해양환경측정망 자료를 활용한 강원 연안 수온상승–수질 공동효과와 살오징어 어획량의 비선형 연계 분석 = Nonlinear Linkages Between Todarodes pacificus Catches and the Joint Effects of Sea-Surface Warming and Water Quality in the Gangwon Coastal Region, Korea

다국어 초록 (Multilingual Abstract)

Climate change–driven ocean warming alters the physicochemical properties of coastal waters, thereby reshaping habitat conditions and the spatial distribution of fishery resources. Leveraging the Marine Environmental Information System (MEIS) surface data and fishery statistics for the Gangwon coast (2005–2024), we quantified the joint effects of sea-surface warming (SST) and water-quality variability on catches of the Japanese flying squid (Todarodes pacificus). We first conducted seasonal regressions between SST and water-quality variables to retain candidates minimally affected by temperature, then combined simple and multiple linear regressions (correlation coefficients, p-values, and CIs, VIF) with Elastic Net to identify robust predictors. Subsequently, Generalized Additive Models (GAMs) were fitted to capture nonlinear response functions between catch and water quality. Total phosphorus (TP) emerged as a consistently significant predictor across May, August, and November. The integrated seasonal GAM revealed an ecological threshold: squid catch increased at TP ≈ 18–39 μg L⁻1, but declined beyond 40 μg L⁻1, indicating a dual regulatory role of TP—enhancing productivity below the threshold while inducing eutrophication and habitat degradation at excessive levels. These results indirectly demonstrate that coastal squid catches are shaped not only by temperature but also by water-quality dynamics, particularly TP, and point to the feasibility of TP-threshold-based management indicators (e.g., monthly risk classes) for operational use. Limitations include reliance on coastal observations, exclusion of offshore data, and limited treatment of exogenous meteorological forcings; future work should integrate coastal–offshore datasets and measure organic phosphorus fractions to refine mechanisms and improve predictability under ongoing climate change.