Water Simulation Lab Report

This lab uses a lake simulation to study how the addition of nutrients and toxins can affect the lake, its inhabitants and the surrounding area. There is a strong focus on the addition of Phosphorous and added toxins because both are key elements in growth in lakes. The Virtual lake includes these five simulated species; green algae, cyanobacteria, bosmina, daphnia, and trout. There are two types of phytoplankton in the lake model, green algae and cyanobacteria. Green algae are a very diverse group that are photosynthetic, aquatic, plant like organisms that have a very simple reproductive structure. Green algae growth is a healthy and natural part of a lake’s ecosystem but the addition of nitrogen and phosphorus from fertilizers and other pollutants can cause an excessive growth problem for some lakes.

Most Cyanobacteria, like the ones in the model, are capable of nitrogen fixation. In order to fuel their growth cyanobacteria, rely on fixed forms of nitrogen such as ammonia and nitrate. Cyanobacteria tends to become very abundant in warm, shallow, undisturbed surface water. These conditions allow for them to form blooms that produce surface scum. They can also produce a toxin called microcystins that makes the water unsafe for consumption. Daphnia are very abundant organisms in freshwater lakes. They tend to live in the upper algae rich portion of the water, feeding on phytoplankton, bacteria and decaying organic matter. Daphnia and bosmina both serve an essential role in he food chain in most lakes, serving as a resource for numerous predators. Trout tend to feed on small crustaceans like daphnia and dosmina. Trout are visual predators and therefore feed on the larger daphnia thus providing bosmina a competitive