Biotic Factors Abiotic factors Plants (producers or autotrophs) Animals (consumers or heterotrophs) Water Fungi (decomposers) Soil

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1 Lab # 18 Experiment Title: Biotic and Abiotic components of the Hudson River Aim: What are some of the biotic and abiotic factors that are found in the Hudson River? Background Information: Please read the background information and be familiar with the vocabularies before attempting the laboratory. You should now (1) What is an ecosystem? (2) What is a biotic factor and examples? (3) What is an abiotic factor and examples? (4) What is a habitat and the different types? (5) What is a community? (6) What is a population? What is an Ecosystem? all the living and nonliving things in an area. Biotic Factors Abiotic factors Plants (producers or autotrophs) Air Animals (consumers or heterotrophs) Water Fungi (decomposers) Soil Bacteria(decomposers) Temperature Algae(producers) Sunlight

2 What is a Habitat? a place where an organism lives, it contains all the conditions that are suitable for the organism to survive.

3 What is a Population? a group of organism of the same species living in the same place What is a community? different species of organism living in the same place In today's lab you will be testing a sample of water obtained from the Hudson river for the following (1) A few Biotic factors (2) A few abiotic factors Biotic factors: there are many living organisms in the Hudson River and in part 2 we will try to observe as much as we can when we visit the river however in today's lab we will be

4 looking at the microscopic aspect (those living things that cannot be seen with the naked eyes) and focus on a large group of living things called Plankton. Planktons exist in two major category the phytoplankton which are producers and make their own food and zooplankton which are consumers and feed on organisms to survive. Fishes and mussels and other organisms rely on these planktons as their food source. Method:

5 Please draw and identify the types of plankton that is found in your water sample. Abiotic factors There are many abiotic factors to be considered however we will be testing a few the dissolved oxygen and the ph (1) Dissolved oxygen is necessary to many forms of life including fish, invertebrates, bacteria and plants. These organisms use oxygen in respiration, similar to organisms on land. Fish and crustaceans obtain oxygen for respiration through their gills, while plant life and phytoplankton require dissolved oxygen for respiration when there is no light for photosynthesis. The amount of dissolved oxygen needed varies from creature to creature. Bottom feeders, crabs, oysters and worms need minimal amounts of oxygen (1 6 mg/l),

6 while shallow water fish need higher levels (4 15 mg/l).microbes such as bacteria and fungi also require dissolved oxygen. These organisms use DO to decompose organic material at the bottom of a body of water. Microbial decomposition is an important contributor to nutrient recycling. Dissolve Oxygen Test Step 1: fill a tube completely with water sample. Step 2: Drop 2 dissolve oxygen tablets into the sample. Step3: Shake the tube until the tablet is dissolved. Step 4: Wait 5 minutes until a color has developed. Step 5: Compare the color to the chart below, and note the number in your lab notebook (2) ph is a measure of how acidic/basic water is. The range goes from 0 14, with 7 being neutral. phs of less than 7 indicate acidity, whereas a ph of greater than 7 indicates a base. ph is really a measure of the relative amount of free hydrogen and hydroxyl ions in the water. Water that has more free hydrogen ions is acidic, whereas water that has more free hydroxyl ions is basic. effects on aquatic life Most freshwater lakes, streams, and ponds have a natural ph in the range of 6 to 8. Acid deposition has many harmful ecological effects when the ph of most aquatic systems falls below 6 and especially below 5. Here are some effects of increased acidity on aquatic systems: As the ph approaches 5, non desirable species of plankton and mosses may begin to invade, and populations of fish such as smallmouth bass disappear. Below a ph of 5, fish populations begin to disappear, the bottom is covered with undecayed

7 material, and mosses may dominate nearshore areas. Below a ph of 4.5, the water is essentially devoid of fish. Extreme ph can kill adult fish and invertebrate life directly and can also damage developing juvenile fish. It will strip a fish of its slime coat and high ph level chaps the skin of fish because of its alkalinity. When the ph of freshwater becomes highly alkaline (e.g. 9.6), the effects on fish may include: death, damage to outer surfaces like gills, eyes, and skin and an inability to dispose of metabolic wastes. ph test. Step 1: Fill the test tube with water sample. Step 2: add one ph tablet into the water. Step: 3 Cap and mix the tube until the tablet is dissolved. Step 4: Compare the color to the ph color chart and record the number in your lab notebook Please write a short paragraph indicating your findings. You can discuss if there was a lot a lot of plankton in the water of the hudson river and if there is a lot what would that mean for other organisms living there. You can also discuss if the dissolve oxygen and ph is at optimum ( suitable ) level to support life.

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