Content. ii. Experiment of barnacles

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2 Content 1. Introduction 2. Objective 3. Experiment i. Experiment on sea water ii. Experiment of barnacles iii. Experiment of apple snails 4. Discussion 5. Conclusion 6. References Abstract Polluted sea water can affect barnacles and apple snails in terms of activity and structure. Two beaches, Anglers beach (representing polluted beach) and Casam beach (representing cleaner beach) were visited. The nitrate and phosphate levels (which are the indicators of water pollution) were compared between the sea water from the two beaches. The activity (such as distance travelled in 1min), appearance (such as the colour and shell hardness) and the distribution of the barnacles and apple snails in the two beaches were also compared. It was found that the nitrate and phosphate levels of Anglers beach were higher, indicating that it was more polluted. The activity and appearance of the barnacles and apple snails from the Anglers beach were also lower and showed an unhealthy sign respectively. There were also fewer barnacles and apple snails in Anglers beach. It could be concluded that polluted sea water could affect the barnacles and apple snails. 2

3 1. Introduction Background information of Anglers beach Anglers beach (Fig. 1) is located in the Castle Peak Road, Sham Tseng, New Territories 13 Miles, below Sea Crest Villa Phase III, with the length of 200 meters. In 1975, Anglers beach was once a popular place for swimming. But 20 years later (1995), the Regional Council had taken the large ship oil spill into account, coupled with the Ting Kau Bridge, Tsing Ma Bridge and Kap Shui Mun Bridge construction, leading to the poor water quality since It has been rated unsatisfactory by the Environmental Protection Department and the department announced that this beach was no longer suitable for swimming. The E. coli level, as an indicator of water quality, of the beach water in 2010 was also at a high level. (Fig. 2). When we went to this beach, we found that there were only a small variety of organisms. The organisms were almost black. The stones were polluted and turned black. It seemed that the sea water in Anglers beach is highly polluted. At the same time, we went to another beach called Casam beach (Fig.1). This beach was also once polluted by the oil spillage and bridge construction and was labeled as not suitable for swimming. However, because of the improved water quality, it was stated suitable for swimming in The E. coli level of the beach water was improved in 2010 (Fig. 2). Fig. 1 shows Anglers beach and Casam beach (from CentaMap) 3

4 Fig.2 shows the pollution levels (as indicated by mean E. coli levels) of beach water in Tsuen Wan (from Environmental Protection Department) Effect of polluted water Water pollution upsets the ecosystem or even leads to species extinction. It contains high concentration of impurities or minerals, such as nitrate. Some creatures may not adapt to this environment and some of them may have unhealthy conditions, such as barnacles. Their walls become thicker and darker. They show slow movement and become less sensitive to changes. Why is it important to do this project? There are places with water pollution in Hong Kong, such as Anglers beach. We all know that we cannot swim in these places. Some of us may ignore those species living in such polluted area. Actually, water pollution upsets the ecosystem or even leads to extinction of species. We would like to draw people's attention and let them see how living things are seriously affected. This project aims to remind everyone to keep our sea clean. Objective of the study In this investigation, we are going to find out how polluted sea water can affect the barnacles and apple snails by: 1. Comparing the salinity, conductivity, nitrate and phosphate level, dissolved oxygen content and ph of the polluted and cleaner sea water. 2. Comparing the distribution, behavior, hardness of barnacles in the polluted and cleaner sea water. 3. Comparing the distribution, behavior, hardness of apple snails in the polluted and cleaner sea water. 4

5 2. Materials and methods A. Field Visit We had four field visits on 31/1/2012, 13/2/2012, 10/3/2012 and 27/3/2012. On the last day, we separated in two small groups to go to two beaches, Anglers beach and Casam beach. The reason why we chose one more place to visit was that Anglers beach was regarded as a polluted beach which was our target but we needed a control for comparison. At first, we hoped to carry out the experiments at school (Fig. 3). However, we found that the set up had a lot of limitations and lacked many essential factors for organisms survival. The conditions were completely different from a real beach. Therefore, we decided to carry out the experiment on a cleaner beach. Fig. 3 shows the set up for experiments in our school We chose Casam beach, which is a cleaner beach and could be acted as a control experiment to show that the results were due to the polluted water but not other factors. We searched the information about predicted tides from Hong Kong Observatory and then selected the dates and time which had the height of tides lower than 1.0m (above the Chart Datum which is m below the Hong Kong Principal Datum) which could facilitated our investigation. 5

6 Record of field trips: Date Time Venue Main aims of the visits Temp. Temp. Relative Light Wind (beach) (seawater) humidity intensity speed (km/h) 31/1/20 10:00 Anglers beach 1) Environment and / / / / / 12 13:00 species research 2) Decide the objectives of our project. 13/2/20 15:00 Anglers beach 1) Court the number of 27.9 C 18 C 57% :30 barnacles using quadrat 2) Collect species and sample we need. 10/3/20 15:30 Anglers beach 1) Collect Apple Snails C 18 C 71.3% :00 2) Experiment on the beach(sea Water, etc.) 27/3/20 17:30 Casam Bench 1) Experiments on 25 C 19 C 54.4% :00 & Anglers barnacles and Apple beach Snails. (Quantity, etc.) Table 1 shows the records and physical factors of our field visits During or after each field visit, we conducted our experiments into three main directions: I) Experiment on the sea water, II) Experiment on the barnacles and III) Experiment on the apple snails B. Principles of experiments I) Experiment on the sea water We compared the salinity, conductivity, levels of nitrate and phosphate, dissolved oxygen content and ph of the sea water from the Anglers beach and Casam beach so as to reflect the pollution level of the Anglers beach. i. Salinity On average, the salinity of the seawater in the world's oceans is about %(30 35ppt). A suitable salinity is very important to marine organisms as it will affect the osmotic level and hence the behaviour of the organisms, e.g. the marine organisms may excrete excess salts through their gills. ii. Nitrate and phosphate level 6

7 Nitrates are a compound of nitrogen and phosphates are phosphorous compounds. Excess nitrate and phosphorus concentration in the sea water may lead to eutrophication which means that the environment is enriched with nutrients and this may cause algal blooms. Algae are a group of organisms that live in water and can make their own food through photosynthesis. When there are too much phosphates and nitrate in the sea water, the algae will grow explosively as the phosphate and nitrate will provide nutrient for them. After that, the algae will use up most of the dissolved oxygen at night and cause suffocation of other marine organisms. Besides, when the algae die, bacteria require oxygen to decompose the dead algae. When there are a lot of bacteria to decompose the dead algae, this will use up even more oxygen. The bacteria then will release more phosphates back into the water, which feed more algae, and this makes the problem worse. In sum, the increasing level of phosphate and nitrate will lower the dissolved oxygen concentration in the sea water and cause suffocation of the marine organisms finally. Ideally, the phosphate and nitrate level should be 0 in the sea water. When the phosphate and nitrate level is over 0, it can prove that the sea water has polluted by organic matter. iii. Dissolved oxygen content The concentration of dissolved oxygen in clean sea water is about 85.84%. Dissolved oxygen is a necessary element to the life of all marine organisms as oxygen is required in aerobic respiration. When the sea water is polluted by the oxygen demanding organic matter (like sewage) or nutrients (e.g. nitrate and phosphate) which will stimulate the growth of algae, this will lower the dissolved oxygen concentration in the sea water and affect the marine lives. iv. ph value The normal ph level of clean sea water is about 7.5 to 8.4 which is important for the growth of the marine organisms. The marine organisms may die because of the unsuitable ph (e.g. when the sea is polluted by acid rain). 7

8 II) Experiment on the barnacles Balanus amphitrite is one type of barnacles. It has smooth white walls and there are purple or brown stripe on it. Sometimes, people regard it as ''gooseneck''. Actually, it is called ''acorn''. Acorn barnacles attach to rock or wood. Its walls are made of rigid plates. Those barnacles we can find on the Anglers beach is black in colour (Fig. 4). As compared to those on the clearner beach, the barnacles on the Casam beach are less black in colour and they are even moving (Fig. 5 and 6). In other words, the barnacles on Casam beach are more active than those in Anglers beach. Therefore, we believed that polluted water has great effect on barnacles. We are going to find out why and what the black layer on barnacles surface is by carrying out grease spot test. Fig. 4 shows the black barnacles we find on Anglers beach Fig. 5 shows the barnacles living in Casam beach 8

9 Fig. 6 shows the barnacle living in Casam beach. It is moving. III) Experiment on the apple snails Apple snail is a well adaptable animal. Apple snails inhabit various ecosystems: ponds, swamps and rivers. A typical adaptation of apple snails is the combination of a bronchial respiration system comparable with the gills of a fish (at the right side of the snail body) and a lung (at the left side of the body). This lung/gill combination expands the action radius of the snail in searching for food. We have found many apple snails near or covered by sea water in Anglers beach (Fig. 7) which is polluted mainly because of industrial wastes and reclamation project carried out by the government. As compared to those in Casam beach, we can find out how polluted water affects the apple snails. Fig. 7 shows the apple snail on the Anglers 9

10 C. Procedures and equipments: I. Experiment on the sea water Procedures: 1. The sea water was collected from Anglers beach and Casam beach. 2. The salinity, nitrate level, phosphate level, dissolved oxygen level and ph were checked by the salinity and conductivity meter (Fig. 8), nitrate and phosphate test kit (Fig. 9 and 10), dissolved oxygen data logger (Fig. 11) and ph meter (Fig. 12) respectively. 3. The results were compared with tap water. Fig. 8 shows the salinity meter Fig. 9 shows the nitrate test kit 10

11 Fig. 10 shows the phosphate test kit Fig. 11 shows the dissolved oxygen meter Fig. 12 shows the ph meter 11

12 Equipment: 1. Salinity and conductivity meter 2. Nitrate and phosphate test kit 3. Dissolved oxygen data logger 4. ph meter II. Experiment on the barnacles Procedures: Experiment carried out at our school: 1. Three barnacles collected in Anglers beach were put into three beakers of distilled water separately for 2 days 2. Grease spot test was performed using the distilled water soaking the barnacles Experiment carried out at Anglers beach and Casam beach respectively: 1. The black level of the barnacles were rated using the self made colour scale (Fig. 13) by two group members for three times each. (1 is the least black while 5 is the most black ) The mean and standard deviation of the value were calculated. Fig. 13 shows the self made colour scale to rate the black level of the barnacles 2. The shell hardness of the barnacles were rated (1 is the softest while 5 is the hardest) by two group members for three times each. The mean and standard deviation of the value were calculated. 3. The distributions of the barnacles were found by putting a 1m x 1m quadrat on three randomly chosen areas on the beach and counting the number of barnacles in the quadrat. The mean and standard deviation of the count were calculated. Equipment: 1. Distilled water 2. Alcohol 3. Beakers x3 4. Filter paper 5. Self made colour scale 6. 1m x 1m quadrat III. Experiment on the apple snails Procedures: 1. The distance traveled by the apple snails in the Anglers beach and Casam beach in 1min was measured by two group members for three times. 12

13 2. The shell hardness of the apple snails were rated (1 is the softest while 5 is the hardest) by two group members for three times each. 3. The distribution of the apple snails were found by putting a 1m x 1m quadrat on three randomly chosen area on the beach and counting the number of apple snails in the quadrat. 4. The mean and standard deviation of the each value were calculated. Equipment: 1. Ruler 2. 1m x 1m quadrat 3. Results I) Experiment on the sea water sea water (Anglers beach) sea water (Casam beach) Tap water Salinity (ppt) Conductivity (ms/cm) Nitrate level (mg/l) Phosphate level (mg/l) Concentration of dissolved oxygen(%) ph Table 2 shows the profile of water quality on the sea water from Anglers beach and Casam beach and the tap water The results show that the salinity and conductivity of the water from the two beaches are the same. Meanwhile, the nitrate and phosphate level, which indicate the polluted level, of the water from Anglers beach are higher than that of Casam beach. The dissolved oxygen content in Casam beach is higher than that in Anglers beach. It seems that Anglers beach is more polluted. II) Experiment on the barnacles Barnacles in the Anglers beach Barnacles in the Casam Colour rating using self made colour 4.67 ± ± 0.58 scale* (arbitrary unit) Shell hardness* (arbitrary unit) 3.33 ± ±0.58 Distribution** (per m 2 ) 17.67± ±

14 Observation after grease spot test Permanent No permanent translucent spot translucent spot can be removed by alcohol Table 3 shows the results about the barnacles from Anglers beach and Casam beach *Data are expressed as mean values of three different barnacles and two raters ± standard deviation. **Distribution of the barnacles is expressed as mean values of density of barnacles per unit area (m 2 ) on three different stones ± standard deviation. The results showed that the barnacles in the Anglers beach are more black (Fig. 14), with softer shell (Fig. 15) and fewer in number (Fig. 16) than those in the Casam beach. It seems that barnacles in the Anglers beach are in a less healthy condition. At the same time, the result from the grease spot test shows that the black substance on the barnacles is probably oil. Fig. 14 shows the colour rating of the barnacles in the two beaches (1 is the least black while 5 is the most black) 14

15 Fig. 15 shows the shell hardness of the barnacles in the two beaches (1 is the softest while 5 is the hardest) Graph showing the distribution of the barnacles in the two beaches Mean value of number of barnacles per unit area Barnacles of Anglers' Barnacles of Casam Fig. 16 shows the distribution of the barnacles in the two beaches III) Experiment on the apple snails Apple snails in Anglers beach Apple snails in Casam' Appearance of the substances on Yellowish oil Transparent substance the shell surface Observation after grease spot test Transparent spot appeared on the filter paper after drying and the spot can be removed by ether No transparent spot was formed after drying 15

16 Distance travelled in 1min* (mm) ± ± 6.08 Shell hardness* (arbitrary unit) 4.33 ± ± 0.58 Distribution** (per m 2 ) ± ± 4.00 Table 4 shows the results about the apple snails from Anglers beach and Casam beach *Data are expressed as mean values of three different apple snails and two raters ± standard deviation. **Distribution of the apple snails is expressed as mean values of density of apple snails per unit area (m 2 ) on three different area ± standard deviation. The results showed that the apple snails in the Anglers beach travelled a shorter distance in 1min (Fig. 17), with softer shell (Fig. 18) and fewer in number (Fig. 19) than those in the Casam beach. It seems that apple snails in the Anglers beach are in a less healthy condition and less active. Graph showing the distance travelled by the apple snails in 1min in the two beaches Mean value of distance travelled (mm) Apple snails of Anglers' Barnacles of Casam Fig. 17 shows the distance travelled of the apple snails in 1min in the two beaches 16

17 Fig. 18 shows the shell hardness of the apple snails in the two beaches (1 is the softest while 5 is the hardest) Graph showing the distribution of the apple snails in the two beaches Mean value of number of apple snails per unit area Apple snails of Anglers' Barnacles of Casam Fig. 19 shows the distribution of the apple snails in the two beaches 4. Discussion I) Experiment on the sea water According to the result, we found that the salinity and the conductivity of the sea water sample collected from the Anglers beach was the same as the clean sea water (Casam beach) but the nitrate and phosphate level was much higher than clean sea water. Ideally, the nitrate and phosphate level of the sea water should be 0. If it continues to increase, it will be very dangerous to the lives in the sea as it will stimulate the growth of algae which will lower the concentration of dissolved oxygen in the sea water. At the same time, we found that the concentration of dissolved oxygen of the sea water sample collected from the Anglers beach was lower than that of the clean sea water. It shows that the sea water in the Anglers beach is more polluted. II) Experiment on the barnacles Since the translucent spot appeared on filter paper when substance on the barnacles from the Anglers bench is added, it indicates that the substance is oil. Presence of oil on the surface of barnacles indicates the barnacles may have been living in an oil polluted area. The other organisms of that area may also have been polluted. The barnacles in Casam beach were bigger, harder and less black in colour. On the contrary, the barnacles from Anglers beach were smaller, softer and have more black substance on the surface. They were also less active than the barnacles in Casam 17

18 beach as we noticed that those on Casam beach were moving. This shows that the barnacles in Casam beach are healthier than that in Anglers beach. III) Experiment on the apple snails According to the results, the apple snails in the Anglers beach travelled a short distance than those in the Casam beach in the same time interval. It shows that the activity of the apple snails in polluted water is lower. At the same time, apple snails in the Anglers beach had a softer shell and this may act as an indicator of the unhealthy condition in the polluted area. At the same time, there were fewer apple snails in the Anglers beach. This shows that Anglers beach, with more serious water pollution, affects the lives of apple snails. Limitation and improvement 1) As we use our bare hand to measure the hardness of the shell of the barnacles and apple snails and naked eye to observe the colour of the barnacles, the measurement is quite subjective and not accurate enough. Although we tried to solve the problem by using two raters, even more raters are suggested to make it more objective. At the same time, machines testing the hardness and colour are more preferable to provide the objective results. 2) The Casam beach may not be a very good control because it might also be fairly polluted by oil spillage or bridge construction and it was just open for swimming a few months ago because of the improved water quality. It may not be a very good representation of a clean beach. A cleaner beach like Clear Water Bay can be an alternative next time. On the contrary, Anglers beach may not be the most polluted area. In order to draw a valid conclusion that polluted sea water affects the organisms, we should visit more beaches with polluted sea water to improve the validity of the result. 3) In this experiment, because of the time and resources, we just focus on one species of the barnacles and snails. As different species may have different adaptation on the environment, it is suggested that more species could be included in the experiment for comparison in order to draw a more representative conclusion. 4) We only used the nitrate and phosphate levels to indicate the pollution level of the sea water in our experiment. Due to the lack of facilities, we could not find out the E. coli level of the sea water which could show a better picture of the pollution level. We only used the information from the Environmental Protection Department as a comparison. It is suggested that the E. coli level in 18

19 the Anglers beach and Casam beach should also be checked. Suggested further research: 1) In this experiment, we just visited two beaches. Investigation on more beaches with a variety of polluting levels (e.g. very clean, clean, fair, polluted, highly polluted etc.) could be conducted in order to give a fuller picture on the polluting effect on organisms. 2) We had just investigated two kinds of species of barnacles and apple snails. In order to know more about the water polluting effect on the living things, more kinds of organisms (e.g. algae or other kinds of periwinkle) could be included in the study. 3) We just made observation at day time in later winter and early spring. As the activities of the organisms may vary with light intensity and temperature, the investigation could be conducted at night time or in other seasons. Perhaps we could get another ecological distribution in summer or autumn. 5. Conclusion 1) The sea water collected from the Anglers Bench is more polluted than the sea water collected from the Casam beach by comparing their difference in ph, salinity, nitrate and phosphate level, and the dissolved oxygen concentration. 2) The sea water in Anglers beach might be polluted by oil spillage as shown by the black substance on the barnacles. 3) The polluted sea water can affect the activity and the health of the barnacles and apple snails. 19

20 6. References 1. Science Clarified Ex/Eutrophication.html 2. Wikipedia (Eutrophication) 3. Environmental Protection Department (Water quality) etal.html#%e9%8a%85_metal 4. The Exotic Guides 5. Dissolved oxygen and water quality 6. Water on the web 20