former shrimp ponds totaled
93 ha of the measured area. Fish culture was practiced on 9%
of the area and salt pans represented 4%.
Interviews and observation in individual study areas provided more information about land dereliction. In Chachoengsao, when shrimp crops began to fail, farmers converted to fishponds. These farmers often returned to shrimp culture, or rented land to others for that purpose. The net result was a 5Ð10% decrease in the number of shrimp farmers over the past 12Ð13 years. In Samut Sakhon, however, it was difficult to find active farmers. Approximately 95% of ponds appeared to be unused. A former employee of a feed company identified several locations where many square kilometers of shrimp ponds had been converted to other uses, mainly industrial or housing developments and salt pans. In Chanthaburi, the majority of abandoned ponds seemed to be owned by absentee companies, and these represented approximately 5Ð10% of current ponds.
A wide variety of activities were being conducted on land that had formerly been intensive shrimp ponds (Table 2). The perception in the literature that abandoning ponds results in barren and unproductive land was not supported by field observations. Many farmers used banks of
the ponds to grow crops such as lemongrass, flowers, and squash varieties for additional income. In some cases, however, environmental conditions made it impossible to grow terrestrial crops in former shrimp ponds, and alternate forms of aquaculture were practiced. The sample included a large number of fallow ponds that owners indicated were still primarily used for shrimp production.
With sites aggregated, the most popular conversion was adoption of polyculture (39% of farmers and 26% of ponds). The most popular polyculture was fish with shrimp (Table 3). Fifteen percent of farmers had converted to fish monoculture with the species of choice being tilapia (4 farms) and sea bass
(3 farms). Some of these farms used fish to improve pond water and soil quality in order to return to intensive shrimp culture. The category of land use labeled "other" included a number of farms that returned to rice culture or coconut plantations. Crab culture and vegetable farming were also observed in a number of former shrimp ponds.
Presence or absence, and the proportions of various land-use activities, demonstrated distinct conversion options within study sites (Table 4). Intensive shrimp farms dominated Chanthaburi (58% of area), while conversions were more difficult to identify. The sample included only eight
Figure 1 Shows the possibilities for a farmer to convert their land from agricultural pursuit of intensive shrimp culture, to another use, once shrimp production failed.
