Biology Field Trip Essay

Data Sheet Animals found inside the quadrats: Animal names| Number of Individuals| | Quadrat 1(near sea water)| Quadrat 2(intertidal zone)| Quadrat 3(splash zone)| Periwinkles| 0| 16| 0| Barnacles| 0| 19| 0| Bivalves| 0| 10| 0| Hermit crabs| 15| 0| 0| Snail| 1| 0| 0| Animals found outside the quadrats: Animal names| Nos. | Micro-habitat| periwinkles| 42| Rocky shores| oyster| 20| Rocky shores| sea cucumber| 51| Gravel beds offshore| crab| 2| Gravel beds offshore| Shrimp| 1| Gravel beds offshore| Sea urchin| 4| Shallow water| Adaptation features of animals: a.

Against dislodgement by wave action: i. hard shells (e. g.

barnacles) ii. strong attaching devices/ are immobile (e. g. oyster) iii. flattened body form (e. g. oyster) b.

Preventing predators: iv. hard shells (e. g. hermit crab) v. flattened body form (e.

g. oyster) c. Other adaptations: vi. Against desiccation, wave and salinity vii. Retreat to sheltered areas viii. Protective cover ix. Internal gill x. Strong adhesive power (byssus threads, muscular food) xi.

Flattened body xii. Red pigment in algae for deep water illumination Relationships between living organisms: i.Commensalism a. Barnacles attach onto crabs to benefit from the movement brought by crabs and the food remains on the surface of the crabs. b.

Small crabs live in oysters’ shells for protection and food by snatching food particles from the oysters without harming them. ii. Competition c. Interspecific competition among mussels and barnacles for food and space on the rock surface.

d. Intraspecific competition among barnacles for space and food. iii. Predation e. Crabs (blue crabs) feed on periwinkles. f. Periwinkles feed on green algae.

g. Barnacles eat seaweeds and planktons in the water. . Limpets eat small algae on the rock surface. i.

Sea urchins are eaten by crabs and snails. j. Sea urchins feed mainly on algae, but can also feed on sea cucumbers and a wide range of invertebrates, such as mussels.

k. Bivalves are eaten by crabs. Crabs crack the shells with their pincers.

iv. Mutualism l. Sea anemones attach onto hermit crabs to obtain food remains from them, and also the movement brought by them. m.

In lichens, algae undergo photosynthesis and provide food, fungi forms sponge-like body to hold water, anchorage ;amp; provide protection. n.Hermit crabs gain protection from the tentacles of the sea anemones in which the cells are toxin-containing. o. Shrimps attach onto sea cucumbers and benefit from the movement brought by them. Sea cucumbers act as a transport for shrimps to the food sources. v.

Parasitism p. The parasitic barnacles feed on the living crab’s tissue. Recent weather conditions: Sai Kung: * Minimum Air Temperature: 23. 9 C * Maximum Air Temperature: 27.

6 C * Relative Humidity: 64 – 82% * The mean UV index recorded at King’s Park was 2, the UV intensity was Low. * The maximum UV index was 6. (Source: Hong Kong Observatory http://goo.

gl/epDQu)Physical environment near field site: a. Shore orientation: Southeast of Clear Water Bay Peninsula of Sai Kung, Hong Kong b. Habitats types: Rocky intertidal zone, coastal forest, beaches Sketch map of the site: Physical Factors: Site:| General Environment| Rock Gaps| Rock Pool| Shaded Area| Air temperature (? )| 32.

5| 32. 4| 31. 7| 30. 5| Relative humidity (%)| 54| 49| 45| 54| Light intensity (Lux)| 615 x 100| 208 x 100| 300 x 100| 24 x 100| Wind speed (ms-1) ;amp; direction| 6, SW| 4, SW| 0, SW| 5, SW| Water Sample: * Dissolved oxygen (mg/l): 7.

6 mg/l * pH (h): 8. 2h * Water Salinity (ppt): 32%