2018 Volume 68 Issue 2 Pages 81-99
The identification of Ecologically or Biologically Significant Areas (EBSAs) as candidate Marine Protected Areas is a critical step in protecting marine ecosystems and biodiversity from the impacts of human activity. However, delineating EBSAs in offshore pelagic waters can be difficult due to the high cost of collecting biological information in such areas. One potential solution is to use the distributions and movements of marine mammals, seabirds, and large predatory fish to delineate the boundaries of EBSAs. Here, we discuss the usefulness of seabird distribution data for identifying biologically productive areas with high primary production and energy flow through multiple trophic levels (one of the criteria for determining EBSAs). As seabirds are easily observed at the surface, many ship-based surveys have examined their at-sea distribution. These studies have shown that seabird density positively correlates with the density of their prey—zooplankton and forage fishes—at a 10-km scale, indicating biologically productive areas. Colony censuses and bio-logging studies have accumulated global data on the distribution and size of breeding colonies, as well as at-sea movement of individual seabirds. These datasets can be used to delineate EBSAs at a practically manageable spatial scale. By integrating these distribution data with remotely sensed environmental data, we can understand the processes that structure biologically productive areas and predict their variability. By monitoring diet, breeding success, and chemical markers accumulated in the tissues of seabirds whose ranges include these biologically productive areas, we can also assess anthropogenic stresses, including those imposed by fisheries and pollution. Though the inherent biases and limitations of seabird data must be considered carefully, these data could be a useful tool in delineating EBSAs, enabling better marine spatial management for biodiversity conservation.
