Special Session
Integrating Invasion Science and Management Across Realms: Learning from Terrestrial, Marine and Freshwater Experiences

This session aims to identify ways in which knowledge and tools can be more effectively exchanged between scientists and managers working in different study systems. It will compare successes and challenges for risk assessment, eradication, biological control and other management approaches used to deal with invasive species in terrestrial, freshwater and marine environments to set the stage for collaboration to improve outcomes across taxa boundaries.


Joe Caffrey, INVAS Biosecurity Ltd.

Joe worked as a Senior Scientist with Inland Fisheries Ireland (IFI) for 39 years. Here, he headed up the Invasive Species Section, which researched and developed control methods for invasive alien species, some of which have received worldwide application.

Joe has project-led many national and international research/management projects dealing with invasive species and has been directly involved with the development of national and EU legislation relating to these species. He has written in excess of 100 peer reviewed scientific and management papers for national and international journals.

In 2015 Joe joined INVAS Biosecurity Ltd. as a Director, where he is continuing his work with invasive species. This Company provides a professional contracting and consultancy service, based on the most up-to-date scientific evidence, which targets invasive species in aquatic and terrestrial situations.


Optimal Planning of Invasive Species Surveillance Campaigns
Denys Yemshanov, Natural Resources Canada – Canadian Forest Service

Surveillance is critical for timely detection of biological invasions. We discuss the optimization-based approaches for planning complex surveillance campaigns aimed to detect the spread of biological invasions.
We adopt a network based approach to plan inspections during the survey campaign and use an acceptance sampling technique to develop an optimal surveillance strategy. We compare two application methodologies for terrestrial invasive pests (such as planning surveillance of emerald ash borer (EAB), a harmful pest of ash trees) and invasive aquatic species (such as planning watercraft inspections for detecting the spread of invasive aquatic organisms through a network of lakes and waterways). We also explore the impact of uncertainty about local infestation rates and detection probabilities on the surveillance strategy. Accounting for the uncertainty addresses possible temporal and spatial variation in infestation rates and helps develop a more robust survey strategy. The approach is generalizable and can support surveillance programs for detecting biological invasions at various spatial scales.


Risk Assessment: Cornerstone of an Aquatic Invasive Species Program
Becky Cudmore, Fisheries and Oceans Canada

Effective aquatic invasive species (AIS) programs are based on risk analyses, where risk assessments provide valuable information that can be applied to many areas of an AIS program. Based on biological and socio-economic risk assessments, appropriate risk management actions related to prevention, early detection and rapid response, and control can be undertaken. This presentation identifies some of these activities, with emphasis on using risk assessment to mitigate introduction of AIS from live trade.


Experiences in Ballast Water Management across Freshwater and Marine Ecosystems
Sarah Bailey, Fisheries and Oceans Canada

The movement of ballast water is a prominent pathway for the dispersal of harmful aquatic species. The risk of this pathway, and the efficacy of different management strategies, varies according to habitat type (freshwater vs. marine). Research undertaken to examine different management strategies has been complicated by the myriad of regulators on the Great Lakes, as well as activities at the international scale.

This presentation will present some of the experiences in ballast water across freshwater and marine ecosystems, in the context of different regulatory regimes, with a view to sharing common challenges and lessons learned.


New Technologies for Invasion Management: Will they Work in Water?
Daniel Simberloff, University of Tennessee

Several new technologies to prevent, detect, or manage invasions are in various stages of development, mostly for terrestrial invaders. Only eDNA has been widely used for aquatic invaders. However, drones and robots can be used to detect some aquatic and marine invaders, and perhaps to kill them. Vibrometers used to detect invasive insects suggest the possibility of similar sound-based detection for aquatic and marine animals. Among genetic approaches, gene-silencing is already used to manage invasive insects, and the idea has been suggested for invasive aquatic species. Oxitec’s genetically engineered Friendly© Aedes aegypti mosquito, though controversial, has been massively released in nature in the wake of the zika epidemic, and two major gene-editing projects employing CRISPR Cas 9 gene drives to eradicate invasive terrestrial animals are under development despite substantial controversy regarding potential unintended consequences. There seems no reason why gene-editing technology could not be applied to aquatic or marine invasions, though the same concerns would obtain.

  Asian Long-Horned Beetle versus Emerald Ash Borer Eradication: Even with Good Ingredients You Still Need a Recipe for Success
Taylor Scarr, Natural Resources Canada – Canadian Forest Service

Even though there was only one year between the discovery of emerald ash borer (EAB) and Asian long-horned beetle (ALB) in Ontario, the success of the management programs are vastly different. While we expect soon to be able declare ALB eradicated, EAB continues to kill trees and spread across the country. ALB success is due to several key ingredients: the biology of the insect, the geographic location of its establishment, experience from other jurisdictions, an effective survey method, and effective control measures. On the other hand, EAB biology encourages long distance spread, it was not contained in an urban area, we had no experience from other jurisdictions, surveys were highly inaccurate, and control measures were ineffective.
Both case studies provide lessons that we can apply to other terrestrial, aquatic, and marine invasions. The recipe for success included working with political allies and champions, managing communications and expectations, incorporating research to reduce uncertainties, collaborating with local interests and all levels of government, and recognizing the long-term commitment of 10 or more years. These two case studies also provide insight into the differences between terrestrial and aquatic and marine invasions, such as survey methods, control methods, public and political support, available legislation, and intergovernmental collaboration.


Biological Control of Invasive Alien Species in the Anthropocene
Dr. Peter G. Mason, Agriculture and Agri-Food Canada

Invasive alien species are a major threat to global food security. The Food and Agriculture Organization (FAO) promotes integrated pest management (IPM) as the preferred approach to crop protection. Biological control is a key component of IPM and the FAO Commission on Genetic Resources for Food and Agriculture identified biological control as a top priority for future work on the sustainable use and conservation of micro-organism and invertebrate genetic resources for food and agriculture. The Convention on Biological Diversity considers that “the application of classical biological control for the management of established invasive alien species causing environmental impacts is relevant to the work of the Convention on Biological Diversity.” Despite significant successes, biological control has been subjected to greater scrutiny in recent years due to unintended effects. The lessons learned have enabled biological control to evolve into a stronger scientific discipline.


Overcompensation, Eradication Failure and the Case for Functional Eradication of Aquatic Invasive Species
Edwin Grosholz, University of California, Davis

Population dynamics models show that harvesting can paradoxically increase the equilibrium level of a population. Formally known as overcompensation, this phenomenon known as the ‘hydra effect’, has been documented in several systems, but has rarely been documented with the reduction of an invasive species and never in marine systems. We documented a dramatic population explosion of the invasive European green crab (Carcinus maenas) in a California estuary following five years of intensive removal efforts. After a >90% removal of the adult population from 2009-2013, we recorded a 30-fold increase in population size in 2014 relative to the previous year. We found this is the result of overcompensation as the result of loss of adult control of recruitment due to intensive removal efforts. Concurrent survey data from nearby estuaries and subsequent genomic studies confirmed that recruitment dynamics were internal. Mesocosm experiments also showed size dependent cannibalism that was consistent with model predictions and the unusual population dynamics. We view these results as an important, cautionary lesson for resource managers.

Consequently, we propose practical guidelines for identifying management targets for invasions for which eradication is not likely, based on achieving ‘functional’ eradication—defined as suppression of the invader below population levels which cause unacceptable ecological effects—within high-priority management locations. We outline the key ecological information needed to develop strategies for functional eradication and illustrate the potential for improving the management of broadly distributed aquatic invasive species. Identifying targets for suppression allows managers to estimate the removal required to mitigate ecological impacts, and the management resources needed to achieve these levels of control.


Additional Panelist
Nicholas Mandrak, University of Toronto Scarborough

Dr. Nicholas Mandrak is a Professor in the Department of Biological Sciences at the University of Toronto Scarborough. He is the Director of a professional Master’s program in Conservation and Biodiversity.
His research lab examines the biogeography, biodiversity, and conservation of freshwater fishes.