Title
Fisheries management for the redbelly yellowtail fusilier (Caesio cuning) in the waters of the Karimunjawa Island, central Java Sea, Indonesia
Author(s)
Budy Wiryawan; Siska Agustina; Nindia Pertiwi Ningrum; Regi Darmawan; Siti Utami Pratiwi; Riza Pasaribu; Intan Destianis Hartati; Wahid Suherfian; Puji Prihatiningsih
Published
2021
Abstract
The Redbelly Yellowtail Fusilier (Caesio cuning) is a member of the Caesionidae and is one of the main species targeted by fishers in the Karimunjawa Islands in the central Java Sea. Redbelly Yellowtail Fusilier (RBYF) form schools in the water column and are often found in areas with coral reefs. In Karimunjawa today, this species is fished mainly using spearguns, although, in the early 2000s, muroami – a destructive circular netting and scaring technique – was the main fishing method. Spearguns are used with and without surface-supplied air via a hookah compressor. The hookah compressor allows fishers to dive deeper and for longer. It also allows fishers to catch a diverse range of species to meet their targeted yield and selling price. Consequently, fish are caught in large numbers and without regard to size. In terms of species composition, an evaluation of extensive data from landings surveys from 2009 to 2017 suggested that RBYF comprise 46% of total fish caught in the waters of the Karimunjawa Islands. However, 43% of the landed RBYF were below the size at 50% maturity and the estimated spawning potential ratio (SPR) of 19% is low (SPR <20%). This indicates that the exploitation rate of RBYF in Karimunjawa is high and is an example of growth overfishing, when the catch is dominated by immature fish. Currently, there is no defined fisheries management policy or harvest strategy for RBYF in the Karimunjawa region, at either local or central government level. Thus, management is needed to overcome existing problems and to sustain the fishery into the future. The Method Evaluation and Risk Assessment (MERA) tool was used to evaluate management options for the fishery. This approach synthesises all current information on the biology, fishery and management of a fishery to evaluate policy strategies for the fishery, building in uncertainty in the projections. The five best management procedures selected, based on their probability score and feasibility of implementation, were two size-based measures (Matlenlim and Matlenlim2 – setting a size limit equivalent to the size at 50% maturity, or a limit 10% greater than this size, respectively), total allowable effort (ITe10 – setting total allowable effort [TAE] with a maximum change of 10% annually), and two spatial closures (MRnoreal and MRreal – spatial closure with either no reallocation or reallocation of fishing effort outside the closure). The management procedures with the highest yield for the short and long term were total allowable effort (ITe10), size limit (Matlenlim and Matlenlim2), and spatial management (MRreal and MRnoreal). These three procedures also had a high probability of maintaining the biomass in the population above 0.5 of the biomass at maximum sustainable yield. These management procedures (size limit, TAE, and spatial closure) could be effective in the Karimunjawa islands because of (a) sufficient available data, including a commitment from the WCS-IP (Wildlife Conservation Society – Indonesia Program) to continue monitoring catches (species composition and size distribution); (b) strong compliance from local fishers; and (c) strong enforcement by the national park authority of the zoning regulations. Nevertheless, the WCS-IP should work with both local government (provincial fisheries authority) and the national park authority to encourage the allocation of funding and human resources for catch monitoring.
Full Citation
Wiryawan, B., S. Agustina, N.P. Ningrum, R. Pasaribu, I.D. Hartati, W. Suherfian, and P. Prihatiningsih (2021). Fisheries management for the redbelly yellowtail fusilier (Caesio cuning) in the waters of the Karimunjawa Island, central Java Sea, Indonesia. In: Loneragan, N.R., Wiryawan, B., Hordyk, A.R., Halim, A., Proctor, C., Satria, F., Yulianto, I. (Eds), Proceedings from Workshops on Management Strategy Evaluation of Data-Limited Fisheries: Towards Sustainability – Applying the Method Evaluation and Risk Assessment Tool to Seven Indonesian Fisheries, 85-106. Murdoch, Australia and Bogor, Indonesia: Murdoch University and IPB University.

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