Suggest one reason why there is insufficient data available to categorise the conservation status of a large proportion of marine mammals, as shown in Figure: Conservation status of indigenous species groups in New Zealand.
a. Lack of expertise / lack of technology for underwater research;
b. Lack of existing relevant keys/identification resources;
c. Difficulty in identifying/sampling species in the water (due to turbidity/reduced visibility);
d. Species can be difficult to find in deep water / difficult to find species hiding on seabed/under rocks/within vegetation;
e. Large size of oceans so difficult to explore;
f. Species migrate making them difficult to find at certain times of the year / species are motile moving from one location to another and therefore difficult to identify;
g. Insufficient human resources;
Marking guidance:
Do not accept only 'difficult to access the water" or "some areas are inaccessible".
Do not accept "difficult to explore/find" without giving reason.
Do not accept only "migration".