Chris J. Wiley

Evaluating Efficacy of an Environmental Policy to Prevent Biological Invasions

Enactment of any environmental policy should be followed by an evaluation of its efficacy to ensure optimal utilization of limited resources, yet measuring the success of these policies can be a challenging task owing to a dearth of data and confounding factors. We examine the efficacy of ballast water policies enacted to prevent biological invasions in the Laurentian Great Lakes. We utilize four criteria to assess the efficacy of this environmental regulation: (1) Is the prescribed management action demonstrably effective? (2) Is the management action effective under operational conditions? (3) Can compliance be achieved on a broad scale? (4) Are desired changes observed in the environment? The four lines of evidence resulting from this analysis indicate that the Great Lakes ballast water management program provides robust, but not complete, protection against ship-mediated biological invasions. Our analysis also indicates that corresponding inspection and enforcement efforts should be undertaken to ensure that environmental policies translate into increased environmental protection. Similar programs could be implemented immediately around the world to protect the biodiversity of the many freshwater ecosystems which receive ballast water discharges by international vessels. This general framework can be extended to evaluate efficacy of other environmental policies.

Relative risk assessment for ballast-mediated invasions at Canadian Arctic ports

Vector-based risk assessment is a powerful and efficient management approach for nonindigenous species (NIS). By managing a vector, an entire assemblage of associated NIS is simultaneously considered. The majority of current risk assessment frameworks have been conducted for a single, or selected few, target species and thus are not useful for managing vectors transporting a large number of potentially unknown species. Here we develop a predictive framework to assess relative invasion risk for a vector (ballast water) transporting an unknown species assemblage, using the Canadian Arctic as a case study. Ballast water discharge is a known high-risk vector globally, but its magnitude in the Arctic has not been well characterized. Our framework determined relative invasion risks between different transit pathways by quantifying the probability of NIS successfully transiting all stages of the invasion process and the magnitude of consequences of introduction to those ports. Churchill, Manitoba was ranked at ‘higher’ invasion risk via ballast water discharged by international merchant vessels than any other recipient port studied. The overall pattern of ballast water discharge suggests that water originating from coastal domestic sources carried by international merchant vessels may be important for dispersal of NIS. In addition, ballast-mediated NIS are more likely to arrive to the Hudson Bay region during summer months. These results can be useful for developing prevention and early detection programs for the region. Our risk assessment framework is not limited to ballast water and could be applied to other vectors for effective management of NIS.

Estimating establishment probabilities of Cladocera introduced at low density: an evaluation of the proposed ballast water discharge standards.

The International Maritime Organization has proposed ballast water discharge standards to reduce densities of taxa transported in ballast water. While reduced propagule pressure will almost certainly lower the risk of species introductions, we ask if the proposed standards will be effective against taxa capable of rapid population growth from small inocula, such as parthenogenetic taxa. We modified a diffusion approximation to calculate establishment probabilities as the probability of reaching a critical threshold density necessary to initiate sexual reproduction (and production of diapausing eggs for long-term persistence) before the onset of adverse environmental conditions. We parameterize our model for six Cladocera using growth rates measured during enclosure experiments conducted under favourable environmental conditions (i.e., using a precautionary approach). We then examine predicted establishment probabilities at different inoculum densities to determine the efficacy of the proposed ballast wate...

Ballast Water Management Under the Ballast Water Management Convention

The importance of ballast water as a vector for moving non-indigenous species was initially addressed in a 1973 International Maritime Organization (IMO) resolution. Subsequently IMO worked towards the finalization of the International Convention for the Control and Management of Ships’ Ballast Water and Sediments (BWM Convention) which was adopted in February 2004 at a diplomatic conference in London. The BWM Convention’s main aim is to prevent, minimize and ultimately eliminate the risks to the environment, human health, property and resources which arise from the transfer of harmful aquatic organisms and pathogens via ships’ ballast waters and related sediments. It should be noted that harmful aquatic organisms in this context are not limited to non-indigenous species, but covers all aquatic species irrespective of their origin. As defined at IMO “Ballast Water Management means mechanical, physical, chemical, and biological processes, either singularly or in combination, to remove, render harmless, or avoid the uptake or discharge of Harmful Aquatic Organisms and Pathogens within Ballast Water and Sediments.” The BWM Convention and its supporting guidelines are described in this chapter, outlining the ballast water exchange and performance standards, warnings concerning ballast water uptake in certain areas, ballast water reception facilities, sediment management as well as exemptions and exceptions from ballast water management requirements. This chapter ends with the description of implementation options of the BWM Convention.

Policy and Legal Framework and the Current Status of Ballast Water Management Requirements

There is a wealth of policy and management options addressing species introductions including conventions, treaties, multilateral agreements and codes of practices. Together these instruments support an internationally consistent management of specific transport vectors, quarantine or other biosecurity measures. This chapter lists selected global legal frameworks addressing species introductions. Chronologically, the first international instrument on unintentional introductions may have been the International Health Regulations issued in 1969 by the World Health Organization (WHO). These regulations were prepared to support public health care operations and to ensure the prevention of the spread of epidemics (e.g. plague, cholera). This chapter addresses legal frameworks addressing species introductions with the focus on ballast water related policy and legal frameworks. It gives an update on the current status of ballast water management requirements world-wide. A number of countries have taken the approach to nationally implement ballast water management requirements. We describe that most of these national requirements are based upon the IMO Ballast Water Exchange Standard, some countries refer to the Ballast Water Performance Standard and a minority addresses land-based ballast water reception facilities.