Figure 3 focuses on one year and allow us to see the migration pattern and its timing in association with the C:N evolution in detail. Until the C:N reaches the low threshold of 6.5, the community is into diapause. As soon as it reaches this low threshold, the biomass is transferred to the active phase that will migrate toward the surface target depth of 25 meters. The migration will take two weeks for the community to reach the surface. During that time they are not feeding so not excreting nitrogen either. Because they were still relying on their lipid reserves, but have an active respiration, the C:N of the community still decreased. As soon as the ingested biomass goes above the grazing-threshold of 8.64e-7 mmol C m-3 d-1 the community will start accumulating lipids and hence actively excrete nitrogen. This is what is happening when the C:N increase in early july when the majority of the community have reached the surface. Then as soon as the community reaches the high C:N threshold of 12, all the biomass at this depth level will be transferred into the diapause phase and migrate toward the resting depth of 300 meters where the excretion is stopped (since they are supposed to rely on the nitrogen-deprived lipids) with a reduced metabolism (resting respiration being one fourth of the active respiration, Maps et al. 2011) which explains the change in the C:N slope.