[Note: this is the fifth in a series of commentaries by researchers with WCS (Wildlife Conservation Society) during Shark Week documenting challenges and successes in shark and ray conservation today.]
Wedgefish and giant guitarfish comprise a group of highly threatened shark-like rays. The IUCN Red List of Threatened Species assessed them as Critically Endangered in 2019 due to recent rapid declines, primarily caused by overfishing. The Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) lists them on their Appendix II, which means international trade should be managed for sustainability.
Wedgefish and giant guitarfish are globally distributed from Eastern Africa to the Indo-Pacific, and Indonesia is a hotspot for these species. In particular, the Java Sea is important habitat for wedgefish and giant guitarfish due to the ideal muddy substrate that they typically live in.
Unfortunately, fishing pressure in the Java Sea is high, and currently threatens this wedgefish and giant guitarfish hotspot. Indonesia is the world’s largest shark and ray fishing country, and also the 3rd largest exporting country for shark and ray commodities, including wedgefish and giant guitarfish.
Local people utilize all body parts — including fins, meat, skin, cartilage, and even intestines. Wedgefish and giant guitarfish fins hold particular value in the international fin trade, and are known as ‘king of shark fin’ in Hong Kong. Many others prize the meat for smoked fish.
Indonesia is the world’s largest shark and ray fishing country, and also the 3rd largest exporting country for shark and ray commodities, including wedgefish and giant guitarfish.
Recognizing the threats faced by wedgefish and giant guitarfsih in the Java Sea, The Rekam Nusantara Foundation and the Wildlife Conservation Society Indonesia Program initiated a collaboration with local stakeholders — the Central Java Marine and Fisheries Agency, Diponegoro University, and IPB University. This initiation aims to understand the condition of wedgefish and giant guitarfish in Java Sea to inform fisheries management.
As a first step, we monitored wedgefish and giant guitarfish landings at four main fishing ports in Northern Coast Java. The data included fishery and biological information, in order to understand which species were being caught, and which fishery characteristics posed the greatest risk.
With support from the provincial government, we believe these comprehensive research results can be turned into effective conservation measures.
We recorded four species of wedgefish and two species of giant guitarfish on the North Coast of Java between April 2019 and March 2020. That includes 5,701 individuals of wedgefish and 273 individuals of giant guitarfish, including the species Rhynchobatus australiae, Rhynchobatus springeri, Rhynchobatus laevis dan Rhina ancylostoma, Glaucostegus typus, and Glaucostegus thouin. It showed there is a possibility that population density and species distribution of wedgefish in Indonesia is higher than giant guitarfish.
This monitoring of landings represents a first step towards improved management for these species. We have made significant inputs to government policy processes for CITES implementation, and are now working with local stakeholders to develop management measures. The Rekam Nusantara Foundation, the Central Java Government, and Diponegoro University have established an official collaboration with a Memorandum of Understanding.
With support from the provincial government, we believe these comprehensive research results can be turned into effective conservation measures. While the high catches of these critically endangered species are worrying, they also indicate healthy and abundant populations in the Java Sea. This new collaboration gives us hope for the conservation of wedgefish and giant guitarfish in the Java Sea and Indonesia.
Een Irawan Putra is Executive Director for the REKAM Nusantara Foundation; Dwi Yuwandana is a researcher at the Faculty of Fisheries and Marine Sciences, IPB University, and REKAM Nusantara Foundation; Benaya Simeon is Sharks and Rays Senior Officer with the Indonesia Program at WCS (Wildlife Conservation Society).
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Read the other pieces in this WCS series for Shark Week here: