1st January 2003
Expanding Shrimp Aquaculture on Sandy Land in Vietnam: Challenges and Opportunities
Recently, aquaculture—especially the culture of tiger shrimp—has brought about much higher profits in comparison to agricultural activities, and has thus attracted farmers eager to earn money. The unplanned and spontaneous expansion of this culture in many parts of Vietnam is accompanied by the dangerous potential of severe negative impacts both in terms of economical and environmental losses. “Explosion” of the shrimp culture area was reported in the Lower Mekong River Delta, and Central Provinces are already running out of potential inland areas. As a result of an ongoing search for new solutions to the problem of limited land resources, Ninh Thuan province, among others, has experimented with cultivating shrimp on sandy soil. The sandy land shrimp culture currently prevalent in Ninh Thuan province is based on a semi-intensive model that has no major differences when compared to the culture of similar species in ponds on soil or in lakes and paddies. Its only distinctive characteristic is that the pond is constructed on sandy land.
Until now, wastewater from the culture ponds has been discharged directly into the surrounding environment without being treated or filtered. High pollution risks therefore threaten adjacent land areas and water sources, leading to an increased risk of shrimp diseases. In addition to considering these environmental concerns, the expansion of the tiger shrimp cultivating industry must also be examined in light of price-influence. As has been seen with coffee, a massive increase in supply can reduce prices, which can be fatal for the industry in the long run.
In all of the Central Provinces combined, the total sandy land area is approximately 100,000 ha. Provinces covering particularly large areas include Quang Binh (39,000 ha), Phu Yen (14,000 ha), Quang Tri (13,000 ha) and Quang Ngai (10,000 ha). Within the five surveyed provinces of Quang Binh, Quang Tri, Quang Ngai, Ninh Thuan and Thua Thien Hue, the sandy land area suitable for shrimp cultivation is roughly 15,000 ha, distributed as 4,500 ha in Quang Binh, 4,000 ha in Quang Tri, 4,000 ha in Quang Ngai, 1,500 ha in Ninh Thuan and 600 ha in Thua Thien Hue. According to survey data collected during the preparation of this report, the areas already cultivated include 200 ha in Ninh Thuan, 60 ha in Quang Ngai, 16 ha in Thua Thien Hue, 14 ha in Quang Binh and 6 ha in Quang Tri. Average yields per crop range from three tonnes/ha (in Quang Tri and Thua Thien Hue) to six tonnes/ha (in Ninh Thuan). The highest yields fluctuate between four tonnes/ha (in Thua Thien Hue) and ten tonnes/ha (in Ninh Thuan) and the average lowest between 1.72 tonnes/ha (in Binh Dinh) and 3.6 tonnes/ha (in Ninh Thuan).
In considering the advantages and disadvantages of developing sandy land shrimp aquaculture, a list of recommendations, with the objective to secure sustainability, has been put forward by the ministerial research institutes and provincial departments engaged in this study. The list of recommendations complies with the existing legal framework and overall policy of the government, but may in itself also include suggestions on the design of new rules and plans when these are believed to be necessary. A list of the main findings is presented below, but is by no mean exhaustive.