Prioritizing candidate OECMs in Korea requires an ex ante framework that compares institutional constraints across candidate types while mitigating data deficiency and selection bias before site-level assessments are finalized. This study groups nationally discussed candidates into 17 candidate types and represents OECM suitability through five latent axes bounded between 0 and 1: non-protected area status (nonPA), boundary clarity (boundary), governance stability (governance), long-term durability (longterm), and biodiversity outcomes (biodiv). Axis scores are modeled with Beta priors whose means and uncertainties are elicited via transparent, rule-based flags extracted from structured textual descriptions, thereby preserving traceability of how assumptions shift each axis. Joint dependence among axes is introduced using a copula, and an additional directional mechanism links governance to long-term durability to reflect the institutional premise that durable outcomes are underpinned by stable authority, responsibility, and coordination capacity. Decisions are evaluated with a two-stage rule consisting of a minimum-threshold gate across all axes and a weighted composite score applied to gate-passing samples. Complementary analyses examine single-axis mean-shift interventions, rank stability under alternative weight interpretations, and expected utility combining registration likelihood with effective area. Results indicate that feasibility is shaped less by average levels than by bottlenecks generated by simultaneous minimum requirements. Recurrent bottlenecks concentrate in boundary documentation and spatial attribution, outcome-evidence systems, and the justification for reporting units distinct from protected areas. The analysis further reveals a structural separation between types that are relatively easy to register and types that yield larger expected gains once registered, supporting a staged policy portfolio that couples near-term standard-setting through readily registrable types with medium-to-long-term investment in high-impact types. Across most types, governance strengthening emerges as the most consistent leverage for increasing final pass probabilities, suggesting that improvements in durability and overall feasibility are more efficiently achieved through institutional alignment than through isolated, single-axis adjustments.

This study investigates the internal structure of the Habitat and Riparian Health Index (HRI) by identifying conditional dependencies among its components and the mechanisms that form grade boundaries, rather than treating HRI as a simple arithmetic sum. Using the 2024 national river assessment dataset, the analysis combined bootstrap-supported Bayesian Networks for stable dependency inference with classification decision trees for explicit grading rules and threshold identification. A multi-criterion priority scheme integrating network centrality, contribution to total-score variability, and classification contribution was also applied to derive management priorities within and across basins. Across all basins and analytical perspectives, Flow Velocity Diversity consistently emerged as the most influential component. It occupied the central position in the dependency structure and accounted for the largest share of variability in the composite score, indicating that it operates as a system-level outcome in which channel morphology, bed condition, and anthropogenic constraints converge. The grading mechanism was strongly asymmetric. Deficiencies in riverbank protection functioned as a dominant trigger for rapid grade deterioration, whereas attainment of the highest grade required a conjunctive and non-linear pathway in which sufficient flow heterogeneity was accompanied by the sequential resolution of structural constraints, particularly those associated with transverse structures and embankments. Basin-level comparisons further showed that network structures were not interchangeable, with the Nakdong River basin exhibiting the most distinct configuration and basinspecific priority patterns. These results imply that management should separate strategies aimed at preventing degradation through bottleneck control from strategies aimed at achieving top-tier conditions through coordinated, multi-component interventions.

We attempted to estimate potential habitats of Clithon retropictus and to determine the community structure of benthic macroinvertebrates by presence of C. retropictus. 2016 to 2018 database of “Survey and Assessment of Estuary Ecosystem Health” by the Ministry of Environment were used to identify the distribution site of C. retropictus. The occupancy model was applied to estimate the potential habitat of C. retropictus. Four diversity indices were used to confirm the community structure of benthic macroinvertebrates. C. retropictus was found in the southern coast area and part of the east coast, and this pattern was consistent with previous studies. Additionally, the occupancy model predicted that a potential habitat of C. retropictus could appear in the west coast area. The community structure of benthic macroinvertebrates was relatively high at the site with C. retropictus than the site without C. retropictus. Therefore, the occupancy model can be considered when conserving C. retropictus inhabiting a limited area. Additionally, C. retropictus can be used to the indicator species that can represent the brackish water environment.