ABSTRACT

Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 161 The Great Barrier Reef in Time and Space . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 162 A Walk around the Great Barrier Reef World Heritage Area . . . . . . . . . . . . . . . . 163 The Cross-Shelf Paradigm and Land-Ocean ProcessesHow Far Offshore Does “Land Influence” Extend? . . . . . . . . . . . . . . . . . . . . . . . 168 Cross-Shelf and Inter-Oceanic Connectivity through Food Chain Links . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 170 Connectivity amongst Habitats through Larval Dispersal and Ontogenetic Migration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 173 A Case Study of Baitfish-Predator Links . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 175 Conclusion. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 177 Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 177 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 177

The notion of landscape-scale ecosystem “connectivity” is neither new nor a wholly scientific construct. Australian poet Judith Wright summed up what many scientists intuitively feel about reefs when she wrote:

Biologists now often talk of the Reef as only the main system of an overall system of reefs throughout the whole Indo-Pacific region, and suspect that there may be interconnection of all these reefs through the planktonic movement across the ocean. The Reef cannot be thought of, either, as separate from the mainland coasts, with their many fringes of great mangrove forests that form a tremendously fertile breeding-ground for

many species which during part of their lives may enter the waters of the reef proper. The interlocking and interdependent physical factors which have so long kept the reef alive and growing, such as water temperatures, freshwater replenishment from streams and estuaries, the tidal movements which bring deep ocean water in and out of the calmer and narrower waters within the Barrier, and the winds and weather systems, are probably all indispensable to the maintenance and dynamics of its living species. (Wright, 1977)

A broad knowledge base is associated with the Great Barrier Reef (GBR) province from the earliest navigational survey vessels of the 1800s, subsequent scientific expeditions, and an expanding body of contemporary research literature from the physical, geological, ecological, and molecular sciences. This has been complemented by an important body of unpublished literature and personal observations collected from the public and reef users, making the GBR one of the most comprehensively investigated ecosystems on earth. Across these disciplines “connectivity” is a recurrent theme, and here we give an illustrated overview and examples of some types and scales of ecological connectivity spanning the GBR World Heritage Area, with an emphasis on fish life-history studies.