Some biological aspects and economic value assessment of mud crab fisheries at Welu Estuary, Trat Province

Abstract

Some biological aspects and economic value assessment of mud crabs (Scylla spp.) at Welu Estuary in Trat Province were studied. Data were collected by gill nets from small-scale fisheries between February 2022 to January 2023. Throughout the study, a total of 269 sea crabs were collected, comprising 117 males and 152 females. The carapace width of the majority of the mud crabs found fell within the range of 9.01-10.00 cm. Their weights were predominantly within the range of 90.01-100.00 grams. The highest number of mud crabs was found in April, while the fewest was found in September. The average male-to-female ratio throughout the year was 1:1.29. The relationship equation between weight (Wt) and carapace width (CW) for females was given by Wt=0.1326CW^2.8916 (R² = 0.4650), while for males it was Wt=0.2148CW^2.7964 (R² = 0.6855). The coefficient of abundance for mud crabs reached its peak in March. An assessment of the economic value of mud crab fisheries, utilizing mud crab gill nets in the Welu River, Trat Province, reveals that throughout the year, 1,122.90 kilograms of mud crabs can be harvested. This represents an annual income from mud crab fisheries of approximately 224,580.00 Baht per household. This kind of revenue will encourage fishermen to focus on sustainable fishing and contribute to the preservation of mangrove resources to provide a habitat for mud crabs and other aquatic animals.