Environmental Factors and the Distribution of Breeding Seabird Populations in the Great Barrier Reef World Heritage Area (GBRWHA): A Cartographic Approach (C1.4.2.2S)

Task leader: Mr Darren Grover, CRC Reef and James Cook University

Task associate: Mr M Turner, GBRMPA

Why do seabirds breed when and where they do? The location of seabird breeding colonies is governed by a complex interaction of a wide range of factors including landscape ecology, the availability of breeding habitat, oceanography, island geomorphology, vegetation, and aspects of seabird ecology and breeding biology.

The distance an island is from the mainland, or its location in relation to a key oceanographic feature can be just as important as soil type and the presence or absence of vegetation. Likewise, the way in which seabirds catch their prey, the distance they can travel to access prey, and the means by which they feed their chicks can all contribute to the location of breeding colonies. This complex web of factors can determine which species can breed at certain islands and can also work to exclude a species from other islands.

The islands of the Great Barrier Reef support a breeding population of as many as 1.7 million seabirds from 22 different species. This assemblage of species represents more than 25% of Australia’s tropical seabird breeding population.

By identifying suitable breeding habitat and key oceanographic features I hope to shed some light on the role of environmental factors in influencing breeding seabird distribution. I will seek to discern those areas of seabird ecology in need of further investigation while also distinguishing those factors both natural and anthropogenic that threaten the long-term survival of seabird populations in the Great Barrier Reef.

By gaining an enhanced understanding of the factors which influence where seabirds breed scientists and managers will be able to more accurately predict the impact of human activities such as fisheries, tourism, and pollution. The results of this study will be used to develop recommendations for future seabird research and monitoring actions that will assist seabird conservation management in the GBRWHA.