Effect of Sound Exposure on Oysters - Research Proposal Example

Due to the commercial nature of oysters, developing ways to improve their growth is very valuable. However, no association between sound waves, specifically the effect of high versus low intensity sounds, on the growth of the Pacific oyster have ever been studied. Sound exposure at high frequencies and intensities has been studied with respect to other plants, animals and fish, and the general conclusion is that sound has either no effect, or a positive effect on growth and survival upto a certain level.

Specific Aim: The purpose of this research study is to determine the effect of increasing sound exposure (the intensity and frequency) on (1) the growth rate and (2) the survival of the Pacific oyster, Crassostrea gigas. Hypothesis: The working hypothesis is that increasing the intensity and frequency of sound exposure will cause a corresponding increase in the growth rate and survival of the oysters until a high level of sound intensity and frequency. Further, increasing the frequency and intensity of sound beyond that point will lead to either no further increase in growth, or cause a damaging effect and slow down their growth rate, or cause oysters to die.

This study will be carried out by using oysters from an oyster farm. There will be 2 experiments involved, one will use oyster eggs and the other will use newly-formed larvae. This would be an experimental study using 6 groups of oyster eggs and larvae: 5 groups of eggs will be exposed to sound vibrations of increasing intensities and frequencies as follow: (1) 25 dB and 200 Hz, (2) 50 dB and 400 Hz, (3)75 dB and 600 Hz, (4)100 dB and 800 Hz, and (5)125 dB and 1000 Hz. The 6th will be exposed to no sounds (silence).

Similarly, 6 groups of oyster larvae that are freshly spawned will be exposed to sound as detailed for eggs above. The total sample size of oysters would be 30 (5 in each group). 50 eggs will be used in each eggs group. Duration of the study would be 3 weeks, with the site as the local oyster farm. Sub-aim (1) To determine the effect of increasing sound intensity and frequency on survival during the first stage of oyster life: hatching from eggs to larvae to form ‘spat’. For this experiment, oyster larvae will be used, as normally only a small percentage of eggs spawn into larvae, we will determine whether more larvae are spawned in the presence of sound.

Sub-aim (2) To determine the effect of increasing sound intensity and frequency on oyster growth from the larvae stage to the juvenile form over a period of 3 weeks. This experiment will use larvae newly spawned, and the mass of larvae at the end of 3 weeks will be measured, with some larvae exposed to sound, others to silence. If the mass of larvae that were exposed to sound is greater than the group that was in silence, it would prove the study hypothesis. Sub-aim (3) To determine the optimum intensity and frequency of sound at which the highest oyster growth is seen.

Sound exposure will be given using sound fields into the water, sound intensity of 25 dB, 50 dB, 75 dB, 100 dB and 125 dB, and corresponding frequencies of 200, 400, 600, 800 and 100 Hz will be given to oyster eggs and larvae in different groups, and the mass of oysters will be measured for each group at the end of the experiment. As each group of