IB ESS HL 4.3.11 Water-System Interconnections Question Bank
Analyse links among freshwater, marine and atmospheric water systems.
- Syllabus
- First assessment 2026
- Course
- ESS HL
- Level
- HL
Analyse links among freshwater, marine and atmospheric water systems.

Figure Cape Peninsula map showing Table Mountain National Park

Figure Table Mountain ghost frog
Figure Fact file on Table Mountain National Park
Table Mountain National Park attracts over 4 million tourists per year, lies within the Cape Floristic Region and neighbours Cape Town. It covers 221 km2 of land and manages a 1000 km2 marine protected area where the cold Benguela and warm Agulhas currents meet at the Cape Peninsula. Fishing is managed through permits and quotas, and no fishing is allowed in marine restricted zones that provide breeding and nursery grounds.
Figure Table Mountain ghost frog conservation facts
The Table Mountain ghost frog changed IUCN status from endangered in 1994 to critically endangered in 2004. Its distribution is about 4 km2. Historically it was recorded in eight rivers, but now occurs in five rivers on Table Mountain. Tadpoles live in streams at risk of drying due to invasive vegetation, fires and reservoir construction. A 2019 programme monitors stream conditions and undertakes conservation action such as alien vegetation removal.

Explain why the rates of productivity are high within the coastal waters around the Cape Peninsula.
a. (where two currents meet) upwelling/mixing results in release of nutrients, high levels of nutrients increase levels of (primary) production / confluence of ocean currents mixes nutrients and waters of different temperatures enhancing productivity;
b. shallow waters allow light penetration and therefore increases photosynthesis;
c. release of nutrients into coastal waters from land-based sources, e.g. sewage, could increase (primary) productivity;
d. higher productivity (at any level in the food chain/web) makes more energy available / transfers more energy to organisms along the food chain;
e. varied marine habitats support a variety of species/ecological niches that contribute to complex food webs and overall high productivity;
f. protected areas/marine restricted zones provide a sanctuary/nursery area for species to breed/grow which increases (secondary) productivity / use of permits/quotas/fish restrictions allow stocks of (immature/young) fish to grow fully increasing (secondary) productivity;
Note: Do not accept only 'fishing is managed / restriction of fishing / use of permits'. Do not accept only 'protected area/habitat'.
Marking guidance:
Do not accept 'high biodiversity leads to high productivity'.
Do not accept 'fishing restrictions allow species to thrive'.