Land area change was small compared to other 'gross changes':
"...changes in the planform configuration and position of islands on reef platforms. Modes of island change included: ocean shoreline displacement toward the lagoon; lagoon shoreline progradation; and, extension of the ends of elongate islands."
The composition of the islands is responsible for their dynamism and ability to respond to changing sea levels. As coral atoll islands, the accumulation of coral debris as well as the trapping of sediment by the atolls explains how they are able to grow, because they are made of once-living material that is continuously being added by new growth. The growth of atolls was first explained by Charles Darwin in The Voyage of the Beagle
Because the mechanism of growth and stabilization is specific to this type of island, though, it means that other kinds of landmass, such as sandbar islands, are still susceptible to inundation by rising sea levels. This report does not mean that we have nothing to worry from climate change, though it must come as a partial relief to inhabitants of atoll island nations in the Pacific.
New Scientist magazine has a feature on the research that was erroneously cited by The Australian newspaper as the source where the study was published (their headline: "Pacific islands have not shrunk: New Scientist study").
This is an annoying characteristic of newspaper science journalism, that articles often mis-cite or do not cite the original sources where the research was published. It's frustrating for readers who want to find out more, or to verify for themselves the claims made in the newspaper articles (which may be sensationalized by journalists or subeditors looking for a catchy headline). It's shoddy journalism, too, because the sources were not carefully scrutinized before being written up, though in The Australian's writer's defence, perhaps he didn't know how scientific publishing works.
It's getting better in some places, though. BBC News now names the journals in which research which it features are published, although they still don't cite the year or volume, or state whether the write-up is based on work that's still in press.
Let's hope for more awareness of proper citation; otherwise the so-called 'news' might degenerate into a game of Chinese Whispers.