Question 19N.3.HL.TZ0.15c
| Date | November 2019 | Marks available | [Maximum mark: 3] | Reference code | 19N.3.HL.TZ0.15c |
| Level | HL | Paper | 3 | Time zone | TZ0 |
| Command term | Describe | Question number | c | Adapted from | N/A |
The table below summarizes the number and percentage of marine species worldwide with at least one documented record of becoming entangled and at least one record of ingesting marine debris, such as plastics and fishing nets.
[Source: Küehn et al. 2015 (http://edepot.wur.nl/344861)]
Describe the use of indicator species in monitoring environmental change.
[3]
a. presence/absence indicate environmental conditions ✔ Accept named environmental condition/pollution.
b. changes in the environment affect these species ✔ Number of species or type of species.
c. «relative» numbers of individuals/indicator species can be used to calculate a biotic index ✔
d. changes monitored over time ✔ Accept example of time frame.
e. changes can lead to measures to protect the environment ✔
f. example of an indicator species AND what it indicates «e.g. Tubifex for sediment pollution» ✔ Award marks for a species, not a group.
