Research was done along a section of South Africa's coast to determine a baseline of the numbers of four fish species observed in and around kelp forests - NSC Marine Sciences - Question 2 - 2024 - Paper 2

To find the average number of individuals of each fish species, add the counts for each species and divide by the number of counts.

For Hottentot: Average = (39 + 35 + 37) / 3 = 37

For Galjoen: Average = (22 + 27 + 29) / 3 = 26

For Strepie: Average = (20 + 18 + 19) / 3 = 19

For Blacktail: Average = (18 + 17 + 16) / 3 = 17

To draw a pie chart, take the average counts calculated:

• Hottentot: 37
• Galjoen: 26
• Strepie: 19
• Blacktail: 17

Total = 37 + 26 + 19 + 17 = 99

Now, calculate the degrees for each slice of the pie:

• Hottentot: $(37/99) \times 360 = 134.55 \approx 135°$
• Galjoen: $(26/99) \times 360 = 95.45 \approx 95°$
• Strepie: $(19/99) \times 360 = 69.09 \approx 69°$
• Blacktail: $(17/99) \times 360 = 61.82 \approx 62°$

Draw a pie chart using these rounded degrees.

1. The same time of day for each count.
2. The same site or location for each dive.

The investigation was done along the West Coast of South Africa.

Kelp forests thrive in cold waters rich in nutrients, which support diverse marine life. Upwelling currents bring nutrient-rich water from the ocean floor to the surface, promoting growth and biodiversity. Additionally, the rocky substrate provides anchorage for kelp, and active wave action helps circulate nutrients, further benefiting the kelp ecosystem.

The species of fish that was seen as most abundant is the Hottentot.

1. Hottentots serve as a breeding ground, providing a safe habitat for spawning.
2. They have access to an abundant food supply in nutrient-rich waters of the kelp forest.
3. Their natural camouflage helps them avoid predators, increasing their population density.

Yes, the procedure is suitable as it uses standardized methods and controlled variables, allowing for reliable data collection. Consistent timing and allocation of species to pairs reduce bias and improve accuracy in understanding fish populations.