title: Determinants of Paracentrotus lividus sea urchin recruitment under oligotrophic conditions: Implications for conservation management.
abstract: Sea urchins may deeply shape the structure of macrophyte-dominated communities and require the implementation of sustainable management strategies. In the Mediterranean, the identification of the major recruitment determinants of the keystone sea urchin species Paracentrotus lividus is required, so that source areas of the populations can be identified and exploitation or programmed harvesting can be spatially managed. In this study a collection of eight possible determinants, these encompassing both the biotic (larvae, adult sea urchins, fish, encrusting coralline algae, habitat type and spatial arrangement of habitats) and abiotic (substrate complexity and nutritional status) realms was considered at different spatial scales (site, area, transect and quadrat). Data from a survey including sites subject to different levels of human influence (i.e. from urbanized to protected areas), but all corresponding to an oligotrophic and low-populated region were fitted by means of a generalized linear mixed model. Despite the extensive sampling effort of benthic quadrats, an overall paucity of recruits was found, recruits being aggregated in a very small number of quadrats and in few areas. The analysis of data detected substrate complexity, and adult sea urchin and predatory fish abundances as the momentous determinants of Paracentrotus lividus recruitment. Possible mechanisms of influence are discussed beyond the implications of conservation management.
authors.affiliation: Dipartimento di Scienze della Natura e del Territorio, Università degli Studi di Sassari, 07100 Sassari, Italy. Electronic address: silviaolivaperez@gmail.com.
authors.forename: Silvia
authors.initials: S
authors.lastname: Oliva
authors.affiliation: IMC - International Marine Centre, Loc. Sa Mardini Torregrande, 09170 Oristano, Italy.
authors.forename: Simone
authors.initials: S
authors.lastname: Farina
authors.affiliation: Dipartimento di Scienze della Natura e del Territorio, Università degli Studi di Sassari, 07100 Sassari, Italy.
authors.forename: Stefania
authors.initials: S
authors.lastname: Pinna
authors.affiliation: IMC - International Marine Centre, Loc. Sa Mardini Torregrande, 09170 Oristano, Italy.
authors.forename: Ivan
authors.initials: I
authors.lastname: Guala
authors.affiliation: CNR - IAMC, Via G. da Verrazzano 17, 91014 Castellammare del Golfo, Trapani, Italy.
authors.forename: Davide
authors.initials: D
authors.lastname: Agnetta
authors.affiliation: Université de Nice Sophia - Antipolis, Faculté des Sciences, EA 4228 ECOMERS, Nice, France.
authors.forename: Pierre Antoine
authors.initials: PA
authors.lastname: Ariotti
authors.affiliation: Dipartimento di Scienze della Natura e del Territorio, Università degli Studi di Sassari, 07100 Sassari, Italy.
authors.forename: Francesco
authors.initials: F
authors.lastname: Mura
authors.affiliation: Dipartimento di Scienze della Natura e del Territorio, Università degli Studi di Sassari, 07100 Sassari, Italy.
authors.forename: Giulia
authors.initials: G
authors.lastname: Ceccherelli
mesh_terms: D000818:Animals; D003247:Conservation of Natural Resources / Q000379:methods*; D017753:Ecosystem; D020387:Food Chain; D047328:Paracentrotus / Q000502:physiology*
keywords: Conservation management; Exploitation; Fishing resource; Macrophyte-dominated system; Paracentrotus lividus; Population biology; Recruitment; Sea urchin