During my academic career, I have developed skills and experience in measuring the three main biodiversity facets – taxonomic (species richness and abundance evenness distributions), functional (the role that each species plays for ecosystem functioning) and phylogenetic diversity (the evolutionary relationship between species) – and quantifying their change in space and time. For example, in Trindade-Santos et al. (2020), I used temporal regression models to uncover a substantial increase over time in the exploited functional richness of both ray-finned and cartilaginous species of large marine ecosystems, in line with an increase in the extracted taxonomic richness (Figure 2). These trends show that global fisheries are increasingly targeting species that play diverse roles within the marine ecosystem and underline the importance of incorporating functional diversity in ecosystem management. In Trindade-Santos et al. (2022), I also quantified the biogeography of rare fish in the world’s oceans. Concentrations of rarity were found, in excess of what is predicted by a null expectation, near the coasts and at higher latitudes (Figure 3). Similarly, Rabosky et al. (2018) found faster speciation rates outside the tropics, particularly at higher latitudes; it is possible that those regions act as centres for evolutionary and functional novelty (as shown in my PhD research).

"Global change in the functional diversity of marine fisheries exploitation over the past 65 years"

Figure 2. Change in the functional diversity of marine fisheries catches from the Large Marine Ecosystems (LMEs) in the period 1950 to 2014. The map shows, for each LME, the standardized slope of each metric computed against time. Increasing trends (slope greater than 0.2 in the standardized regression) are coloured red–orange, decreasing ones (<−0.2) as green–blue (see scale). 73% of LMEs exhibited a significant trend in Actinopterygii functional richness, with a further 10% showing a nonsignificant increase (see electronic supplementary material, table S4). The equivalent figures for increasing functional richness trends in Elasmobranchii were 72% (significant) plus 15% (nonsignificant). Functional evenness increased in 14% (7% significant + 7% nonsignificant) of Actinopterygii LMEs and 49% (26% + 23%) of Elasmobranchii LMEs; decreasing functional evenness was detected in 71% Actinopterygii LMEs (33% + 38%) and in 53% Elasmobranchii LMEs (21% + 32%). Functional divergence increased in 30% (15% + 15%) of Actinopterygii LMEs and 49% (26% + 23%) of Elasmobranchii LMEs; it declined in 60% (42% + 18%) of Actinopterygii LMEs and 36% (30% + 6%) of Elasmobranchii LMEs. Please note that we use the conventional p < 0.05 threshold to infer significance, and hence the strength of the relationship, to provide information on uncertainty.

"Global patterns in functional rarity of marine fish"

Figure 3. Global biogeography of rarity for bony fishes (a–Actinopterygii) and cartilaginous fishes (c–Elasmobranchii) across Coastal Systems. The functional index used here was distinctiveness. Plots a and c illustrate the numbers of rare species found in each 2° grid cell (species that are both rare taxonomically and functionally (distinct)). Plots b, d shows the Standardized Effect Sizes (SES), where red shaded cells represent an excess of rare species higher than expected by chance and blue cells represent fewer rare species than expected.