Variation in ocean colour helps predict cod and haddock recruitment

Background/Question/Methods

Characteristics of the spring and fall phytoplankton bloom on the Scotian Shelf, Canada estimated from remote sensing data along with anomalies in the North Atlantic Oscillation were used to explain variation in the recruitment of four populations of cod and haddock. In particular we tested the effects of: the start of the bloom using the chl-a signal, the maximum amount of chl-a, start of the diatom bloom, and the maximum proportion of diatoms for both the spring and fall bloom. 

Results/Conclusions

Only 3 of the 11 models tested explained significant variation in recruitment, but these explained between 80 and 95% of the variation. However, these models were not consistent across populations or species. The differences among models suggest the influence of regional (meso-scale) oceanographic conditions in these areas and indicate that fish larval are probably locally adapted to characteristics of the phytoplankton bloom.