RNR 1001 : Renewable Natural Resources Notes Test 2
Document Summary
As we have talked about, degradation of the planet"s environment has accompanied human population growth throughout history: reductions in biodiversity, habitat complexity, biological productivity, and ecosystem process integrity due to human activities. Pollutants can be solid, liquid, or gaseous, and are found everywhere on the planet. However, in terms of natural resources, runoff into streams and rivers has been a much bigger problem: pesticides- loss of aquatic invertebrates, herbicides- loss of macrophytes and algae, sediment- loss of habitat, high turbidity. Agricultural runoff is a significant source of nutrients, which can lead to the process of cultural eutrophication in streams and lakes. Most obvious effect is excessive plant growth, both macrophytes and algae. Why do fish kills occur: loss of dissolved oxygen, diurnal oxygen production high, nocturnal respiration high, algae can become self-limiting, mortality and decomposition. Some species (cyanobacteria) produce cyanotoxins, such as anatoxin and microcystin. Harmful to many vertebrates, including fish and humans, fish mortality occurs in relatively low concentrations.
