According to a recent journal article, the oceans' low chlorophyl waters are expanding.
See: Polovina J. J., E. A. Howell, M. Abecassis (2008), Ocean's least productive waters are expanding, Geophys. Res. Lett., 35, L03618. doi:10.1029/2007GL031745.
I am an environmenal science librarian. As I see new journal articles and reports on climate change, I will post them here.