Spatially congruent sites of importance for global shark and ray biodiversity

RESEARCH ARTICLE Spatially congruent sites of importance for global shark and ray biodiversity Danielle H. DerrickID*☯, Jessica Cheok☯, Nicholas K. Dulvy☯ Earth to Ocean Research Group, Simon Fraser University, Burnaby, British Columbia, Canada ☯ These authors contributed equally to this work. * dhderric@sfu.ca Abstract Many important areas identified for conservation priorities focus on areas of high species richness, however, it is unclear whether these areas change depending on what aspect of richness is considered (e.g. evolutionary distinctiveness, endemicity, or threatened spe- cies). Furthermore, little is known of the extent of spatial congruency between biodiversity measures in the marine realm. Here, we used the distribution maps of all known marine sharks, rays, and chimaeras (class Chondrichthyes) to examine the extent of spatial congru- ency across the hotspots of three measures of species richness: total number of species, evolutionarily distinct species, and endemic species. We assessed the spatial congruency between hotspots considering all species, as well as on the subset of the threatened species only. We consider three definitions of hotspot (2.5%, 5%, and 10% of cells with the highest numbers of species) and three levels of spatial resolution (1˚, 4˚, and 8˚ grid cells). Overall, we found low congruency among all three measures of species richness, with the threat- ened species comprising a smaller subset of the overall species patterns irrespective of hot- spot definition. Areas of congruency at 1˚ and 5% richest cells contain over half (64%) of all

sharks and rays and occurred off the coasts of: (1) Northern Mexico Gulf of California, (2) USA Gulf of Mexico, (3) Ecuador, (4) Uruguay and southern Brazil, (5) South Africa, south- ern Mozambique, and southern Namibia, (6) Japan, Taiwan, and parts of southern China, and (7) eastern and western Australia. Coarsening resolution increases congruency two- fold for all species but remains relatively low for threatened measures, and geographic loca- tions of congruent areas also change. Finally, for pairwise comparisons of biodiversity mea- sures, evolutionarily distinct species richness had the highest overlap with total species richness regardless of resolution or definition of hotspot. We suggest that focusing conser- vation attention solely on areas of high total species richness will not necessarily contribute efforts towards species that are most at risk, nor will it protect other important dimensions of species richness. Introduction Species distributions are widely used to characterise and explain the patterns seen in biodiver- sity throughout the world and can be used to help identify places of conservation priority [1– PLOS ONE PLOS ONE | https://doi.org/10.1371/journal.pone.0235559 July 6, 2020 1 / 19 a1111111111 a1111111111 a1111111111 a1111111111 a1111111111 OPEN ACCESS Citation: Derrick DH, Cheok J, Dulvy NK (2020) Spatially congruent sites of importance for global shark and ray biodiversity. PLoS ONE 15(7): e0235559. https://doi.org/10.1371/journal. pone.0235559 Editor: William David Halliday, Wildlife Conservation Society Canada, CANADA

Received: February 29, 2020 Accepted: June 17, 2020 Published: July 6, 2020 Peer Review History: PLOS recognizes the benefits of transparency in the peer review process; therefore, we enable the publication of all of the content of peer review and author responses alongside final, published articles. The editorial history of this article is available here: https://doi.org/10.1371/journal.pone.0235559 Copyright: © 2020 Derrick et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Data Availability Statement: All distribution files are available from the IUCN database. Adapted data from the IUCN database used for analysis have been uploaded to the primary author’s GitHub repository (https://github.com/daniellederrickh)