Yes, you should code them according to the NOC coding.
It would also help if your description of your job experience was easily seen to fall into the correct category.
From reading the list of occupations and titles covered under 2121 I think you will be fine!
Just remember to add language similar to NOC #2121 viz:
Plan and conduct studies of the environment, and of the population, distribution, structure and functional characteristics and behaviour of plants and animals
Conduct ecological and environmental impact studies and prepare reports
Study, identify and classify plant and animal specimens
Conduct experiments in plant or animal growth, heredity and breeding
Prepare reports and plans for management of renewable resources
May supervise biological technologists and technicians and other scientists.
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