Location, Location, Location

Sand samples were tested for biotic and abiotic materials. Determining if the amount of biotic material can lead to knowing more about coral reef and beach desctruction.
Eli Forrest Graf
Grade 6

Hypothesis

If the composition of freshwater and saltwater sand is tested, and collected from different locations, then saltwater sand will have more biotic components because of how marine life in the oceans contributes to sand composition. 

 

Research

People like picking up sand and letting it flow through their fingers. Wet sand and dry sand feel very different when picked up. Sand is fascinating because of all the sizes it can be. There is so much sand on earth. People can make sand castles,  dig and play in the sand. Where did all this sand come from? 

Sand is made up of sediment with grain sizes between 0.25 mm and 2 mm in diameter. Sediment is mineral particles that have been created by the erosion of rocks and soil. The rocks and soil have been moved by natural forces, such as water and wind. Sediments include silt, sand, gravel and boulders, from smallest to biggest size. These sizes are classified by the Wentworth scale. The Wentworth scale is used to group different grain sizes into four categories. Larger grain sizes are boulders and gravel and smaller grains are sand and mud. 

The Wentworth scale is used to classify sediment grain sizes. It was invented in 1922 by geologist Chester K. Wentworth. The Wentworth scale classifies sediment into four different groups; boulders, gravels, sands, and mud by decreasing order.

Inside of mud, we have coarse silt, medium silt, fine silt, very fine silt, clay, and dust. Mud ranges from 0.031-0.0005 mm. Inside of sand, we have very coarse sand, coarse sand, medium sand, fine sand, and very fine sand. Sand ranges from 1.0-0.125 mm. Inside of gravel, we have cobbles, pebbles, and granules. Gravel ranges from 65-4 mm. Inside of boulders, we have just boulders which range from 250-100 mm.

Oceanographic processes, such as different waters mixing, waves and currents, affect sand because they move it around. Aggressive waves equal mostly the same size of grains of sand and bigger beaches. Gentle waves equals a very different array of sizes and smaller beaches. Steep beaches equal larger grains of sand, and flatter beaches equal smaller grains of sand. The closer to the water, the larger the grains, and farther from the water (up the slope or the beach) the smaller the grains. These reasons are approximate because of the many factors related to sand size. 

Biotic components in sand include coral, urchin spines and shells. Abiotic components in sand include quartz, granite and other rocks and minerals. We can tell what sand is made of by filtering it, looking at it under a microscope and putting an acid into a sample. Some things that can be seen under a microscope include the size, shape and colour of grains. By filtering it, you can learn the size and type of sediment. By putting an acid into it, if the vinegar reacts to carbonates by fizzing, there might be biotic components. 

Biotic = living or once living, Abiotic = non-living, never living

It takes a long time for sand to form. For example, quartz takes thousands to millions of years to break down to the size classified as sand.

 Rocks are slowly pushed up to thousands of kilometres downstream, breaking down in the process. Once they arrive at the beach location, the waves and/or tides help it further erode.  

Sand can also be made by parrotfish poop! Parrotfish scrape algae off rocks with their beaks. Then they grind up the material, and they excrete it as sand. This also helps the reefs because the fish can make hundreds of kilograms of sand.

Sand can be made up of a lot of things! What sand is made of is called its “composition”. Sand can be made of Quartz, basalt, feldspar, garnet, granite, minerals, mica, olivine, volcanic glass, human-made plastics, spines of anemones, starfish spines and broken-up shells. Sand is mostly made up of weathered rocks and shells. If you take a look the next time you're at the beach you will probably also see bigger pieces of shells and bigger rocks. This is because the sand does not all break down at the same time so there are things that are still eroding.

Colours of sand might be able to give you hints about the composition of sand. For example, if you saw a yellow-ish sand it might have iron oxide in it. Another example is pink sand might have foraminifera. Foraminifera are microscopic fossilized shells that were once living single-celled organisms. Black sand could be volcanic sand! Some white Hawaiian beaches are made of parrotfish excrement.

It is important to protect beaches. Beaches are a way to study the earth and a fun way to spend the day. When beaches erode the oceans can rise causing flooding and loss of homes. This can be a major problem so people have come up with ways to stop it called “beach blockers”. These can be stairs, mats, plants and walls. Beaches are also at risk from poisonous algae like the blue-green algae. 

“Scientists study sand to learn about the biological, chemical, and physical processes in an area.”- Exploring our fluid earth.

  • Geology - Geology is the study of Earth and rocks.
  • Shoreline - Where water meets land
  • Sandbar - A bar of sand that comes out of the ocean.
  • Erosion - The process in which nature moves soil and rock from one place and puts it in another place.
  • Climate - The average weather conditions in a specific place for a long period of time.
  • Oceanographer - The people who study the oceans-some oceanographers are interested in the seafloor.
  • Tides - Slow movements of the entire ocean.
  • Sediment - Material deposited by water, wind or glaciers.
  • Weathering - Deterioration of rocks by natural processes.
  • Currents - Area where the water flows in a specific direction.
  • Seafloor - Another term for ocean floor. 
  • Reefs - Types of rocks and coral close to the surface of the ocean.
  • Mineral - Naturally occurring substances taken from the ground.

 

 

 

Variables

Manipulated Variable

Responding Variable

Multiple Controlled Variables

Location of sand samples

-freshwater

-saltwater

Composition of sand sample

-Biotic/abiotic factors

-Size

-Common components (minerals, corals, shells etc.)  

-Shape 

Process of sorting

Zoom on microscope

Type and amount of vinegar for biotic tests

Weight of sand sample

Procedure

  • Microscope
  • Glass slides/dishes
  • Sample containers
  • Freshwater and saltwater sand samples
  • Vinegar
  • Sieves - three different sizes (kitchen strainer, tea strainer, nut milk bag, coffee filter is optional) 
  • Funnel
  • Magnet
  • Flashlight
  • Kitchen scale

 

  1. Collect sand samples and note location coordinates of each sample
    1. Salt water above high tide line
    2. Salt water below low tide line
    3. Freshwater river  
    4. Human made lake 
  2. Measure 13 grams of each sample into a sample container, marking the sample location. 
  3. Sieve the 13 gram sample using a 1mm sieve (colander) to sort into “very coarse sand.” This is the sand that doesn’t go through. Save and label this part of the sample. 
  4. Sieve the remaining sample using a 0.5mm tea strainer to find the “coarse sand.” The course sand will not go through the sieve. Label this sample. 
  5. Sieve the remaining sample through a nut milk bag, which is about 300 microns or 0.3mm. What doesn’t go through is “medium sand”. What doesn’t go through this will be the “fine sand” or smaller. Label this sample. 

See next page for more.

  1. Sieve the remaining sample through a paper coffee filter, which is about 10-20 microns (0.015mm) and will reveal the “very fine sand.” Label this sample. (There was no remaining sample to filter from the samples I collected.) 
  2. Using the “data” chart look at “course sand” and “very fine sand” samples for each location under microscope to determine:
    1. Shape
    2. Composition (materials like coral and minerals like quartz) + use magnetic to determine magnetic mineral grains
      1. You may need to shine a flashlight to better see the samples, or you could use a dissection microscope.
  3. Recombine filtered samples for each location, so you have 13 grams and add 10 ml vinegar to test each locations sample for biotic and abiotic components. If the sample has biotic components, it may fizz. (Vinegar tests for carbonates which can show that there are biotic components.) 
  4. Research the location and beach type and add to the chart. 
    1. Slope, flat, waves etc. 
  5. Use data to affirm or disprove the hypothesis.

Observations

 

  • Some samples didn’t have fine sand or smaller 
  • All samples had quartz in them
  • Most of the coarse sand samples were angular
  • Most of the locations that had two samples taken from them were nearly the same
  • The salt water samples reacted to vinegar less than the freshwater samples
  • Some of the sand was magnetic
  • The angularity changed between the fine (or smaller) and the coarse sand
    • Fine sand become smoother
  • The fine sand was much finer than expected

Analysis

Data 

Different sizes present

(Wentworth Scale) 

Fine Sand or smaller

Shapes present

Coarse Sand

Shapes present

Fine Sand or smaller

Composition

Coarse Sand

Composition

Description of beach 

-steep/gentle slope

-aggressive/gentle waves

Hollyhock - low tide

Very coarse, coarse, medium, fine sand or smaller

sub-rounded/rounded

sub-rounded

Quartz, magnetic mineral grains, olivine

Quartz, granite, olivine, magnetic mineral grains

Almost no slope,low-medium wave action.

Hollyhock - 

High tide

Very coarse, coarse, medium, fine sand or smaller

sub-rounded

angular

Magnetic mineral grains, quartz, olivine

Quartz, magnetic mineral grains, granite, olivine

Gentle slope,low-medium wave action.

Manson’s Lagoon - Beach

Very coarse, coarse, medium

N/A

angular

N/A

Quartz, magnetic mineral grains, granite, volcanic stone

Low slope,low wave action, very strong currents that can pull you downstream.

Manson’s Lagoon - Sandbar

Very coarse,coarse,medium, fine sand or smaller

sub-rounded

angular

Volcanic stone,quartz, magnetic mineral grains, granite

Quartz,volcanic stone, magnetic mineral grains, granite

Low slope,Medium wave action.

Curmies Islands

Very coarse, coarse, medium

sub-rounded

Very angular

Quartz, magnetic mineral grains, granit

Quartz, magnetic mineral grains, granite

No wave action, we couldn't find sand so we took it from a tidepool.

Bridget’s Beach 

Very coarse, coarse, medium, 

N/A

sub-angular

N/A

Quartz, granite, magnetic mineral grains, volcanic stone

Gentle slope, medium wave action.

Lake Sundance

Very coarse, coarse, medium, fine sand or smaller

sub-rounded

angular

Quartz, granite

Quartz, granite

Gentle slope,minimal wave action.

Bow River Beach 

Very coarse, coarse, medium

N/A

angular

N/A

Quartz, granite

Gentle slope,very little wave action because it was a river.

 

Beach

Reaction

Hollyhock - low tide

Low fizzing

Hollyhock - 

High tide

Low fizzing

Manson’s Lagoon - Beach

Low to medium fizzing

Manson’s Lagoon - Sandbar

Low fizzing

Curmies Islands

Medium to high fizzing

Bridget’s Beach 

Low-no fizzing

Lake Sundance

Medium to high fizzing

Bow River Beach 

High fizzing

 

 

Ocean/salt water samples fizzed less than the bow river, which might mean that the ocean sand samples collected didn’t have that many carbonates such as corals and shells. 

 

It was noticed visually and under the microscope that sand is made of lots of different materials.

 

The shape of the sand materials a lot different than expected. Sand appears more rounded but under a microscope it was very angular. 

 

The sample were likely newer sand because they hadn’t been tumbled as much. 

 

These samples were likely also from closer mountains and locations and spent less time rumbling in rivers towards the ocean. 

 

The sizes of the grains were smaller than expected, although two samples didn’t even have finer grains than medium on the Wentworth Scale. The finest sieve was not needed for these samples. 

 

Sand is complex and interesting.

 

Shells, even after the animal is dead, are still considered biotic because it was once living. The shells fizzed a lot during the vinegar test. 

 

Most of the sand was composed of abiotic (non-living) materials. In the collected samples, there was less biotic materials than expected. It was mostly rocks. 

 

Hollyhock beach is a big, flat, and gentle beach. Research says that this beach would have varied sizes, similar shapes and smaller sand higher up the beach. Data reveals that this was partially correct for this sample. For example, the sizes were varied and the sand was similar shapes (rounded). However, the sand at low tide actually had more smaller sizes, and the sand at high tide has less fine or smaller sand. This shows that there are many factors related to sand size and shape. 

 

Natural freshwater sand from the Bow River didn’t have any sand finer than medium, so that indicates that it hasn’t tumbled for that long. That could mean that it might have come from larger rocks nearby, for example the Rocky Mountains. 

 

Sand collected in the Curmies was noted as being very angular. It was collected from a tide pool, as there was no beach at all. It hadn’t tumbled for as long, so it may have come from larger rocks on the Curmie Island it was found on. This sand was mostly abiotic, which was surprising. It was also varied in sizes, which supports the idea that it hadn’t traveled far. 

 

Conclusion

The experiment worked as hoped, however the data proved that the hypothesis was incorrect.  It was thought that the salt water sand would have a lot of biotic components, but it was mostly quartz. Therefore, the saltwater sand samples did not have more biotic components than the freshwater samples proving the conclusion wrong.

 

Application

This project teaches people the importance of shoreline protection in Canada and beyond. The ocean sand samples had less biotic components than the fresh water sand samples. This could mean that there are decreasing amounts of biotic material in the oceans, which could be caused by shoreline destruction. Also it takes a long time for sand to form so if beach erosion happens too quickly, new sand won’t be created in time so the beach will turn into dirt which erodes faster. 

The ocean is rising due to climate change and beaches and other places all over the world are being affected. Since many of beaches and islands are only a couple feet in elevation it is thought that by 2050 some will be uninhabitable.

Beaches are important because they absorb waves that otherwise could cause erosion. If the oceans keep rising flooding rates will rise and homes will be destroyed. Giants floods have happened before and if the ocean keeps rising these monster floods will become more and more frequent.

Another thought about it is that beaches across the world will be flooded over and these places will get less and less visitors until the beach is just water and people will stop coming to them. Beaches attract a lot of tourism and if beaches are destroyed tourists will stop coming which will affect the economy.

It is important to protect beaches because we can study the sand so see what it is made of and determine where it came from. This can tell scientists if there is big changes, if mountains are eroding too fast, changes to currents in the oceans, if the water is changing and other things. Then scientists can track changes that are occurring on earth and learn why. 

 

Sources Of Error

Some sources of error include: 

The procedure listed a filter that was not needed, because the sand wasn’t small enough. This could be a source of error because the experiment used household filters and not filters designed for sorting sand. 

The tea filter took a long time to filter and some grains may have been incorrectly sized. 

We were not able to measure sand size under microscope, so relied on the sorting filters to determine general size of grains. 

Samples were not collected at the same time or same location on beach. They were also left to sit for a period of time before testing. Some samples (from below low tide line) were wet. Samples from above high tide and other locations were dry. Wet samples were dried with low heat which could impact the biotic materials.

Observations and photos were used to determine the composition of sand, including the type of rocks and minerals. This could lead to some inaccuracy.

 

Citations

Blueford, Joyce R. “Analyzing and Interpreting the Shape of Sand Particles.” Www.msnucleus.org, 1992, www.msnucleus.org/membership/html/k-6/rc/rocks/4/rcr4_5a.html.

Exploring Our Fluid Earth. “Beaches and Sand | Manoa.hawaii.edu/ExploringOurFluidEarth.” Manoa.hawaii.edu, 2022, manoa.hawaii.edu/exploringourfluidearth/physical/coastal-interactions/beaches-and-sand.

Flexamat. “How to Prevent Beach Erosion | Flamat.” Flexamat, 27 Mar. 2022, www.flexamat.com/post/ways-to-prevent-beach-erosion.

Gray, Susan H. Oceanography the Study of Oceans. C. Press/F. Watts Trade, 2012.

Hallberg, Robert. “Ocean and Ice Processes.” Www.gfdl.noaa.gov, Princeton University Forrestal Campus, www.gfdl.noaa.gov/ocean-and-ice-processes/#:~:text=Examples%20include%20wind%2D%20and%20buoyancy. Accessed 12 Nov. 2023.

Hayati, Hasti, et al. “Dynamic Behaviour of High Performance of Sand Surfaces Used in the Sports Industry.” Vibration, vol. 3, no. 4, 29 Oct. 2020, pp. 410–424, www.mdpi.com/2571-631X/3/4/26/pdf, https://doi.org/10.3390/vibration3040026.

King, Hobart M. “The “Acid Test” for Carbonate Minerals and Carbonate Rocks.” Geology.com, 2019, geology.com/minerals/acid-test.shtml.

Leavitt, Duane. Activity 29: Constructing a Set of Soil Sieves Maine Geological Survey. Maine Geological Survey.

 

NOAA. “How Does Sand Form?” Noaa.gov, 2019, oceanservice.noaa.gov/facts/sand.html. Accessed 12 Nov. 2022.

Science Buddies Staff. “Building Beaches | Science Project.” Science Buddies, 20 Nov. 2020, www.sciencebuddies.org/science-fair-projects/project-ideas/OceanSci_p011/ocean-sciences/building-beaches.

Short, Andrew. “Coastal Processes and Beaches | Learn Science at Scitable.” Nature.com, 2012, www.nature.com/scitable/knowledge/library/coastal-processes-and-beaches-26276621/.

Susan Heinrichs Gray. Geology. Childrens Press, 2012.

US Army Corps of Engineers. “Learn about Sand: Compare and Contrast.” Experience.arcgis.com, 2022, experience.arcgis.com/experience/f55871e51fcd4ae7a3a855e9f89a1f2a/page/Learn-about-Sand/. Accessed 12 Nov. 2023.

US Department of Commerce, National Oceanic and Atmospheric Administration. “What Is the Difference between Weather and Climate?” Oceanservice.noaa.gov, oceanservice.noaa.gov/facts/weather_climate.html#:~:text=Weather%20reflects%20short%2Dterm%20conditions.

US Department of Commerce, NOAA. “Beach Hazards and Safety.” Www.weather.gov, www.weather.gov/safety/beachhazards#:~:text=Unfortunately%2C%20many%20people%20are%20injured. Accessed 12 Nov. 2023.

 

 

 

 

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