Sustainable management of fisheries resources in Java Sea: Utilization status of longtail tuna (Thunnus tonggol) in Indramayu waters West Java case study

Abstract

Longtail tuna (Thunnus tonggol) is a pelagic fish which is generally found in tropical waters. Research on fishery resource sustainability by applying bioeconomic and length weight assessments is necessary to be done in order to determine status of longtail tuna. This research was conducted in south part of Java Sea namely Indramayu waters West Java from January 2020 to April 2020 which aims to estimate utilization status of longtail tuna (T. tonggol) namely exploitation rate, Maximum Sustainable Yield (MSY), Total Allowable Catch (TAC), Maximum Economic Yield (MEY), and Open Access (OA), and to determine length and weight relationship. The research used quantitative descriptive method based on catch and effort data from 2010 to 2019 as well as length weight primary data as much as 987 fish. Result showed that catch and effort at MSY level was 8,453 tons/year and 2,974 trips/year respectively with value of TAC as much as 6,762 ton/year. While the estimated values of catch and effort at MEY level was 8,168 tons/year and 2,427 trips/year with optimum profit as much as 88.98 billion Indonesia dollar rupiah (IDR). Another analysis indicated that OA level was achieved when effort reached at 4,855 trips/year and whilst exploitation rate was 93%. Meanwhile length weight relationship analysis showed that fish had a balance length weight growth which b value = 3.039 with equation W = 0.0147L3.0393. In conclusion, the fish has an isometric length weight relationship and the utilization status of fish is in fully exploited condition hence additional fishing effort must be prohibited in order to maintain stock sustainability.

Biological parameters and spawning potential ratio of Longtail Tuna Thunnus tonggol landed in Kranji fishing port, Lamongan District, Indonesia

“…This condition occurs if the SPR value obtained is in the range of 20-40%. This is supported by research from Bintoro et al (2022), which states that the utilization status of large pelagics in FMA-712 has reached 63% of the MSY (Maximum Sustainable Yield) value and shows a fully exploited condition. Fishing activities for Longtail Tuna at the Kranji fishing port can still be conducted but must be monitored closely to ensure long-term sustainability.…”

Sustainable economic analysis and length weight relationship of Bullet Tuna (Auxis rochei) fishery in east area of Bali Strait, Indonesia

“…The sustainable economic analysis of the Gordon Schaefer model begins by determining the relationship between catch (C) and effort (f) with the following formula (Bintoro et al 2022a)…”

“…These data can be used to analyze the status of fish resources in the East area of Bali Strait, Jembrana, Bali. These methods have been applied to justify fisheries resource sustainability not only in Bali Strait (Bintoro et al 2021a) but also in several waters such as south of East Java waters (Bintoro et al 2021b) and the west area of Java Sea (Bintoro et al 2022a).…”