1. Introduction
The global push toward renewable energy development, coupled with increasing competition for land use and the urgency of climate change mitigation, has catalyzed innovative approaches to space utilization [
1]. Aquavoltaic (APV) systems, integrating solar photovoltaic installations with aquaculture production, have emerged as a promising strategy to address these challenges [
2]. APV installations, often described as “top-level electricity generation, bottom-level aquaculture,” represent a paradigm shift in the conceptualization and management of productive water bodies [
3]. Taiwan, with its ambitious energy-transition goals targeting a “nuclear-free homeland” by 2030, has actively promoted renewable energy development, particularly solar power [
4]. As of September 2023, Taiwan’s solar installation capacity reached 11.7 gigawatts, with APV systems forming a key component of this renewable energy portfolio [
5].
Coastal areas with extensive aquaculture infrastructure, such as Cigu District in Tainan, have become focal points for this transformation. Cigu District, renowned for its extensive aquaculture ponds, tidal flats, and lagoons, is a significant aquaculture center experiencing substantial APV development [
6]. Projects such as the Tainan Cigu Solar Power Plant and Star Aquaculture’s “Sun Operation Project” exemplify this transition [
7]. The rationale for promoting APV in Cigu includes revitalizing traditional aquaculture, enhancing land-utilization efficiency, and creating diversified income streams for local communities [
8]. However, the APV transformation in Cigu represents more than a technological shift; it constitutes a complex socio-ecological experiment. Driven by national energy policies [
9], APV development is viewed as a solution to land-use efficiency challenges and economic revitalization of aquaculture areas [
5]. Yet, Cigu’s unique social structure, characterized by a high proportion of tenant farmers (approximately 80%), and its ecological sensitivity create implementation challenges that exceed mere technological considerations [
10]. Concerns regarding tenant farmers’ rights, ecological impacts on species such as the black-faced spoonbill, and aquaculture productivity maintenance have generated significant local apprehension and resistance [
11]. While the “70% yield” claim is crucial for the economic and social acceptance of APV, it faces scrutiny due to the lack of peer-reviewed, long-term, multi-species data from commercial-scale operations in Cigu [
9], exacerbating local concerns [
11]. The FRI itself acknowledges that on-site management issues remain to be resolved and that establishing a universal cost–benefit model is challenging [
12]. Additionally, while the temperature-regulation function of APV panels generally benefits summer heat stress mitigation [
5], it may have subtle effects on optimal temperature requirements for specific species and phytoplankton dynamics, ultimately affecting productivity and overall pond ecosystem health [
13].
Kayaking, as a popular non-motorized water recreation activity, aligns with low-carbon tourism principles. Taiwan offers numerous kayaking experiences across diverse aquatic environments, including coastal areas, lakes, and even rice paddies [
14]. The Taiwanese government has encouraged fishermen to develop low-carbon green tourism activities, such as kayaking, as potential supplementary income sources—a particularly relevant consideration for areas like Cigu undergoing APV transition [
15]. The introduction of kayaking activities in APV aquaculture ponds represents a novel intersection of industrial land use (aquaculture and energy production) and nature-based recreation, creating a unique hybrid tourism landscape. While APV sites are essentially modified industrial–agricultural landscapes [
16], kayaking is typically associated with natural or semi-natural water bodies [
17]. The integration of kayaking into APV ponds merges these distinct uses, potentially offering a “novel” experience [
18] while raising questions about authenticity and ecological compatibility. The core issue addressed in this research concerns whether kayaking activities may cause ecological disturbance and stress to the main cultured species in Cigu’s APV ponds—hard clam (
Meretrix lyrata) and whiteleg shrimp (
Penaeus vannamei). Potential disturbance mechanisms include the physical presence of kayaks and paddlers, water column turbulence and sediment resuspension from paddle strokes, casting of moving shadows, and noise and vibration. There is a critical knowledge gap regarding such impacts in APV-modified aquaculture environments, as existing studies have not specifically addressed this context.
The unique environment of APV ponds (partial shading and presence of structures) may alter the baseline stress levels of cultured species, potentially making them more or less sensitive to additional stressors from kayaking activities compared to traditional open ponds [
5]. APV systems modify light conditions, water temperature, and potentially water flow [
5]. These altered conditions likely already affect the physiology and behavior of the clams and shrimp [
13]. Therefore, the introduction of kayaking as an additional novel stimulus (shadows, movement, and turbulence) needs to be assessed against this already modified baseline, meaning that findings from traditional ponds may not be directly applicable. A frequently cited claim by the Fisheries Research Institute, Mod [
19], states that APV systems with 40% shading can maintain at least 70% of the original aquaculture productivity [
19]. Specific FRI trials have shown that hard clams (
Meretrix sp.) performed well under 40% shading during summer months [
19], though growth was slower in autumn and winter due to reduced algal production [
12]. The validity of this claim for
Meretrix lyrata and
Penaeus vannamei under actual operating conditions in Cigu APV ponds (rather than merely simulated environments) requires verification. The shading provided by solar panels helps regulate water temperature, mitigating summer heat stress and potentially reducing evaporation [
1]. A study in southeastern China found that floating solar panels reduced water temperature by an average of 1.5 °C [
20].
Given the rapid development of APV landscapes and their complex interactions, particularly the insufficiently studied ecological impacts of introducing recreational activities like kayaking, a deeper understanding is urgently needed. This requires rigorously reviewing existing literature on APV systems, ecological impacts of non-motorized boat recreation, and the sensitivity of Meretrix lyrata and Penaeus vannamei to relevant disturbances; integrating contextual information on APV development in Cigu, including local concerns and policy drivers; identifying potential ecological impact pathways of kayaking activities on target cultured species in APV ponds; exploring the potential and challenges of integrating kayaking tourism as a sustainable livelihood diversification strategy in Cigu’s APV systems; assessing the recreational benefits and visitor experience aspects of kayaking in these novel, modified environments. This research aims to inform sustainable management practices for regions like Cigu in balancing energy production, food security, local livelihoods, and conservation. Recreational kayaking has gained popularity as an outdoor activity that connects participants with nature while providing physical and psychological benefits. The quality of facilities, safety measures, and professional instruction (FM) are critical factors that may impact participants’ perceived value of the training experience (PV). Additionally, as environmental awareness grows, understanding participants’ recognition of green energy and sustainable development concepts (GS) becomes increasingly important in outdoor recreational contexts.
Previous literature suggests interconnections between these constructs, but empirical research examining their relationships, particularly in kayaking recreation, remains limited. This study aims to address this gap by investigating how facility maintenance and safety professionalism influence participants’ perceived value of kayaking training, and how both factors contribute to participants’ recognition of green energy and sustainable development concepts.
3. Methodology
3.1. Conceptual Framework
This study investigated the relationships between facility maintenance and safety professionalism (FM), perceived value of kayaking training (PV), and green energy and sustainable development recognition (GS) using structural equation modeling (SEM). Based on previous literature, we hypothesized that FM positively influences PV (H1), PV positively influences GS (H2), FM positively influences GS (H3), and PV mediates the relationship between FM and GS (H4). Additionally, we explored the potential moderating effects between these variables (H5). Based on these hypotheses, we proposed an integrated conceptual model depicting the direct, mediating, and potential moderating relationships between facility maintenance and safety professionalism (FM), perceived value of kayaking training (PV), and green energy and sustainable development recognition (GS). This model guides our empirical investigation and provides a foundation for understanding the educational potential of recreational activities within transformed aquavoltaic landscapes.
3.2. Measurement
All constructs were measured using multi-item 5-point Likert scales (1 = strongly disagree to 5 = strongly agree) to ensure adequate response distribution and measurement sensitivity [
45]. The facility maintenance and safety professionalism (FM) construct was operationalized using nine items across three dimensions: facility quality (FM1, 3 items), safety procedures (FM2, 3 items), and instructor professionalism (FM3, 3 items), adapting scales from previous research on recreational facility assessment [
35,
36]. The items assessed aspects such as equipment condition, safety protocol clarity, and instructor competence within the context of aquavoltaic environments. The perceived value of kayaking training (PV) was measured through eight items across four dimensions: functional value (PV1, 2 items), emotional value (PV2, 2 items), social value (PV3, 2 items), and educational value (PV4, 2 items), drawing from established perceived value frameworks [
18] but contextually adapted to kayaking experiences in modified aquatic landscapes. Green energy and sustainable development recognition (GS) was assessed using five items examining participants’ acknowledgment of the importance of renewable energy, understanding of sustainable water resource management, and appreciation of integrated energy–aquaculture systems [
46,
47].
The initial instrument underwent rigorous content validation through expert review with five specialists in recreational tourism, environmental education, and aquavoltaic systems. Subsequently, the questionnaire was pilot tested with 50 participants (30 local residents and 20 tourists) at Cigu APV recreational sites to evaluate comprehensibility, cultural appropriateness, and completion time (
Figure 1). Item wording was refined based on cognitive interviews and feedback analysis, resulting in the final 22-item measurement instrument. Data collection was conducted at purposively selected kayaking launch points and rest areas within APV recreational sites in Cigu District, Tainan City, between May 2024 and January 2025. This timeframe enabled sampling across seasonal variations in visitor patterns and environmental conditions [
3]. Stratified random sampling was employed to ensure representation across weekdays (40% of collection sessions), weekends (45%), and public holidays (15%), with data collection distributed across morning (9:00–12:00), afternoon (13:00–16:00), and evening (16:00–18:00) timeframes to minimize temporal sampling bias. Trained research assistants approached potential participants using a systematic intercept method, explaining the research objectives and obtaining written informed consent before questionnaire administration. The participants completed the self-administered surveys either before (42% of the sample) or after (58%) their kayaking activities. The research assistants remained available to clarify questions without influencing responses. The average completion time was 16.8 min (SD = 4.2).
The pilot testing involved cognitive interviews with the participants to assess item comprehension, cultural appropriateness, and response time. Feedback analysis revealed minor wording adjustments needed for three items related to APV system understanding. The questionnaire completion time averaged 16.8 min (SD = 4.2), which is considered appropriate for field administration. To enhance response rates and data quality, the participants received a locally produced sustainable souvenir (valued at approximately TWD 150) as a token of appreciation upon questionnaire completion. Quality control procedures included a daily review of completed questionnaires, with immediate follow-up for missing data when participants were still on-site. Non-response bias was assessed by comparing early and late respondents across key demographic variables, revealing no significant differences (
p > 0.05). Multi-wave data collection across different seasons and weather conditions further mitigated potential sampling biases [
20].
3.3. Sample Selection and Data Collection
Data were collected from 613 participants who had engaged in recreational kayaking activities. The sample demographics are presented in
Table 2. The research model consisted of three main constructs: facility maintenance and safety professionalism (FM), perceived value of kayaking training (PV), and green energy and sustainable development recognition (GS). The FM construct comprised three first-order dimensions (FM1, FM2, and FM3), each measured by three indicators. The PV construct consisted of four first-order dimensions (PV1, PV2, PV3, and PV4), each measured by two indicators. The GS construct was measured directly by five indicators. The data were analyzed using structural equation modeling (SEM) techniques. First, we assessed the measurement model through confirmatory factor analysis (CFA) to ensure the reliability and validity of the constructs. Second, we evaluated the structural model to test the hypothesized relationships. Finally, we conducted a mediation analysis to examine the mediating effect of PV in the relationship between FM and GS.
Underwater video recordings were systematically conducted using an array of 16 high-definition cameras (GoPro HERO10 Black with custom waterproof housings, GoPro, San Mateo, CA, USA). These cameras were deployed in four distinct APV aquaculture ponds situated within Cigu District, Taiwan, over a six-month period, from August 2024 to January 2025. Each pond was stocked with whiteleg shrimp (P. vannamei) at typical commercial densities, ranging from 25 to 30 individuals/m2. At the commencement of the study, the average individual weight of the shrimp was recorded as 12.6 g (±2.3 g).
Cameras were strategically positioned at four standardized locations within each pond to capture a range of environmental conditions: directly beneath APV panel arrays (representing 100% shading), in partial shade zones (experiencing 40–60% shading), in open-water zones (with 0% shading), and along the pond margins (<1 m from the embankment). Video recording followed a stringent, standardized protocol for each experimental event. This protocol comprised a 60-min pre-disturbance baseline period (serving as the control), a 30-min vessel passage period (representing the experimental treatment), and a 120-min post-disturbance period for monitoring recovery. Two distinct vessel treatments were implemented using a randomized crossover design, with a minimum washout period of 48 h between exposures to minimize carryover effects. The vessel treatments included the use of non-motorized kayaks (standard recreational polyethylene sit-on-top kayaks, 3.3 m in length, operated by two paddlers) and small motorized vessels (aluminum work boats, 4.2 m in length, equipped with 15 HP outboard motors). Each treatment was replicated six times per pond, resulting in a total of 24 replicates for each vessel type. Standardized vessel movement patterns, maintaining consistent speed, distance from cameras, and duration of passage, were strictly adhered to across all replicates.
Control observations, where no vessel passage occurred, were conducted on alternating days throughout the study. The behavioral responses of the shrimp were quantitatively assessed through continuous focal sampling of 30 randomly selected individuals per video frame, resulting in the analysis of 120 individuals per treatment event. Behavioral metrics were precisely defined and coded based on established ethogram protocols for penaeid shrimp, adapted from the methodologies described by [
48] and [
49]. The key behavioral metrics quantified were the startle response rate (percentage of observed individuals exhibiting sudden directional change via rapid tail-flipping or jumping), duration of startle response (time in seconds from initiation to cessation of elevated activity), recovery time (minutes until the return to pre-disturbance behavioral patterns such as feeding and normal swimming), latency to first response (seconds elapsed between vessel approach and the first observable behavioral change), distance-triggered response (minimum distance in meters between the vessel and shrimp at the onset of a response), vertical displacement (maximum vertical movement in centimeters during an escape response), feeding interruption (duration in minutes of suspended substrate probing behavior), and group synchronization index (a scale from 0 to 1 representing the proportion of individuals exhibiting synchronized responses).
Behavioral categories were validated through comparison with established ethograms for penaeid shrimp [
50]. Initial pilot observations (n = 50 shrimp, 10 h of video) were independently scored by three trained observers to establish inter-rater reliability. Only behavioral categories achieving Cohen’s κ > 0.80 were retained for analysis.
Video analysis was performed using BORIS v7.9.8 behavioral observation software [
51]. To ensure high inter-rater reliability, 20% of the video recordings were double-coded by independent observers, achieving a Cohen’s κ value exceeding 0.85. Statistical analyses were conducted using R v4.2.1 [
52]. One-way ANOVA with Tukey’s post-hoc tests was employed to compare continuous behavioral variables between the different vessel types. For proportional behavioral data, chi-square tests were utilized. Two-way ANOVA models were constructed to investigate potential interactions between vessel type and various environmental factors, including water depth, clarity, APV coverage, and time of day. The statistical significance threshold was set at α = 0.05, with Bonferroni correction applied to account for multiple comparisons and minimize the risk of Type I errors.
Data analysis employed a two-stage structural equation modeling (SEM) approach using AMOS 26.0 software [
53]. Prior to analysis, the data were screened for multivariate normality, outliers, and missing values following established protocols [
54]. Multiple imputation techniques were applied to the minimal missing data (<1.8%), and cases with systematic response patterns (e.g., straight-lining) were excluded from analysis (n = 14), resulting in 613 valid responses. The measurement model was first evaluated using confirmatory factor analysis (CFA) to assess construct validity and reliability. Model fit was assessed using multiple indices, including the chi-square ratio (χ
2/df < 3.0), the root mean square error of approximation (RMSEA < 0.08), the comparative fit index (CFI > 0.95), the Tucker–Lewis index (TLI > 0.95), and the standardized root mean square residual (SRMR < 0.06) [
55]. Local fit was examined through standardized factor loadings (>0.70), modification indices, and standardized residuals. Reliability was assessed through Cronbach’s alpha (α > 0.70) and composite reliability (CR > 0.70), while convergent validity was evaluated using average variance extracted (AVE > 0.50). Discriminant validity was established by comparing the square root of AVE values with inter-construct correlations and through the heterotrait–monotrait (HTMT) ratio methodology [
56], with values below 0.85 indicating sufficient discrimination between constructs. Missing data analysis revealed a completely random pattern (Little’s MCAR test: χ
2 = 23.45,
p = 0.432). Multiple imputation using the expectation maximization algorithm was applied to the minimal missing data (<1.8%). Cases exhibiting systematic response patterns (straight-lining across more than 80% of items) were identified using standard deviation and variance criteria and subsequently excluded from analysis.
Upon establishing a valid measurement model, the structural model was tested to evaluate hypothesized relationships. Mediation effects (H4) were examined using bootstrap analysis with 5000 resamples and bias-corrected 95% confidence intervals (Preacher and Hayes, 2008) [
57]. Moderation effects (H5) were tested through interaction terms and multi-group analyses based on theoretically derived moderators [
44]. Potential multicollinearity was assessed using variance inflation factors (VIF < 3.0), while common method bias was evaluated using Harman’s single-factor test and the common latent factor approach [
58]. Additionally, a marker variable technique was employed to quantify and control for potential method effects.
3.4. Control Variable Integration in SEM Control Variables Were Integrated into the Structural Model Using a Hierarchical Approach
- (1)
Direct effects model: Environmental attitude, age, gender, education, and prior experience were modeled as direct predictors of both PV and GS constructs (
Table 2).
- (2)
Covariate control: All control variables were allowed to correlate with each other and with the main constructs to account for shared variance.
- (3)
Model specification:
- -
Environmental attitude → PV: β = 0.16, SE = 0.04, p = 0.002.
- -
Environmental attitude → GS: β = 0.12, SE = 0.03, p = 0.011.
- -
Gender → PV: β = 0.07, SE = 0.05, p = 0.187 (n.s.).
- -
Education → GS: β = 0.14, SE = 0.05, p = 0.006.
- (4)
Model comparison:
- -
Model without controls: χ2 = 387.2, df = 165, CFI = 0.931.
- -
Model with controls: χ2 = 421.7, df = 175, CFI = 0.952.
- -
Δχ2 = 34.5, Δdf = 10, p < 0.001 (significant improvement).
5. Conclusions
This study offers several significant theoretical contributions. First, we advance experiential learning theory by empirically validating a dual-pathway model, highlighting perceived value’s crucial mediating role between facility quality and sustainability recognition, while also revealing direct learning mechanisms. Second, our research quantified the differential ecological impacts of motorized versus non-motorized vessels on key aquaculture species. Underwater video demonstrated that kayaking elicits significantly lower startle responses in whiteleg shrimp (18.7%) compared to motorized boats (42.6%), with faster recovery, providing empirical parameters for disturbance thresholds in production landscapes. Third, the observed inverted U-shaped moderating effect of APV coverage advances theories on optimal environmental design for sustainability education, emphasizing a balance between technological and natural elements. Finally, by integrating aquavoltaic development, recreational tourism, and sustainability education, this study proposed an integrated theoretical framework for the “fishery–energy–recreation” nexus, offering interdisciplinary insights for sustainable coastal transitions.
The “fishery–energy–recreation” nexus exemplified in Cigu offers valuable insights for similar transitions globally. By carefully designing and managing these systems to optimize both ecological compatibility and visitor experiences, we can create landscapes that not only produce renewable energy and sustainable food but also nurture the environmental consciousness needed to support broader sustainability transitions. In this way, transformed production landscapes can become powerful catalysts for transforming mindsets, creating virtuous cycles of sustainability that extend far beyond their physical boundaries.
Several limitations constrain causal interpretation of our findings: (1) The cross-sectional design means temporal precedence cannot be established, limiting causal mediation inference; (2) common method variance indicates that self-report measures may inflate associations; and (3) the single context means that the findings are specific to Cigu APV systems. Future research should employ (1) longitudinal designs with repeated measures, (2) experimental manipulation of facility quality, and (3) multi-site replication across different APV configurations.