Essay Questions
1. There are many reasons how human activities can lead to an imbalance of biochemical cycling, anything that the natural environment is not familiar with can damage or throw off biochemical balance. One of the negative impacts of eutrophication and increased algae growth is a loss of available oxygen, known a s anoxia. These anoxic conditions can kill fish and other aquatic organisms such as amphibians. However, how does eutrophication actually lower oxygen levels when it is common knowledge algae produce oxygen, but only when there is enough light. Eutrophication reduces the clarity of water and underwater light. In eutrophic lakes, algae are starved for light. When algae don’t have enough light they stop producing oxygen and start consuming it.
2. Opportunistic species use the “R-strategy”, where R= the species’ intrinsic rate of increase. They produce millions of eggs and sperm since only a small percent will actually meet, join, and become offspring. Examples are most insects, and corals, barnacles, clams, scallops and oysters, who spawn and fertilize their eggs in the water. Opportunistic species are often the first to colonize a new environment and their population growth is often exponential. They tend to “crash” when they run out of food, space, oxygen, sunlight, or whatever the limiting factor is in that environment. Equilibrium species use the “K-strategy”, where K= the carrying capacity of the environment. These species produce much fewer offspring and usually brood them and/or take care of them in other ways. Most birds and mammals use this strategy, as well as some live bearing fish like sharks. The populations of these species may first grow exponentially, but the growth levels off when they reach the carrying capacity of the environment.

3. The direct value include food resources like grains, vegetables, fruits which are obtained from plant resources and meat, fish, egg, milk and milk products from animal resources. These also include other values like medicine, fuel, timber, fiber, wool, wax, resin, rubber, silk and decorative items. Biodiversity provides indirect values to human beings which support the existence of biological life and other benefits which are difficult to quantify. These include social and cultural values, ethical values, aesthetic values, option values and environment service values.

4. Two traits that represent a sustainable society is an emphasis on egalitarianism where there would be a tendency to strive towards a society of equals. Another would be an emphases on using renewable energy. On the other hand, an unsustainable society would have an emphasis on using fossil fuels due to being cheaper and having an ever increasing production of goods, not considering how taxing this might be on the planet.