Analisis Hubungan Suhu Permukaan Laut (SPL) dan Klorofil-a terhadap Zona Potensial Rajungan (Portunus sp.) di Pantai Labu, Sumatera Utara

Abstract

Blue Swimming Crab is a fishery commodity with a fairly high selling value, both as a local commodity and an export commodity. This study aims to analyze the relationship between oceanographic parameters in the form of sea surface temperature (SPL) and chlorophyll-a to crab catches (Portunus sp.) in the waters of the Strait of Malacca. The data used were in the form of Aqua-MODIS satellite images for temperature and chlorophyll-a, fishermen's catch data, and field measurement data for pH and salinity parameters. The analysis was carried out using descriptive statistical approaches, correlation, multiple linear regression, and mapping of potential zones using ArcGIS software. The results showed that the SPL in the study area ranged from 29–31.8°C, and the chlorophyll-a value ranged from 0.3–6.0 mg/m³. The highest crab catch occurred in December (1035 kg), while the lowest was in April (247 kg). Correlation analysis showed that chlorophyll-a had a strong relationship with catch (r = 0.758; R² = 0.7804), while SPL has a moderate correlation (r = 0.449; R² = 0.4994). Multiple linear regression showed that both variables contributed significantly to the catch with a determination coefficient (R²) of 0.762 and a significance value of F = 0.0006. The pH and salinity parameters in the field range from 6.75–6.92 and 29–31 ppt, which is a category very suitable for crab habitats. The Blue Swimming Crab Fishing Potential Zone (ZPPR) based on sea surface temperature and chlorophyll-a is located at Belawan 3°59'2.06"N 99° 1'31.24"E to 4°8'34.11"N 99°7'48.14"E and Labu Beach 4°12'8.43"N 99°23′52.02"E