Assessing the impact of population decline on mating system in the overexploited Mediterranean red coral

11 pages, 2 figures, 4 tables, supporting information https://doi.org/10.1002/aqc.3327.-- This is the pre-peer reviewed version of the following article: Jean‐Baptiste Ledoux, Silvia Frias‐Vidal, Ignasi Montero‐Serra,Agostinho Antunes, Clara Casado Bueno, Sergi Civit, Paula Lopez‐Sendino, Cristina Linares, Joaquim Garrabou, Assessing the impact of population decline on mating system in the overexploited Mediterranean red coral Aquatic Conservation - Marine and Freshwater Ecosystems 30(6): 1149-1159 (2020), which has been published in final form at https://doi.org/10.1002/aqc.3327. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Use of Self-Archived Versions
Understanding the interactions among demographic parameters, mating system and population dynamics is key to predict the response of populations to global change. The Mediterranean red coral is a precious octocoral suffering from population decline due to overfishing and warming-driven mass mortality events. While the demographic consequences of these two pressures are well characterized, little is known regarding their impact on population dynamics and evolution of red coral populations. The main objective of this study was to fill this gap focusing more particularly on mating pattern and genetic drift. Combining sibship and progeny arrays analyses, a genetic characterization of the red coral mating system was conducted. In addition, a synchronic approach was developed comparing mating patterns in two populations with contrasting demographic patterns: a pristine-like population and a declining population. The results show that polyandry is likely to be the norm in red coral. The similar patterns of genetic diversity between adults and larvae combined with the lack of differential reproductive success among putative fathers did not support significant sweepstakes effects during larval production. While instantaneous biparental inbreeding was detected, no long-term inbreeding was observed even in the declining population. Mating patterns and effective population sizes in the two populations were not statistically different. Nevertheless, a trend towards a slightly higher inbreeding and a lower number of breeders was observed in the declining population. Accordingly, we hypothesized that an increase in male gamete dispersal may buffer the increase of genetic drift expected in the declining population. This feedback between demographic decline and reproductive pattern may potentially take part in the long-term persistence of red coral populations. However, the negative trend reported in the declining population unambiguously supports the need to maintain high densities of reproductive colonies to the functioning of red coral populations
This research was supported by national funds through FCT‐Foundation for Science and Technology within the scope of UIDB/04423/2020 and UIDP/04423/2020., the Spanish MINECO (CGL2012‐32194), the TOTAL Foundation PERFECT project, the MIMOSA project funded by the foundation Prince Albert II de Monaco, and the European Union's Horizon 2020 research and innovation programme under grant agreement N° 689518 (MERCES). [...] J.B.L. was supported by a postdoctoral grant (SFRH/BPD/74400/2010) from Fundação para a Ciência e a Tecnologia (FCT), C.L. by a Ramon y Cajal (RyC‐2011‐08135), IMS by a FPI grant (BES‐2013‐066150) and S.C. by research project SGR 622 (GRBIO) from the Departament d’ Economia i Coneixement de la Generalitat de Catalunya and (PGC2018‐095931‐B‐I00) MINECO (Spain). Genotyping was performed at the Genome Transcriptome Facility of Bordeaux (grants from the Conseil Régional d'Aquitaine n°20030304002FA and 20040305003FA, from the European Union FEDER n°2003227 and from Investissements d'Avenir ANR‐10‐EQPX‐16‐01)
With the funding support of the ‘Severo Ochoa Centre of Excellence’ accreditation (CEX2019-000928-S), of the Spanish Research Agency (AEI)