BACKGROUND:
The successful closed aquatic ecosystem is an operating ecosystem where all the needs of life are sufficiently met and life grows and thrives in an encapsulated world. All of the parts of the aquatic ecosystem perform vital functions. For example, the sediment on the bottom is important. It allows for a microbial community to establish itself. It can act as both a biological and mechanical (physical) filter. In the water and in the sediment many
microscopic organisms, including bacteria, consume the deadly ammonia (NH4) that fish and other aquatic animals excrete, and they convert it to a usable form of nitrogen and nitrates for plants to use. The sediment acts as a mechanical filter, trapping particles of matter as they sink down through the water. If small particles of fish feces and excess food were to remain suspended in the water, the gills of fish or systems of other animals could be damaged.
It will be your team’s responsibility to collect data about your jar. You will need to take detailed data of all aspects of your jar. This will include both qualitative and quantitative data relating to both abiotic and biotic factors.
*Examples of Quantitative Data: Measure pH, temperature, sediment depth, area of water (3-d), numbers and sizes of abiotic and biotic factors, etc… metric units will be used (mm or cm). *Examples of Qualitative Data: Note color, smell, physical description of water clarity, interactions between your producers and consumers, etc…
Day 1: Abiotic
Factors-Background: Abiotic factors are nonliving characteristics of an ecosystem that affect the organisms or biotic factors of the ecosystem. It is a combination of abiotic factors that provide the setting that best suits certain organisms. Your ecosystems have a variety of abiotic factors that will affect the life within it. We will investigate some of those abiotic factors. Once understood, these abiotic factors can be used to better understand and even predict the life that would best live within your ecosystem.
Quantitative Data:
Red Litmus paper: (test results)
Blue Litmus Paper: (test results)
pH paper: (pH value)
Temperature (0C)
sediment:
water:
Sediment Depth
(from bottom of jar, in cm, measure outside of jar)
Water Depth
(above sediment, measure outside of jar, in cm)
Area of the water
(3-dimensional, L(cm) x W(cm) x H(cm))
Qualitative Data Smell:
(Smell the sediment and water and describe the smell…(be specific)
*** A strong rotten-egg smell indicates a high level of sulfur. This usually indicates a high number of bacteria.
Clarity of the Water:
(Describe the clarity / color of the water)
Available Light:
(Describe how much light gets through your jar)
Other:
Day 1 and Day 2:
Biotic Factors
Welcome to the Community!
Background:
In an ecosystem, a community is the collection of the various populations that share the
resources of a particular area. These organisms interact in many different ways. Some produce their own food and are collectively known as producers or autotrophs. Other organisms feed upon the autotrophs, as well as each other, and are therefore considered consumers or heterotrophs. Another very important component of a healthy community are the
decomposers. These organisms break down complex organic molecules into simple compounds so that they can be recycled and used again in the cells of organisms. Without decomposers the dead organisms would not rot and the nutrient matter of the dead organisms would be forever locked up in their cells. Each part of a healthy ecosystem must be in balance for the ecosystem to thrive.
Procedure:
As you begin investigating the living organisms with in your ecosystem it is important to have an image to go along with description. Look up the following Common Pond Water Organisms on the internet (to know what they look like) and determine if they are present in your ecosystem. If they are present, take a good picture, draw a good picture, or find a good picture on the internet as a representation of that organism. Include this picture in the chart below. If an organism is not found in your jar, note that in the data table.
Common Pond Water Organisms (Your ecosystem will have most of the following but not all)
Macroscopic Life – these are living things than can be seen without a
microscope. They can be carefully taken out of your jar (using a spoon or pipet) for closer observation. Once out of the jar, this organism should be placed on a watch glass. If you would like to magnify these organisms, you have two options: use the hand lens provided in your basket OR use a Stereoscope – keep the organism on the watch glass and just set the entire glass on the stage of the stereoscope for observation. When finished observing, return the organism to the jar.
Macro - PRODUCERS: Algae, Milfoil, Duckweed, Elodea
Macro - CONSUMERS: Pond Snail, Large Aquatic Insects, Insect Larvae (mosquito larvae), Dragonfly or damsel fly nymphs, worms.
Microscopic Life – these are living things that cannot be seen without the aid of a compound light microscope. Prepare a few different slides of pond water and observe them through the compound light microscope.
Micro – PRODUCERS: Algae, Diatoms
Labeled Pictures
Organism Where Found in
Ecosystem
Consumer or Producer Algae
Milfoil
Duckweed
Elodea
Daphnia
Cyclops (Micro-invertebrate)
Aquatic Free Living Roundworm
Euglena
Stentor
Hydra
Cyanobacteria
Soil Bacteria
Planarian
Pond Snail
Diatom
Large Aquatic Insects (Beetle?)
