Time series for the chlorophyll-a concentration (chlo-a) over seven years (2005–2012) and for the δ¹⁵N from one vibrissa.

a) Periods detected (23, 49, 60, 7, 21, and 115) in the time series for the chlo-a around San Esteban Island. For the chlo-a, the two main harmonics were located temporally at 23 and 49 weeks; b) Peaks detected (36, 20, 29, and 16) in the time series for δ¹⁵N in the longest vibrissa in our sample. The resulting number of significant periods in the δ¹⁵N of each vibrissa is associated with six months of growth.