*2.2. Sampling and Survey Procedures*

Identification of the survey sites followed the criteria of [33]: the presence of BCEs, the proximity of coastal communities, and accessibility of the village. The interviews were conducted in the municipality of Busuanga in Busuanga Island and in Karimunjawa Island in KNP (Figure 1). Given the set conditions, the respondents were selected randomly; surveying one household in every five-household interval where possible [33,34]. Also, stating the purpose of the survey and asking the permission of each respondent was carefully observed. Furthermore, field enumerators who are associated with the respective government units assisted in the conduct of the surveys. For clarity and consistency purposes in presenting the results and discussions, the sites will be delineated simply as "Busuanga" and "Karimunjawa".

The sample size computation was carefully done to get an appropriate representation of the populations and reliable inferences [51]. Although a sample size with the smallest margin of error (i.e., 2–5%) will always be considered a good representative of the population [52], the level of precision could also depend on the amount of risk a researcher is willing to accept [51]. Thus, in this study, we calculated the sample size in each site at a 95% confidence level with a 10% sampling error using Cochran's formula [53]: n = n0/(1 + n0/N), where n<sup>0</sup> = (t<sup>2</sup> ∗ *p* ∗ *q*)/d<sup>2</sup> , and t = value of selected alpha level (in this study, α is 0.05, so the critical value is 1.96), *p* = estimated proportion of the population which has the attribute in question, *q* = 1 − *p*, and d = acceptable margin of error (in this study, 0.10), and N = population size (22,046 for Busuanga [54] and 9249 for Karimunjawa [45]). The confidence interval of 95% and the margin of error of 10% were selected based on previous works on household surveys (i.e., [33,34]).

A total of 98 locals were randomly interviewed in Busuanga from 19–25 July 2019 whereas only 47 residents were surveyed in Karimunjawa from 8–12 October 2019. Due to limited time in the field survey in Karimunjawa, we were only able to interview 47 respondents instead of 95 people, which is based on our sample size calculation. Due to this, the sampling error for Karimunjawa has increased to 14% from the planned 10% margin of error. We accepted this risk and limitations in accordance with the principles of [51] and the value of internationally comparative survey results was considered and the results were used in this study, carefully considering the difference in the levels of precision.
