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Invasive Alien Species Control and Public Participation:
Case Study of the Ogasawara Islands
Akemi ORI
Graduate School of Global Environmental Studies, Sophia University
7-1 Kioi-Cho, Chiyoda-ku, Tokyo 102-8554, Japan
E-mail: a-ori-c4t@sophia.ac.jp

Abstract
The Ogasawara Islands were registered as a Natural World Heritage in 2011. The land snails of theOgasawaras are an important group of organisms that guarantee their universal value as a World Heritage Site.
In particular, the uninhabited island of Ani-Jima has high genetic diversity and is of great importance forconservation. In recent years, however, there has been noticeable damage to the land snails of Ani-Jimacaused by rats. The Ministry of the Environment has implemented a rodenticide aerial spraying project for rat
control since FY2009. The project failed, however, due to lack of communication with residents and lack oftrust. In this study, introducing strategies for measures against alien species and conservation of endemic
species by introducing an analysis of residents’ interests and proposals for procedures based on the findings ofthe rat verification committee, in which the author has been involved as a chairperson. In projects with highuncertainty, such as rat control, it is important to adopt not only the concept of adaptive management but also
an adaptive governance approach, which can be used to formulate a decision-making process for community
participation that fully takes into account the concerns of the local residents.
Key words :	adaptive governance, invasive species, public participation, risk communication

1. Introduction
The Ogasawara Islands were registered as a Natural
World Heritage site in 2011 as “the islands serve as an
outstanding example of the ongoing evolutionary
processes in oceanic island ecosystems,” as evidenced by
the high levels of endemism; speciation through adaptiveradiation; evolution of marine species into terrestrialspecies; and their importance in the scientific study ofsuch processes.
Land snails are an important group of organisms thatguarantee universal value as a World Heritage site, andthe uninhabited islands, especially Ani-Jima, have highbiodiversity and high conservation importance. In recentyears, however, there has been notable damage to theland snails of Ani-Jima caused by invasive rats (Rattusrattus). To solve this issue, aerial spraying of rodenticide
has been carried out by the Ministry of the Environment.
However, in the aerial spraying of rodenticides conductedin FY2014, there were too few numerical values related
to toxicity in the explanatory materials and indications ofinsufficient consideration of environmental impacts at
local briefings before the project’s implementation. As aresult, distrust towards the project’s administration
became apparent and rodenticides in the planned Ani-Jima
Island project were abandoned. The Rat Countermeasures
Global Environmental Research
23/2019: 053-058
printed in Japan

Verification Committee was established in FY 2017 toprotect conservation targets, including land snails, bydiscontinuing use of rodenticides and proposing ideal
countermeasures for rats with appropriate considerationof the environment. The purpose of the Verification
Committee was to verify (1) the environmental impact of
the rodenticide spraying project carried out in FY2009,and (2) the process leading to the cancellation of therodenticide spraying. As chairperson of the Rat
Countermeasures Verification Committee, the author
introduces in this paper what has been clarified by the Rat
Countermeasures Verification Committee to share what
was learned in the Ogasawaras.
The reason this great distrust occurred and theproject was postponed with urgency was that social
scientific approaches such as risk communication andconsensus building were not considered due to theurgency to take natural scientific measures against thethreat. The problem of rat control in the Ogasawaras
shows the importance of paying sufficient attention to
public participation and risk communication regarding
alien species control. Below, based on the Rat
Countermeasures Verification Committee’s findings, I
introduce points regarding public participation and risk
communication that were clarified in the Ogasawaras’case.
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2. Towards Adaptive Governance
2.1 Public Participation
In addition, because biological interactions need tobe considered in natural resource management, an“adaptive management” system should be established tocontrol island invasive species. However, to solve
problems more rationally, it is necessary to consider how
to establish not only an “adaptive management system,”
but also an “adaptive governance” system (Miyauchi etal., 2014). This incorporates public participation andconsensus building processes. Before introducing thecase study, I examine why it is necessary to consider
public participation and risk communication in alien
species control. In the past, natural science approaches
have been regarded as important in nature restoration
projects, such as countermeasures for rats, but theimportance of consensus building with stakeholders,
including the residents living there has not been
considered a concern. Recently the importance of theadapted governance concept in the natural science
approach has begun to be discussed (Brunner et al, 2005).
In policy decisions in the field of natural science, noabsolutely correct answers can be derived. So in theprocess of policy decision making, the most appropriate
method is selected from various methods and thenimplemented. For this choice to be accepted by society,procedural fairness must be ensured by essential citizen
participation in a democratic society (Kitamura, 2002). It
could be said that in policy decisions, there are two
important functions: (1) justification and (2)rationalization. The justification function serves tolegitimize decision-making for the policy through the
democratic process as required in a democratic society.
The rationalization function serves to make risk
management more efficient and rational in terms of theenvironment and economy. It is expected that theparticipation of the public at an early stage will clarify
interests and problems and at the same time, will bring
together a lot of knowledge and help in selecting the mostappropriate, rational method (Ruckelshous, 1985).
For public participation to be substantive, sufficientamounts and quality of information and opportunities forparticipation must be provided. To that end, it is necessary
to consider risk communication regarding what kind ofinformation is provided by what method, in addition toconstructing procedures for public participation.
2.2 Risk Communication
The traditional form of communication in the policy
decision-making process has been unilateral informationtransmission. To switch from unilateral informationtransmission to two-way communication, it is necessary
for the information sender to understand the receiver (theperson who is the target of communication). Information
on how the risk message is understood and accepted, andwhat information the stakeholders really want to know isprovided, taking into account the differences between thesender’s and receiver’s position and the risk perception
gap (Renn & Kastenholz, 2000). Lack of such efforts will
eventually lead to the distrust where, “We couldn’t get
the information we really wanted, only unnecessaryinformation.” In this case, not only does communication
become meaningless, but it can also create new sourcesof distrust. It is important, to understand the regional
characteristics, culture and climate, to comprehend thecurrent situation and to grasp what kind of risks arerecognized and how they differ from those ofadministration (Kikkawa, 1999). To promote appropriate
risk communication, building relationships of trust isimportant. Elements that build relationships of trust
include the reliability of the outgoing messages, thesenders, the procedures and the organizations.

3.	Rat Countermeasures Verification
Committee Findings
3.1 Verification of Past Business
To clarify such matters as what residents areconcerned about regarding the Ministry of theEnvironment’s rat countermeasures, the following
questions were asked: “Where is the cause of distrust?”
and “What kind of information is required?” We
conducted a survey and interviews with residents. As aresult, the biggest source of distrust for the residents wasthat there were no clear answers to the following
questions: “Why was Diphacinone selected?” “Why wasaerial spraying chosen?” and “Is the implementation
proceeding without involvement of the islanders?” As
shown in Figs. 1 and 2, resident’s interests related to therat control project and ways they could be dealt with,there was no scientific response to matters regarding thelack of procedures to promote communication/
participation or to the islanders’ questions and concerns.
This was a problem of distrust toward scientificverification, consideration of the characteristics of theOgasawara Islands and rats, and the necessity for andimplementation of comprehensive measures.
We considered keywords on how to deal with issues
that had been clarified in the verification process toidentify the cause of anxiety and distrust (Fig. 1), andclassified these keywords (Fig. 2).
①Anxiety and Distrust due to Issues with Communication
and Processes
・Diphacinone was selected as a rodenticide spray, andthere was insufficient explanation about the basis forselecting this formulation;・The reason for selecting an aerial spraying method wasnot clearly communicated to the community;・Concerns of residents who risked contact withrodenticides were not properly considered (nor werethey consulted);Invasive Alien Species Control and Public Participation

Fig. 1 Anxieties/interests related to the rat control project.
Source: Environmental Risk Verification Report on Ogasawara National Park Rats Control in 2015.

Fig. 2 Ways in which the anxieties/interests related to the rat control project could be handled.
Source: Environmental Risk Verification Report on Ogasawara National Park Rats Control in 2015.

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only by the Ministry of the Environment (including thepublic works budget and contractor selection process),
engendering distrust;・Although there was a risk of re-invasion fromsurrounding islands, no countermeasures were indicated.
In risk communication, as mentioned above, it isnecessary to provide information that responds to theinterests and concerns of the residents. It was also
confirmed that it is necessary to provide detailed
information according to age and gender, and secure
opportunities for participation. In addition, as a premisefor public participation and risk communication,
discussions were also held on how to provide information
to people who are not very interested in the conservationof land snails. Study sessions for general countermeasures
were also held.
②Distrust of and Anxiety about Scientific Verification
There was insufficient verification of environmental
impacts such as residues and effects on other animals(pre- and post-environmental impact monitoring wasinsufficient). Insufficient consideration was given tomitigating effects on other animals or the spillage ofrodenticides into the ocean.
Therefore, the Committee assessed the direct impact
of Diphacinone in soil and water runoff tests and on
various non-target species (seawater fish, freshwaterorganisms, hermit crabs, freshwater turtles, several
arthropods, etc.) In addition, the Committee conducteddemonstration experiments such as analyzing the amountaccumulated in the body and further consideredsecondary effects on predators, such as Buteo buteo
toyoshimai, endemic to the islands. As a result, potential
impacts on rare birds and animals were revealed that had
thus far been considered to be unaffected by
implementation of the project. Specifically, feral pigeons(Columba livia), which are closely related to the redheaded wood pigeon (Columba janthina nitens), an
endengered endemic subspecies, showed higher sensitivity
to Diphacinone than had previously been assumed, andthere was also a risk of poisoning due to accidental
consumption of granules. Concerns about secondary
poisoning caused by rats that had eaten rodenticides werealso raised. Some worrisome issues with rodenticides
were also revealed, including indications that fish andturtles could eat packets or granules that had spilledoffshore. Therefore, the following countermeasures weretaken: (1) precise post-mortem monitoring of rats andenvironmental impacts from the spraying of rodenticides;(2) measures to mitigate the impact on the naturalenvironment, non-target organisms and living environment
when spraying rodenticides; (3) review of the timing ofspraying from the viewpoint of balance between risks andeffects; (4) consideration of combinations of methods formitigating impacts and promoting technologicalimprovements; and (5) prevention of outflow to the ocean

as much as possible, and further investigation of theeffects on food organisms.
③Public Participation Process
To promote appropriate risk communication, it isimportant to ensure opportunities for the public toparticipate in decision-making. To ensure the reliabilityof risk messages, in addition to the reliability of senders
and organizations, it is essential to ensure opportunities
for participation by ensuring procedural fairness.
Participation in the decision-making process can change
one-sided communication into two-way communication,
which can be expected both to reduce misunderstandingsin the communication process and to deepen mutual
understanding (National Research Council, 1989). Thereis no doubt that early public participation is an importantfactor in promoting proper risk management andcountermeasures to invasive species. For this reason, theCommittee proposed a decision process that embodied
the concept of an adaptive government that incorporates
public participation in addition to the adaptive
management approach of flexibly correcting problems
when they occur. The process was examined based on theresults of the above questionnaire, and the Committee
proposed a policy decision process that incorporated theconcept of adaptive governance (Figs. 3 and 4).
④Request for Resumption of Bait Station
Although it has become clear that the rat
countermeasure project of 2009 was conducted without
such considerations and insufficient environmental
consideration in general, it is impossible to predict how
the land snail crisis will unfold. In response to advice
from the Science Committee, the Verification Committee
requested the Ministry of the Environment to implement
an emergency response in August 2015 with reference tothe measures on Nishi-Jima Island, using a bait station.
As an emergency response in some importantconservation areas on Ani-Jima Island, measures toreduce the damage caused by rats to land snails wereimplemented.

4. Conclusions
To preserve the native nature of islands around theworld, including Japan, we have long fought against alien
species brought by humans (Wegmann et al., 2011).
Among them, rats are particularly difficult to eradicate,and various methods such as rodenticides and traps havebeen tried and tested. Each method has its own merits anddemerits, and it is not easy to select final methods
conclusively. It is also difficult to obtain theunderstanding of residents about such selections. Incountermeasures to alien species such as those against
rats, the conventional administrative response emphasizes
ensuring the effectiveness of each countermeasure usinga natural scientific approach. However, this does not giveenough consideration to residents’ participation. The risk

Invasive Alien Species Control and Public Participation

Fig. 3 Flowchart of policy decision process proposed by the Rat Countermeasures Verification Committee.
Source: Environmental Risk Verification Report on Ogasawara National Park Rat Control in 2015.

Fig. 4 Process for improving risk communication with residents and other stakeholders.
Source: Environmental Risk Verification Report on Ogasawara National Park Rat Control in 2015.

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communication and decision-making process withresidents who are actually exposed to risks such as
contact with rodenticides has become more and more
important. To avoid the danger of the Ogasawara Islands
going from “world heritage to crisis heritage” (Yoshida,2008), we need to reduce snail damage by reducing thedensity of rats in important conservation areas for thetime being. To avoid extinction of natural heritages suchas snails, it is necessary to formulate strategies to control
alien species and conserve endemic species throughout
the Ogasawara Islands. To ensure effectiveness ofimplementation, it is necessary to grasp the environmental
impact of implementing measures through monitoring,
implement mitigation measures as much as possible andcommunicate risks to local residents, among othermeasures. Countermeasures must also be implemented on
an ongoing basis, and it is imperative to incorporate
public understanding and participation on a continued
basis in the process (for example, in New Zealand whereeradication has been successful, subsequent re-entry byinvasive species has been prevented. A collaborative
project was undertaken with residents to accomplish this(Project Island Song, 2019).
In Japan, natural heritage sites include not only theOgasawara Islands, but also Shiretoko, Shirakami-Sanchi
and Yakushima. As with the Ogasawara Islands, there
will be future discussion about risk communication withresidents and how to cooperate with residents toimplement continuous protective measures. Since this is
an issue that needs to be addressed, the Ogasawara rat
countermeasures, disseminated on the basis of mattersverified by the Verification Committee, are based onconservation efforts at other World Heritage sites, risk
communication with residents and the ways in whichpeople participate. They will also provide suggestions. I
would like to thank everyone who has cooperated in our
verification over these many years and all of the people
concerned.

Kitamura, Y. (2002) Citizens’ Participation in the Formation andImplementation of Environmental Policies and Measures.
National Institute of Autonomous Research, 288, p82.
Miyauchi, T., Tomita, R., Suzuki, K., Ninomiya, S., Terabayashi,A., Takeuchi, K., Yamamoto, S., Tsuka, K., Seki, R., Fukunaga,M., Kikuchi, N., Matsumura, M., Shimizu, M., Sato, T.,Maruyama, K. (2014) Naze kankyouhozenn ha umakuikanainoka: genbakara kangaeru “jyunnoutekigabanansu” no kanousei(Why environmental conservation does not go well-possibilityof adaptive governance from the field), Shinsen-Sya. (inJapanese)
National Research Council (1989) Improving Risk Communication,
National Academy Press, Washington.
Project Island Song (2019) https://www.projectislandsong.co.nz/(Accessed 9 December 2019)
Renn, O. and Kastenholz, H. (2000) Risk communication forchemical risk management. Risk Communication Chemical
Product Risks, An OECD Background Paper, OECD WorkshopBerlin (8-20 September 2000).
Ruckelshous. W.D. (1985) Risk, science and democracy. Issues inScience and Technology, 1(3), 19–38.
Wegmann, A., Buckelew, S., Howald, G., Helm, J., Swinnerton, K.
(2011) Rat eradication campaigns on tropical islands: novel
challenges and possible solutions. Turning Tide, 239–241.
Yoshida, M. (2008) Sekaiisannjyouyaku to seibutsutayousei nohozen (World Heritage convention and conservation ofbiodiversity). Chikyu Kankyo, 13, 15–22. (in Japanese)

Acknowledgement
This work was supported by JSPS KAKENHI Grant
Number JP70367267. Grants-in-Aid for Scientific Research(Academic Research Grant C) “Risk communication andconsensus building method research in the Ogasawara
Islands” 2016-2019.
References
Brunner, R.D., Steelman, T.A., Coe-Juel, L., Cromley, C.M.,
Edwards, C.M., Tucker, D.W. (2005) Adapted Governance:
Integrating Science, Policy, and Decision Making, New York,
Columbia University Press.
Kikkawa, T. (1999) Risuku comunike-syon:sougoutekirikai toyoriyoi isikettei wo mezasite (Risk Communication: Toward
Mutual Understanding and Better Decision Making), Fukumura
Publishing, p. 20. (in Japanese)

Akemi ORI
Akemi Ori graduated from the Waseda University
Faculty of Law in 1986. In March 2003, she
received her JD from Hitotsubashi University. In
2015, she became a professor at the Graduate
School of Global Environmental Studies atSophia University. Dr. Ori specializes inenvironmental law and administrative law,
especially in the fields of chemical management and waste management.
Regarding risk communication of chemical substances, she has been a longtime facilitator for conflict settlement between chemical companies andresidents, and since 2017 has chaired the Rat Control Committee of theOgasawara Islands. She is also a member of the Ogasawara World Heritage
Science Committee. Recently, she has been conducting research on waste
policies and alien species control in the Galapagos, Micronesian and otherislands, focusing on SDGs and sustainable islands.
(Received 9 December 2019, Accepted 23 December 2019)