Wedgies on the Edges

After more than half a year of surveying in Sungai Kakap, we got plenty of information regarding the fisheries, trade, and biology of wedgefish.

When fishing, fishers use specialised tangle nets or jaring liong bun or jaring kemejan to catch wedgefish and many other shark and ray species in the waters of western Kalimantan, Indonesian Borneo.

We also recorded biological information from more than 50 specimens across three species of wedgefish, namely bottlenose wedgefish (Rhynchobatus australiae), broadnose wedgefish (Rhynchobatus springeri), and bowmouth guitarfish (Rhina ancylostoma) (Photo 1-4).

Wedgefish and bowmouth guitarfish landed in Sungai Kakap. Photo © Muhammad Ichsan

Rizky was conducting species data collection in Sungai Kakap. Photo © Muhammad Ichsan

Studying what wedgefish eat in our diet study. Photo © Muhammad Rizky

Measuring wedgefish eggs as part of our reproduction study. Photo © Muhammad Rizky

Some of us might be wondering what the motives for catching these species are and why this fishery is so specialised in its targets. Here is why…

The king of shark’s fin (they are not even sharks!)

Due to its shark-like shape, this group of species is often mistaken as shark. In the international shark fin trade, fins of rhinorays (Order Rhinopristiformes), known as “Qun chi” in Chinese, fetch the highest price and are well-known as the “King of Shark Fins” due to its quality and texture (Hau et al., 2018).

The fins of Rhynchobatus spp can reach a value of up to IDR 1,700,000 – 2,700,000 per kilogram in the international market. From Kalimantan, dried fins from these three species alone reached more than 53,000 kg with an economic value of more than IDR 116 billion in 2019 (BPSPL Pontianak, 2019; Oktaviyani et al., 2023). Not only for fins, many body parts are utilised, such as meat, skins, cartilage, and various secondary products (Photo 5 and 6).

Sharks and rays, including wedgefish body parts. Photo © Muhammad Ichsan

Wedgefish cartilages dried under the sun. Photo © Muhammad Ichsan

How to save The King?

Despite their critically endangered status, many countries, such as Indonesia, still catch and utilise this group of species not only for international trade but also for domestic consumption.

Current management of trade regulation will not be sufficient since target species might already be dead and processed when facing the first stage of management, and stricter measures are needed to halt population decline that can result in local extinction.

Here full protection of species is most likely tough to implement for economically valuable species, some of the recommendations, including size and catch limitation and properly monitored spatial protection for critical habitat, might be more realistic solutions.

To support the development of proper regulation, solid scientific information is needed. This study aims to gain basic information on fisheries, their life histories, and the population of wedgefish in West Kalimantan as part of a larger research effort in the Indo-Pacific region.

This lucrative fishery provides incomes to many vulnerable groups in coastal communities, such as small-scale fishers, processor workers, small-scale retailers and many more (Figure 7). Thus, beyond species protection, sustainable alternative livelihood is needed to improve community welfare and this one surely needs all stakeholder’s commitment and hard work.

**References

BPSPL Pontianak, 2019. Report of provision shark and ray population data series in PPN Pemangkat, PPI Sungai Kakap, PPI Muara Kintap and PPI Manggar. BPSPL Pontianak, Pontianak.

Hau, C.Y., Abercrombie, D.L., Ho, K.Y.K., Shea, S.K.H., 2018. “King of shark fins” not quite sharks…So what is in my soup. A rapid survey on the availability of shark-like batoid fins in Hong Kong SAR and Guangzhou, China retail markets. BLOOM Hong Kong Shark Foundation, Hong Kong.

Oktaviyani, S., Kurniawan, W., Indrawati, A., Faricha, A., Simeon, B.M., Mutaqin, E., Sualia, I., Chodrijah, U., Dharmadi, Fahmi, 2023. Non-Detriment Findings (NDF) for Wedgefishes (Family Rhinidae) from Indonesian Waters.