Reuben P. Keller

Risk assessment for invasive species produces net bioeconomic benefits

International commerce in live organisms presents a policy challenge for trade globalization; sales of live organisms create wealth, but some nonindigenous species cause harm. To reduce damage, some countries have implemented species screening to limit the introduction of damaging species. Adoption of new risk assessment (RA) technologies has been slowed, however, by concerns that RA accuracy remains insufficient to produce positive net economic benefits. This concern arises because only a small proportion of all introduced species escape, spread, and cause harm (i.e., become invasive), so a RA will exclude many noninvasive species (which provide a net economic benefit) for every invasive species correctly identified. Here, we develop a simple cost:benefit bioeconomic framework to quantify the net benefits from applying species prescreening. Because invasive species are rarely eradicated, and their damages must therefore be borne for long periods, we have projected the value of RA over a suitable range of policy time horizons (10–500 years). We apply the model to the Australian plant quarantine program and show that this RA program produces positive net economic benefits over the range of reasonable assumptions. Because we use low estimates of the financial damage caused by invasive species and high estimates of the value of species in the ornamental trade, our results underestimate the net benefit of the Australian plant quarantine program. In addition, because plants have relatively low rates of invasion, applying screening protocols to animals would likely demonstrate even greater benefits.

Invasive species in Europe: ecology, status, and policy

Globalization of trade and travel has facilitated the spread of non-native species across the earth. A proportion of these species become established and cause serious environmental, economic, and human health impacts. These species are referred to as invasive, and are now recognized as one of the major drivers of biodiversity change across the globe. As a long-time centre for trade, Europe has seen the introduction and subsequent establishment of at least several thousand non-native species. These range in taxonomy from viruses and bacteria to fungi, plants, and animals. Although invasive species cause major negative impacts across all regions of Europe, they also offer scientists the opportunity to develop and test theory about how species enter and leave communities, how non-native and native species interact with each other, and how different types of species affect ecosystem functions. For these reasons, there has been recent growth in the field of invasion biology as scientists work to understand the process of invasion, the changes that invasive species cause to their recipient ecosystems, and the ways that the problems of invasive species can be reduced. This review covers the process and drivers of species invasions in Europe, the socio-economic factors that make some regions particularly strongly invaded, and the ecological factors that make some species particularly invasive. We describe the impacts of invasive species in Europe, the difficulties involved in reducing these impacts, and explain the policy options currently being considered. We outline the reasons that invasive species create unique policy challenges, and suggest some rules of thumb for designing and implementing management programs. If new management programs are not enacted in Europe, it is inevitable that more invasive species will arrive, and that the total economic, environmental, and human health impacts from these species will continue to grow.

Species Invasions from Commerce in Live Aquatic Organisms: Problems and Possible Solutions

ABSTRACT In the Laurentian Great Lakes region, commercial activities involving live fish bait, horticultural and water-garden plants, biological supplies, pets, and live food are the principal pathways for intentional introductions of live aquatic organisms. We sampled species for sale in these trades and found that the risks of new invasions and of spreading known invaders are high. Moreover, most animals were identified by common name only, and even though scientific names were more often applied to plants, consumers cannot be certain what species they are receiving because misidentification is common. Finally, 90 percent of plant orders arrived contaminated with unordered live organisms. The policy goal of US and Canadian national and state or provincial agencies is to reduce the risk of harmful introductions. Our results demonstrate that meeting this goal will require accurate identification of species by vendors, the removal of known and likely invasive species from trade, and reductions in the number of contaminant organisms.

Preventing the spread of invasive species: economic benefits of intervention guided by ecological predictions.

Preventing the invasion of freshwater aquatic species is the surest way to reduce their impacts, but it is also often expensive. Hence, the most efficient prevention programs will rely on accurate predictions of sites most at risk of becoming invaded and concentrate resources at those sites. Using data from Vilas County, Wisconsin (U.S.A.), collected in the 1970s, we constructed a predictive occurrence model for rusty crayfish (Orconectes rusticus) and applied it to an independent data set of 48 Vilas County lakes to predict which of these were most likely to become invaded between 1975 and 2005. We nested this invasion model within an economic framework to determine whether targeted management, derived from our quantitative predictions of likely invasion sites, would increase the economic value of lakes in the independent data set. Although the optimum expenditure on lake protection was high, protecting lakes at this level would have produced net economic benefits of at least

From Bait Shops to the Forest Floor: Earthworm Use and Disposal by Anglers

6 million over the last 30 years. We did not attempt to determine the value of nonmarket benefits of protection; thus, our results are likely to underestimate the total benefits from preventing invasions. Our results demonstrate that although few data are available early in an invasion, these data may be sufficient to support targeted, effective, and economically rational management. In addition, our results show that ecological predictions are becoming sufficiently accurate that their application in management can produce net economic benefits.

Economic and environmental impacts of harmful non-indigenous species in Southeast Asia.

ABSTRACT Nonindigenous earthworms are causing large and undesirable changes to forests across the U.S. Upper Midwest. Because earthworms have slow rates of natural spread, and because their distribution remains patchy in many areas, it would be possible to slow the rate of invasion if vectors of introduction can be identified and controlled. Earthworm populations are often found near lakes, and it has been suggested that anglers discarding unwanted bait are a vector for the establishment of new populations. Here, we have surveyed the bait trade and anglers to determine whether bait stores sell known invasive species and whether angler behavior is likely to lead to these species becoming introduced near lakes. All bait stores surveyed sold known invasive species and 44% of anglers who purchase bait dispose of unwanted bait on land or in trash. We conclude that the bait trade and subsequent disposal of worms by anglers constitute a major vector for earthworm introductions. Thus, slowing the spread of invasive earthworms will require efforts to change the species sold at bait stores and/or efforts to change angler behavior.

International Policy Options for Reducing the Environmental Impacts of Invasive Species

Harmful non-indigenous species (NIS) impose great economic and environmental impacts globally, but little is known about their impacts in Southeast Asia. Lack of knowledge of the magnitude of the problem hinders the allocation of appropriate resources for NIS prevention and management. We used benefit-cost analysis embedded in a Monte-Carlo simulation model and analysed economic and environmental impacts of NIS in the region to estimate the total burden of NIS in Southeast Asia. The total annual loss caused by NIS to agriculture, human health and the environment in Southeast Asia is estimated to be US

Improving management of aquatic invasions by integrating shipping network, ecological, and environmental data: data mining for social good

33.5 billion (5th and 95th percentile US

Integrating invasion and disease in the risk assessment of live bird trade.

25.8–39.8 billion). Losses and costs to the agricultural sector are estimated to be nearly 90% of the total (US

Confronting the risks of large-scale invasive species control

23.4–33.9 billion), while the annual costs associated with human health and the environment are US