The three species across the top are, left to right, Pied Shag (Phalacrocorax varius), Little Pied Shag (Microcarbo melanoleucos) of the white-throated morph, and Black Shag (Phalacrocorax carbo) (aka Great Cormorant).
The lower group of five species are, from left to right, Auckland Island Shag (Leucocarbo colensoi), Chatham Island Shag (Leucocarbo onslowi) [at the back], Pitt Island Shag (Stictocarbo featherstoni) [at the front], Spotted Shag (Stictocarbo punctatus), and New Zealand King Shag (Leucocarbo carunculatus).
The size differences between the species aren't as obvious in the photo as they are when looking at the display in real life. The King Shag is enormous compared to the other species, and the Chatham Island Shag is particularly small.