Seabirds and turtles have the unfortunate habit of paying no attention to national borders.

Jennifer Lavers, CSIRO - CERF Off Reserve Management Program

Seabirds and turtles have the unfortunate habit of paying no attention to national borders. Effective conservation of these species within Australian waters typically requires a regional or broader effort. Marine Biodiversity Hub scientists are working in several international partnerships to increase research relevance and uptake. A research program with the National Center for Ecological Analysis and Synthesis (NCEAS) in California, and CSIRO, is investigating ‘equivalency ratios’ so that proposed biodiversity offsets for the bycatch of seabirds and sea turtles in fisheries are on a like-for-like basis. This work addresses a significant challenge in our ability to mitigate bycatch, by taking into consideration life-history parameters such as delayed recruitment (up to 38 years in sea turtles) and reproductive value. We have also developed a novel tool to estimate equivalency ratios for poorly known species with little or no demographic data.

Hub scientists are also collaborating with the Memorial University of Newfoundland (Canada), the National Institute of Water and Atmospheric Research (NIWA) in New Zealand, and countless museums (including the Paris and American Museums of Natural History) to develop a geographic assignment model where seabirds taken as bycatch on fishing vessels of unknown provenance are assigned to their colony of origin using biochemical markers, including genetics, stable isotopes, and trace elements. This enables wildlife managers to identify colonies that are at the greatest risk from fisheries bycatch, and to understand the connection between observed population trends (usually declining) and known bycatch events.

Working with Cornell University, Hub scientists have conducted a review of the demographic benefits of removing predators for birds. The role of predator type (rat vs fox), nest location (burrow vs. surface), bird size, and other factors were considered. These results are used to develop a predictive model that estimates the benefits of predator removal programs for birds that are still at risk (eg the critically endangered Tristan Albatross which suffers extensive mouse predation on Gough Island).

Photo: Removing predators for birds - rats