Investigating the changes in concentration of chlorophyll a across 8 different physical parameters

Published:

Chapter 4: RESULTS

4.1 AVERAGE CONCENTRATION OF CHLOROPHYLL FOR OCTOBER AND NOVEMBER 2014

""

Figure 4.1 concentration of chlorophyll-a for October and November 2014

Figure 4.1 shows the concentration of chlorophyll-a for October and November at different stations, firstly it seems that the average concentration of October in all stations from S1 to S6, are higher than November, except S4 (developed corals) where the concentration for October was not detected since the concentration was too low. The concentrations for S7 and S8 have been taken only on November and it seems that S7 have the largest concentration (0.008091 mg"" ) of chlorophyll compare to other stations for November. In October the station where most chlorophyll is S3 (0.007915 mg""), the sandy patches.

Lady using a tablet
Lady using a tablet

Professional

Essay Writers

Lady Using Tablet

Get your grade
or your money back

using our Essay Writing Service!

Essay Writing Service

4.2 AVERAGE CONCENTRATION OF PHOSPHATE FOR OCTOBER AND NOVEMBER 2014

""

Figure 4.2 average concentration of phosphate for October and November 2014

The bar charts above shows the average concentration of phosphate of the 6 stations in October and 8 stations in November. Overall for stations 1 to 5 it is observed that the concentration of phosphate for November is more than October. Station 6 which is found at the reef it seems that there is very little change in phosphate. S8, the lagoon of Mahebourg have the highest of amount of phosphate(4.901mg/L), this may be due to high activity of human activity because of a religious ceremony, the sea water was polluted with foods such as coconut and flowers found nearby. Since samples were taken only in November it will be difficult to confirm that it was only due to this religious ceremony.

4.3 AVERAGE CONCENTRATION OF NITRATE FOR OCTOBER AND NOVEMBER 2014

""

Figure 3.3 average concentration of nitrate for October and November 2014

The bar chart above shows the average concentration of nitrate for the 6 stations October and 8 stations in November. The concentration of nitrates varies for each station. For S1 the concentration of nitrate is greater in November (0.49275 mg/L) than in October (0.266275 mg/L). For S2 and S3 the concentration of nitrate is greater in October S2 (0.6495 mg/L), S3 (0.25725 mg/L) than in November S2 (0.24185 mg/L) and S3 (0.06703 mg/L). S4 and S5 the concentration of nitrate is greater in November than in October as seen on the bar chart. But the greatest concentration of nitrate is recorded on S7 (0.827915 mg/L) on November. S6, for the control it remain approximately the same concentration with a very little increase for October in the concentration of nitrates.

4.4 AVERAGE CONCENTRATION OF SILICATE FOR OCTOBER AND NOVEMBER 2014

""

Figure 4.4 average concentration of silicate for October and November 2014

This bar chart above represent the average concentration for silicate, as it seems on the bar chart only S4, developed coral where the concentration of silicate for October have been obtained (0.012497 mg/L). For the other stations from S1 to S8 the concentration was too low to be obtained by the method used

4.5 AVERAGE SALINITY IN PPM FOR OCTOBER AND NOVEMBER 2014

""

Figure 4.5 average salinity in ppm for October and November 2014

This bar chart above indicates the average salinity in October and November, as it show on the bar chart the salinity for November from S1 to S6 are higher which are 40 ppm and S6 is 41 ppm than October S1, S2, S4 at 34 ppm, S3 at 35 ppm and S5 at 33.6 ppm and S6 at 35.4 ppm. S7 and S8 remain the same at 36 ppm for November.

4.6 AVERAGE TEMPERATURE IN DEGREES CELSIUS FOR OCTOBER AND NOVEMBER 2014

""

Lady using a tablet
Lady using a tablet

Comprehensive

Writing Services

Lady Using Tablet

Plagiarism-free
Always on Time

Marked to Standard

Order Now

Figure 4.6 average temperature for October and November 2014

The bar chart above indicates the average temperature of sea surface for October and November. The average temperature is higher for the 8 stations November, the mean temperature from S1 to S4 and S7 is 28 ""C. The average temperatures for October have a maximum of 26 °C for S1 and S2 and least temperature at S4 at 24.6 °C. At the reef, the mean temperature for November is 27 °C and October is 26 °C.

4.7 AVERAGE PH FOR OCTOBER AND NOVEMBER 2014

""

Figure 4.7 average pH for October and November 2014 for eight stations around ile aux aigrettes

The bar chart above represents the average pH of the eight stations of sea surface around ile aux aigrettes and Mahebourg lagoons. It shows that the average pH from S1to S6 is approximately the same with very little variation between the average pH of October and November. The pH for S8 is alkaline at a pH of 8.6 perhaps of the religious ceremony.

4.8 AVERAGE TURBIDITY FOR OCTOBER AND NOVEMBER 2014

""

Figure 4.7average pH for October and November 2014 for eight stations around ile aux aigrettes

The figure above shows a bar chart representing the average turbidity, on overall it indicates that October have the higher turbidity on all six stations over November, and also have a great difference between all of them. The turbidity for S3, the sandy patches have the highest turbidity for October 29 compare for November of the same station have the least turbidity 5.5. The stations S2, sandy deep water have the highest turbidity of 9.5 for the month of November. Most turbidity for October are above 25 ntu except for stations S4 and S5 which are 23.5 and 23 ntu respectively.

TABLE 4.1 SHOWS RESULTS OF THE SHAPIRO-WILK TEST FOR NORMALITY

Dependant variables

Shapiro-Wilk

p-value

Chlorophyll-a

0.00

phosphate

0.00

nitrate

0.00

silicate

0.00

salinity

0.012

temperature

0.00

PH

0.00

turbidity

0.00

The Shapiro-Wilk test indicates that chlorophyll-a, the three nutrients and the physical parameters shows a negative results to the test that is all the data are not normally distributed as most of them have p- value too small or even zero.

TABLE 4.2 RESULTS FOR CORRELATION TEST FOR RELATIONSHIPS BETWEEN CHLOROPHYLL-A AND MONTHS, STATIONS, PHOSPHATE, NITRATE, SILICATE, PH, SALINITY, TEMPERATURE, AND TURBIDITY USING SPEARMAN’S RHO

CHLOROPHYLL-A

VARIABLES

CORELATION COEFFICIENT

SPEARMAN’S RHO

p-value

MONTHS

-0.031

0.874

STATIONS

0.152

0.442

PHOSPHATE

-0.099

0.616

NITRATE

0.090

0.647

SILICATE

-0.286

0.140

SALINITY

0.092

0.640

TEMPERATURE

0.017

0.931

PH

-0.175

0.374

TURBIDITY

0.172

0.380

SIGNIFICANT VALUE WHEN P<5% (2 TAILED TEST)

By using the non parametric method of the Spearman’s Rho correlation since the data are not normal, the results in the table above shows that all data have a significant value greater than 0.05. It indicates that there is no relation between chlorophyll-a does not correlate spatially for stations p-value is 0.442, temporally for months p- value is 0.874, among nutrients for example nitrate p value is 0.647 and also with physical parameters for example pH is 0.374

Lady using a tablet
Lady using a tablet

This Essay is

a Student's Work

Lady Using Tablet

This essay has been submitted by a student. This is not an example of the work written by our professional essay writers.

Examples of our work

TABLE 4.3 SHOWS KRUSKAL-WALLIS ONE WAY ANOVA FOR THE INTERACTION OF CHLOROPHYLL-A, NUTRIENTS AND PHYSICAL PARAMETERS ACROSS STATION

Dependent variables

Kruskal-wallis one way anova

p-value

Chlorophyll-a

0.609

phosphate

0.712

nitrate

0.443

silicate

0.540

salinity

0.583

temperature

0.271

PH

0.000

turbidity

0.974

The table above shows the Kruskal-Waillis one way anova for the interaction of chlorophyll-a, nutrients and physical parameters across the eight stations the significant value p <5% this test is a non parametric test since the data are not normally distributed, it indicates that chlorophyll-a, all nutrients, salinity, temperature and turbidity does not have interaction among stations since the value of p is greater than 0.05 therefore the null hypothesis is favour since there is no significant different among stations. PH only has an interaction among the stations since the p-value is 0.0, hence there is a significant difference of ph among the staions

TABLE 4.4 SHOWS KRUSKAL-WALLIS ONE WAY ANOVA FOR THE INTERACTION OF CHLOROPHYLL-A, NUTRIENTS AND PHYSICAL PARAMETERS ACROSS MONTHS

Dependent variables

Kruskal-wallis one way anova

p-value

Chlorophyll-a

0.871

phosphate

0.01

nitrate

0.119

silicate

0.248

salinity

0.000

temperature

0.000

PH

0.191

turbidity

0.000

The table above shows the Kruskal-Waillis one way anova for the interaction of chlorophyll-a, nutrients and physical parameters across the month October and November the significant value p <5% this test is a non parametric test since the data are not normally distributed, it indicates that chlorophyll-a, nitrate, silicate and pH have no interactions spatially since the p-value are above 0.05, the null hypothesis that there is no significance difference across months. Phosphate, salinity, temperature and turbidity have the p-value is less than 5% hence it indicates that there is a significant change of phosphate, temperature and turbidity across month.

CHAPTER 6: DISCUSSION AND CONCLUSION

6.1 DISCCUSION

The coastal water of ile aux aigrettes shows that there a difference between the concentration of chlorophyll-a and phosphate, shows on the bar chart figure 4.1 and 4.2, the concentration of phosphate is not significant to chlorophyll-a comparing for October and November of both phosphate and chlorophyll-a. When the concentration of phosphate is high the amount of chlorophyll-a is low, S1, massive corals, indicates concentration of phosphate is 0.025 mg/l the concentration of chlorophyll-a is 0.004 mg"", it is similar for S2, S3, S4 and S6 for both October and November where the phosphate is high and chlorophyll-a is low and when phosphate concentration is low there is a higher level of chlorophyll-a concentration. S7 and S8 since there are data only for November also show the trend. Only S5, corals ecosystem, is different since when there is an increased of phosphate there is also an increased on chlorophyll-a. Past studies, proven that high level of phosphate affects can affect the photosynthetic capacity (Lewis, Griffin, Thomas and Strain (1993)). The correlation of Spearman’s Rho between phosphate and Chlorophyll-a have a p-value of 0.616 showing that it is not significant indicating the high level of phosphorus does not correspond to a high level of chlorophyll.

The results of figure 4.1 and 4.3 indicates that the concentration of nitrate varies to that of concentration of chlorophyll-a, from S1 to S8 there is any interaction between nitrates and chlorophyll-a neither for stations nor for months as for S1, massive corals and S5, corals ecosystem the concentration of nitrate for October are 0.266275 mg/l and 0.067 mg/l the concentration of chlorophyll-a are 0.004 mg""and 0.003 mg"" comparing the two stations to November where the concentration of nitrate are 0.49275 mg/l and 0.302535 mg/l the concentration of chlorophyll-a are 0.000495 mg"" and 0.001523 mg"". A low concentration of nitrate indicates a high concentration of chlorophyll-a for October but a high concentration give a lower concentration of chlorophyll-a for November. But comparing S2 to S1 and S5, a high level of nitrate for October 0.6495 mg/l indicates a high level of chlorophyll-a 0.007 mg"" and in November there was a low level of nitrate concentration 0.24185 mg/l and hence the concentration of chlorophyll-a was also low at 0.001131 mg"". The correlation of Spearman’ Rho between nitrates and chlorophyll-a have a p-value of 0.647 showing that there is any correlation among the level of nitrate and chlorophyll-a.

The concentration of silicate in figure 4.4 , are undetectable with method used only for the month of October where the concentration of silicate was 0.012497 mg/l. this unique data will be difficult to compare with the concentration of chlorophyll-a figure 4.1. This reason by the correlation Spearman Rho the p-value is 0.248 showing any correlation among silicate and chlorophyll-a.

The salinity shown in figure 4.5 indicates that there is a difference among the month since the salinity is much higher in November than October from S1 to S8, with S1,S3, S4 and S5 are 40 ppm and the highest the recorded on the reef at 41 ppm. The kruskal-Wallis one way anova on table 4.4 have a p- value for salinity 0.00 which is less than 0.05 that reveal that effectively there is change in salinity among the month of October and November, but the kruskal-Wallis one way anova on table 4.3 for stations have a p-value of 0.583 which is greater than 0.05 significant level that is there is no significant difference of salinity among stations. The correlation of salinity and chlorophyll-a is not significant since the results of Spearman’s Rho correlation p-value is 0.640 which is higher than 0.05 significant level, therefore salinity does not affect the concentration of chlorophyll-a in this case.

Figure 4.6 indicates the surface temperature of water around the station of ile aux aigrettes, the temperature varies among month as temperature is much higher in November than October from S1 to S8, with S1,S2, S3,S4, S5 and S7 are 28 °C which are the highest. The kruskal-Wallis one way anova on table 4.4 have a p- value for temperature 0.00 which is less than 0.05 that reveal that effectively there is a change in temperature among the month of October and November, but the kruskal-Wallis one way anova on table 4.3 for stations have a p-value of 0.271 which is greater than 0.05 significant level that is there is no significant difference of temperature among stations. The correlation of temperature and chlorophyll-a is not significant since the results of Spearman’s Rho correlation p-value is 0.931 which is higher than 0.05 significant level, therefore temperature does not affect the concentration of chlorophyll-a in this case.

The pH of the surface waters indicates (figure 4.7) little variation among the stations from S1 to S7. It is proven by the Kruskal-Wallis one way anova (table 4.3), the p-value is 0.00 , reveals that there is a change of pH among the stations, Table 4.4 where the p-value is 0.191 which is greater than 0.05 significant level, that is we do reject the null hypothesis that is there is no change of pH among the month of October and November. The Spearman’s Rho correlation between chlorophyll-a and pH have a p-value of 0.374 which indicates that there is no correlation between chlorophyll-a and pH.

6.2 Conclusion

At the end of my project, it can be say that chlorophyll-a

RECOMMENDATION

In order to make the project work more interesting a few recommendations may be considered:

  • More samples collection to get a better value
  • The experiment could have been carried out of the island for a more valuable study
  • Test for heavy metals to known whether there other limiting factors that can affect the chlorophyll contents.
  • Adding high tides and low tides will be very significant to known whether there a difference in the concentration of chlorophyll

LIMITATION

  • Moreover, the project would have been more professional if adequate apparatus were available.
  • Means of transport was also a problem since sometime due to lack of transport facilities on field works were delayed