Hobbies And Interests
Things You'll Need
Instructions
Obtaining and Preparing the Sample
Purchase a water sampler from a dealer if you desire to get a sample from depths greater than 10 to 15 feet. You also can attach a plastic cup or bottle to the end of a length of PVC tubing to gather your sample. Drill two holes at the end of the PVC tubing and two matching holes in the cup or bottle. Attach the cup with two nuts and two bolts so that it is secure. Be sure the PVC tubing is long enough to reach your intended depth. With a tape measure, mark off or tape off the PVC tubing to measure depth when you gather your sample.
Lower your sampler into the body of water and obtain your sample. Transfer your sample to a plastic bottle. Seal the bottle. Repeat at different locations and depths for the best results. Keep your samples in separate bottles and label them with the location and depth of the sample.
Take the samples back to the lab or to your microscope. If you want to observe the organisms alive, place them in a refrigerator or ice chest until ready for viewing, but only for one to two hours if possible. For long-term analysis, fix the samples by adding formalin to them. Alternatively, Lugol's solution is a good fixative for flagellated and ciliated phytoplankton.
Take a small amount of the sample and drop it onto your slide; use a dropper. Cover with a coverslip and view under the light microscope. If there are no organisms on your slide, repeat with another sample until you find some organisms.
Identification of Phytoplankton
Scan the slide for possible phytoplankton. If you find a candidate, increase the magnification to better view the details of the organism. If the organism has a bluish or red tint, it may be a cyanobacteria. Cyanobacteria can be single organisms, clumped together in groups or as filaments in a line. They move by gliding, rotating, oscillating, jerking and flicking. They have no nucleus or chloroplasts.
Determine if your organism is a diatom. Diatoms are easily recognized by their glassy shells, and look like a flat, round or elongate box. They often form elaborate crystallinelike structures when found in groups. Diatoms are the most common phytoplankton encountered.
Determine if your organism is a dinoflagellate. Dinoflagellates are characterized by the presence of two flagella, whiplike structures that propel the organisms along. One flagella will be wrapped around a groove in the middle of the cell, and is used for rotation, the other trails freely and is used for propulsion. Dinoflagellates have plates made of cellulose, and may have spines, pores or other ornaments.
Determine if your organism is a silicoflagellate. Silicoflagellates are characterized by their starlike appearance.
Determine if your organism is a coccolithophorid. Coccolithophorids have calcium carbonate shells that are round and flagellated. These are most often found in the open ocean.