**Water Stress Induced by Enrichment of Nutrient and Climate Change Factors**

Daniela Simina Stefan and Mircea Stefan

Additional information is available at the end of the chapter

http://dx.doi.org/10.5772/64665

### **Abstract**

Human activities accelerate the rate of water, air, and soil environment degradation. In this paper, we propose to present the effects of important stressors for water bodies, represented by continuous enrichment with nutrients and climate change. Nutrients' concentration increases especially nitrogen and phosphorus, associated with tempera‐ ture increases and extreme weather events, involve important physical, chemical, and biological alterations of water quality. The effect of the stressors' factors can be seen on the main parameters which characterize water: temperature, pH, dissolved oxygen, transparency, chlorophyll *a*, nitrogen and phosphorus compounds, and plankton population. The main changes which occur in the water reservoirs consist of modifica‐ tions of taste and odor, increased acidification, decreased transparency, oxygen depletion, increased toxicity, increased sediments quantity, excessive growth of phytoplankton, and macrophytes vegetation. The water quality of lakes, streams, and estuaries can be assessed using the trophic status that can be described mainly using limiting nutrients' concentrations (N total, P total), primary productivity (chlorophyll *a*), and Secchi disc parameters, and also the Carlson's index that includes all of these.

**Keywords:** eutrophication, stress factors, nitrogen, phosphorus, climate change, tem‐ perature, dissolved oxygen, transparency, chlorophyll a, trophic status assessment, Carlson's index
