Enhancing reef restoration by assessing stakeholder knowledge, attitudes, and preferences
Author contributions: CSLN, TCT, KBT, DH conceived and designed the research; CSLN, TCT, SQS, YPK performed the surveys; CSLN, KBT, DH analyzed the data; all authors wrote and edited the manuscript.
Abstract
Coral restoration has largely focused on improving techniques and biological yield to hasten reef recovery. However, as socioeconomic considerations can affect restoration success, it is important to also consider inputs from various stakeholders in the design and execution of restoration projects. Through online questionnaires, the knowledge levels and attitudes of 142 participants toward coral ecology and restoration in Singapore, and their preferences toward species traits they felt were most beneficial for restoring reefs, were analyzed. Comprising varied sociodemographic profiles and stakeholder groups, participants fared better in general coral biology (up to 90% of answers correct) than local coastal resource management (35% of answers correct). More than 79% of participants agreed that Singapore's reefs were rapidly degrading and required restoration to slow the decline; however, over 63% of them disagreed that restoration was the sole domain of scientists or that the topic had been sufficiently communicated to the public. These knowledge scores and attitudes were most influenced by stakeholder group, educational level, and familiarity with local reefs, underscoring the need to improve environmental education and science communication to these groups. In the trait prioritization exercise involving 76 respondents, resilience and resistance to stress were regarded as most important for restoring reefs. Marine science professionals and nondivers preferred using species that could cope with stress, while nature enthusiasts and recreational divers considered habitat contribution by various coral growth forms as more important. The adaptable framework here facilitates integration of stakeholder inputs with the necessary strategies to boost restoration outcomes.
Implications for Practice
- While performance indicators relating to biodiversity and ecology are often tracked as part of reef restoration efforts, those pertaining to human attitudes and preferences are less measured. Identifying the influence of the latter component is important because sociocultural and governance considerations can affect the implementation and success of restoration initiatives.
- Gathering inputs from community partners by determining their levels of technical understanding and perceptions toward reef restoration will enable future strategies to be more informed and targeted.
- The analytic hierarchy process can be used to highlight unanimity or differences in strategies preferred by multiple stakeholders, thereby enhancing resource utilization in reef restoration.
Introduction
Coral reefs across the world are threatened by a multitude of climatic and anthropogenic impacts (Pandolfi et al. 2003; Halpern et al. 2008), compromising the provision of key ecosystem functions such as habitat and food supply (Pratchett et al. 2014). This has necessitated the development of adaptive management strategies, including the enhancement of environmental protection and conservation efforts, to stem further reef decline (Bellwood et al. 2004; Kennedy et al. 2013). Reef restoration is one such intervention that aims to boost the recovery of degraded reefs by reinstating their structure and function, thereby improving their resilience to further disturbances and helping to support coastal communities such as those dependent on fisheries production and local tourism (Rinkevich 2005; Edwards & Gomez 2010; Hein et al. 2020b). Recent decades have seen the emergence of numerous restoration techniques focusing on improvements to reef substrate quality and the generation and introduction of coral material to degraded sites, with varying motivations and degrees of effectiveness (Bayraktarov et al. 2019; Boström-Einarsson et al. 2020; Hein et al. 2020a).
Ecosystems cannot be decoupled from social systems (Swart et al. 2018). Therefore, to holistically evaluate the effectiveness of reef restoration outcomes, there have been growing calls for comprehensive assessments to be made of performance indicators spanning not only aspects of biodiversity (e.g. coral cover, diversity, and structural complexity) but also socioeconomic ones (e.g. reef user satisfaction, stewardship, capacity building, and economic value). This is because restoration efforts sustained over the long term have numerous wide-ranging downstream benefits such as improved reef ecosystem functioning and the provision of livelihoods (Frey & Berkes 2014; Hein et al. 2017). Current indicators of reef restoration success are, however, skewed toward ecological outcomes, with at least three out of every four studies in the scientific literature focusing on metrics such as the survival, growth, and productivity of coral transplants (Hein et al. 2017; Bayraktarov et al. 2019). Conversely, research on the benefits of restoration on sociocultural capital and capacity such as human well-being is limited (Bayraktarov et al. 2019). As coral reefs are common assets, identifying such effects is necessary because there are cultural, economic, and governance considerations apart from ecological ones that affect how restoration initiatives may be implemented (Hein et al. 2019). These issues, which may be overlooked if researchers were working in silos, could be adequately raised if inputs were solicited from stakeholders of different backgrounds and incorporated into various aspects of reef management (e.g. Cavasos & Bhat 2020). Restoration scenario planning can benefit from the consultation of stakeholders with the power to influence restoration efforts (e.g. government officials, academics) and those affected by the projects (e.g. the public) (Metzger et al. 2017).
Quantifying how knowledge, attitudes, and preferences vary across the sociodemographic landscape enables processes to be fine-tuned to the needs and expectations of specific groups to ensure their support at different stages (e.g. Gumucio et al. 2011). Characterizing these aspects at the initial stages serves as baselines against which subsequent comparisons can be made, so that strategies can be adjusted to increase the likelihood of success. Restoration efforts that involve community partners have also seen improved cost-effectiveness and ecological outcomes, as well as increased environmental awareness and knowledge among the participants (dela Cruz et al. 2014; Hesley et al. 2017; Toh et al. 2017). However, just as how restoration strategies should be customized to local environmental conditions to ensure the best outcomes (Rinkevich 2014; Boström-Einarsson et al. 2020), stakeholder inputs should similarly be garnered at the appropriate levels and scales. Knowledge levels and perceptions toward individual aspects may be highly divergent among stakeholders due to differing priorities or access to resources, thus generating inputs that could either greatly advance or hinder restoration outcomes. For example, people with higher educational levels or income, or from younger demographic groups, may view biodiversity and environmental conservation more favorably (Vodouhê et al. 2010; Masud & Kari 2015; Torres et al. 2020). Conversely, older respondents could be more conscious toward environmental degradation (Obiri & Lawes 2002), while higher levels of formal education may not correlate with increased environmental awareness (Heneghan & Morse 2018). The difference in attitudes may translate to varied preferences of management approaches. For example, people who are cognizant of environmental issues could display an increased willingness to contribute to the costs of ecological engineering measures (Kienker et al. 2018) or have stronger preferences toward certain habitat rehabilitation strategies (Garcia et al. 2020). Concurrently, the majority of the reef restoration literature is also focused on testing methods for improving posttransplantation biological responses (i.e. survivorship, growth), highlighting the technical focus of contemporary reef restoration science (Hein et al. 2017). Together, these observations suggest that varied perspectives may be needed to achieve greater synergies in enhancing reef restoration, especially when there are multifaceted issues to be considered. Where there may be conflicting views on the appropriate means to optimize outcomes, multicriteria decision-making tools could be adopted to identify strategies that have higher consensus than their alternatives (Doropoulos et al. 2019; Lee et al. 2020).
One avenue where the inclusion of stakeholder inputs may inform restoration practices is in the selection of corals for nursery-rearing and transplantation. The potential exists because coral transplantation is widely used by scientists and nonscientists alike for accelerating reef recovery at target sites (Okubo & Onuma 2015; Hein et al. 2017; Boström-Einarsson et al. 2020). Although some stakeholders may possess limited biological knowledge, understanding why they prefer certain species over others could help in structuring environmental education programs and clarifying misconceptions. While it would be ideal to transplant all species that provide a full suite of ecosystem functions at a target site, such an approach would be infeasible because of resource limitations. An approach focused on prioritizing corals based on species traits—which are known proxies of various biological, ecological, and physiological processes on reefs (Madin et al. 2016)—may address not only the experimental motivations of restoration, but also the biotic (i.e. biodiversity enhancement), pragmatic (i.e. ecosystem service enhancement), and aesthetic rationales (Tribot et al. 2016; Bayraktarov et al. 2019). Selecting from a range of traits (e.g. local availability, response to stress, space colonization ability, capacity for habitat contribution to other reef organisms) potentially increases the chances of attaining the levels of reef ecosystem structure and function that previously existed, such as reef structural complexity or coral carbonate production rates.
Singapore, a highly urbanized island state in Southeast Asia, has undergone over five decades of intensive coastal development to support economic growth, but consequently has also lost over 60% of its original reef area (Chou et al. 2019). The high sediment levels and unstable reef substrate have compromised the establishment of corals and restricted the growth of most reefs to shallow depths (<6 m) (Tun 2012). In recent years, mass coral bleaching events have also occurred with increasing frequency and severity (Ng et al. 2020). Despite the multiple stressors, the reefs still support considerable biodiversity (e.g. Taira et al. 2018; Ng et al. 2021). Efforts at restoring the reefs have been ongoing for more than two decades as it is deemed a viable management strategy, with various techniques developed to enhance reef recovery in this urbanized reef system (Ng et al. 2016). The main approaches have been to enhance substrate quality (e.g. via artificial reef deployment; Ng et al. 2017) and to augment live coral cover (e.g. transplanting nursery-reared corals; Toh et al. 2017). In tandem with the global push for more stakeholder involvement to improve reef management (e.g. Hein et al. 2020a), members of the public have also participated in scientist-led restoration efforts in recent years, (e.g. Toh et al. 2017), highlighting the potential for partnerships among different groups in Singapore to be better understood and strengthened.
The current study thus aimed to characterize the knowledge and attitudes of various stakeholder groups toward coral reef ecology and restoration, and to examine their preferences toward specific traits which they felt were key to enhancing restoration outcomes. The sociodemographic variables that best influenced these attributes were explored. This study represents the first research on public perceptions on reef restoration in Singapore, and the results are expected to help identify gaps in current efforts and help refine future protocols, thereby contributing tangibly to the management of its coastal and marine ecosystems. More broadly, the study provides an adaptable framework for evaluating stakeholder inputs in urbanized coastal cities, which can then be complemented with the necessary strategies to achieve more effective restoration outcomes.
Methods
Survey Participants
The study was developed by adapting the knowledge, attitude, practices (KAP) framework, which has been used to identify and quantify a population's knowledge levels, social attributes, and know-how regarding specific issues such as public health (Gumucio et al. 2011). The approach offers an avenue to link people's level of awareness to issues with their opinions and receptivity toward problems and solutions, and has been employed in numerous biodiversity management and conservation programs, including analyses of opinions regarding specific environmental protection strategies, perceptions of local wildlife conservation efforts, and attitudes leading toward human–animal conflicts (e.g. Tonin & Lucaroni 2017; Sophat et al. 2019; Deutsch et al. 2021). Between September and November 2018, two online questionnaires (National University of Singapore Departmental Ethics Review Committee SRP18-012) were disseminated via social media, public outreach events, and talks (Supplement S1). The first questionnaire directed participants to answer a series of questions to assess their level of knowledge and attitudes toward coral reef ecology and restoration in Singapore; the second enabled the same participants to indicate their preferences with regards to coral traits that they felt were most beneficial in designing reef restoration strategies. Participant responses across both questionnaires were linked via their respective identifier codes.
Only persons aged 18 years old or older who were residing in Singapore, and who were interested in contributing their views toward reef conservation and restoration in the country, were surveyed. No vulnerable groups were involved. No personal information was collected, apart from their age, gender, educational qualifications, annual income, and the stakeholder roles that they most identified themselves as (person interested in nature; marine environmental group and volunteer; marine science professional; nondiver; government official working on environmental issues; recreational diver; and “others,” an option for participants who did not fall into these groups). To ascertain their familiarity with reefs in Singapore, the participants were also queried on the frequency and location of reefs (including both subtidal and intertidal) that they may have visited, and their purpose for visiting these sites. They were also asked if they had participated in any kind of reef restoration activity, such as the setting up of nurseries or transplantation of corals.
Knowledge
Nine questions were formulated with reference to the scientific literature (e.g. Huang et al. 2009) and mass media (e.g. Tan 2016a, 2016b) to gauge the stakeholders' level of understanding of coral reef ecology. Multiple-choice questions were posed on Singapore's reef environment (e.g. number of species recorded to date, relative abundance of common coral taxa, geographical location, known impacts), and the relevance of certain traits (e.g. growth patterns, skeletal density, stress response, morphology) to coral fitness.
To understand the potential variables that correlated with the participants' knowledge on reef ecology and restoration, the total proportion of correct answers was modeled using a binomial logistic regression with 10 explanatory variables based on sociodemographic characteristics (age, gender, education level, income bracket, stakeholder group) and familiarity with Singapore's reefs and reef restoration (number of reef visits; frequency of visits to the reefs in the past year; number of activities conducted on reefs; number of types of media where one had learnt about reef restoration; number of reef restoration activities attempted). Multicollinearity was assessed visually with the package “performance” (Lüdecke et al. 2020). The R package “glmulti” (Calcagno 2019) was used to rank models with all possible combinations of only the main effects based on Akaike information criterion (AIC) scores. The relative importance of each explanatory variable was calculated from the Akaike weights of each model that it appeared in.
Attitudes
To understand the attitudes of the participants toward Singapore's coral reefs and reef restoration efforts, they were asked to first list three words describing Singapore's reefs. Responses that were phrases or sentences were omitted, and only single word entries—including adjectives, verbs, and nouns—were analyzed. Words sharing the same root (e.g. “conservation,” “conserve”) were grouped and the respective connotations (positive, negative, or neutral) were determined based on open discussion between the authors to achieve a consensus. A word cloud—employed for the analysis of qualitative information across various disciplines, including that of environmental management (Marchese et al. 2018; Barbosa-Filho et al. 2020)—was constructed to visualize the most frequently used words (R packages “wordcloud,” “XML,” “SnowballC,” “tm,” “RCurl,” “RColorBrewer”; Fellows 2012; Lang & Lang 2013; Bouchet-Valat 2014; Neuwirth 2014; Lang & Lang 2016; Feinerer & Hornik 2019).
The participants were then requested to express the extent of their agreement to six attitude statements on a 5-point Likert scale (strongly agree—5, agree—4, neutral—3, disagree—2, strongly disagree—1). The statements focused on: the rate of reef degradation in Singapore; the validity of pursuing coastal development with reef restoration as a safety net; the justification of restoration as a reef management strategy; the limits of reef restoration; the extent to which scientists have communicated on reef ecology and restoration efforts; and whether reef restoration activities should be exclusive to scientists. Each attitude statement was modeled using an ordinal logistic regression to determine the effects of knowledge scores and sociodemographic variables on the participants' attitudes (function “polr” in R package “MASS”; Venables & Ripley 2002). Models were adjusted for “stakeholder group,” “educational level,” and “age” in the model simplification process (“stepAIC” function in package “MASS”), as these sociodemographic variables were known to influence attitudes in environmental conservation. The most significant variables influencing each attitude statement were identified.
Preferences
The analytic hierarchy process (AHP) (Saaty et al. 2022), commonly used in decision-making problems characterized by multiple criteria, was employed for participants to select from a suite of traits (or trait states) that they deemed most important for enhancing restoration outcomes in Singapore. The traits (and trait states) were abundance in Singapore (common or rare), response to stress (little or no effect, or affected but recovers eventually), ability to colonize an area (growth rate or skeletal density), and contribution of habitat to other reef organisms (branching coral, plating coral, or dome-shaped coral).
A web-based AHP software (https://bpmsg.com/ahp/), which computes pairwise comparisons of criteria in a hierarchical manner and generates local and global priorities for each criterion, was used (Goepel 2018). Within each pair of traits (or trait states), participants were asked to indicate whether they felt one was more important than its alternative, followed by the intensity of importance (from “1” representing equal importance between traits, to “9” representing extreme importance) that they accorded to the former. As logical inconsistencies could occur between choices, participants were also guided by the software to modify their responses until a consistency ratio of less than 10% was individually achieved (Goepel 2018), thus minimizing potential contradictions among the multiple trait choices.
Only participants who had answered both questionnaires and kept within the required consistency ratio of <10% were considered for this set of analyses. The preferences of each stakeholder group for the respective traits were then visualized with the use of a heatmap (package “ggplot2”; Wickham 2016). Since the AHP is primarily designed to support the multicriteria decision-making process rather than for the purposes of inference, the influence of knowledge scores and sociodemographic variables on trait preferences was not examined in this study.
Results
Profile of Survey Participants
A total of 142 survey participants completed the first questionnaire on “knowledge” and “attitudes.” The participants were 57% male and 43% female. A considerable portion of them were of the ages 20–29 (62%) and 30–39 (25%) (Fig. 1A). Most (42%) had a bachelor's degree, 41% held qualifications up to the level of a diploma, while 17% possessed postgraduate degrees (Fig. 1B). A total of 43% of them made up the lowest annual income bracket of $0–20,000 (bracket 1), followed by 22% earning $20,001–40,000 annually (bracket 2; Fig. 1C). As the participants surveyed did not fall into stakeholder roles spanning similar sizes, some of the smaller groups were merged for more even representation (between 22 and 29%) in each of four major stakeholder groups. Participants who selected the category “others” had listed terms such as “just like nature,” “passionate conservationist,” and “someone interested in marine science.” These participants, together with “People who were interested in nature,” were consolidated with “marine environmental group and volunteers” to form the stakeholder group “Enthusiasts,” while “marine science professional” and “government official working on environmental issues” were grouped as “Marine science professionals” (Fig. 1D).
Familiarity of Survey Participants with Singapore's Coral Reefs and Reef Restoration
A total of 51% (n = 73) of participants had not visited any of Singapore's intertidal or subtidal reefs in 2018; this was followed by those who visited one to two reefs (23%), seven or more reefs (15%), three to four reefs (8%), and five to six reefs (3%) (Fig. 1E). Of those who had visited Singapore's reefs in the past year (n = 69), 39% had visited only once in the past year, 15% once in half a year, 22% once per quarter, 14% once per month, 4% once in 2 weeks, and 6% had visited more than once a week (Fig. 1F).
Nearly half of all participants (49%) had never carried out any activities on the reefs, followed by 26, 18, 5, and 2% who had carried out one, two, three and four activities, respectively (Fig. 1G). The most common reef activity they engaged in was the intertidal walk (n = 40 participants), followed by scientific research (n = 35), diving (n = 29), teaching, and other activities (n = 8 each), and fishing (n = 1).
A total of 34% of participants had learnt about reef restoration through one type of media, while 25% learnt it from two and three media types; 6% each learnt it from four and five media types; while 4% had never encountered the topic before (Fig. 1H). Most participants indicated that they encountered the topic on social media (n = 76 participants), followed by from friends or relatives (n = 67), the mass media (n = 63), from school (n = 50), on their travels (n = 33), and other avenues, including public talks (n = 13).
The majority (83%) had never carried out any reef restoration activity, while 4% had carried out all six activities listed (Fig. 1I). The other participants carried out between one (5%), two (3%), three (4%), and four (1%) activities, respectively. Coral transplantation and artificial reef installation were the most common activities (n = 15 participants each), followed by the maintenance of nurseries and coral transplants (n = 11 each), the maintenance of artificial reefs and setting up of nurseries (n = 9 each), and others (n = 4).
Knowledge
Overall score of the nine knowledge questions was 56.6 ± 19.4% (mean ± SD; approximately five out of nine questions correct). The question that most participants answered correctly was the relevance of coral skeletal density toward resisting physical impacts (90.1%). The lowest scoring questions were related to the relative abundance of common corals, and the number of species recorded in Singapore to date (35.2% each).
Knowledge scores were most correlated to educational level, frequency of visits to reefs, and number of reef restoration activities attempted, with these variables having featured in all the top nine models (Table 1). Knowledge score increased with more frequent visits to the reefs, and with increasing number of restoration activities attempted (Fig. 2A & 2B). Knowledge score was similar in participants with bachelor's and postgraduate degrees, but significantly lower for those with qualifications up to a diploma level (Fig. 2C).
| Model Rank | Gender | Age | Education | Income Bracket | Stakeholder Group | No. of Reefs Visited | Frequency of Visits to Reefs | No. of Reef Activities | No. of Media Encountered | No. of Reef Restoration Activities Attempted | AIC | Model Weight | Pseudo r2 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1 | + | + | + | 514.805 | 0.054 | 0.2818 | |||||||
| 2 | + | + | + | + | 515.926 | 0.031 | 0.2918 | ||||||
| 3 | + | + | + | + | 515.997 | 0.030 | 0.2824 | ||||||
| 4 | + | + | + | + | 516.057 | 0.029 | 0.2802 | ||||||
| 5 | + | + | + | + | 516.150 | 0.027 | 0.2781 | ||||||
| 6 | + | + | + | + | + | 516.318 | 0.025 | 0.2836 | |||||
| 7 | + | + | + | + | 516.545 | 0.022 | 0.2779 | ||||||
| 8 | + | + | + | + | 516.599 | 0.022 | 0.278 | ||||||
| 9 | + | + | + | + | 516.721 | 0.021 | 0.2769 | ||||||
| Variable weight | 0.3349 | 0.2482 | 0.7766 | 0.1940 | 0.3834 | 0.3565 | 0.9939 | 0.3175 | 0.1754 | 0.9823 |
Attitudes
A total of 357 word entries (comprising 142 unique words) were analyzed. The most frequently cited words used to describe Singapore's reefs were “diverse” (n = 24), “resilient” (n = 22), and “endangered” (n = 14) (Fig. 3). There was a slightly higher proportion of words with negative (46.5%) rather than positive (41.2%) connotations, while those with neutral connotations comprised the remaining 12.3% (Table S1).
Most participants were in agreement or strong agreement that Singapore's reefs were being lost or degraded faster than they could be conserved (79.7% for statement A1), and that restoration was a worthwhile approach at trying to save the reefs (93.7%; statement A3) (Fig. 4). They also mostly disagreed or strongly disagreed that restoration should only be carried out by coral scientists (67.8%; statement A6), and that scientists had adequately communicated with the public on reef ecology and restoration efforts (63.6%; statement A5).
Adjusting for stakeholder group, educational level, and age, the best models explaining each attitude statement were obtained (Table 2). The best models of statements A1 and A6 were not different from the null models. Among the variables, stakeholder group appeared to be the most important predictor as it featured in three statements (A3, A4, and A5).
| A1 | A2 | A3 | A4 | A5 | A6 | |
|---|---|---|---|---|---|---|
| Age | 0.97 (0.93–1.01) | 1.01 (0.97–1.05) | 1.02 (0.97–1.07) | 1.01 (0.96–1.05) | 1.03 (0.99–1.07) | 1.00 (0.96–1.04) |
| Educational level | ||||||
| Bachelors | 1.00 (Ref) | 1.00 (Ref) | 1.00 (Ref) | 1.00 (Ref) | 1.00 (Ref) | 1.00 (Ref) |
| Masters/PhD | 1.25 (0.47–3.33) | 0.84 (0.32–2.22) | 0.79 (0.28–2.26) | 0.92 (0.36–2.39) | 0.60 (0.24–1.50) | 0.74 (0.29–1.83) |
| PSLE/ GCE/Diploma | 0.86 (0.40–1.83) | 2.58 (1.24–5.45) | 0.73 (0.32–1.68) | 1.21 (0.59–2.48) | 1.23 (0.59–2.57) | 0.52 (0.23–1.15) |
| Stakeholder group | ||||||
| Enthusiast | 1.00 (Ref) | 1.00 (Ref) | 1.00 (Ref) | 1.00 (Ref) | 1.00 (Ref) | 1.00 (Ref) |
| Marine science professional | 0.52 (0.18–1.48) | 0.83 (0.30–2.27) | 0.38 (0.12–1.13) | 0.24 (0.09–0.64) | 1.50 (0.56–4.05) | 0.80 (0.31–2.08) |
| Nondiver | 0.82 (0.33–2.07) | 2.23 (0.90–5.61) | 0.35 (0.13–0.89) | 0.32 (0.13–0.76) | 1.20 (0.46–3.18) | 1.17 (0.48–2.82) |
| Recreational diver | 0.55 (0.22–1.38) | 1.51 (0.63–3.67) | 0.75 (0.28–1.96) | 0.84 (0.35–1.99) | 2.81 (1.15–6.97) | 0.84 (0.35–2.00) |
| No. of reef activities engaged in | 0.71 (0.49–1.02) | 1.47 (1.00–2.16) | ||||
| No. of types of media one has learnt about restoration | 1.46 (1.09–1.97) | |||||
| Gender | ||||||
| Female | 1.00 (Ref) | 1.00 (Ref) | ||||
| Male | 0.54 (0.26–1.11) | 1.66 (0.84–3.31) | ||||
Participants without a university degree were more likely than university graduates to agree that urbanization could proceed at a faster pace because of a better understanding of restoration science (statement A2). Compared to enthusiasts, nondivers (and marine science professionals) were less likely to agree that restoration was worthwhile (statement A3) and that it could return a degraded reef back to its original condition (statement A4). Recreational divers were also more likely than enthusiasts to agree that restoration should be carried out by reef scientists (statement A5).
Preferences
As some participants did not complete both questionnaires, while others had generated consistency ratios beyond the acceptable range of <10% in the second questionnaire, the actual number of participants for whom preferences could be analyzed along with the knowledge and attitude data was 76 (53.5% of all participants; hereafter referred to as “respondents”). Despite the reduced sample size, the composition of respondents in the four stakeholder groups remained fairly even (between 21 and 30% across groups). The most preferred traits in restoration were related to stress response, followed by habitat contribution, colonization ability, and local abundance. Collectively, the respondents prioritized stress resilience (20.2%) and stress resistance (13.2%) the highest, but commonness (7.7%) and a domed growth form (7.2%) the lowest (Fig. 5). Among stakeholder groups, marine science professionals and nondivers most preferred corals that could cope with stress, enthusiasts preferred the use of branching corals, and recreational divers deemed the use of all coral growth forms to be similarly important (Fig. 5).
Discussion
The urgent need to curb coral reef decline has given rise to the development of numerous restoration strategies in the past three decades, but the research to date has mainly taken an ecological focus (Bayraktarov et al. 2019; Ladd & Shantz 2020). Although researchers have increasingly called for socioeconomic dimensions to be considered so that the benefits of restoration may be more holistically assessed (Kittinger et al. 2016; Cooke et al. 2019), such studies remain scarce. Here, our survey has generated a spectrum of inputs from various stakeholders, clearly highlighting the importance of such analyses. The study has also provided restoration practitioners and resource managers a framework for obtaining such inputs that is adaptable over the course of any restoration initiative if periodic assessments are needed.
The knowledge scores were wide-ranging, showing that the level of knowledge participants had regarding coral reefs and restoration was not uniform. They appeared to display greater familiarity with aspects of coral fitness (e.g. skeletal density and habitat creation), but scored poorly for questions specific to Singapore's reefs (e.g. species richness and bleaching temperature thresholds). The data indicated that respondents were more cognizant of general coral biology and ecology than specific facts related to local coastal resource management. Expectedly, marine science professionals scored the highest, but “stakeholder group” was not a significant predictor of knowledge score. Rather, respondents with undergraduate and postgraduate degrees had higher knowledge scores, highlighting the role of formal education in furthering people's understanding of environmental issues (Hanson et al. 2019). The increase in knowledge scores with the frequency of reef visits and number of restoration activities clearly shows the value of field experiences in enhancing learning (Scott et al. 2012) and demonstrates their benefits to environmental management.
There was consensus among participants regarding how they perceived reefs and restoration in Singapore. Analyses of the words that participants used to describe Singapore reefs reflected a slightly negative sentiment and appeared to support those of the attitude statements. The participants were most in agreement that Singapore's reefs were rapidly degrading, and that restoration was necessary to slow the decline; however, they also generally disagreed with the statements that reef scientists had communicated sufficiently on reef restoration to the public, and that restoration should be the sole domain of scientists. While the lack of communication between restoration practitioners and the public has also been noted from projects in other parts of the world (Hein et al. 2019), it is apparent here that local stakeholders in Singapore are willing to participate in restoration initiatives, thus bearing positive implications for subsequent education and outreach activities. This is supported by the receptivity of volunteers in Singapore and elsewhere toward conservation and restoration issues after they participated in outreach activities (Hesley et al. 2017; Toh et al. 2017). Collaborative efforts between researchers and the public have also uncovered the diversity and distribution of various taxonomic groups (Oh et al. 2019; Lim et al. 2020), highlighting the potential for citizen scientists to contribute toward advancing reef restoration in Singapore.
Interestingly, the participants' attitudes were strongly influenced by the stakeholder groups they identified with, especially with opinions divided on whether a degraded reef could be restored to its original condition. Marine science professionals and nondivers were less likely than enthusiasts to agree with this statement. Presumably, the professionals recognized that the current state of restoration science does not allow for the original reef habitat and its functions to be fully reinstated (Edwards & Gomez 2010; Hein et al. 2021). In contrast, to a person untrained in restoration ecology, the term “restoration” evokes the possibility that an ecosystem can be returned to a predisturbance state, when it is extremely difficult to recreate that state in a rapidly changing world (Hobbs et al. 2011). Even if resources are available, limited information on historical conditions would prevent the predisturbance state from being achieved (Hobbs et al. 2011). The disparate levels of understanding between stakeholder groups are highlighted by Edwards and Gomez (2010), who emphasized the need to caution decision-makers on these limits. The differing opinions could also have arisen from insufficient communication to the nonscientists (as indicated by the general sentiment of disagreement with statement A5), who would naturally perceive marine conservation issues and restoration goals (e.g. socioeconomic vs. ecological and impact-management) differently (Oigman-Pszczol et al. 2007; Okubo & Onuma 2015; Hein et al. 2021).
While the AHP approach revealed the diversity of views and low consensus in trait preferences, it also simplified the decision-making process by identifying traits respondents had considered to be more important. Respondents generally regarded the ability of a coral to rebound and resist stress as two of the most essential traits they would prioritize when selecting species for restoration projects. An awareness of the increasing frequency and severity of disturbance events that threaten coral reefs worldwide could have accounted for these trends. For example, in 2016 alone, more than 10 articles on mass coral bleaching were published in Singapore's main broadsheet (Tan 2016a, 2016b), which could have helped educate stakeholders not usually exposed to issues relating to coral reefs, such as the nondivers. Expert opinion has also tended toward the prioritization of reef-scale resilience to stress (via stress-resistance in corals or their symbionts) in reef management (McClanahan et al. 2012). Others have proposed using biomarkers to identify stressed corals (Parkinson et al. 2020), assisted evolution to generate stress-tolerant coral propagules (van Oppen et al. 2015), or assisted migration to climate-harden target reefs (Anthony et al. 2017). Similarly, marine science professionals here also placed high priority on the capacity of corals to recover from stress over all other traits. On the other hand, traits related to habitat provision were more important to the enthusiast and recreational diving groups. This could be due to their interest in the diversity of reef organisms that depend on the various growth forms for shelter. The lowest overall priority was accorded to domed-shaped species, suggesting that respondents were less aware of the nuances in habitat creation with respect to coral growth forms. Alternatively, they could have felt that domed corals do not contribute as much habitat to reef inhabitants. Albeit exploratory, the use of species traits as proxies to explore the differing motivations (e.g. resilience, function, aesthetics) of stakeholders in Singapore toward reef restoration has underscored the importance of considering views from different segments of society in such efforts. Although the significance of the other sociodemographic variables on trait preferences was not analyzed, there is clearly a need for future studies to examine how these factors could, independently or in concert, influence restoration protocols and outcomes.
While the avenues through which the current surveys were disseminated did not reach other stakeholder groups such as the shipping and fishing industries, the current slate of respondents comprise groups known to potentially interact directly (e.g. professionally or recreationally) with Singapore's coral reefs, and therefore were deemed to be able to provide a quantifiable range of responses. As “stakeholder group” and “educational level” featured most frequently as the variables that influenced the participants' level of knowledge and attitudes, formulating strategies specific to enhancing environmental education for these groups could be beneficial for reef management. Successful restoration efforts require that stakeholders be conscious of the relevant issues that exist not only globally, but also locally.
This study showed that gaps clearly exist in environmental awareness among participants. Therefore, key research findings should be regularly communicated to nonscientists in a manner that would directly benefit the local marine environment. For example, the impact of increasingly frequent mass bleaching events can be conveyed to citizen scientists, who can then be encouraged to document and share their field observations, enabling reef surveillance to be carried out over larger areas or when high sea temperatures have been projected. This may be achieved via the CoralWatch and Reef Check programs, which have equipped citizen scientists worldwide with simple tools and essential skills to monitor and report their observations on reef health (Marshall et al. 2012; Forrester et al. 2015). To leverage the benefits of experiential learning, education and outreach activities could be catered toward nonuniversity graduates and nondivers to convey relatable messages on local issues and foster environmental stewardship. Ultimately, this helps increase trust among stakeholder group and lead to greater conservation success, compared to a scenario where only stakeholder involvement was increased (Young et al. 2013).
Many of the participants' perceptions were influenced by their familiarity with local reefs, ranging from the number of reef activities they had engaged in to the media types from which they learnt about restoration. Social media was the main vehicle conveying information on reef restoration, and therefore will be useful for communicating scientific findings and soliciting inputs from the public. For example, the micro-blogging site Twitter provided an avenue to study public perceptions on restoring the Great Barrier Reef (Newlands & Martin 2018). Conversely, far fewer participants indicated that they learnt about restoration from public talks. This could be remedied via webinars and online workshops, which are likely to have broader reach than traditional platforms. The COVID-19 pandemic has accelerated the uptake of these outreach tools. Open events hosted online such as World Oceans Day 2020 and the Asia Dive Expo have featured local marine scientists and their research. To date, there have been more than 2,500 views each on topics spanning marine ecosystem resilience, coastal recreation, and marine conservation for the webinars and online discussions hosted on Facebook, as part of a slew of Asia Dive Expo events in mid-2020 (e.g. ADEX 2022).
Amidst calls to rebuild marine life and ensure a sustainable future (Duarte et al. 2020), ensuring the robustness of the myriad of science-based methods for reef restoration (Boström-Einarsson et al. 2020; Ladd & Shantz 2020) is as critical as incorporating social, cultural, and economic perspectives in reef management (Darling et al. 2019). Understanding how various stakeholders perceive environmental issues and identifying gaps between public knowledge and preferences can assist in the identification of potential conflicts and pooling of resources toward common goals, which would ultimately improve restoration outcomes. Such an approach would be key to advancing reef restoration science in the foreseeable future and is especially apt with the period of 2021–2030 having been declared as the United Nations Decade on Ecosystem Restoration (United Nations General Assembly 2019; Young & Schwartz 2019).
Acknowledgments
The authors thank J. C. Lopez for his assistance with the study, and everyone who facilitated and participated in our survey. This research was supported by the Temasek Foundation under its Singapore Millenium Foundation Research Grant Programme. The authors have no conflicts of interest to declare.
