Relationship between algae and tidepool chemistry
Intertribal Rockford is one of the harshest environment in marine ecosystem. Most of the organisms living in it has to have adoptions to survive in harsh conditions, especially algal. A research was done to see if biotic factors such as temperature, dissolved oxygen, temperature and pH value could have a significant correlation with total percentage of algal cover. Initial hypothesis was dissolved oxygen and pH value are correlated to total algal cover.
Each pool sample’s water hammiest were measured and tested for 2 day period. The correlation between dissolved oxygen and algal cover is weak, proving that dissolved oxygen is not fairly important, where pH value has stronger correlation than the other chemical property tested. Most of the rockroses observed has high percentage cover of coralline algal. INTRODUCTION Rocky shore are coastal shores that are consists of hard substrates. It is regarded as the most ecological part of the marine system (Library et al, 2012).
Rocky shore has three zone; low, mid and high with variety of communities living on each intertribal matrix (Phenylalanine’s, 2007). High intertribal zone has rockroses and go to several months without being replenished from the seawater (McAllen & Taylor, 2001). Intertribal Rockford have a relative stable environment where that has few changes in terms of physical conditions when the water reaches low tide (Kemp, 2009). Both McAllen & Taylor (2001) and Berkshire et al (1987) stated that rockroses undergoes many extreme physic-chemical conditions and few organisms are able to live in rockroses.
These biotic factors have a significant influence in community dynamics and population (Theatrical, 2002). Thus, it has large abundance of specialized tax vying in rockroses, such as algae (Murals, 2013). The water chemistry of rockroses fluctuates rapidly when low tide, particularly oxygen concentration, pH value, temperature and salinity. Temperature and salinity is important for algae, whereas oxygen concentration and pH value is produced by algae. Oxygen is important to all living organism and the availability of oxygen in rockroses is low, which can lead to hypoxia to organisms living in it (Berkshire et al, 1987).
However, high algal cover could increase the saturation level of oxygen in rockroses, but there is little research done on hyperemia on rockroses. Algae requires sunlight and carbon dioxide for photosynthesis, which in return produce more oxygen in rockroses. It will also produce hydrogen, which makes the Rockford more acidic. Temperature is also important, because the temperature in rockroses is relatively higher than normal seawater temperature. Increasing temperature could affect the algae in terms of physiology and actions of algae (Library et al, 2012).
According to Kemp (2009), increasing water temperature can be caused by long exposure from sunlight and also the location of Rockford. In a study done by Kemp at the coast of South Africa, he water temperature in rockroses were ranging from low ICC to high ICC during peak hours. Northern (1998) specified that sunlight has a tremendous effect on primary production in the aquatic system in rockroses. Salinity also can affect the water chemistry of rockroses.
The changing level salinity of rockroses are varied according to location and geographically and it can be caused either by input from seawater during high tide, evaporation and terrestrial runoff or rainfall (Kemp, 2009). Ended et al (2014) showed that salinity has large role in terms of species richness in rockroses. The purpose of this study is to investigate if the total algal cover is being affected by the water chemistry in rockroses during low tide. The aim of this experiment is to observe the relationships between algal cover and water chemistry, especially dissolved oxygen concentration.
I expected to see high level of oxygen saturation in rockroses due to photosynthesis. I also expecting high algal cover in alkaline rockroses. Since there is few fauna living in rockroses, I do not take them as measurement in this experiment because I more interested in functional algal group. From this, I deduced a hypothesis for this experiment. The hypothesis is percentage of algal cover is positively correlated with pH value and dissolved oxygen and negatively correlated with salinity and temperature.
METHOD Location The study site was at Cape Palliates, southern most point in North Island and the experiment ran for three days, from February 1st to February 3rd 2014. Pool sample A transect line of 50 meter was laid out across the high rocky shore and began find suitable Rockford samples. I try to locate good pools sample with pool criteria of a depth of 1 CM, area around 2-mm and the presence of algal cover per pool. I assure depth of each pool by measuring the depth 3 times at different deepest point in the pool to obtain an average depth.
The length of the pool is measured across by a measuring tape. A total of twelve pools that quite meet the measuring criteria similar were marked at high shore in a two day period. As a reference, one pool sample from lower rocky shore was marked and measured to compare water chemistry only. After pools were marked, a CACM x CACM quadrant were put on the pool, a Perspex glass layer with 25 random points were put on top of the quadrant. The quadrant is used to measure percentage of algal cover and functional algal cover y using point intercept method.
Each pool sample has it chemical properties measured on the 2nd and 3rd of February Measurement of oxygen concentration Measurement of oxygen concentration was made by using a portable oxygen measurer that is measured twice, one when the water reached low tide and one an hour later for a maximum exposure from the environment. Measurement of salinity Measurement of Rockford salinity was made by using a refractors. The salinity was measured twice, one when the water reached low tide and one an hour later for a maximum exposure from the environment. Measurement of temperature
The temperature of the Rockford was measured by using a simple thermometer twice, one when the water reached low tide and one an hour later for a maximum exposure from the environment. Measurement of pH value The pH value of the Rockford is measured using a pH meter and measured twice, one when the water reached low tide and one an hour later for a maximum exposure from the environment. However, while measuring the chemical properties of Rockford, I discovered that 5 out the 12 pool sample has geographical problems, such as drainage, constant terrestrial runoff and shadowed that will alter findings.
It was decided that problem pool samples was not counted, and 7 remaining sample is used for the experiment. Statistical analysis I used ASS Enterprise Guide 5. 1 to obtain the linear regression to see the relationship between algal cover with 4 water chemistry; percentage of dissolved oxygen, salinity, temperature and pH value. I also will use ASS to obtain the p-value of each correlation, regression (RE) and F ratio for each correlation. RESULTS Table 1 : measurement of water chemistry of pool sample at low tide after being exposed Pool sample pH value Temperature (co) salinity (ISIS)
Dissolved oxygen (%) 8. 4 28 40. 5 266. 1 2 7. 8 239. 4 3 8. 6 26 37 260. 7 4 7. 7 25 134. 6 5 8. 3 29 185. 1 6 7. 6 50 174. 2 7 7. 5 19 110. 7 Table 2: List of functional algal group calculated in pool samples in percentage (%) with mean value Rockford Crosses Filament Coralline Leathery Bare rock Foliose Algal cover 6. 68 46. 68 29. 32 17. 32 82. 68 34. 68 12 9. 32 56 24 92 37. 32 49. 36 50. 64 6. 7 45. 3 21 . 3 33. 3 66. 7 1. 3 38. 7 Mean 15. 997 16. 95 32. 28 5. 14 28. 56 0. 95 Figure 1: in algal cover (%) against dissolved oxygen (%) shows the p-value is 0. 1865, RE is 0. 3189 and Fl,5 is 2. 4. Based on the shatterproof and RE, we can see that the correlation between dissolved oxygen and algal cover is significantly positive. Figure 2: algal cover (%) against salinity (US) shows that the p-value is 0. 3108, RE is 0. 2026 and Fl is 1. 27. From the shatterproof, it is clearly that there is no significant interaction between the two. The regression equation (RE) is also supports that no significant correlation. Figure 3: Algal cover (%) with water temperature (co) with p-value of 0. 3703, RE is 0. 1622 and Fl is 0. 97.
Based on the regression equation RE, there is no significant interaction between the two. This is also can be seen in the shatterproof above. Figure 4: Algal cover (%) against pH value with p-value 0. 0086, RE is 0. 7776 and Fl is 17. 48. Since RE is close to 1, we can say there is a strong positive correlation between the two. PH value has a stronger correlation compared to other water chemistry properties tested. DISCUSSION From all the correlations done with algal cover (%), it is clear that the correlation between algal cover (%) and pH value has the strongest and positive correlation between the two (see Figure 4).
The regression equation also validate the shatterproof RE = 0. 7776). From figure 4, we can concluded that the percentage of algal cover is higher if the water pH value is alkali (pH > 7). Two reasons on why algal cover is high; because of the importance of carbon dioxide (CA) in photosynthesis, as it requires carbon dioxide to perform photosynthesis and respiration, because CA is product released from photosynthesis. This can be seen a relatively same study that was conducted by Oligarchies (2013) where increased CA in Rockford enhances the metabolism of algae Alva.
His findings was expected from him, that higher argental of CA encourages photosynthesis of the algae, which is an important food source for algae to use as energy source (Oligarchies et al, 2013). There is few studies done on pH value having an effect on algal cover in rockroses. Our initial hypothesis of where dissolved oxygen having a profound effect on algal cover is no longer accepted because regression equation is low (RE = 0. 3189) and the shatterproof supports it in figure 1, therefore the correlation is weak. In table 1, the percentage of dissolved oxygen is incredibly high (mean average = 195. 2%), where the water is in a indention called hyperemia, but the total algal cover was low. However, Noel et al (2010) shows that supersaturated level of oxygen constrain photosynthesis for primary production and therefore, the rate decreases. Little is known why high dissolved oxygen has no profound effect on algal growth, since most study is focused on the effect of oxygen to intertribal fishes and crustaceans, where Berkshire et al (1987) and McAllen & Taylor (2001) studied. The role of water temperature affecting total algal cover has no significant correlation between the two (Figure 3). The regression value is significantly low (RE = 0. 22). Based on the data obtained, temperature has no effect to total algal cover. This could because the water temperature is always constant, as it increasing in a slow rate when there is a presence of sunlight, and the temperature can drop rapidly when high tide approaches to recycle the water trapped in rockroses (Berkshire et al, 1987). However, temperature might have an impact on total algal cover if experiment was done longer, especially on cold and warm seasons. Jackson et al (2013) stated that the temperature of the rockroses during warm season would increase the stress level in he rockroses compared to colder season.
The effect of salinity (us) to total algal cover has small effect because it has weak correlation as seen in figure 2 (RE – 0. 2026). There are many study done between salinity and Rockford fishes and crustaceans, but there is no sufficient study on the effects to algal cover. Of all the functional algal cover we observed and classified in Table 2, most of the pool sample has high percentage of coralline algae (mean = 32. 28%) and one of the most well studied algal group living in rockroses.
Coralline algae (Chronological) is often found t the edges of rockroses and it is the most dominant group of algae, which has tremendous roles in shallow waters in term of biologically and ecologically (Selenologist et al, 2013; Noisiest et al, 2013; Gunter & Marten, 2014). According to a study done by Gunter & Marten (2014), coralline algae are able to tolerate extreme water condition, especially temperature and light. From all the data and results, the initial hypothesis of pH value and dissolved oxygen having a strong correlation is half accepted, since dissolved oxygen is has an insignificant correlation with coral cover.
For the hypothesis of negative correlation that was tested on Rockford salinity and temperature is accepted. Even though the experiment went well, the data obtained from this is still inadequate. For instance, only 7 pool sample is used, where the normality of data is not meet. The study period is also affecting the data, since monitoring fluctuations of water chemistry composition varied rapidly. Recommendations for increasing the quality of experiment is having a longer study period. This can obtained more accurate data from more pool sample.