UCSC-SOE-11-01: Environmental forcing on northeast Atlantic bluefin tuna abundance

Ricardo T. Lemos, Bruno Sanso and Henrique N. Cabral
01/03/2011 09:00 AM
Applied Mathematics & Statistics
In this work we analyze the association between northeast Atlantic bluefin tuna abundance, August sea surface temperature, zonal wind speed and the North Atlantic Oscillation, during the 19th and 20th centuries. We provide a single statistical framework to extract a dominant nonlinear trend in each data type, check parameter convergence and assess goodness-of-fit. Temporal autocorrelation and spatial residual coherence are accounted for, even in data sets with abundant missing values. We also describe a means to do regression analysis that propagates estimation uncertainty. Such an approach brings novel methods to the field of ecological analysis. Results show that bluefin tuna abundance fluctuated widely in the last 200 years, with a possible link to the predictor variables that were selected. A causal chain is discussed, followed by a reflection on the current status of the stock.