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.
Climate change driven alterations in the distribution and abundance of marine species, and the timing of their life history events (phenology), are being reported around the globe. However, we have ...limited capacity to detect and predict these responses, even for comparatively well studied commercial fishery species. Fisheries provide significant socio-economic benefits for many coastal communities, and early warning of potential changes to fish stocks will provide managers and other stakeholders with the best opportunity to adapt to these impacts. Rapid assessment methods that can estimate the sensitivity of species to climate change in a wide range of contexts are needed. This study establishes an objective, flexible and cost effective framework for prioritising future ecological research and subsequent investment in adaptation responses in the face of resource constraints. We build on an ecological risk assessment framework to assess relative sensitivities of commercial species to climate change drivers, specifically in relation to their distribution, abundance and phenology, and demonstrate our approach using key species within the fast warming region of south-eastern Australia. Our approach has enabled fisheries managers to understand likely changes to fisheries under a range of climate change scenarios, highlighted critical research gaps and priorities, and assisted marine industries to identify adaptation strategies that maximise positive outcomes.
Complex surveillance problems are common in biosecurity, such as prioritizing detection among multiple invasive species, specifying risk over a heterogeneous landscape, combining multiple sources of ...surveillance data, designing for specified power to detect, resource management, and collateral effects on the environment. Moreover, when designing for multiple target species, inherent biological differences among species result in different ecological models underpinning the individual surveillance systems for each. Species are likely to have different habitat requirements, different introduction mechanisms and locations, require different methods of detection, have different levels of detectability, and vary in rates of movement and spread. Often there is a further challenge of a lack of knowledge, literature, or data, for any number of the above problems. Even so, governments and industry need to proceed with surveillance programs which aim to detect incursions in order to meet environmental, social and political requirements. We present an approach taken to meet these challenges in one comprehensive and statistically powerful surveillance design for non-indigenous terrestrial vertebrates on Barrow Island, a high conservation nature reserve off the Western Australian coast. Here, the possibility of incursions is increased due to construction and expanding industry on the island. The design, which includes mammals, amphibians and reptiles, provides a complete surveillance program for most potential terrestrial vertebrate invaders. Individual surveillance systems were developed for various potential invaders, and then integrated into an overall surveillance system which meets the above challenges using a statistical model and expert elicitation. We discuss the ecological basis for the design, the flexibility of the surveillance scheme, how it meets the above challenges, design limitations, and how it can be updated as data are collected as a basis for adaptive management.
We consider the problem of designing a surveillance system to detect a broad range of invasive species across a heterogeneous sampling frame. We present a model to detect a range of invertebrate ...invasives whilst addressing the challenges of multiple data sources, stratifying for differential risk, managing labour costs and providing sufficient power of detection. We determine the number of detection devices required and their allocation across the landscape within limiting resource constraints. The resulting plan will lead to reduced financial and ecological costs and an optimal surveillance system.
Aim: We developed a new method to design objective, risk-based surveillance systems for non-indigenous species of invertebrates, vertebrates and plants, which might be introduced to a natural area ...through an industrial project; here, we provide the invertebrate case study. The method addresses issues common to complex surveillance design problems: a statistical standard (e.g. power); information gaps; multiple targets of unclear identity; a large surveillance area of heterogeneous risk of invasion; integrating multiple sources of surveillance data; optimizing for cost. Location: Barrow Island, Western Australia. Methods: We mapped the surveillance area for risk to target surveillance activities. An expert group identified a set of exemplar species and identified and characterized a set of detection methods for each, such that all potential invaders would be detected. We devised multi-element surveillance systems to detect each exemplar to the design power (0.8), then integrated them to a single system that was optimized for cost. Results: The surveillance system was deployed on the island to specification over 1 year, then reviewed for redesign in a second period. Main conclusions: The new method provided practical, risk-based surveillance system designs that met application requirements and overcame complex issues common to many surveillance applications. A review of experiences from surveillance in the first year led to practical improvements and design efficiencies.
A qualitative screening-level risk assessment was developed to evaluate relative levels of risk from climate change to aquaculture industries. The assessment was applied to 7 major industries in the ...temperate south-east region of Australia and involved a simple, transparent and repeatable methodology that was appropriate for a range of different aquaculture systems and taxa. Two key stages were involved: the development of comprehensive expertise-based literature reviews or 'species profiles' and a scoring assessment, with the latter providing a defined framework within which industries could be ranked (from high to low risk). In addition to informing the second stage of the risk assessment process, the species' profiles also highlighted important climate change drivers and key information uncertainties and knowledge gaps. There was good resolution among the scoring assessments, with only 2 industries receiving the same risk score. The results indicated that oysters farmed from wild spat (Sydney rock oysters Saccostrea glomerata) were at most risk to climate change, with warm temperate hatchery-based finfish species (yellowtail kingfish Seriola lalandi) being the least at risk. This study provides critical guidance for scientists, resource managers and stakeholders for future research, both in addressing key knowledge gaps and focussing the development of more detailed risk analyses for high risk aquaculture industries in south-east Australia.
Surveillance for invasive non-indigenous species (NIS) is an integral part of a quarantine system. Estimating the efficiency of a surveillance strategy relies on many uncertain parameters estimated ...by experts, such as the efficiency of its components in face of the specific NIS, the ability of the NIS to inhabit different environments, and so on. Due to the importance of detecting an invasive NIS within a critical period of time, it is crucial that these uncertainties be accounted for in the design of the surveillance system. We formulate a detection model that takes into account, in addition to structured sampling for incursive NIS, incidental detection by untrained workers. We use info-gap theory for satisficing (not minimizing) the probability of detection, while at the same time maximizing the robustness to uncertainty. We demonstrate the trade-off between robustness to uncertainty, and an increase in the required probability of detection. An empirical example based on the detection of
Pheidole megacephala on Barrow Island demonstrates the use of info-gap analysis to select a surveillance strategy.
Abstract
Aim
We developed a new method to design objective, risk‐based surveillance systems for non‐indigenous species of invertebrates, vertebrates and plants, which might be introduced to a natural ...area through an industrial project; here, we provide the invertebrate case study. The method addresses issues common to complex surveillance design problems: a statistical standard (e.g. power); information gaps; multiple targets of unclear identity; a large surveillance area of heterogeneous risk of invasion; integrating multiple sources of surveillance data; optimizing for cost.
Location
Barrow
I
sland,
W
estern
A
ustralia.
Methods
We mapped the surveillance area for risk to target surveillance activities. An expert group identified a set of exemplar species and identified and characterized a set of detection methods for each, such that all potential invaders would be detected. We devised multi‐element surveillance systems to detect each exemplar to the design power (0.8), then integrated them to a single system that was optimized for cost.
Results
The surveillance system was deployed on the island to specification over 1 year, then reviewed for redesign in a second period.
Main conclusions
The new method provided practical, risk‐based surveillance system designs that met application requirements and overcame complex issues common to many surveillance applications. A review of experiences from surveillance in the first year led to practical improvements and design efficiencies.
A recent advance in biosecurity surveillance design aims to benefit island conservation through early and improved detection of incursions by non-indigenous species. The novel aspects of the design ...are that it achieves a specified power of detection in a cost-managed system, while acknowledging heterogeneity of risk in the study area and stratifying the area to target surveillance deployment. The design also utilises a variety of surveillance system components, such as formal scientific surveys, trapping methods, and incidental sightings by non-biologist observers. These advances in design were applied to black rats (Rattus rattus) representing the group of invasive rats including R. norvegicus, and R. exulans, which are potential threats to Barrow Island, Australia, a high value conservation nature reserve where a proposed liquefied natural gas development is a potential source of incursions. Rats are important to consider as they are prevalent invaders worldwide, difficult to detect early when present in low numbers, and able to spread and establish relatively quickly after arrival. The 'exemplar' design for the black rat is then applied in a manner that enables the detection of a range of non-indigenous species of rat that could potentially be introduced. Many of the design decisions were based on expert opinion as data gaps exist in empirical data. The surveillance system was able to take into account factors such as collateral effects on native species, the availability of limited resources on an offshore island, financial costs, demands on expertise and other logistical constraints. We demonstrate the flexibility and robustness of the surveillance system and discuss how it could be updated as empirical data are collected to supplement expert opinion and provide a basis for adaptive management. Overall, the surveillance system promotes an efficient use of resources while providing defined power to detect early rat incursions, translating to reduced environmental, resourcing and financial costs.
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