Mangrove Restoration at Can Gio Mangrove Biosphere Reserve
By Elissa Chott
Our class spent New Year’s Eve outside Saigon at the Can Gio Mangrove Reserve wading through calf-deep mud past crabs and mudskippers, digging holes to be filled with mangrove saplings. Defoliants used by Americans in the 1960’s and 1970’s destroyed all the mangroves in the region, devastating the forests beyond recognition. Mangroves fulfill important ecological services including protecting the coastline from storms and erosion, providing habitat for wildlife, cleansing soil toxins, creating a pollution sink, and entrapping sediment from upland runoff. Many livelihoods in the region depend on resources harvested from the rivers and coastal areas in which mangrove forests thrive. Realizing the need for both ecological diversity and human resource use, restoration efforts began in 1978 by transferring seedlings from the mangroves in Ca Mau (to the south) to replant the moonscape forests of Can Gio.
A sparsely vegetated field of dense, slippery clay once functioning as a salt farm is being restored to a mangrove forest one volunteer group at a time. Our class toted spades and saplings across the slick surface and dug holes one square meter apart. The mud created fantastic sound effects as shovels were hefted through the thick clay. Crabs went scuttling off as mudskippers leapt out of the way from under rubber boots. Mangroves will die if the mud is tamped down around their root system, so after placing a sapling in its new home, mud is carefully filled in around the small clod of soil protecting the roots. In a matter of a sweaty and muddy hour, the field had several dozen new mangroves.
Protection for the Can Gio Reserve is organized into Forest Management Units and coordinated between the Hamlets People Committee, farmers, local police, and border police. Households oversee management at a local level to ensure sustainable fishing and farming practices are followed. This nested management system is useful to provide on the ground monitoring of resources, but enforcement is sometimes difficult. Mangrove harvesting is prohibited in all management units to facilitate growth and continued recovery, but farming and fishing are allowed at sustainable levels. Mangrove growth increased in the past 10 years due to widespread restoration efforts and aid from international groups.
As a result of vigorous forest restoration practices, Can Gio Reserve now boasts diversity of:
157 species of plants
100 species of invertebrates
137 species of fish
31 species of reptiles
19 species of mammals
130 species of birds
We visited a 58 hectare shrimp farm within the mangrove forest management units. Government subsidies compensate the farmer per hectare for conserving the forests. This income is in addition to that received from his shrimp harvests and inviting tourists to visit his farm. Bimonthly lunar tides bring young shrimp and fish into his ponds through sluice gates where they grow to harvestable size. When the second monthly tide recedes, he catches the shrimp and fish on their way downriver, returning those too small to sell into the pond to grow larger. In the face of climate change and severe reduction of shoal size resulting in unsustainable harvests, the farmer stated he would be forced to move from his property in the forest and find other income. As the mangrove forests recover and increase in area, the acreage he has available to farm diminishes. Since he is contracted within the forest management zone, mangrove harvests are not allowed and there must be 100% forest coverage. While the future of his livelihood is uncertain, his current conservation efforts and those of restorationists are enabling the coastal ecosystem to flourish in an area once devoid of both flora and fauna.