Zero-tolerance biosecurity protects high-conservation-value island nature reserve

John K Scott,Barbara Marks,Andrew A Burbidge,Peter G Kendrick,Simon M O’Connor,Kerrie Mengersen,Malcolm Nairn,Justin Downs,Melissa L Thomas,Keith Morris,Richard Stoklosa,Johann Van Der Merwe,Roy Green,Russell Lagdon,Simon J Mckirdy,Darryl C Hardie,Greg Pickles,Kristin L Horton

doi:10.1038/s41598-017-00450-y

Abstract

Barrow Island, north-west coast of Australia, is one of the world’s significant conservation areas, harboring marsupials that have become extinct or threatened on mainland Australia as well as a rich diversity of plants and animals, some endemic. Access to construct a Liquefied Natural Gas (LNG) plant, Australia’s largest infrastructure development, on the island was conditional on no non-indigenous species (NIS) becoming established. We developed a comprehensive biosecurity system to protect the island’s biodiversity. From 2009 to 2015 more than 0.5 million passengers and 12.2 million tonnes of freight were transported to the island under the biosecurity system, requiring 1.5 million hrs of inspections. No establishments of NIS were detected. We made four observations that will assist development of biosecurity systems. Firstly, the frequency of detections of organisms corresponded best to a mixture log-normal distribution including the high number of zero inspections and extreme values involving rare incursions. Secondly, comprehensive knowledge of the island’s biota allowed estimation of false positive detections (62% native species). Thirdly, detections at the border did not predict incursions on the island. Fourthly, the workforce detected more than half post-border incursions (59%). Similar approaches can and should be implemented for all areas of significant conservation value.

Highlights

Biological invasions are a major threat to conservation areas, but the effectiveness of biosecurity systems is notoriously difficult to predict due to the lack of data on entry and establishment of organisms[1,2,3]
100% of cargo was subjected to pre-border cleaning, treatment, packaging and inspection prior to moving to the island, and verification upon arrival at the Barrow Island (BWI) border
The example reported here for BWI shows the remarkable scale of effort, and investment, necessary to achieve an effective biosecurity system to protect an area of high conservation value

Summary

Introduction

Biological invasions are a major threat to conservation areas, but the effectiveness of biosecurity systems is notoriously difficult to predict due to the lack of data on entry and establishment of organisms[1,2,3]. We show the effort required to establish what we believe to be one of the world’s most effective and comprehensive biosecurity systems, with specific focus on the pathways involved in invasive species’ introductions and the importance of workforce participation This project included inspection and verification for all cargo items arriving at the border, which enabled us to provide a comprehensive analysis of the numbers and types of organisms crossing a biosecurity barrier. A government condition required that the Project prevent the introduction of any NIS to BWI and surrounding waters[13] This requirement, and a lack of data on the base-rate of invasions or which organisms posed a biosecurity threat[2, 14,15,16] mandated that the Project implement an exceptionally high level of biosecurity. This six year period covers the main construction phase of the Gorgon Project

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