Plankton Lab

Introduction:

Plankton, or planktos ("wanderer" in greek), are miniscule living creatures that haunt the world's waters. They lack the means to move against the current or wind. Though there are numerous types of plankton, they are generally classified based on four different traits: diet, color, lifestyle, and size. They obtain their sustenance from either the sun (Phytoplankton) or from other living creatures (Zooplankton). Different colors include green (producer of 90% of Oxygen), brown, blue, red, and gold. Plankton also have a few different lifestyles they can be classified by. For example, holoplankton stay plankton for their entire lives. Common holoplankton include algae and jellyfish. Meanwhile, meroplankton remain true plankton for only part of their life. This class includes larval fish and barnacles. Finally, plankton are also classified by their size. Technically, there are six size classes that plankton are generally categorized in, but we'll only cover three for this lab. First up, megaplankton. They can grow bigger than 2 mm, which, for plankton, is huge. Next we have microplankton, spanning lengths from 0.06 mm to 0.5 mm. And, last but not least, we have ultraplankton, which never exceed 0.005 mm.

Question:

What is the diversity of Plankton in South Maui?

Hypothesis:

Though we may find it difficult to accurately identify some of the different species, I believe we will be able to identify at least 30 different kinds of plankton.

Prediction:

If my hypothesis correct, then we will be able to categorize at least thirty different types of plankton in water samples taken from South Maui beaches.

Materials:

• Plankton net
• Vial
• Jars
• Journal & writing utensils
• Microscope
• Microscope slides & cover slips
• Plankton identification book
• Thermometer
• pH testing kit
• Phosphate testing kit
• Nitrates testing kit
• Dissolved oxygen testing kit
• Turbidity testing kit

Procedure:

Thermometer/pH Tester

1. Turn device on.
2. Remove cap.
3. Submerge tip in seawater.
4. Read and record data displayed for pH levels and temperature.
5. Replace cap and turn device off.

Phosphates/Nitrates/Dissolved Oxygen/Turbidity

1. Fill vial with seawater sample.
2. Place tablet from kit inside vial.
3. Shake well for approximately five minutes.
4. Compare the water's color with chart inside kit.
5. Record results.

Collecting Plankton Samples

1. Go to area where you want to take sample.
2. Drag plankton net firmly through open water for approximately five minutes, avoiding coral and barnacles.
3. For the small net, simply reach inside net and carefully remove sample container.
4. For the medium sized net, place a jar under the capture jar then carefully uncap the capture jar
5. For large net, squirt water through the fine mesh and allow plankton to fall into collection jar

Microscope:

1. Plug microscope into power source and turn on backlight.
2. Carefully place seawater samples onto slides. Place slides on microscope observation tray.
3. Adjust focus and position of microscope for the clearest view of the plankton.
4. Look for plankton in the water, particularly in clusters of dirt or sand.
5. Record and identify all plankton types you see.
6. Power down and carefully put microscope away.

Proscope:

1. Take proscope out of case, set up near computer.
2. Plug into computer.
3. Locate proscope program on computer and open it.
4. Pour small sample of seawater into half a petri dish. Place dish under proscope.
5. Focus proscope on seawater.
6. Search the sandy clusters for plankton.
7. Record and identify all plankton types you see.
8. Clean off lens, power down and put away carefully.

Data:

Temperature: 20.4 degrees Celcius

Salinity: 26 parts per thousand

Dissolved Oxygen: 0

Phosphates: 4 parts per thousand

Nitrates: 2 parts per thousand

pH: 8.09 pH

Turbidity: 0

Tide: Low

Wind: Gentle

We were able to loosely identify only six species of plankton. We did see others, but were unable to classify them.

Conclusion:

Unfortunately, this lab did not even come close to proving my hypothesis. In response to a question about the number of plankton species in South Maui, I confidently predicted that we would be able to identify at least thirty. In the end, we were only able to identify six. However, I feel sure that under different circumstances, we could have easily proved my hypothesis. For example, we had very limited time to actually search our samples for different plankton species, and equally limited time to actually search the identification books and make conclusions about them. With more time, we most likely could have found more species nestled deep in the sand clusters and incorporated them into our conclusions. Secondly, when you are working with creatures at the microscopic level, there are bound to be mistakes made. The proscope I was using didn't exactly yield a clear image, and occasionally we were forced to guess which species a particular plankton might belong to. There is always the possibility that we counted the same species twice because we were looking at it from different angles, or that we didn't count a different species simply because it looked similar to one we already had identified. It didn't help that all we had with which to identify the plankton were booklets containing a single, black-and-white rough drawing of each species. With better resources to refer to, I feel we could have more accurately drawn a conclusion for this lab. However, I did learn a lot during this lab, and I also enjoyed myself. I always have fun using microscopes in the classroom. I just can't resist finding out how random objects look zoomed in x200 . . .

I mean . . . who can? :)

In a somewhat unrelated topic, I am positive that we misread the results in the dissolved oxygen test. How am I so certain? Well, if our seawater sample's dissolved oxygen content had really been zero, we would have found no living plankton in the sample later on (they need to breathe too). Obviously, this was a mistake. Fortunately, the dissolved oxygen content is basically irrelevant to our conclusion, so we can all move along now.