Beach Quality and the Effect of Breakwaters
| Author(s): | Globe students |
| School: | Laniteio Lykeio A in Lemesos Cyprus |
| Grade/Age Level: | age 15-18 |
| GLOBE Teacher: | not specified |
| Partner Schools: | not specified |
| Partner Students: | not specified |
| Date Submitted: | June 07, 2003 |
Summary
Through our investigation we aimed to discover the quality of our town's seawater and whether breakwaters have a negative effect on seawater's quality
For the complete report, please see the online report.
Abstract
1. Research Question/Hypothesis
The troubling of many citizens of our town about the condition of our sea and the results of previous research, have led us to the following questions:
What is the quality of Limassol?s seawater today?
Do breakwaters have a negative effect on the quality of seawater?
2. Research Method
In order to gather data and answer our research questions, we selected two different locations, one of which was near breakwaters. Using Globe protocols we measured the transparency, temperature, dissolved oxygen, pH, salinity, alkalinity and nitrogen on these locations, as well as their coordinates using a GPS receiver.
3. Data Summary
All the measurements are presented in tables and graphs, including labels for the date, the code number of the study site and its coordinates.
4. Analysis
Average values were obtained for each measurement, for each study site separately. The average values, as well as the graphs, were compared in order to locate differences between the two study sites.
5. Conclusions
It appears that, even if the two locations are very near to each other, the values of some parameters are a little different. However, there is nothing concerning about the quality of Limassol?s seawater. At the same time, it is proved another once that the salinity of the Mediterranean is higher than the average salinity of the world?s seawater.
6. Discussion
We feel that more measurements should be taken, especially in the summer, when the conditions at the beach are completely different.
7. Bibliography
Globe Protocols
Research of the Department of Fisheries and Marine Research - Ministry of Agriculture, Natural Resources and Environment - Cyprus
Hypothesis
2. Research Question/Hypothesis
2.1 Introduction to Hydrology
We do not just drink water; we are water. Water constitutes 50 to 90 percent of the weight of all living organisms. It is one of the most abundant and important substances on the Earth. Water sustains plant and animal life, takes part in the formation of weather, helps to shape the surface of the planet through erosion and other processes and covers 71% of the Earth?s surface. Water continually circulates between the Earth?s surface and its atmosphere in what is called the hydrologic cycle or water cycle ? one of the most important processes in nature. Water may be chemically inactive, however it takes part in many important chemical reactions and most substances are soluble in water. That is why truly pure water can rarely exist in nature. During its cycle, water carries many natural but also human-introduced impurities. These impurities give each amount of water its distinctive chemical makeup or quality. For example, rain and snow capture small dust particles or aerosols from the air, and sunlight causes emissions from the burning of gasoline and other fossil fuels to react with water to form Sulfuric and nitric acids. These pollutants return to Earth as acid rain or snow. The acids in the water slowly dissolve rocks, placing dissolved solids in water. Small but visible pieces of the rocks and soils also enter the water, resulting in suspended solids and making some waters turbid. When water percolates into the ground, it is in very close contact with rocks and more minerals dissolve into the water. All these impurities dissolved or suspended in water determine its quality.
The science that studies water and its quality is called Hydrology. Hydrology is an important field that becomes more valuable for the life on Earth as clean water becomes scarcer. Water as Η2Ο hasn?t got much interest in its chemistry. It?s the impurities in water that are of interest and concern at the same time. The object of hydrology is to see how all the impurities, not necessarily pollutants, just anything other than Η20, affect the organisms living in water or using the water. Each amount of water around the world is unique, so hydrology gives us the opportunity to gather information about the quality of certain water bodies and analyse the data in order to draw conclusions.
2.2 The problems of Limassol?s beach
Limassol is nowadays the largest town in Cyprus and at the same time, the largest port of the island. Its history begins at the prehistoric times and reaches our days. The town started to develop after 1960 and especially after the sudden increase of its population because of the Turkish invasion in 1974. Limassol owes its development to its privileged geographic position, which is also in favour of the development of tourism, and additionally to its port. Many hotels, blocks of flats and other tourist facilities have been built along the beach of Limassol, covering the area from the old port to the ancient town of Amathounta. In addition, many industrial units are located in the area between the old and the new port.
Under these circumstances, there was a big possibility that the seawater was being polluted, something with serious consequences for the marine life. Surveys conducted by the department of fisheries and other organisations however, showed that all the parameters related to water quality were normal and that there was no reason for concerns. This might have been a result of the operation of the sewerage system and other measures taken in order to prevent pollution.
The only problem seemed to be the large concentration of nitrogen compounds at areas near breakwaters. A study by the department of fisheries resulted that there was an abnormal situation with respect to the nitrogen compounds, something that would certainly have an effect on the marine life. They concluded that the existence of breakwaters parallel or perpendicular to the shoreline enhanced the problem, as they resulted in low circulation of the water. They suggested that the breakwaters should be removed but the costs of such a work were very high and many other factors would need to be taken in mind so until today nothing has been done yet. The measurements of their survey are shown in the following page. As it can be clearly shown, the concentration of nitrites at the reference stations A and B, as well as the stations F and K which were situated towards the seaward side of the breakwaters, is within the natural background levels (0.0 to 1 ppb). However for the stations D, E, G, H and J, which were situated towards the lee side of the breakwater, the concentration of nitrites is abnormal.
A possible explanation for these results leads to the hypothesis that there is an input of nitrogen compounds through leaching or drainage of contaminated groundwater from the adjacent coastal installations and aquifer. This, in combination with an expected limitation of water circulation due to coastal defence structures may explain the relatively high values.
2.3 The purpose of our research
Since our research is connected to such a significant subject as water, our results and conclusions will be very important. They concern not only the people living in our town or the tourists but most of all the sea life
First of all, we want to develop a better understanding of our local water resources. This knowledge can help us make better decisions about how to use or manage the resources. Then, we want to assess the extend to which human activities are affecting the quality of our water and thus affecting how we will be able to use it in the future as well as the life of water organisms.
After taking measurements of some chemical and physical parameters at one or two coastal areas, we intent to answer the following questions:
What is the quality of Limassol?s seawater?
Do breakwaters appear to have a negative effect on the quality of seawater?
ResearchMethod
3. Research Method
3.1 Hydrology Study Sites
3.1.1 Enaerios Pier
The first location selected for taking measurements is a pier in an area called ?Enaerios?. This area is located in a central part of the town, at the beginning of the seaside road that leads up to ancient Amathounta. The reason why it was chosen is because it is very near the town centre and the old port, while many ships anchor some kilometres away from the beach. These facts might result in some pollution of the water, which we may be able to detect. Additionally, the pier was convenient, because it is very close to our school and it was also easy to take the measurements on site, immediately after obtaining the water sample.
The coordinates of our first study site were found using a GPS receiver (Global Positioning System) and are shown in the following table:
We have taken a total of 8 measurements at this location, during the period 18.11.02 ? 26.1.03. The measurements were taken approximately 11.00 ? 11.30 local time (GMT +02:00) and took us about one and a half hours.
The measurements were taken by groups of three or four students, together with their teacher. They were all taken on site, immediately after collecting the water sample and were recorded on Data work Sheets. Whenever it was possible, two sub-groups repeated the measurements, in order to ensure their accuracy.
3.1.2 KOT Beach
In order to locate possible differences in the quality of water in an area near breakwaters, we took measurements from a second location. Our second study site was 1-2 kilometres from the first one, near the public beach of the Cyprus Tourism Organisation (CTO)
The coordinates of the second study site were again found using a GPS receiver and are presented in the following table:
We have taken only three measurements at this location, on 20/2/03, 6/3/03 and 23/3/03. The procedure followed was exactly the same as on the first site.
3.2 Collecting the Water Sample
Collecting the water sample is the first and one of the most important steps of taking the measurements. The water sample must be collected from the same location every time and be tested immediately. If unavoidable, samples may be bottled and tested later, but only for pH, alkalinity and salinity. All the other measurements must be taken on site.
Materials and Tools:
4-L bucket with a strong rope attached securely to the handle
Paper towels
500-mL polyethylene sample bottles
Notebooks, pens, Data work sheets
Latex gloves
Sampling Technique
1. Holding onto the rope, lower the bucket into the water and allow it to fill partially with water. Once some water enters the bucket, retrieve the bucket and swirl the water around to clean out the bucket. Discard this water and repeat the procedure once more. Do not use distilled water to rinse the bucket as this will change the sampling results. Likewise never let the sampling bucket be used for cleaning or other purposes since this will also affect the sampling results. If you are sampling from a lake, bay or the ocean, take samples from the shore and throw the bucket out as far as possible to take your sample. Do not let the bucket fill up and sink. Also be careful not to stir up bottom sediment.
2. To obtain a sample, allow the bucket to fill to about 2/3 to 3/4 full. Then hoist the bucket out of the water.
Bottling Technique
1. Label a 500-mL polyethylene bottle with your school?s name, the teacher?s name, the site name, the date and time of collection.
2. Rinse the bottle and cup with sample water.
3. Fill the bottle with sample water until the water forms a dome shape at the top of the bottle so that, when the cup is put on, no air is trapped inside.
4. Seal the cap of the bottle with masking tape.
5. Store these samples in a refrigerator at about 4 oC until they can be tested.
6. Once the seal is broken, do the pH test first, then the tests for salinity, alkalinity and nitrate. Ideally, one opened, all the measurements should be performed during the same lab session.
3.3 Protocols
3.3.1 Water Transparency Protocol
Light, essential for growth of green plants, travels further in clear water than in either turbid water that contains suspended solids or coloured water. There are two methods that are commonly used to measure the transparency, the Secchi Disk and the turbidity tube. Secchi disk transparency was first measured in 1865 by Father Pietro Angelo Secchi, scientific advisor to the Pope. This simple and widely used measurement is the depth at which a 20-cm black and white disk lowered into water just disappears from view, and reappears again when raised.
Materials and Tools:
Secchi Disc
5m length of rope
Waterproof markers
Meter tape
1. The Secchi Disc is a plastic disk with 20cm diameter, divided into four quadrants. The two opposite quadrants are painted black and the other two white.
2. Lower the disk slowly into the water until it just disappears. If possible, grab the rope at the surface of the water and mark this point on the rope. If it is not possible to mark the rope at the water surface, mark the rope a known distance above the water.
3. Then raise the Secchi disk until it just reappears into view. Grab the line at the surface of the water when the Secchi disk reappears and mark this point. The rope should now be marked at two points.
4. If the two depths differ more than 10cm the procedure must be repeated.
5. Record both depths on the Hydrology Investigation Data Work Sheet to the nearest 1cm.
6. Using the Cloud Cover Protocol, determine the cloud cover. Determine the distances between where each observer marked the rope and the water surface. Record both on the Data Work Sheet.
7. If the Secchi disk reaches the bottom of the study site and it has not yet disappeared, record the depth to the bottom and put a greater than symbol (>) in front of the measurement.
Sunlight provides the energy for photosynthesis, thus penetration of sunlight into a water body determines the depth to which algae and other plants can grow, and the relative amount of growth. Transparency decreases as colour, suspended sediments or algal abundance increases. Water is coloured by the presence and action of some bacteria, phytoplankton and other organisms, by chemicals leached from soil and by decaying plant matter. Most natural waters have transparency ranging from one metre to a few metres. A low value, less than 1 metre, would be expected in a highly productive body of water or can be due to high concentration of suspended solids. Extremely clear waters can have transparency up to 30-40 metres
3.3.2 Water Temperature Protocol
Water temperature is largely determined by the amount of solar energy absorbed by the water and the surrounding soil and air. More solar heating leads to higher water temperatures. Water that has been used in manufacturing and discharged into a water body may also increase water temperature. Water evaporating from the surface can lower the temperature of the water but only for a thin layer at the surface.
Materials and Tools:
Thermometer
Clock
Long piece of string
Data sheets
1. Tie one end of a piece of string securely to the end of the thermometer. Immerse the thermometer to a depth of 10cm in the water for 3 to 5 minutes.
2. Raise the thermometer only as much as is necessary to read the temperature. Quickly note the temperature reading. If the air temperature is significantly different from the water temperature or it is a windy day, the thermometer reading may change rapidly after it is removed from the water.
3. Lower the thermometer for another minute and note the reading. Repeat the same once more.
4. If the values have a difference of 0.5 οC or more, repeat the procedure. Otherwise, record the measurements on the Work Sheets.
We need to measure water temperature to understand the patterns of change over the year because the temperature of a water body strongly influences the amount and diversity of its aquatic life. Lakes that are relatively cold and have little plant life in winter bloom in the spring and summer when water temperatures rise and the nutrient-rich bottom waters mix with the upper waters. One also finds periods of mixing in the fall. Because of this mixing and the warmer water temperatures, the spring overturn is followed by a rapid growth of microscopic aquatic plants and animals. Many fish and other aquatic animals also spawn at this time of year when the temperatures rise and food is abundant. Shallow lakes are an exception to this cycle, as they mix throughout the year. One concern is that warm water can be fatal for sensitive species.
3.3.3 Dissolved Oxygen Protocol
Water is a molecule made of two hydrogen atoms and one oxygen atom ?hence H2O. However, mixed in with the water molecules of any body of water are molecules of oxygen gas (O2) that have dissolved in the water. Dissolved oxygen is a natural impurity in water. Aquatic animals do not breathe the oxygen in water molecules; they breathe the oxygen molecules dissolved throughout the water. Without sufficient levels of dissolved oxygen in the water, aquatic life suffocates. Dissolved Oxygen levels below3mg/L are stressful to most aquatic organisms.
Materials and Tools:
Dissolved Oxygen Test Kit (La Motte Code 5860)
Distilled water
Thermometer
Data work Sheets
Latex gloves
1. Follow the instructions of the test kit carefully.
2. Record the values from the student groups on the Hydrology Investigation Data Work Sheet.
3. Take the average of the DO values. If the values are all within 1mg/L of the average, accept the average DO value. Otherwise repeat the measurement
In the atmosphere, roughly one out of every five molecules is oxygen. In water, about one to ten molecules in every million molecules are oxygen. Vigorous mixing of air and water increases the amount of oxygen dissolved in water. So does photosynthesis by aquatic plants. Oxygen is consumed by fish, zooplankton and the bacteria that decompose organic materials. Near sources of organic material the dissolved oxygen levels tend to be very low.
3.3.4 pH Protocol
pH is a measure of the acid content of water. The pH of a water influences most of its chemical processes. Pure water with no impurities (and not in contact with air) has a pH of 7. Water with impurities will have a pH of 7 when its acid and base content are exactly equal. At ph values below 7 we have excess acid and at pH levels above 7 we have excess base in the water. The pH scale is logarithmic, which means that a one-unit change in pH represents a factor of ten change in the acid content of the water.
Materials and Tools:
pH meter
Five 50-mL beakers
pH buffer solutions for pH 4,7 and 10
1. Prepare the buffer solutions and calibrate the pH mete
DataSummary
4. Data Summary
During our research, eleven sets of measurements have been taken. The first eight sets correspond to the first study site (?Enaerios Pier?) while the other three correspond to the second location (?KOT Beach?). All the measurements are shown in the following table:
Analysis
5. Analysis
5.1 Water Transparency
We have taken measurements only at the first study site and every time, the secchi disk reached the bottom before disappearing. Therefore, we might say that our waters our clear, since the transparency is obviously more than 3 metres. However, a specific conclusion on how transparency changes during the year can not be drawn since our measurements are constant.
5.2 Water Temperature
For the first study site the average is 19,06 degrees while for the second location is 16,3 degrees, which is lower than the temperature of the first site.
5.3 Dissolved Oxygen
The average values for the dissolved oxygen are 7,65 mg/L and 8,53 mg/L for the first and second site respectively. The fact that the second site has a larger average might be due to the fact that the water mixes with the air while crashing on the rocks of the breakwater.
5.4 Water pH
The average of the second site, 8.36 pH units, is higher than the average of the first site which is 7.67 units.
5.5 Salinity
For the first and second site the average values for the salinity are 40.04 and 38.8 respectively.
5.6 Alkalinity
The average values are 149,5 for the first site and 169.3 for the second site.
5.7 Nitrate Nitrogen
The average is 0 for both sites.
Conclusions
It appears that, even if the two locations are very near to each other, the values of some parameters are a little different. The average values for the dissolved oxygen, the pH and the alkalinity are slightly higher for the second site than for the first site, but we must have in mind that the temperature was in average lower at the second site.
However, there is nothing concerning about the quality of Limassol?s seawater. At the same time, it is proved another once that the salinity of the Mediterranean is higher than the average salinity of the world?s seawater.
Discussion
We feel that more measurements should be taken, especially in the summer, when the conditions at the beach are completely different.
Bibliography
7. Bibliography
Globe Protocols
Research of the Department of Fisheries and Marine Research - Ministry of Agriculture, Natural Resources and Environment - Cyprus