Preview

Execise 8: Light transparency and turbidity

Good Essays
Open Document
Open Document
520 Words
Grammar
Grammar
Plagiarism
Plagiarism
Writing
Writing
Score
Score
Execise 8: Light transparency and turbidity
Abstract
Clarity refers to how deep the light penetrated the water and turbidity is the measure of the light scattering property of water. In this experiment, Secchi disk was used to directly measure the amount of penetrated sunlight and indirect amount of the suspended materials in the seawater. The study site was at the littoral zone of the ocean. The coordinates recorded for the study site were found to be N 160 23’ 56.0” E 1190 54’ 06.5” and N 160 24’ 02.5” E 1190 53’ 59.5”. When the rope was lowered down until the disk was no longer visible, the depth measurement was 9.6858 meters for the first site and 7 meters for the second site and when it was pulled up and reappeared, the depth measured was 9.3048 and 6.3048 meters respectively. The average of the two depths resulted to 9.4953 and 6.6524 which represents the transparency reading or also known as the Secchi depth. Therefore, the clarity of water is concluded to be proportional to the depth of the water and amount of creatures dwelling in that certain area.

Introduction
The term water clarity refers to the transparency or clearness of water. The visibility of seawater depends primarily on the reflectance, contrast, color of water, sea state, incident illumination and optical image. The more materials are suspended in the water, the less transparent it becomes.

Turbidity is used to describe the cloudiness or “lack of transparency” of water (Wilson, 2013). It is a physical characteristic where the light is scattered and absorbed by particles and molecules rather than being straightly transmitted through a water sample. According to Shoulejkin, there are four factors that affect the transmission of light in the sea: (1) selective absorption of light by water, (2) scattering of light by tiny suspended particles such as small bubbles of air or gas, (3) selective reflections of light by other particles such as fine dust or plankton and (4) an admixture of the reflected light of the sky.

In the

You May Also Find These Documents Helpful

  • Satisfactory Essays

    Libarary Assignment

    • 363 Words
    • 2 Pages

    C) In the experiment figure 3. Depicts the key results for Daphnia it showed the proportion of population and depth of ambient UVR and UVR shield in the day and night.…

    • 363 Words
    • 2 Pages
    Satisfactory Essays
  • Good Essays

    Essay On Daphnia Magna

    • 753 Words
    • 4 Pages

    As expected, the control group had a feeding rate between that of the higher and lower light intensities. Buikema (1973) mentions that light intensities that exceed a certain threshold tend to suppress the filtering rate. We theorized that their feeding rate increased in the dark environment because it reflects their natural habitat. Populations of D. magna perform diel vertical migration, which means that they only spend the night in surface layers of the water and migrate downwards into the lower water layers during the day (Dodson, 1990; Haney, 1985). The ultimate cause for this is to protect themselves from predators. The proximal cause is the change in light intensity. D. magna present with photosensitive behaviour and they tend to move into areas of low light (Dodson, 1990). Young et al. (1984) report a decrease in the rate of limb beating when exposed to increased light intensity. The rate of limb beating directly affects the rate of filtration. If there is a decrease in the rate of limb beating then the feeding rate will also…

    • 753 Words
    • 4 Pages
    Good Essays
  • Powerful Essays

    It must also filter large amounts of water to strain these particles, and it does this by rhythmically beating its legs, pumping water through the space under its carapace, and using the bristles on its legs as strainers. Because algae are the daphnia’s main food source, it is clearly and advantage for the daphnia to stay where the algae are most densely populated. This is done by sight, but not by spotting the algae at a distance and heading for it. If the daphnia stumbles across a group of algae, the light seen by the daphnia will be slightly red, as most of the blue light in sunlight is removed as it passes through the cloud of algae. The slight redness of the light will cause the daphnia to remain in the location of the algae. The daphnia is in turn eaten by other, larger organisms, making it an important link in the aquatic food…

    • 3528 Words
    • 15 Pages
    Powerful Essays
  • Better Essays

    Ocean Lab Report

    • 853 Words
    • 4 Pages

    On June 19th, my classmates and I had field trip for Oceanography Lab (OCN 101) class with Professor Ocean Matt Horrigan. We went to Corte Madera Salt Marsh, which is located 12 miles North of San Francisco, to examine how rising and falling of tide effect on water level in the marsh and channel. My hypothesis is tide and water level of marsh and channel has positive relationship. The rising tide may raise the water level of marsh and falling tide make water level of marsh decrease. Therefore, since our experiment was limited in few hours, the water level of marsh will be changed (up or down) in few centimeters. The location map (M-1) and study area map (M-2) will be attached on next page.…

    • 853 Words
    • 4 Pages
    Better Essays
  • Powerful Essays

    Biological Productivity – what is it? What is Photosynthesis? (its inputs, its outputs); The nature of light, the wavelength (blue vs red), light penetration in the oceans; What is the euphotic zone?… The sea “plants”: what are they? The 3 broad groups and…

    • 743 Words
    • 3 Pages
    Powerful Essays
  • Good Essays

    3.03 Calorimetry Lab

    • 681 Words
    • 3 Pages

    Turbidity is the clearness/cloudiness of water when a light is shown through. "It is an optical characteristic of water and is an expression of the amount of light that is scattered by material in the water when a light is shined through the water sample"(“Turbidity”). Because the cost of a professional turbidimeter is quite expensive, there will be separate tools combined to substitute one, including a LED light source (flashlight), a photoresistor, and a multimeter, which measures the resistor value of the photoresistor. The reason the photoresistor is used is because it can show if the water is actually dirty or not objectively, because the naked eye is subjective. When the photoresistor is covered, the multimeter-which is connected to the photoresistor, indicates a higher resistor number when there is less light, and lowers in number when it is in contact and receives more light.…

    • 681 Words
    • 3 Pages
    Good Essays
  • Satisfactory Essays

    Good Earth Lab

    • 555 Words
    • 3 Pages

    6. If there are things floating in the water list or describe the types of things you observe in the water.Little pieces of dirt and small rock type pieces…

    • 555 Words
    • 3 Pages
    Satisfactory Essays
  • Better Essays

    Once the sample was collected, pH, temperature, dissolved oxygen, and turbidity were measured. To determine turbidity, a transparency tube with a checkerboard pattern was used. The trasparency tube was emptied and then filled with water so that the pattern on the bottom could bnot be seen. Water was then slowly released and a measurement was taken when the checkerboard was visible again. There were some measurements that were not taken due to the lack of a thermometer on September 13th at Wellwoods Bayou and Wellwoods Lake. A sample bottle from each site was collected and analyzed by Meredith McManus in the lab to determine biological oxygen demand (BOD). Salinity was also measured at each site, but there was no salt present because all sites consisted of fresh…

    • 1281 Words
    • 6 Pages
    Better Essays
  • Satisfactory Essays

    * Counter shading - The dorsal or top of the fish is darker than the bottom of the fish, making them difficult to see as they blend into the darkness of the deeper water when viewed from above or blend into the brightness of sunlit waters when viewed from below. Many predators use this form of coloration.…

    • 430 Words
    • 2 Pages
    Satisfactory Essays
  • Good Essays

    a. Their wavelengths are long enough that anywhere in the ocean the water depth is less than L/20…

    • 1849 Words
    • 8 Pages
    Good Essays
  • Satisfactory Essays

    Hsc300 Unit 7

    • 352 Words
    • 2 Pages

    I will like to put Water quality as the worth or degree of goodness of water at a point in time. While water quantity is the amount of available water at a point in time…

    • 352 Words
    • 2 Pages
    Satisfactory Essays
  • Satisfactory Essays

    Chapter 2 Marine Biology

    • 1093 Words
    • 5 Pages

    4. The yellow-green color of coastal waters as compared to the blue color of the open ocean is a result of what?…

    • 1093 Words
    • 5 Pages
    Satisfactory Essays
  • Good Essays

    We gathered and analyzed water samples from different depths from different depths. This was recorded by using a system of bottles attached to a winch. A stopper at each of end of the bottles are pulled back and attached to a closing mechanism. The cable was lowered to the proper depth then a messenger was sent down the cable to trigger the closing mechanism and the enclosed sample then was returned to the surface.…

    • 965 Words
    • 4 Pages
    Good Essays
  • Powerful Essays

    Animal Behavior Final Notes

    • 2849 Words
    • 12 Pages

    b. You would expect the color of the ocean to be contrasting to the fish's colors. So you would find it in very blue/green waters like reefs…

    • 2849 Words
    • 12 Pages
    Powerful Essays
  • Powerful Essays

    Evr1001 Research Paper

    • 1732 Words
    • 5 Pages

    Before this discussion can proceed, a little background information must be given for better understanding. What exactly is the significance of water quality? According to the National Marine Sanctuaries, “water quality describes the condition of the water, including chemical, physical, and biological characteristics, usually with respect to its suitability for a particular purpose” (2011). In this case, drinking water quality gives an idea of how safe water is for consumption.…

    • 1732 Words
    • 5 Pages
    Powerful Essays

Related Topics