Fig 1.
Temporal dynamics of fish community.
A. nmMDS biplot illustrating temporal changes in the community structure. Squares and circles respectively depict the years before and after the regime shift, detected by MRT. Axis 1 appears particularly discriminant in this respect. B. Chronological clustering by MRT and the two successive structures of the fish community. C. Taxonomic richness. D. Pielou’s evenness. E. Shannon diversity. Black lines represent average indices and shaded areas are standard deviation intervals. Straight blue lines represent the PWR results on indices while dashed ones indicate breakpoints in the time series whenever detected.
Fig 2.
Changes in fish community structure.
A. Taxonomic structure based on species abundance before and after the regime shift (species are ordered according to their mean abundance before the shift). The species pictured correspond to the first and last decile of the distribution of absolute changes in abundance before and after the shift. Results of permutation tests for change in each species abundance before and after 1998 accounting for multiple testing: ***: p < 0.001; **: 0.001< p <0.01; *: 0.01< p <0.05. B. Percent abundance variation between the two periods. For a given species i, the percentage is computed as follows: (Ni after 1997 –Ni before 1997) ×100/ Ni before 1997, with Ni the average abundance of species i. C. Evolution of mean body length in fish community. Line types are as in Fig 1C to 1E. D. Boxplot representing thermal preferendum of negatively and positively impacted species.
Fig 3.
Relationship between the fish community dynamics and potential forcing factors.
A. Evolution of community structure represented by values on the nmMDS first axis B. AMO time series C. Fdemersal time series. D. MRT of the fish community structure time series on AMO and Fdemersal. The blue and red shaded areas correspond to the period before and after the regime shift, respectively.