In another blow to the "Everything is Everywhere" tenet of
bacterial distribution in the ocean, scientists at the Marine
Biological Laboratory (MBL) have found "bipolar" species of
bacteria that occur in the Arctic and Antarctic, but nowhere
else. And, surprisingly, they found even fewer bipolar species
than would turn up by chance if marine bacteria were randomly
distributed everywhere. "That suggests that there are forces
that are limiting the dispersal of bacteria in the ocean," says
Linda Amaral-Zettler, a scientist in the MBL's Bay Paul Center
and faculty member in the Brown-MBL Partnership. The discovery
is reported this week in Proceedings of the National Academy of
Sciences, with Amaral-Zettler as corresponding author. "Our
study shows that marine bacteria are not just homogenous
populations in the ocean. They are more selective than that.
Different bacteria prefer certain temperatures, levels of
nutrients, light and salinity, " Amaral-Zettler says.
"Understanding their distribution is really importan