Dear colleagues,
A new paper describing the genetic population structure of the Mexican
populations of the California sea lion has been recently published. You can
send PDF requests to: [email protected]<[email protected]>
González-Suárez, M; Flatz, R; Aurioles-Gamboa, D; Hedrick, P; Gerber LR.
(2009) Isolation by distance among California sea lion populations in
Mexico: redefining management stocks. *Molecular Ecology*, 18:1088-1099.
DOI:10.1111/j.1365-294X.2009.04093.x* *
*Abstract*: Understanding the spatial structure of a population is critical
for effective assessment and management. However, direct observation of
spatial dynamics is generally difficult, particularly for marine mammals.
California sea lions (*Zalophus californianus*) are polygynous pinnipeds
distributed along the Pacific coast of North America. The species’ range has
been subdivided into three management stocks based on differences in
mitochondrial DNA, but to date no studies have considered nuclear genetic
variation, and thus we lack a comprehensive understanding of gene flow
patterns among sea lion colonies. In light of recent population declines in
the Gulf of California, Mexico, it is important to understand spatial
structure to determine if declining sea lion colonies are genetically
isolated from others. To define population subdivision and identify sex
biases in gene flow, we analysed a 355-bp sequence of the mitochondrial DNA
control region and 10 polymorphic microsatellite loci from 355 tissue
samples collected from six colonies distributed along Mexican waters. Using
a novel approach to estimate sex biases in gene flow, we found that male sea
lions disperse on average 6.75 times more frequently than females. Analyses
of population subdivision strongly suggest a pattern of isolation by
distance among colonies and challenge current stock definitions. Based on
these results, we propose an alternative classification that identifies
three Mexican management units: Upper Gulf of California, Southern Baja
Peninsula, and Upper Pacific Coast of Baja. This revised classification
should be considered in future assessment and management of California sea
lion populations in Mexican waters.
Thank you
Manuela
--
"I have never let my schooling interfere with my education."
Mark Twain
Manuela Gonzalez Suarez, Ph.D.
CNRS - UMR 7625
Fonctionnement et évolution des systèmes écologiques
Université Pierre et Marie Curie
Case 237, Bâtiment A, 7 Quai St Bernard
75005 Paris, France
http://ecologie.snv.jussieu.fr/eem/manuela_gonzalez_suarez
_______________________________________________
MARMAM mailing list
[email protected]
https://lists.uvic.ca/mailman/listinfo/marmam
