O-LevelGeographyThe natural environment2217/12 · May/June 2024 · Q325 Marks

Study Fig. 3.1 (Insert), a map showing coral reefs and mangroves on the island of Pohnpei (in the Pacific Ocean).

(a)(i)What is the distance across the island of Pohnpei from west to east at the widest point? .......................................................................... km[1]
(a)(ii)Compare the distribution of coral reefs and mangroves.[2]
(a)(iii)Describe three different characteristics of a coral reef. 1 2 3[3]
(a)(iv)Describe the conditions that are required for the development of a coral reef.[4]
(b)(i)Study Fig. 3.2 (Insert), a photograph showing mangroves. Using Fig. 3.2 only, describe the features of the mangroves.[3]
(b)(ii)Explain how coral reefs and mangroves can benefit people living on the coast.[5]
(c)Explain how a spit is formed in a coastal area. Include a labelled diagram.[7]

This question uses a diagram from the original paper, which isn't shown here. Open the full paper from the past papers archive to see it.

Mark scheme

Marking points from the official mark scheme (May/June 2024). The mark or mark type is shown in brackets.

[1] 20-25 (km) 1 mark
[2] Coral is more widespread/bigger area/more coral; Mangroves are closer to the shore/land/coral is further from the coast/offshore; More mangrove to south/west but more coral to north-east/south-west; Coral surrounds the island, but mangrove does not/there are small areas of coastline where mangrove is not present; Mangroves are within 2/3 km of land/islands, but coral is 2–10 km. 2 @ 1 mark
[3] They are alive/consist of living creatures/polyps/zooxanthellae/underwater plants; There are (many) fish/shellfish/crustaceans around/shelter for fish; There are many different species/it is an (entire) ecosystem/food web; Made of calcium (carbonate); Very colourful/iridescent; (Small) holes in structure; They are fragile; Could be fringing reef/barrier reef or atoll; Etc. 3 @ 1 mark
[4] Needs sunlight/cannot grow where there is no light; Water/sea/ocean temperatures between 18 – 27 °C/warm water/will not grow where water is too cold; Shallow water/near surface/water shallower than 60/70 metres; Water free from sediment/clear/unpolluted/clean/cannot grow in polluted water; Plentiful supply of oxygen in water/presence of waves/water needs to be moving/cannot grow where water is lacking in oxygen; Plentiful supply of algae/plankton/nutrients/food/cannot grow where there are no nutrients; (Relatively) calm water/no strong currents/no large waves; PH is alkaline/basic/8 or above/cannot grow in acidic water; Salty/saline water/32 to 42 parts per 1000/cannot grow in freshwater; Solid base/foundation; Etc. 4 @ 1 mark
[3] Bushes/trees; Varying heights; Varying density; Same species; Green/dense leaves/lots of leaves; Aerial roots/roots stick out of water/stilt roots; Growing in shallow water/mud/inter-tidal zone/partly submerged by water/water is not deep; Etc. 3 @ 1 mark
[5] Protection of coast from erosion/storms/flooding/tsunamis; So roads/housing etc are not damaged (dev); Fishing/catching crabs/shellfish; For food supply (dev); Medicinal value; Maintain water quality/reduce water pollution/filter water; Wood supplies; Tourism; Encourages economic development/earns revenue (dev); Remove carbon from the atmosphere/are carbon sinks; So global warming is reduced (dev); Etc. Note: no reserve on coral reefs/mangroves. 5 @ 1 mark or development
[7] Level 1 (1–3 marks) Statements including limited detail which explain how a spit is formed. Level 2 (4–6 marks) More developed or linked statements which explain how a spit is formed. Level 3 (7 marks) Comprehensive and accurate statements which explain how a spit is formed, including an accurate diagram or series of diagrams. Content Guide: Ideas such as: Longshore drift; Prevailing winds determine wave/swash direction; Waves/swash approach at angle/same angle as wind; Backwash at right angles; Zigzag movement; Beach materials move along coast; Deposition at change in coastline; Winds/waves from different direction recurve spit at end; Etc.