I am working on invertebrate marine population genetics, connectivity and phylogeography. My main interest stands in understanding the evolutionnary processes driving genetic diversity and speciation in coral reef associate bivalves. To answer these questions I combine field work, observation studies, molecular biology and genetic statistics.

Genetic diversity and Connectivity of the Black Lipped pearl Oyster in French Polynésia

Pinctada margaritifera is an important commercial species that has been extensively translocated between Polynesian atolls for pearl production. It is strictly dependant on coral reefs and is mostly found inside atoll lagoons, in shallow water, attached to coral formations. As for most lagoonal species in the Pacific region, it has faced several sea levels fluctuations over the Holocene and earlier, known to be responsible for reduction and/or loss of genetic diversity as a result of complete dry out of atoll lagoons. Such major disturbances will have direct consequences for the genetic structure of lagoonal species like the pearl oysters.
I investigated the population genetic structure and connectivity of Pinctada margaritifera throughout French Polynesia based on natural stocks prior to aquaculture exploitations. I was able to make hypothesis on the partial contribution of different forces acting on the distribution of genetic diversity and connectivity within the studied area and emphasize the role of geomorphology and oceanography creating habitat patchiness and limiting long dispersal, as well as past and ongoing human impact. 

 
sarah.lemer@gmail.com
sarahlemer@oeb.harvard.edu
Dept. of Prganismic and Evolutionary Biology
Museum of Comparative Zoology
Harvard University
26 Oxford St.
Cambridge MA, 02138
USA
Phone: 1 617 496-5308
Fax: 1 617 496-5854