SIP report

I have finished my report. However, I am still adding finishing touches to refine it further. It has been a challenging process as I tried to compile the information. Nevertheless, it was a rewarding experience as I looked at the results of my very own, very first official experiment. It had been a successful experiment, much to my relief. Writing the report was quite a tedious process because there was just so much information and so much to write about. It was fun though as I looked back at the hard work that had birthed forth from my hands and brains. :D

Properly formatted references

(n.d.). Principles of Underwater Sound Chapter 8. Retrieved from http://www.fas.org/man/dod-101/navy/docs/fun/part08.htm

(n.d.). Acoustic Monitoring Program: Underwater Acoustics Tutorial. Retrieved from http://www.pmel.noaa.gov/vents/acoustics/tutorial/tutorial.html

Bowles, A.E., Graves S.K. & Yack, T.M. (2007). Aquatic Noise Pollution from Oil Tankers and Escort Vessels in Prince William Sound, Its Effects and Impacts on the Marine Environment of the Sound: Literature Search from 1980 to Present. Retrieved from https://docs.google.com/viewer?a=v&q=cache:QgmFZNKh8DYJ:www.pwsrcac.org/docs/d0045400.pdf+how+ocean+noise+pollution+aqautic+eggs&hl=en&gl=sg&pid=bl&srcid=ADGEESjn1jlqTwwVTiAHYd44f16pCFiDf41Ne2d8V9PGCMrvdzHlU6khbejt0ZVhrInagyOSAQOzKP3a6E71HzTsJ8Kk0qh9IlEO31DYFtxs8ophspbXcUS87ujJ5X8oMkcGU43T_S5Y&sig=AHIEtbQEp-8prIn892v0qWFD3we-2RddpQ

Brine Shrimp. Last edited June 15 2011. In Wikipedia. Retrieved July 2, 2011, from http://en.wikipedia.org/wiki/Brine_shrimp

Desislava, Orlin & Hristo. (1999). Sound & Hearing. Retrieved from http://library.thinkquest.org/28170/36.html

How to raise brine shrimp. Last edited February 14 2011. In Wikihow. Retrieved July 2, 2011, from http://www.wikihow.com/Raise-Brine-Shrimp

The Regents of the University of California. (2011). Fossweb: Brine Shrimp. Retrieved from http://lhsfoss.org/fossweb/teachers/materials/plantanimal/brineshrimp.html

References

These are all the references I may have used. I am putting it here for easy reference and collation!

http://lhsfoss.org/fossweb/teachers/materials/plantanimal/brineshrimp.html

http://www.wikihow.com/Raise-Brine-Shrimp

http://en.wikipedia.org/wiki/Brine_shrimp

http://www.pmel.noaa.gov/vents/acoustics/tutorial/tutorial.html

http://library.thinkquest.org/28170/36.html

http://www.fas.org/man/dod-101/navy/docs/fun/part08.htm

https://docs.google.com/viewer?a=v&q=cache:QgmFZNKh8DYJ:www.pwsrcac.org/docs/d0045400.pdf+how+ocean+noise+pollution+aqautic+eggs&hl=en&gl=sg&pid=bl&srcid=ADGEESjn1jlqTwwVTiAHYd44f16pCFiDf41Ne2d8V9PGCMrvdzHlU6khbejt0ZVhrInagyOSAQOzKP3a6E71HzTsJ8Kk0qh9IlEO31DYFtxs8ophspbXcUS87ujJ5X8oMkcGU43T_S5Y&sig=AHIEtbQEp-8prIn892v0qWFD3we-2RddpQ

Time constraints

My trial experiment is the one where I tested the brine shrimp but they refused to hatch up till the 2nd or 3rd attempt where they finally appeared from their cysts! Afterwards, I carried out my actual experiment twice. However, due to time constraints, I am unable to carry it out a third time! The ideal was to carry out the experiment 5 times. If I were able to do this experiment again, I would carry out each set-up more times to increase consistency of data and reliability of results. This is one limitation of my experiment.

Tentative Summary of Research

This is the summary of my research. I am using it in my Data Discussion section of my report. I edited out bits and used them in other sections of my report. Some bits were also unnecessary so I did not use them.

***

The frequency of a sound wave is the rate of oscillation or vibration of the wave and is measured in cycles/sec or Hertz (Hz). Sound waves propagating underwater are alternating compressions and rarefactions (decrease in density and pressure of sound wave) of the water. They travel through the air and get refracted when they pass through a medium with gradually varying properties (e.g. water).

Sound waves are transmitted through water as a pressure waves (repeating pattern of high-pressure and low-pressure regions). Longitudinal and transverse pressure waves cause vibrations of water particles. Low-frequency sounds are classified as high intensity sound that is transmitted by high intensity pressure waves. High intensity pressure waves cause greater vibrations of water particles which pose as disturbances that negatively affect the hatching process of brine shrimp eggs by hampering it.

Important things to take note of

These are some important pointers that I have to take note of regarding my SIP report. We went though the pointers in class when Ms Tan went through the rubrics. Also, some information was gathered from my friends from other classes.

1. Methodology must be reproducible

2. Point out control variables that cannot be controlled

3. Variables that we are unable to control should be listed under Limitations

4. Extension of further questions from our experiment

Experimental results

This is the data I collated from the whole experiment. Two beakers (Beaker 1 and Beaker 2) were exposed to the same frequency and conditions at one go. In other words, there were 2 identical set-ups). After which, the data from each beaker was collated over the period of 48 hours. This was to increase the consistency of data and reliability of results, eliminating any other external factors that could affect the results, by increasing the number of times each frequency was tested through increasing the number of set-ups.

The data might look really perfect but that is due to the limitation that I cannot be sure that I added 3000 shrimp eggs into the beaker. That might be more or less because the eggs are too small for me to count and I can only estimate. Therefore, there is a certain room of error in these results. The gap between the number of eggs that hatched from each frequency in the same period of time is clear and distinct with a considerable distance between most.

In Fig. 1 and Fig. 2, the lower the Hz of the frequencies are, the lesser the total number of brine shrimp eggs within a shorter period of time. In other words, lower frequencies result in slower hatching speed of the brine shrimp. In Fig 2, 171 Hz resulted in 15 hatched shrimps whereas 186 Hz resulted in 19 hatched in the same period of 12 hours.

Experiment videos (evidence)

[After 12 hours] Hatched brine shrimp
http://www.youtube.com/watch?v=hp5FxkCs5xQ

[After 24 hours] Hatched brine shrimp
http://www.youtube.com/watch?v=ZR6lUEB79m8

[After 36 hours] Hatched brine shrimp

http://www.youtube.com/watch?v=kOF3iFEXK0s&feature=channel_video_title

More photographs of the experiment

The white dots in the photographs are actually hatched brine shrimp.

Experiment photographs (evidence)

Side view of beaker of brine shrimp eggs after 12 hours


Side-view of the beaker of brine shrimp eggs after 48 hours
- The difference in the number of hatched brine shrimp is not clearly visible in the photographs of "48 hours" and "36 hours" Top view of a petri dish of brine shrimp eggs after 36 hours
- I poured out about 200 ml of brine shrimps eggs/salinated water from the beaker into the petri dish, in order to take a clearer and more intimate photograph of the brine shrimp

Side-view of the beaker of brine shrimp after 36 hours

Top view of the beaker of brine shrimp eggs after 24 hours

Another top view photograph of the beaker of brine shrimp eggs after 24 hours

NOTE: The number of hatched brine shrimp cannot be counted from the photographs as some might not have been captured by the camera.

NOTE2: The photographs are not in order but they're all of the same set-up

When I took these photographs, I switched off the lights in the room and placed a flashlight at the side of the beaker. Brine shrimp are attracted to light and would gather at lit areas, hence giving me the opportunity to count them reliably and take good quality photographs.

The photographs here are all of the control set-up (with no exposure to low-frequencies). The set-up just consists of 2 beakers of salinated water containing brine shrimp eggs. No other materials or apparatus were used except the counter in counting the brine shrimp. Two beakers were used in order to increase the number of times the experiment was carried out which would improve the consistency of data and reliability of results.

Photographs of experimental set-up

Photograph of the experimental set-up.

The distance of the beaker and Mac speaker is 5cm. The numbers on the markings are not displayed clearly enough in the photograph due to poor photo quality. However, 5 markings can be visibly counted from the mouth of the beaker to the bottom of the Mac and hence, 5 cm.
Photograph of the hands lens used in the experiment. Courtesy of the school's biology lab.

Photograph of the transparent beaker used in the experiment.

Successful hatching

I followed the method I used in hatching the brine shrimp eggs of my trial experiment. This resulted in successful hatching of all the brine shrimp eggs in my experiment! I ensured that I maintained a suitable level of salinity and type of water (boiled water). I was so worried that the eggs would go back to not hatching again. However, the eggs were of good quality and had not lost its viability so my worries were unfounded. The eggs hatched within just 12 hours and carried on doing so up till 48 eggs. From that point onwards, there was no further hatching of eggs. From the 3rd day onwards, the hatched brine shrimp started dying off because they did not have any food to survive. From the 1st hour they hatched, they were fueled by energy from their eggs. However, once the energy had been used up, they required a pinch of baker's or brewer's yeast or else they would perish.

I formatted the table in Microsoft Word and plotted the data directly into it. Therefore, there are no rough notebook photographs or rough data collation work whatsoever.

Final aim and hypothesis

My previous aim and hypothesis are as follows:

Aim: To find out if different levels of low-frequency sound waves (ocean noise pollution) emitted by the human's marine activities affect the hatching rate of brine shrimp

Hypothesis: Different levels of low-frequency sound waves (ocean noise pollution) emitted by the human's marine activities affect the hatching rate of brine shrimp

However, I have decided to refine it to make it less of a "yes, no" question but more of one that would allow for greater research. In other words, I would like to change it to a "How" question. Another point is the words "hatching rate". Rate is a rather vague term and does not accurately define what I would like to measure. The dictionary's definition of rate is " A quantity measured with respect to another measured quantity" which is not how I am going about with my experiment. Therefore, I am changing it to "speed".

Therefore, my new aim and hypothesis are as follows:

Aim: To find out how different levels of low-frequency sound waves (ocean noise pollution emitted by human's marine activities) affect the hatching speed of brine shrimp.

Hypothesis: The lower the level of low-frequency sound waves (ocean noise pollution emitted by the human's marine activities), the slower the hatching speed of brine shrimp eggs

Revised experimental procedure

Since I have to set up two set-ups testing the same frequency at one go, I have revised my experimental procedure.

Materials and apparatus

1. Artemia (Brine Shrimp) eggs
2. Macbook with the app, Tone Generator X
3. Hands lens
4. Counter
5. 2 transparent beaker
6. 160g of sea salt
7. Boiled water
8. Science journal

Procedure

1. Place 2 beakers in a semi-lit room
2. Pour 1000 ml of boiled water into each beaker
3. Add in 20g of sea salt into each beaker
4. Place the speaker of the Macbook directly above the mouth of both beakers
5. Switch the software, Tone Generator X, on to 186 Hz at the volume level of 80%
6. Add in half a teaspoon of Artemia (brine shrimp) eggs
7. Check the set-up with a hands lens at every 12-hour interval and use the counter to count the number of eggs that have hatched
8. Record down in my journal the number of eggs that hatched
9. Repeat steps with 171 Hz, 259 Hz and 223 Hz

[Video] Successful trial experiment

I am elated! After several failed attempts, the brine shrimp have finally hatched! This is a video of the successful hatching of my brine shrimps.

http://www.youtube.com/watch?v=daPWk3hEzLA&feature=channel_video_title

New experimental aim and hypothesis

Aim: To find out if different levels of low-frequency sound waves (ocean noise pollution) emitted by the human's marine activities affect the hatching rate of brine shrimp

Hypothesis: Different levels of low-frequency sound waves (ocean noise pollution) emitted by the human's marine activities affect the hatching rate of brine shrimp

Research

This is the raw research I've found. I will be summarizing it and using it in my report.

***

Artemia (Brine shrimp) are a food source for crustaceans and fish. Cultured brine shrimp feed on yeast, wheat flour, soybean powder or egg yolk. Sea, aquarium or kosher salt and pH of 8-9 is required for the eggs to hatch. Their young hatch out of cysts, which are metabolically-inactive, at the optimal temperature of 25 to 27 degrees Celsius (room temperature). Artemia eggs take about 24 to 48 hours to hatch. Crustaceans, like Artemia, do not have ears. They have tiny hairs, called mecanoreceptors, on their shell that respond to physical stimuli such as water movement, vibration or touch by sending a message to the nervous system. A type of mechanoreceptors that respond particularly to vibration or changes in water pressure are called "hearing hairs". Some crustaceans use noise for orientation.

Sound waves propagating underwater are alternating compressions and rarefactions (decrease in density and pressure of sound wave) of the water. They travel through the air and get refracted when they pass through a medium with gradually varying properties (e.g. water). Sound waves are transmitted through water as a pressure waves. High intensity sound is transmitted by high intensity pressure waves. These pressure waves cause vibrations in the water and hence, affect the hatching process of brine shrimp eggs.

Frequency is the number of cycles/waves a sound makes per second. It is a periodic vibration and a property (subset) of sound that determines pitch. It is measured in Hertz (Hz). Low-frequency noise refer to sounds below 200Hz. Broadband source levels are the sum of the acoustic energy over all of the frequencies generated by the source. Lower frequencies result in higher intensity sound waves that cause greater vibrations of the water.

The world's oceans are mostly polluted with low-frequency sounds due to boats, ships, underwater industrial activities, or seismic military and scientific explorations. I intend to test broadband source levels of:

• Ships- 186 Hz (noise generated by a large tanker ship)
• Ships- 171 Hz (noise generated by a tug and barge aka tugboat)
• Seismic survey- 259 Hz (noise generated by airgun array)
• Military sonar- 223 Hz (noise generated by U. S. Navy tactical mid-frequency sonar, center frequencies 6.8 to 8.2 kHz)

Prawns [shrimps] are very sensitive to sound, just like many fish, and hence, ocean noise have potential impacts on them in the marine ecosystem. (Lovell et al. 2005). Such low-frequency sounds have shown to have detrimental, lethal effects on marine life, damaging their hearing and interfering with their feeding habits and other life cycles such as reproduction.

Hard materials, such as plastic, are dissimilar to the air that sound waves move through and hence, the walls reflect most of the sound waves and little is absorbed. This would cause a reverberation, prolonging the music and diffusing it to all parts of the tank. Therefore, plastic is an ideal material for the tank.

Consultation with Ms Tan

Yesterday, I consulted Ms Tan regarding by SIP project. The following was what we discussed:

• Instead of testing the effects of music on brine shrimp (heavy metal, pop, country and classical), I should test on the effects of different audio frequencies on the hatching rate of brine shrimp. Such a research would have great environmental advantages in marine conservation.
• Upload photographs/drawing of set-ups
• I do not have to photograph the brine shrimps of each set-up at every 12-hour interval unless there is a significant change in number. I just have to photograph the set-up at the start of the experiment.
• I have to get a counter from the Bio lab to help me count the brine shrimp more quickly and accurately. With each brine shrimp that I see, I will just have to click the counter. After counting all the brine shrimp, I can check the counter for the number of clicks that I have logged.
• I could go to the Bio lab to photograph the brine shrimp with a microscope-cum-camera so that I could track its hatching progress at every 12-hour interval more clearly as the pictures would be enlarged.
• I should carry out each set-up twice to ensure greater accuracy of results and consistency of data collected. For example, I should set up two set-ups testing 171 Hz at the same time.

Brine shrimp hatching: Success!

The brine shrimps have finally hatched! It turned out that there was a problem with the eggs and not the hatching conditions. The eggs that I got had probably rotted and lost their viability. Hence, I went to an aquarium shop to buy new brine shrimp eggs, imported from Germany. They hatched in less than 24 hours! I can properly start on my experiment now.