Apparatus and materials
For animal capturing and sampling
*aquarium net 1 piece
*dip net 1 piece
*enamel tray 1 piece
*forceps 1 pair
*plastic bucket 1 piece
*quadrat 1 piece
*trowel 1 piece
*vials, different sizes 10 pieces
for measuring physical factors
*Alcohol-in-glass-thermometer 1 piece
*compass 1 piece
*cotton thread 1 piece
*environmental comparator with light probe 1 set
*hand-held wind meter 1 set
*meter rule 1 piece
*pH paper some
*ranging poles 2 pieces
*spirit level 1 piece
*whirling hygrometer 1 piece
Methods
To determine the relative humidity
- The reservoir of the hydrometer was fully filled with water and was stoppered.
- The relative humidity was determined by finding the difference of temperature of the two bulbs and then read off from a special scale provided
To determine the wind speed.
- The wind speed was taken where the plastic ball reached maximum height.
pH of sea water.
- The colour change was compared with a standard scale to find out the pH value.
Results
A table showing the abiotic factors of the rocky shore at Shek O
Discussion
Principles of the methods used in the procedures.
The whirling hydrowind meter
As the wet bulb is always filled with water, when water evaporates during the whirling action, the temperature on the bulb is lowered and it is lower than the dry-bulbed one. The difference between the reading of both the dry and wet one can be found out and there is a special scale(an accessory of the windmeter) that provide an easy and convenient way to check out the actual relative humidity.
Adaptive features exhibit by the organisms found
As the rocky shore is constantly under the strong tidal action, animals inhibiting on the shore is always subjected to the threat of being washed away, desiccation, fluctuation of salinity and temperature. They should therefore have some means to protect themselves from the threats in order to survive.
Chitons
Chitons cling to rocks by using suction. Their calcareous shell is so hard and strong that are hard to be removed from the rocks. This not only prevents them from being washed away by strong tidal actions but also makes them harder to be a prey of predators.
They are mostly herbivores and eat tiny plants (algae) which they scrape off rocks with their rasping tongue or radula
Crab
A crab shell is called a carapace and it protects its soft body from predators. Its large claws are used for catching and killing prey.
Conclusion
The most noticeable thing about rocky shores is the zonation of organisms. This is common to rocky shores all over the world. The particular species of organism in each zone may vary with different climates and levels of wave and air exposure, but all show special adaptations to living in this area, and the basic structure is recognisable on most rocky shore environments.
