| Date | May 2013 | Marks available | 1 | Reference code | 13M.3.HL.TZ2.11 |
| Level | Higher level | Paper | Paper 3 | Time zone | Time zone 2 |
| Command term | Distinguish | Question number | 11 | Adapted from | N/A |
Question
Distinguish between in situ and ex situ conservation.
The Atlantic cod is considered in many countries to be endangered due to overfishing. Describe two methods that could be used to estimate the cod population.
Outline one reason for the extinction of a named animal species.
Markscheme
in situ within the organism’s natural environment whereas ex situ taken out of natural environment / OWTTE
a. record size of catches from fishing boats;
b. capture, tagging, releasing and recapturing fish / Lincoln index;
c. sample fishes with trawling nets;
d. estimate population with echo sounder/sonar/fish finder;
Award marks only for the first two methods if more than two written.
name of species and what caused it to become extinct (both needed)
The named species must be extinct and not endangered.
eg:
passenger pigeon (became extinct when) hunted as a source of food
Examiners report
Most candidates managed questions (a) to (d) relatively well.
Most candidates managed questions (a) to (d) relatively well.
Some candidates confused between methods to estimate the size of the population in (b) with methods to estimate the population structure, which was not answering the question; also some suggested quadrats, which is not appropriate for fish.
Most candidates managed questions (a) to (d) relatively well.
A few candidates confused extinct with endangered species in (d).
