I think that this paper has some information you may need its title Connecting thermal physiology and latitudinal niche partitioning in marine Synechococcus
Article Connecting thermal physiology and latitudinal niche partitio...
A bit late but I hope you have found these links already (http://roscoff-culture-collection.org/rcc-strain-details/2533) and (http://mmo.embrc-france.fr/en/bacteria/synechococcus/public_private_genomes), i.e it is the same strain as Synechococcus sp. RCC 2533 and the links have some info on pigmentation and sampling location etc.