Status and changes of mangrove forest in Mekong Delta: Case study in Tra Vinh, Vietnam

Status and changes of mangrove forest in Mekong Delta:

Case study in Tra Vinh, Vietnam

Phan Minh Thu a,

*, Jacques Populus b

a Institute of Oceanography, 01 Cau Da, Nha Trang, Khanh Hoa, Vietnam b IFREMER, Centre de Brest, Technopole Brest-Iroise, BP 70, 29280 Plouzane, France

Received 9 August 2006; accepted 10 August 2006

Available online 28 September 2006

Abstract

Because shrimp culture in the Mekong Delta develops rapidly, it has negatively impacted the environment, socio-economics and natural re￾sources. In particular, mangrove forests have been altered by the shrimp culture. The area of mangrove forests in the region has been reduced and

this is seen especially in Tra Vinh province. The results obtained from GIS (Geography Information System) and RS (Remote Sensing) show the

status of mangrove forests in Tra Vinh province in 1965, 1995 (Northeastern part of Tra Vinh Province) and 2001. In 1965, the area of mangrove

forests was 21,221 ha making up 56% of total land-use, while in 2001 it was 12,797 ha making up 37% of total land-use. Also based on GIS

analysis, over the 36 years (1965e2001), the total coverage of mangrove forests have decreased by 50% since 1965. However, the speed of

mangrove forest destruction in the period from 1965 to 1995 was much less than that in the period from 1995 to 2001. The average annual

reduction in mangrove forest coverage in the first period (1965e1995) was 0.2% whereas it was 13.1% in the later period (1995e2001). For

the long time, mangrove deforestation has been caused by war, collection of firewood and clearing for agriculture, and recently, shrimp farming

has significantly contributed rate of mangrove destruction.

2006 Elsevier Ltd. All rights reserved.

Keywords: mangrove forest; GIS; remote sensing; Mekong; mangrove changes; mangrove management

1. Introduction

Tropical mangrove forest ecosystems play an important

role in coastal zones, not only in the biogeochemical cycle

but also in the economic life of the region through activities

such as aquaculture and fishing. Mangrove forests in the Me￾kong Delta used to cover more than 250,000 ha (Hong and

San, 1993). War, forest fire, collection of fuel wood and other

human activities have resulted in the reduction of the man￾grove forests in the Mekong Delta. Especially, since the end

of the 1990’s, mangrove forests have been cleared for shrimp

farming in many areas (Hong and San, 1993; Hong, 1995;

Hao, 1999).

Despite the many factors that have affected the mangroves of

the Mekong Delta, the most important factor that has contrib￾uted to mangrove destruction is the shrimp culture activities.

The herbicides sprayed by the USA in the war (1962e1971)

destroyed about 104,939 ha, about 36% of the total mangrove

area in South Vietnam (NAS, 1974). Population pressure has

led to an increased need for land for agricultural production.

In addition, environmental degradation and sedimentation

have also negatively affected mangrove forests (Macintosh,

1996; Le and Munekage, 2004).

Earlier studies (Hong, 1995; Macintosh and Zisman, 1995;

Vits and Tack, 1995; Macintosh, 1996; Phuong and Hai, 1998;

Lakshmi and Rajagopalan, 2000; Lin, 2000; Srinath et al.,

2000; Yap, 2000) have demonstrated that mangrove and

shrimp farming have shown a complex relationship. Mangrove

forests serve as nurseries and food-supply base for marine and

brackish water animals. The mangroves also absorb waste

* Corresponding author.

E-mail address: [email protected] (P.M. Thu).

0272-7714/$ - see front matter 2006 Elsevier Ltd. All rights reserved.

doi:10.1016/j.ecss.2006.08.007

Estuarine, Coastal and Shelf Science 71 (2007) 98e109

www.elsevier.com/locate/ecss