Fig. 7: Spatial aggregation and seasonality of spawning is greater at higher latitudes.
The relationship between: a the Spatial Aggregation Index and Latitude (F-statistic (25 degrees of freedom) = 11.8, p = 0.002014, r2 = 0.32, 95% confidence intervals = [0.71, 4.26]) and b the Seasonality Index and Latitude (F-statistic (25 degrees of freedom) = 32.42, p = 0.000006266, r2 = 0.56, 95% confidence intervals = [0.11, 1.10]) assessed using a two-sided linear model are shown across all taxa for each hemisphere. Data points are by taxon for each hemisphere (North Hemisphere points are shown as blue circles and South Hemisphere points are shown as orange triangles): SKP skipjack tuna, YFT yellowfin tuna, ALB albacore, BET bigeye tuna, FRI frigate tuna, STRM striped marlin, SAU sauries, SBFT Southern bluefin tuna, BFT Pacific bluefin tuna, SHOS shortbill spearfish, SWO swordfish, LESC longfin escolar, SLT slender tuna, BLUM blue marlin, and SAIL sailfish. Data in (a) are presented as mean values ± SEM of the calculated Spatial Aggregation Index across seasons for each taxon. Data in (b) are presented as the calculated Seasonality Index ± SEM for each taxon.
