Stock enhancement or sea ranching? Insights from monitoring the genetic diversity, relatedness and effective population size in a seeded great scallop population (Pecten maximus)

Type Article
Date 2016-09
Language English
Author(s) Morvezen R.1, Boudry PierreORCID2, Laroche J.1, Charrier G.1
Affiliation(s) 1 : Inst Univ Europeen Mer, UMR LEMAR UBO CNRS IRD Ifremer 6539, Lab Sci Environm Marin, Technopole Brest Iroise,Rue Dumont Urville, F-29280 Plouzane, France.
2 : Ctr Bretagne, UMR LEMAR UBO CNRS IRD Ifremer 6539, IFREMER, Lab Sci Environm Marin, Plouzane, France.
Source Heredity (0018-067X) (Nature Publishing Group), 2016-09 , Vol. 117 , N. 3 , P. 142-148
DOI 10.1038/hdy.2016.42
WOS© Times Cited 7
Abstract The mass release of hatchery-propagated stocks raises numerous questions concerning its efficiency in terms of local recruitment and effect on the genetic diversity of wild populations. A seeding program, consisting of mass release of hatchery-produced juveniles in the local naturally occurring population of great scallops (Pecten maximus L.), was initiated in the early 1980s in the Bay of Brest (France). The present study aims at evaluating whether this seeding program leads to actual population enhancement, with detectable effects on genetic diversity and effective population size, or consists of sea ranching with limited genetic consequences on the wild stock. To address this question, microsatellite-based genetic monitoring of three hatchery-born and naturally recruited populations was conducted over a 5-year period. Results showed a limited reduction in allelic richness but a strong alteration of allelic frequencies in hatchery populations, while genetic diversity appeared very stable over time in the wild populations. A temporal increase in relatedness was observed in both cultured stock and wild populations. Effective population size (Ne) estimates were low and variable in the wild population. Moreover, the application of the Ryman-Laikre model suggested a high contribution of hatchery-born scallops to the reproductive output of the wild population. Overall, the data suggest that the main objective of the seeding program, which is stock enhancement, is fulfilled. Moreover, gene flow from surrounding populations and/or the reproductive input of undetected sub-populations within the bay may buffer the Ryman-Laikre effect and ensure the retention of the local genetic variability.
Full Text
File Pages Size Access
7 211 KB Access on demand
2 89 KB Access on demand
Author's final draft 27 470 KB Open access
Top of the page

How to cite 

Morvezen R., Boudry Pierre, Laroche J., Charrier G. (2016). Stock enhancement or sea ranching? Insights from monitoring the genetic diversity, relatedness and effective population size in a seeded great scallop population (Pecten maximus). Heredity, 117(3), 142-148. Publisher's official version : https://doi.org/10.1038/hdy.2016.42 , Open Access version : https://archimer.ifremer.fr/doc/00344/45530/