Effects of Bait and Soaking Time of Umbrella Traps (Bubu Payung) on Catch in Rawa Pening Lake, Central Java, Indonesia

Abstract

Rawa Pening Lake supports diverse freshwater fisheries where umbrella trap catches are strongly influenced by bait type and soaking duration, prompting this study to evaluate optimal bait–soaking combinations for improved fishing efficiency and sustainability. This study analyzed the effects of bait type (rucah fish, shrimp paste, golden apple snail) and soaking time (6, 12, 24 h) on umbrella trap catch in Lake Rawa Pening, Central Java, using a 3×3 factorial completely randomized design with seven replicates (63 units). Data included the number of individuals, weight, and species composition. A Generalized Linear Model (GLM) with a Poisson distribution was applied for count data (number of individuals), while a negative binomial GLM was used for weight due to extreme overdispersion. Total catch was 60 individuals (3,733 g), comprising marble goby (dominant: 90% of individuals, 95% of weight), freshwater crayfish, and silver rasbora. No significant interaction was found between bait type and soaking time for either number of individuals (p = 0.575) or weight (p = 0.391). Soaking time had a significant main effect, with 24 h producing 2.47 times as many individuals and 2.93 times as much weight as 12 h (6 h did not differ from 12 h). Bait type was not globally significant (p = 0.051 for individuals; p = 0.123 for weight). Pairwise comparisons showed that rucah fish and golden apple snail did not differ significantly (p > 0.05), but shrimp paste produced significantly fewer individuals than rucah fish (p = 0.048). Descriptively, golden apple snails with 24‑h soaking gave the highest mean catch (2.43 ± 0.79 individuals; 177.14 ± 90.32 g). Based on these findings, 24‑h soaking with rucah fish or golden apple snail is recommended; golden apple snail is a statistically equivalent and more economical alternative. Further studies with larger replicates and environmental controls are needed.