Conservation and management must be combined with sustainable exploitation of sawtooth oysters.

Despite having a proper scientific name, local fishermen often call serrated oysters “king oysters”, meaning top quality, used to make delicious dishes to entertain important people. Perhaps that is why this oyster species is sought after and exploited a lot in the Con Co Island Marine Reserve. In this context, conservation, management and sustainable exploitation of serrated oysters are very necessary.

Fishermen on Con Co Island exploit saw-tooth oysters - Photo: BQLKBT

Island specialties

For many tourists, coming to Con Co Island without enjoying the sawtooth oyster is considered as not having been there. The scientific name of the sawtooth oyster is Hyotissa hyotis Linnaeus, 1758. However, local fishermen often call this species the “king oyster”. This is considered a delicious oyster when processed, rich in nutrients, and many people want to enjoy it at least once.

Due to the demand of tourists, the exploitation of saw-tooth oysters in Con Co Island Marine Reserve is quite popular. Normally, fishermen exploit this oyster species from March to September every year. The main exploitation area is the service - administrative subdivision of Con Co Island Marine Reserve. To exploit saw-tooth oysters, people often use bamboo boats, small composite boats, equipped with 8 - 12 CV diesel engines to access the sea area where this species often lives. Saw-tooth oysters are often exploited by hand or using tools such as: small hammers, crowbars, diving knives...

Sawtooth oysters exploited in Con Co Island Marine Reserve are large in size and have high economic value - Photo: TL

According to information from the Management Board of Con Co Island Marine Reserve, sawtooth oysters are mainly exploited to serve the culinary needs of Con Co Island. In addition, a small proportion of this type of oyster is transported to the mainland for consumption as gifts. In 2023, the output of sawtooth oysters exploited is about 8,000 individuals, estimated at about 16 tons. Each oyster is exploited by fishermen and sold to restaurants on the island at a price ranging from 25 - 45 thousand VND/live individual. After purchasing from fishermen, businesses process and sell to tourists at a price of 70 - 100 thousand VND/oyster, accounting for more than 50% of the price of a tourist meal.

Bringing sawtooth oysters into the research topic

The leader of the Con Co Island Marine Reserve Management Board said that among the species distributed in the reserve, the saw-tooth oyster is highly characteristic and has economic value. This mollusk belongs to the mollusk class, has two shells, and is large in size. Oyster meat is very rich in nutrients. It is estimated that the protein content in oyster muscle accounts for 67.8-89.6%. That is also the reason why many people buy it to enjoy despite knowing the price is quite high.

Since 2017, sawtooth oysters have been exploited extensively to prepare dishes for tourists visiting Con Co Island. The demand for this oyster species is increasing, so the area for exploiting sawtooth oysters is increasingly expanded by fishermen. This has created great pressure on the management and protection of this species. Without timely management measures, sawtooth oysters may gradually become scarce or even extinct.

Faced with this reality, the development of solutions for sustainable management and exploitation of saw-tooth oysters in the Con Co Island Marine Reserve is an urgent issue. However, it is worth mentioning that up to now, surveys and studies on saw-tooth oysters in the reserve, especially on the current exploitation and distribution status, are very few. Therefore, relevant levels and sectors have difficulty in assessing the current status of resources in terms of density, reserves, exploitation output, distribution... of saw-tooth oysters. From here, management solutions can hardly be proposed in accordance with the characteristics and situation.

Staff of the Con Co Island Marine Protected Area Management Board inspect the status of sawtooth oysters, corals and other seabed creatures - Photo: Con Co Marine Protected Area Management Board

Realizing that, since January 2023, Deputy Director of the Con Co Island Marine Reserve Management Board Tran Khuong Canh and his colleagues have conducted a research project on saw-toothed oysters. The research focuses on assessing the distribution and exploitation status of this oyster species. Thereby, the members found that the density of saw-toothed oysters distributed in the waters managed by the Con Co Island Marine Reserve is quite high, averaging 0.13 individuals/m2. Saw-toothed oysters exploited in the waters of the Con Co Island Marine Reserve have an average mass of about 1.94 kg/individual and an average length of about 16.7 cm. In each functional sub-zone, the distribution density of saw-toothed oysters tends to increase with depth. Rocks and corals are two types of bottom suitable for saw-toothed oysters. It is estimated that the number of sawtooth oysters with shell lengths of 5 cm or more distributed in the functional zones of Con Co Island Marine Reserve as of July 2023 is over 5 million individuals.

Need to establish a joint management and exploitation team for sawtooth oysters

As the person directly implementing the above topic, Deputy Director of the Management Board of Con Co Island Marine Reserve Tran Khuong Canh commented that currently, compared to the estimated reserves, the exploitation of saw-tooth oysters to serve the culinary needs of tourists when coming to Con Co is still within the allowable threshold. However, recently, the number of fishermen exploiting this type of oyster to bring it to the mainland for consumption has tended to increase. This has given rise to many problems, the most obvious of which is the reduction of saw-tooth oyster resources in Con Co Island Marine Reserve and the reduction of the inherent characteristics of this species on the island.

To solve the above situation, according to Mr. Canh, the participation of relevant levels, sectors and units is extremely necessary. In particular, the Management Board of Con Co Island Marine Reserve and the People's Committee of Con Co Island District need to have good coordination to link conservation, management with sustainable exploitation of sawtooth oysters. The establishment of a co-management and exploitation team for this oyster species can be considered one of the important solutions.

By joining the group, members will be given the opportunity to exploit oysters to serve the culinary needs of tourists right on the island. However, they must commit to comply with and strictly implement the regulations on the maximum number of sawtooth oysters exploited per year; permitted exploitation areas; exploitation seasons; fishing gear and exploitation methods...

Relevant levels, sectors and units need to agree on the viewpoint of minimizing the exploitation of saw-tooth oysters to bring them to the mainland for consumption because this will invisibly reduce the resources as well as the inherent characteristics of Con Co island.

If implemented seriously, it is believed that the above specific regulations will help saw-tooth oysters grow and develop sustainably in the Con Co Island Marine Reserve, contributing to the conservation of biodiversity and rare genetic resources. From here, saw-tooth oysters will be exploited reasonably, contributing to promoting the development of the tourism sector in Con Co Island District.

Tay Long

Source: https://baoquangtri.vn/kinh-te/can-gan-bao-ton-quan-ly-voi-khai-thac-ben-vung-hau-rang-cua/183829.htm