BIO220 Lab Chapter 1 Eutrophication Notes
• Eutrophication, results from continuous pollution in the form of agricultural run-
off or sewage outflows.
• High in N, P; essential for plant growth
• Concentrations are increased to high levels, primary production can explode,
resulting in eutrophication
• N eutrophication in inshore marine waters, P eutrophication in freshwater systems
• First stage: algal bloom; algae exponential growth, organisms that feed on algae
also increase in number
• Decomposition low oxygen levels, high carbon dioxide, detrimental to aquatic
organisms that require oxygen. Dead organisms, most noticeably, fish.
• Oxygen levels still high, green algae common. When oxygen levels decrease, blue-
green algae, cyanobacteria (tolerant to low oxygen) produce a lot of toxic
• Asexual, bud off from parent
• Dissolved ions, indirect measure of salinity, detecting chloride ions from salt.
• Greater conductivity, greater amount of ions
• Polluted waters higher conductivity
• Over-fertilization reduce oxygen levels in aquatic environments.
• When plants die, they become food for bacteria, multiply and use large amounts of
• Nitrogen cycle: bacteria break down toxic ammonium waste into nitrite and then
• Nitrates essential for plant growth: major ingredient of farm fertilizer
• Nitrates stimulate growth of plankton and aquatic plants that provide food and
habitat for fish, these fish populations may increase.
• If algal growth is excessive, oxygen levels will be reduced and fish will die
• Affected by its age and chemicals