Lab Notess.docx

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Department
Biology
Course
BIO220H1
Professor
James Thomson
Semester
Winter

Description
Chapter 1: Eutrophication - Eutrophication is caused by continuous pollution in form of agricultural run off or sewage outflows, resulting in high N and P (essential for plant growth) o Nitrogen eutrophication occurs in inshore marine waters o Phosphorus eutrophication occurs in freshwater - Stages of eutrophication: o 1. Algal Bloom- exponential growth of algae due to high nutrients. Build up prevent sunlight from getting to other organisms beneath. o 2. Algae (aka phytoplankton) are short lived and when dead, decomposed by bacteria that use up oxygen and release CO2, detrimental to other organisms.  Green algae (Chlorophyta) exist when some oxygen is still present  Blue-green algae (Cyanobacteria) lives in CO2 rich waters. - In The Lab: 3 water treatments are studied (control, medium, high fertilizer) o 2 species of each cyanobacteria and chlorophyta + s.molesta o The following is measured over time:  Conductivity- total number of dissolved ions. Used to study the salinity of water (saltiness). Run off have high measure. Conductivity of each treatment will raise overtime (with some fluctuation)  Dissolved Oxygen- over fertilization can reduce levels. Results showed an increase in oxygen overtime  Nitrate- from fertilizer was used to see the effects. Results showed increase in levels overtime (especially in high)  Phosphate- again from fertilizer showed same results and nitrogen  pH – measuring the acidity showed to be quite steady, with some decrease in pH due to higher CO2 levels  Turbidity- measured how unclear the water was and as weeks proceeded, more foggy water. - Enriching the Sea to Death (Scott W. Nixon) - Initial invention of toilets and running water lead to pollution of water sources like the ocean and rivers. - Wastewater-treatment technologies were put into place in 1880 to stop animals from dying. What this treatment did was remove visible debris and pathogenic organisms. BUT, this didn’t remove the excess nitrogen and phosphorus that was building up. - Where nutrients are scarce, phytoplankton are sparse and the water is clear - Fertilizers cause phytoplankton to multiply exponentially, turning water green. This ultimately increases the supply of organic mater to aquatic ecosystems= eutrophication. - Initially, this was not thought to be a problem until 1950’s because people only saw the benefits in agricultural practices. But water circulates less readily than air so the build up nutrients can have detrimental effects - Phytoplankton near surface of water get sunlight, plenty of oxygen o Short life causes them to die and sink to bottom. - Dead zones o most at risk waters are those that do not experience winds or tides to mix the waters (thus greater concentration of nutrients in particular parts- often at shores) o coastal areas are most vulnerable to oxygen depletion due to rivers and streams draining o Build up of dead phytoplankton block sunlight and remove oxygen for other organisms. o Can result in breaking of aquatic food chain - Cattle, Corn, and Cars o Release from human waste has been increasing drastically. o Human population has skyrocketed and with high population, huge quantities of crops need to be grown o Resulted in increase use of fertilization o Phosphorus induces aquatic plants to bloom in most freshwater environments. This is good because P is easier to manage  P can bind easily with other substances, precipitating at making it easier to remove.  Phytoplanktons do not respond as much to P than N o Fossil fuel combustion has contributed to rise in N - Future Stock o New sewage treatments are being implemented to prevent build up of running nutrients. o Major Problem is the increase in population Chapter 2: Evolution of Antibiotic Resistance - Antibiotics is any substance made by microorganisms that has a negative impact on growth of other microorganisms o Bactericidal antibiotics kill bacteria by inhibiting DNA replication and repair OR synthesis of preventing synthesis of cell walls o Bacteriostatic antibiotics stop replication by interfering with protein synthesis. -
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