On the independence between clupeid stocks and their recruitment

The statistical independence between the reproductive stock and its corresponding recruitment to a fishery was tested for 43 stocks of clupeids in the Ransom Myers database by using the chi-squared test of a contingency table. The method was validated by simulating stock and recruitment (SR) contingency tables for data close to hypothetical SR curves that represent several known phenomena. The clupeid SR data were grouped by the criteria of percentile points to build the contingency tables. The independence test of the clupeid stocks was rejected in only 15 cases, thus the independence hypothesis was sustained in the remaining 28 cases. This demonstrates that fitting an SR model in these clupeid stocks is not justified because their abundance could be affected by several causes other than reproductive stock fluctuations.