Assessing the success of invasive species prevention efforts at changing the behaviors of recreational boaters

Modeling the risk of aquatic species invasion spread through boater movements and river connections

Aquatic invasive species (AIS) are one of the greatest threats to the functioning of aquatic ecosystems worldwide. Once an invasive species has been introduced to a new region, many governments develop management strategies to reduce further spread. Nevertheless, managing AIS in a new region is challenging because of the vast areas that need protection and limited resources. Spatial heterogeneity in invasion risk is driven by environmental suitability and propagule pressure, which can be used to prioritize locations for surveillance and intervention activities. To better understand invasion risk across aquatic landscapes, we developed a simulation model to estimate the likelihood of a waterbody becoming invaded with an AIS. The model included waterbodies connected via a multilayer network that included boater movements and hydrological connections. In a case study of Minnesota, we used zebra mussels (Dreissena polymorpha) and starry stonewort (Nitellopsis obtusa) as model species. We simulated the impacts of management scenarios developed by stakeholders and created a decision-support tool available through an online application provided as part of the AIS Explorer dashboard. Our baseline model revealed that 89% of new zebra mussel invasions and 84% of new starry stonewort invasions occurred through boater movements, establishing it as a primary pathway of spread and offering insights beyond risk estimates generated by traditional environmental suitability models alone. Our results highlight the critical role of interventions applied to boater movements to reduce AIS dispersal.

Diversity in invasive species management networks

Effective management of invasive species requires collaboration across a range of stakeholders. These stakeholders exhibit diverse attributes such as organisation types, operational scale, objectives, and roles within projects. Identifying the diverse attributes of stakeholders is beneficial for increasing collaboration success while minimising potential conflicts among multiple stakeholders when managing invasive species across landscapes. Despite the increasing number of studies on connections among stakeholders, there is little understanding of the diverse attributes of stakeholders involved in invasive species management. This is a notable gap because the diversity of stakeholders is one of the significant factors that can influence collaboration success. To bridge this knowledge gap, we used a social network approach to identify the attributes of stakeholders that influence their participation in collaborations using a case study of invasive wild pig (Sus scrofa) management in Queensland, Australia. Our findings suggest that even though the overall stakeholder network was diverse, the stakeholder network at the project level exhibited a lack of diversity on average, particularly regarding the scale of operation and type of organisation. In other words, stakeholders are highly likely to form ties in projects involving other stakeholders from similar types of organisations or operational scales. We suggest that targeting a greater diversity of stakeholders across types of organisations and scales of operations might enhance the success of collaborative invasive species management.

Understanding and improving biosecurity among recreational anglers in Great Britain

Recreational fishing with the principal motivation of leisure is associated with important economic, social and conservation values. Nonetheless, it is also a primary pathway for the introduction and spread of invasive non-native species and aquatic animal disease. Several studies have explored the overall biosecurity risk posed by recreational anglers based on self-reported behaviours and the awareness of biosecurity campaigns. Nonetheless, there has been little in-depth exploration of the characteristics of key stakeholders who are implementing biosecurity best practices and the barriers that prevent anglers from undertaking biosecurity measures in the field. This study addresses this knowledge gap using an online questionnaire to collect information on angler socio-demographic characteristics, voluntary biosecurity behaviour and barriers affecting the implementation of biosecurity best practices in Great Britain. The results indicated that cleaning behaviours vary considerably among anglers, with angling frequency and the number of pieces of equipment affecting how likely anglers were to clean and dry these items. High levels of disinfectant use were reported among anglers, potentially attributed to the concurrent advocation of disinfectant to prevent the spread of aquatic animal disease. Barriers affecting the implementation of correct cleaning behaviours included a combination of factors, such as practicality, disability, lack of available information and individual values. These findings illustrate the importance for fishery managers, water companies and policymakers to tailor prevention measures and facilities for anglers to maximise the practicality of biosecurity measures and encourage long-term implementation of best practices.

A review of volunteers’ motivations to monitor and control invasive alien species

People make an important contribution to the study and management of biological invasions, as many monitoring and control projects rely heavily on volunteer assistance. Understanding the reasons why people participate in such projects is critical for successful recruitment and retention of volunteers. We used a meta-synthesis approach to extract, analyze and synthesize the available information from 28 selected studies investigating motivations of volunteers to engage in monitoring and control of invasive alien species (IAS). Our findings show how motivations fit three broad themes, reflecting environmental concerns, social motivations, and personal reasons. An important outcome of this study is the description of motivations that are unique to the IAS context: supporting IAS management, protecting native species and habitats, and livelihood/food/income protection or opportunities. In addition, our study reflects on important methodological choices for investigating volunteer motivations as well as ethical issues that may arise in practice. We conclude with a set of recommendations for project design and future research on volunteer motivations in IAS contexts, emphasizing the importance of collaboration with social scientists.

Public Awareness and Perceptions of Invasive Alien Species in Small Towns

Simple Summary

Every year, the South African government spends approximately ZAR 2 billion to control invasive alien species (IAS) that are intentionally or unintentionally introduced into new areas by humans, and have a variety of social, ecological, and economic impacts. Given the link between people and the introduction and spread of IAS, it is important to understand citizens’ knowledge and perceptions of IAS to guide management. For this reason, we conducted a study in small towns of South Africa to assess (1) awareness of IAS by the general public, (2) local perceptions of the impacts associated with IAS, (3) if awareness of IAS is associated with demographic covariates and IAS density, and, (4) people’s willingness to detect, report, and support IAS management. We found that people were not aware of IAS and their impacts, and many perceived them as beneficial. We found that IAS density, education level, and gender influenced people’s knowledge and perceptions about IAS in the region. Some people showed interest and willingness to learn more about IAS. These results could help to inform outreach and educational programs to promote public awareness and engagement in IAS management.

Abstract

Invasive alien species (IAS) are a growing threat globally and cause a variety of ecological, economic, and social impacts. People can introduce IAS and facilitate their spread, and can also implement, support, or oppose their management. Understanding local knowledge, awareness, and perceptions are therefore crucial if management and policy are to be effective. We administered questionnaires to members of the public in eight small towns along the Berg River Catchment in the biodiverse fynbos biome of South Africa. We aimed to assess: (1) awareness of IAS by the general public, (2) local perceptions of the impacts associated with IAS, (3) whether awareness of IAS is correlated with demographic covariates and IAS density, and (4) people’s willingness to detect, report, and support IAS management. Overall, 262 respondents participated in the survey. Most respondents (65%) did not know what IAS are, and 10% were unsure. Many respondents also perceived IAS as beneficial. Using a logistic regression, we found that IAS density, educational level, and gender influenced people’s knowledge and perceptions about IAS in the region. There were a small number (4%) of respondents currently detecting and reporting IAS, but many respondents were interested to learn more. We concluded that people living in small towns in the Western Cape of South Africa remain largely unaware of IAS and their impacts. It is crucial to increase awareness-raising initiatives, and build support and engagement in management of IAS in small towns.

Testing Emphasis Message Frames and Metaphors on Social Media to Engage Boaters to Learn about Preventing the Spread of Zebra Mussels

Message frames are often used to communicate about invasive species due to the additional meaning they provide. They appear in calls to action like "join the battle against invasive species," "unwelcome exotics," or "Stop Aquatic Hitchhikers." However, little is known about how stakeholders respond to these message frames. This research tested five common message emphasis frames used in invasive species communication. These message frames were placed in social media advertisements about zebra mussels to determine the impact each message frame had on user online behavior. For cost-per-click (CPC), ANOVA showed effects for framing and gender. Model coefficients revealed that Hitchhiker and Protective had significantly higher CPC than Science, and that women had a higher CPC. For comments, ANOVA showed effects for framing and gender. Model coefficients revealed that no frame had a significantly different effect on comments than Science, and that women commented on posts less. For shares, ANOVA showed effects for framing. Model coefficients revealed that Hitchhiker was shared more than Science. It is important to note that neither Militaristic nor Nativist outperformed Science on any measured outcome. Coupled with ethical considerations, our results suggest the use of Nativist and Militaristic frames are not necessary to influence online behavior. Message frames without ethical issues can be used to achieve the outcomes we tested without compromising message effectiveness. Within this article, we provide background on commonly used invasive species message frames, explain our methods for testing how they impact user behavior, and suggest limitations and applications of this work.

Disconnection between conservation awareness and outcome: Identifying a bottleneck on non-native species introduction via footwear

Unintentional seed introduction mediated by visitor's clothing and footwear is a major source of biological invasion into natural areas. To effectively avert these unintentional introductions, we must understand the links that connect relevant knowledge and desired outcome (i.e., seeds not carried on visitor's belongings); however, until now, these links have not been examined. Here, we investigated the links among a visitor's knowledge about biological invasion, awareness of biological invasion, behavior to prevent introduction (cleaning footwear), and being a seed carrier to identify a potential bottleneck between visitor knowledge and ecological outcome. In order to achieve this, we conducted a questionnaire survey and soil sampling from the footwear of visitors to an alpine national park. Soil samples (n = 344) were subjected to a germination experiment, and the number of emerged seedlings was recorded for each sample. We observed seedlings emerging from 27 soil samples (7.8 % of visitors; 44 seedlings in total), comprising non-native species. The degree of a visitor's knowledge about biological invasion increased with the increase in the degree of awareness. However, the high degree of awareness was not linked with the actual behavior of cleaning their footwear before the visit, although footwear cleaning effectively reduced the number of emerged seedlings. We found the lack of a clear association between awareness and behavior (cleaning the footwear) to be the bottleneck. We also investigated the major sources of knowledge about human-mediated seed introduction from footwear and found that television was the most important information source. The key to effectively preventing negative impacts on ecosystems caused by the introduction of non-native species could be to revise methods for informing the community, which will help overcome the bottleneck between awareness and behavior.

Understanding how best to engage recreationists in biosecurity to reduce the impacts of tree diseases: a review

Pests and diseases introduced from other countries are known to pose a threat to trees, woods and forests in many locations throughout the world. Once introduced they can be spread inadvertently by countryside visitors hiking, biking or riding along paths and trails through wooded areas. Engaging and communicating with these groups of countryside users to encourage and facilitate positive biosecurity behaviours is crucial for the future resilience of trees, woods and forests. This review draws on literature outlining principles for stakeholder engagement in forestry as well as evaluations of biosecurity campaigns from around the world. Key points are briefly presented for communicators aiming to encourage better biosecurity in the countryside. These include, the need to design campaigns based on the values and motivations of recreationists, using trusted information sources and understanding the importance of combining information with facilities so as to reduce the cost (in terms of effort and inconvenience) to hikers and other countryside users.

What drives private landowner decisions? Exploring non-native grass management in the eastern Great Plains

Non-native grasses used as forage for domestic livestock can negatively impact ecosystem services provided by grasslands. In the U.S., most grazed grasslands are privately owned so the introduction and reduction of non-native grasses are both driven by landowner behavior. Yet, the social factors that shape non-native grass management are rarely explored. To address this knowledge gap, we evaluated how decisions to reduce these grasses through practices such as herbicide application, prescribed fire, and physical removal are influenced by attitudes, norms, and perceived ability. We administered a mixed mode (mailback and online) survey in 2017 to landowners in the eastern Great Plains of the U.S., in a region where cattle production remains the predominant land-use. Using structural equation modeling with parceling, we tested hypotheses related to management decisions derived from a model integrating two theories - the Theory of Planned Behavior and the Norm Activation Model. In this analysis, we identified perceived ability (i.e., access to time, skills, or other necessary resources) as a barrier to adoption for landowners who were already willing to manage non-native grasses. Positive attitudes toward management and increased social norm pressures were both associated with increased sentiments of moral responsibility to reduce non-native grasses. These personal norms, together with attitudes, positively influenced willingness to control non-native grasses. Further, we observed that social norms related to expectations of neighbors had more influence on personal norms than the social norms from natural resource agencies. The power of norms to explain individual management decisions suggests that landowners could be engaged in landscape-scale initiatives by leveraging moral responsibility and influential social groups.

An expert-based risk ranking framework for assessing potential pathogens in the live baitfish trade

As global trade of live animals expands, there is increasing need to assess the risks of invasive organisms, including pathogens, that can accompany these translocations. The movement and release of live baitfish by recreational anglers has been identified as a particularly high‐risk pathway for the spread of aquatic diseases in the United States. To provide risk‐based decision support for preventing and managing disease invasions from baitfish release, we developed a hazard identification and ranking tool to identify the pathogens that pose the highest risk to wild fish via this pathway. We created a screening protocol and semi‐quantitative stochastic risk ranking framework, combining published data with expert elicitation (n = 25) and applied the framework to identify high‐priority pathogens for the bait supply in Minnesota, USA. Normalized scores were developed for seven risk criteria (likelihood of transfer, prevalence in bait supply, likelihood of colonization, current distribution, economic impact if established, ecological impact if established and host species) to characterize a pathogen's ability to persist in the bait supply and cause impacts to wild fish species of concern. The generalist macroparasite Schizocotyle acheilognathi was identified as presenting highest overall threat, followed by the microsporidian Ovipleistophora ovariae, and viral haemorrhagic septicaemia virus. Our findings provide risk‐based decision support for managers charged with maintaining both the recreational fishing industry and sustainable, healthy natural resources. Particularly, the identification of several high‐risk but currently unregulated pathogens suggests that focusing risk management on pathogens of concern in all potential host species could reduce disease introduction risk. The ranking process, implemented here for a single state case study, provides a conceptual framework for integrating expert opinion and sparse available data that could be scaled up and applied across jurisdictions to inform risk‐based management of the live baitfish pathway.

Human-Nature Relationships and Normative Beliefs Influence Behaviors that Reduce the Spread of Aquatic Invasive Species

Human behaviors that contribute to the spread of aquatic invasive species are influenced by myriad social psychological factors that vary across contexts and populations. Understanding such behavior is crucial for forming successful management strategies that minimize environmental impacts while generating support and cooperation among stakeholders. We identify several reasons why recreational anglers and boaters make decisions that benefit the environment. Specifically, our study addresses the following objectives: (1) examine reported behaviors that minimize the spread of aquatic invasive species, (2) test the effects of social normative beliefs on reported behaviors, and (3) determine the role of human-nature relationships in explaining behavioral patterns. Drawing on a path model of the decisions made by respondents who completed an on-site survey at two nature-based case study sites in Illinois, we observed that reported behavior was positively influenced by normative beliefs about those behaviors and human-nature relationships. Specifically, the Participant in Nature and Partner with Nature orientations were positively and negatively correlated with norms, respectively. In turn, norms positively predicted reported stewardship behaviors. These findings advance research on the human dimensions of aquatic invasive species by providing insights on the role of stable psychological processes that shape behavior, while informing management decisions aimed at minimizing biological invasions in freshwater ecosystems.

Risk of invasive species spread by recreational boaters remains high despite widespread adoption of conservation behaviors

The spread of non-native aquatic species among waterbodies has become a major social, environmental, and economic concern. An important mechanism of this spread is the inadvertent transport of organisms on recreational boats as they are moved among waterbodies. Organisms can survive on the exterior of the boat, the interior, attached to fishing tackle, and can be intentionally moved by boaters. In response, local, state, and federal U.S. agencies have invested in outreach campaigns to educate boaters about the impacts of invasive aquatic species and the ways that boaters can reduce the risk of spread. We surveyed boaters in the U.S. state of Illinois to determine their travel patterns and how frequently they clean different parts of their boats. A majority of boaters reported that they always take recommended actions to clean their boat exterior (72% of respondents), boat interior (78%), and fishing tackle (55%), and only 4% reported that they intentionally move organisms. We used network methods to analyze the movement of recreational boaters and found strong connections among 28 highly visited waterbodies. When we removed the 38% of respondents who Always take recommended actions to reduce risk of species spread by all four mechanisms this network was minimally altered and still contained all 28 waterbodies. This indicates that despite high adoption of conservation behaviors there is a continuing risk of non-native species transport among all waterbodies. This work shows that further action is necessary if the impacts of invasive aquatic species are to be reduced in the future.