Trophic status

The recent increase in the understanding of biological processes in lakes has led to the development of ecotechnical methods of manipulating the trophic status of lakes. The most widely used techniques of bio-manipulation involve artificial change in the abundance of predators to enhance grazing of phytoplankton by zooplankton. The increase in grazing pressure reduces phytoplankton densities and results in improved water transparency. 

Matias NG, Boavida MJ (2005) Effects of catchment development on the trophic status of a deep and a shallow reservoir in Portugal. Lake Reserv Manage 21 350-360... 

J. A. W. Morgan and R. W. Pickup, Activity of microbial peptidases, oxidases and esterases in lake waters of varying trophic status. Can. J. Microbiol. 59 795 (1993). 

The methodology for conducting aquatic model ecosystem studies was well established by the late 1990s. However, the use of the data in risk assessments raised a number of uncertainties regarding their interpretation and implementation [32]. Four of the uncertainties that were identified were the extent to which aquatic model ecosystem data generated in one location could be applied to another situation, the potential influence of mixtures of chemicals or stressors, whether the timing (season) of application would influence the outcome of the study, and whether differences in ecosystem properties (e.g., trophic status) might influence the results. 

Komarek J, Kling H (2003) Filamentous cyanobacteria. In Wehr JD, Sheath RG (eds) Freshwater algae of North America ecology and classification. Academic, San Diego, CA, pp 117-196 Kotak BG, Zurawell RW, Prepas EE, Holmes CFB (1996) Microcystin-LR concentration in aquatic food web compartments from lakes of varying trophic status. Can J Fish Aquatic Sci 53 1974-1985... 

Relative rates of sulfate reduction and methanogenesis in lakes of varying trophic status are claimed to indicate that sulfate reduction rates are limited by the supply of sulfate (4, 5, 13). According to this hypothesis, at high rates of carbon sedimentation, rates of sulfate reduction are limited by rates of sulfate diffusion into sediments, and methanogenesis exceeds sulfate reduction. In less productive lakes, rates of sulfate diffusion should more nearly equal rates of formation of low-molecular-weight substrates, and sulfate reduction should account for a larger proportion of anaerobic carbon oxidation. Field data do not support this hypothesis (Table II). There is no relationship between trophic status, an index of carbon availability, and rates of anaerobic... 

Figure 8A. Rates of sulfur and carbon accumulation are highly correlated in surface sediments of 11 Swiss lakes (23). The solid line is the regression line and the dotted lines represent 95% confidence intervals. Variations in the carbon accumulation rates represent differences in trophic status and...

Foligne, B. et al., Trophic status of the small intestine in young and aged rats Modulation by a yogurt-supplemented diet, Dig. Dis. Sci., 49, 1291, 2004. 

Extrapolating toxicant effects among media may differ according to the trophic status of the species under consideration. Whether a species is a primary producer, primary consumer, or secondary consumer will influence which environmental compartments and media, and hence which routes of uptake, need to be considered. 

Roessink I, Arts GHP, Belgers JDM, Bransen F, Maund SJ, Brock TCM. 2005. Effects of lambda-cyhalothrin in two ditch microcosm systems of different trophic status. Environ Toxicol Chem 24 1684-1696. 

Herrera-Silveira, J.A., Medina-Gomez, I., and Colli, R. (2002) Trophic status based on nutrient concentration scales and primary producers community of tropical coastal lagoons influenced by groundwater discharges. Hydrobiologia 475/476, 91-98. 

Productivity Trophic status Mean total P. M-g/L Mean annual chlorophyll, pg/L Oxygen concentration, as % of saturation Secchi disk depth, m... 

Process Organisms Redox environment Trophic status Biochemical role Chapter... 

Figure 18.21 Comparative analyses of fisheries characteristics in relation to trophic status of estuarine and coastal ecosystems around the world (A) fisheries harvest versus primary production (re-drawn from Nixon and Buckley, 2002) (B) ratio of pelagic-to-demersal fish caught in fishery plotted versus phytoplankton chlorophyll concentration (natural logarithm of hoth x and y variahles). Figure 18.21 (B) was re-drawn from de Leiva Moreno et al. (2000) with Chesapeake Bay data added for two time periods.

Lake Erie Point (wastewater) and nonpoint (agriculture) source stresses. Multiple basins illustrate effects of morphometry, stratification, and flushing rates on trophic status. Mitigated via legislated wastewater and laundry detergent nutrient targets. Partially recovered—depends on future nonpoint-source mitigation. 

Provini A., Marchetti R., and Tartari G. (1992) The Italian lakes trophic status and remedial measures. Mem. 1st. Ital. Idrobiol. 50, 147-169. 

For the NJDEP (New Jersey Department of Environmental Protection NJDEP, 2007 Poretti and Franken, 2008) 40 lakes are sampled 3 times per year (spring, summer and fall). The trophic status of the 40 lakes was determined on the basis of Carlson s Trophic State Index (TSI), linked to TP, transparency and levels of chlorophyll-a ... 

Wasmund, N., Andrushaitis, A., Lysiak-Pastuszak, E., Miiller-Karulis, B., Nausch, G., Neumann, T., Ojaveer, H., Olenina, I., Postel, L., Witek, Z., 2001a. Trophic status of the south-eastern Baltic Sea a comparison of coastal and open areas. Estuarine, Coastal and Shelf Science, 53, 849-864. 

K., Jaanus, A., 2000. Trophic status of coastal and open areas ofthe south-eastern Baltic Sea based on nutrient and phytoplankton data from 1993-1997. Meereswissenschaftliche Berichte, Warnemunde, 38, 1-83. 

It is suggested that benchmark sites (type locations) of the various peat types of the world be selected. The criteria for classification could be that recently proposed by the International Peat Society (1980), which include three important properties—botanical composition, degree of decomposition, and the trophic status (base saturation) of peat. 

In a similar study, Hama and Handa (1980) fractionated DOM from three Japanese lakes of different trophic status using gel permeation chromatography. Distribution patterns of DOC, carbohydrates, amino acids, proteins, and organic acids were determined. Bimodal distribution patterns of DOC... 

---