Preface. Selected Atomic Weights. Customary Metric Conversion Factors. 1. Water Quality and Aquaculture: Preliminary Considerations. 2. Ecology of Aquaculture Ponds. 3. Water Quality Requirements. 4. Water Use. 5. Liming. 6. Fertilization. 7. Aeration. 8. Water Circulation. 9. Turbidity and Appearance of Water. 10. Aquatic Weed Control. 11. Off-Flavors and Harmful Algae. 12. Pollution. 13. Chemical, Physical, and Biological Treatments. 14. Waste Management. 15. Measurement of Water Quality. 16. Sustainability and Environmental Issues. References. Index.

Pond aquaculture water quality management

A mechanism to account for macrophyte decline in progressively eutrophicated freshwaters

Publisher Summary This chapter discusses the factors controlling the zonation of freshwater plants The groups of plants classified as macrophytes that comprise aquatic vegetation are presented along with their overall depth distribution Specific examples of the zonation of vegetation in a range of lakes, to emphasize the distinction between environmental factors varying solely in the vertical plane and those that have both vertical and horizontal components are presented in the chapter This distinction underlies the causal analysis of zonation The chapter describes vertical sequences of growth form or individual dominants in relation to gradients in water table The aquatic vegetation ranges along this gradient from woodland to submerged plant communities The chapter discusses the habitat variables, vertical zonation, vertical and horizontal components of zonation, sediments and plant responses, plant adaptations, photomorphogenetic responses underwater, growth forms, plant strategies and interspecific competition, competition with microalgae, and the control of macrophyte zonation by substrate or by light

zonation of plants in freshwater lakes

Nine common species of aquatic macrophytes took all their phosphorus from the sediments when grown in situ in both a mesotrophic and a mildly eutrophic bay. Even under hypertrophic conditions, the sediments contributed an average of 72 percent of all the phosphorus taken up during growth. These experiments unambiguously demonstrate for the first time that submergent macrophytes in nature over-whelmingly depend on the sediments for their phosphorus supply and characterize them as potential nutrient pumps to the open water.

https://science.sciencemag.org/content/sci/207/4434/987.full.pdf

Phosphorus sources for aquatic weeds: water or sediments?

Stomatal density and stomatal index as indicators of paleoatmospheric CO(2) concentration.

A B S T R A C T Rooted stems of three aquatic species were cultured in a two-compartment apparatus which allowed the upper and lower portions of the stem to be kept in different nutrient solutions. p32 was supplied to either the upper or lower compartment. At the end of a 10-day growth period, the specific activity of phosphate was determined in axillary shoots which developed during the course of the experiment from buds in the upper compartment. The results indicated that most of the phosphate in these shoots was not absorbed from the ambient medium but was derived from the rooted stem base in the lower compartment (over 90 % in Myriophyllum brasiliense, 59 % in M. spicatum, and 74 % in Elodea densa). These results give a very different but probably more accurate picture of phosphate absorption in rooted aquatic vascular plants than short-term experiments, in which phosphate is readily taken up from the ambient medium by leaves of M. spicatum and E. densa. In M. brasiliense the amount of phosphate translocated is related to the mass of roots present. Evidence is presented that normal growth of axillary shoots occurs even when all mineral ions have to be obtained by translocation from the lower compartment.

https://www.jstor.org/stable/pdfplus/2441300.pdf

The role of roots in the nutrition of aquatic vascular plants

Increased concentrations of CO2 in air (1-50%) catuse yotunig plants of Marsilea vestita to exhibit many characteristics of the water form when they are grown on a solid substrate under sterile conditions. Thus these plants have longer internodes, shorter petioles, more rectangular-shaped epidermal cells and fewer stomata on the lower leaf epidermis than controls grown in 0.03% CO. Over a 2-week period, dry weight increase is considerably greater in 12.5%', and 25% CO2 than in 0.03% C02. Fifty percent CO2 is inhibitory to growth. C02-enriched air has the same morphogenetic effect when stupplied in the light or the dark. Possible explanations for this effect are discuissed.

Effects of carbon dioxide on the growth and morphogenesis of marsilea

N3 Assessing the impact of the COVID-19 pandemic on inpatient admissions and management of patients with anorexia nervosa within a single tertiary paediatric gastroenterology department

J. Michael Bristow

Papers

The role of roots in the nutrition of aquatic vascular plants

Effects of carbon dioxide on the growth and morphogenesis of marsilea

N3 Assessing the impact of the COVID-19 pandemic on inpatient admissions and management of patients with anorexia nervosa within a single tertiary paediatric gastroenterology department