Rocky Shores

In recent times, the experiment al approaches to understand rocky shores including the studies of the dynamics. A rocky shore is a foreshore intertidal zone that comprises of solid rocks. It is rich in biological habitats such as rock pools which are characterized by the erosion features. Organisms in this area must be able to adapt to the extreme temperature fluctuations and the water and tidal activity. Zonation is the domination of specific species that form distinct zones on each of the rocks. On the other hand, mudflats are wet areas that form on the shore regions when rivers deposit mud.

These regions were characterized by fluctuating temperatures, salinity and moisture. Some parts of the region were wet and sulky with galleys. Most of the rocks in the region were cracked with bands of organisms.

Methods

The methods that were utilised in this research included the transect procedure which accounted for the collection of most of the data for the study. The transect procedure is a survey method mostly utilised in the studying of research sites when looking for obvious bands of zonations. This approach included the division of the study site into different quadrants from where the algae samples for the study were collected.

The selections of areas to use as quadrants included the basing of selection on the range of distribution of each species with the intertidal, abundance and ease of identification.

Data analysis

During the field trip to the Brighton rock pools you have collected data regarding the biodiversity of the intertidal rocky shores and mudflats. Data analysis for this particular study involved the use of Simpson’s Index. Simpson’s Index is a biological and geographical tool of data analysis that is used in the determination of diversity in a particular site or area of study.

Moreover the analysis of the data also included the basic logical interpretation of tabular data. For the data collected from the observations on temperature, salinity and pH, no calculations were necessary for conclusions to be drawn. Basic understanding of biology was the only resource necessary in the interpretation of such data.

Table 1. Environmental conditions – rocky shores

Low tide area

Mid tide area

High tide area

Date and time

9:40

6/March/2018

9:50

6/March/2018

10:11

6/March/2018

Substrate type

Soft bottom

Soft bottom

rocky

Air temperature

6 c

6 c

6 c

Water temperature

7.5 c

7.5 c

7.5 c

Water pH

8.5

8.5

8.5

Distance from water edge

0 cm

10cm

40cm

Salinity

25

26

27

Question 1

Analysis of the data above results in the conclusion that physically, the conditions ranging from the low tide area to the high tide area basically similar, only that the distance from the shore and the texture of the bottom of the areas going from soft in the low tide areas to rocky in the high tide areas. Other physical conditions of the different areas however do not change including the temperature of water and air in these points.

The chemical properties of the areas on the other hand show a gradual increase in salinity of the water as the water approaches the high tide areas. The pH of the water in all these areas shows no alternation however. The explanation behind the salinity of the water at high tide areas is because of the proximity to the sea. As the water approaches the sea away from the water edge the level of salinity increases, explaining the gradual increase in salinity index recorded above.

Question 2

In the low tide areas, they are little to no environmental stressors affecting the algae. In this particular area, the conditions for the growth and prosperity of algae are at optimum levels. The temperatures of both the water and air are perfect, the pH and salinity levels optimum therefore allowing algae in this region to grow at an optimum high; this explains the high level of algae coverage in this particular area.

The mid tidal area on the other hand experiences more tidal and wave activity translating to a higher environment al stress level compared to the low tide areas. The water at this level is more saline compared to the low tide area accounting to a decline in algae coverage.

The high tide area of the shore is the area experiencing the highest levels of environmental stressors; this is in the form of high wave and tidal activity and the higher levels of salinity. Due to this high stress levels the growth and algae coverage at this level are at the lowest accounting for a mere five percent according to the report.

Question 3

After successful running of the transect of the Rocky pools shore, the type of zonation that is observed is vertical zonation with the high tide areas with the distance from the water to the edge assuming a declining slope, with the high tide areas being 40cm lower than the edge of the shore. Transects that are in a defined area and permanently established can allow comparison between seasons or years over time. This particular proved to be big enough to accurately characterize the biotic and abiotic factors of the ecosystem and is determined by the living members in the ecosystem which in this case is the algae. It shows that the algae coverage with decreasing coverage towards the high tide areas perfectly illustrating the argument above.

Table 2. Algal coverage – rocky shore

Tidal area

Algal percentage cover

Species identity

Dominant species

Low tide area

50%

Kelp

Wrack wool

Wrack wool

Mid tide area

20%

Wrack wool

seaweed

Wrack wool

High tide area

5%

Wrack wool

Sea lettuce

Wrack wool

Question 4

 From the graph drawn for the data obtained from the sampling process, it is evident that the percentage coverage of algae is on a progressive decline from the low tide areas to the high tide areas.

This is because water waves and tidy activity has a great impact on the levels of algae growing in many areas. Because intertidal shores form a narrow band fringing the coast, the gradient between marine and terrestrial conditions is sharp, with abrupt changes in physical conditions. This intensifies patterns of distribution and abundance, making them readily observable. Most of the organisms are easily visible, occur at high densities, and are relatively small and sessile or sedentary.

Question 5

From the data above Wrack wool algae demonstrates dominance in all the tidal areas sampled in the study above. The reason behind the success of this particular species lies in the ability of this species of algae to with stand high environmental stress factors like high salinity and high tidal activity. Moreover, the algae’s physical characteristics allow the algae to grow in rocky shores utilising the rocks for anchorage and nutrients.

Species Identity

Low tide area

Number of individuals

Calculate Simpson’s index D using the formula (5 marks)

D=  17506/(210(210-1)

D = 17506/43890

D = 0.3989

Mussels

68

Barnacles

1

Gray top shell

15

cockles

4

Small winkle

9

Edible winkle

113

oyster

0

Species Identity

Mid tide area

Number of individuals

Calculate Simpson’s index D using the formula (5 marks)

D= 3092/35532

D= 0.0870

mussels

34

barnacles

5%

Gray top shell

1

cockles

9

Small winkle

0

Edible winkle

134

oyster

0

Species Identity

High tide area

Number of individuals

Calculate Simpson’s index D using the formula (5 marks)

D = 24878/30102

D = 0.8265

mussels

6

barnacles

0

Gray top shell

4

cockles

6

Small winkle

0

Edible winkle

75%

oyster

0

Question 7

Based on the data collected above and the Simpson’s indices that have been calculated in the tables above, it is evident that the most diverse area is the high tide are of the rocky pools. From the calculated Simpson’s index for this particular area, the figure indicated in the value, that is 0.8265 indicates that the diversity levels at his area is the highest compared to the other areas in the study.

According to Simpson’s Index the value of d ranges from o and 1 with the value of diversity increasing from 0 to 1 directly. While a value of 1 indicates infinite diversity, the value 0 indicates zero diversity.

Question 8

The data above also shows that some algae species thrive in the high tide areas of the area under study. This shows the tenacity and adaptability of the algae in these areas to the high stressor levels in the said areas. The Wrack Wool species of algae for example, depicts a lot of adaptability characteristics for the high tide areas.

Unlike regular plants, seaweeds and algae lack the feature of plants such as laves roots or stems and range in size from microscopic to tall or giant proportions like kelp which normally grows in coastal aquatic forests. The algae in the low tide area do not experience a large number of environmental stressors and therefore their main method of adaptability lies in their high rate of reproduction in order to compete for nutrients and sunlight and air.

The algae on the mid tidal range on the other hand have to adapt to both high tidal activity as well as compete for nutrients air, and sunlight. The major examples of algae found in this range are mostly large types of algae and sewed which adaptability characteristics include streamlining in the form of having blade like structures and root like anchorage in the stable substrate on the ocean or sea floor.

9. Consult your data collected on the trip to Shoreham mudflats and discuss the characteristics of that particular intertidal area: zonation, substrate, organisms (10 marks)

References:

Allan Jones, 2000. Practical skills in environmental science. Prentice Hall.

HEDLEY, J., 1998. FISH, JD and FISH, S. A student's guide to the seashore. Cambridge University Press: 1996. Pp xv, 564. Price£ 19.95. ISBN 0-521-16819-1.

Magsino, R.M., 2014. Enhancing Higher Order Thinking Skills in a Marine Biology Class through Problem-Based Learning. Asia Pacific Journal of Multidisciplinary Research| Vol, 2(5).

Kaiser, M.J., 2011. Marine ecology: processes, systems, and impacts. Oxford University Press.

http://www.mba.ac.uk/fact-sheet-rocky-shore