of greater than 15° are regarded as the first limit to plant growth and the second is depth. The Ross River reservior is shallow with an average depth of less than 3 m, which explains why Hydrilla beds sometimes cover up to 37 per cent of the surface area of the lake. Bill (1977) discussed a protocol for deciding the best and most effective control measures to be used and outlined a checklist of questions. • To what extent is plant growth responsible for the particular problem, e.g. reduction of channel capacity, interference with recreational use? • Are chemical methods of control more suitable than mechanical or biological methods, or could more than one method be used? • What is the most economical long-term approach? • What degree of control is required to provide adequate relief from the particular problem? • If chemical methods are most appropriate, which material is likely to be most effective and how should it be used? Are residues of chemicals in the water following a treatment likely to be detrimental to human health or to fish, wildlife or irrigated crops? • Is it desirable to retain some plants for the benefits of fish and waterbirds? Biological control is not the universal solution to all pest problems, but it may be applied to a vast array of problems and when effective it is the most satisfactory and economical form
mosquitoes. What is the impact of such ecological change and what will it look like in the future? 9.6.2 Mosquito or aquatic plant control? The options for control of aquatic plants such as Hydrilla are mechanical, biological, chemical, or a combination of these methods. The objective of aquatic weed control should be to control growth sufficiently to permit the water to be used in the desired way but without a change in the balance of species (Bill 1977). Aquatic plants are only weeds if they pose a major nuisance or hazard. Clearly there is a case as mentioned previously for clearing buffer zones to mitigate against swimmer’s itch or to facilitate boating and safe swimming. Aquatic plant growth generally relies upon nutrient availability, light availability, adequate physicochemical characteristics and habitat stability. Nutrient availability relies upon substrate type and the presence of dissolved organic and inorganic matter. Light intensity decreases with depth to the point where the energy acquired by photosynthesis cannot meet the energy requirement of vegetation and plant growth ceases. The interrelationships of key factors such as depth, wave exposure, littoral slope and sediment characteristics are complex (Duarte and Kalff 1990), although slopes of greater than 15° are regarded as the first limit to plant growth and the second is depth. The Ross River reservior is shallow with an average depth of less than 3 m, which explains why Hydrilla beds sometimes cover up to 37 per cent of the surface area of the lake. Bill (1977) discussed a protocol for deciding the best and most effective control measures to be used and outlined a checklist of questions. • To what extent is plant growth responsible for the particular problem, e.g. reduction of channel capacity, interference with recreational use? • Are chemical methods of control more suitable than mechanical or biological methods, or could more than one method be used? • What is the most economical long-term approach? • What degree of control is required to provide adequate relief from the particular problem? • If chemical methods are most appropriate, which material is likely to be most effective and how should it be used? Are residues of chemicals in the water following a treatment likely to be detrimental to human health or to fish, wildlife or irrigated crops? • Is it desirable to retain some plants for the benefits of fish and waterbirds? Biological control is not the universal solution to all pest problems, but it may be applied to a vast array of problems and when effective it is the most satisfactory and economical form
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