Aquaculture CRSP 21st Annual Technical Report
A Study Of Aquaculture Brownfields: Abandoned And Converted Shrimp Ponds In Thailand
Tenth Work Plan, GIS: Planning, Policy, and Global Data Analysis Research 1 (10GISR1)
Melinda Clarke, C. Kwei Lin, James S. Diana, and Steven R. Brechin
School of Natural Resources and Environment
University of Michigan
Ann Arbor, Michigan, USA
This study examined the current state of abandonment and conversion of shrimp ponds in several areas of Thailand and identified patterns in conversion activities. A semi-structured questionnaire was used to gather data from farmers, head villagers, and stakeholders in villages throughout Chanthaburi, Chachoengsao, and Samut Sakhon provinces. These areas were selected because they had experienced a rapid growth in shrimp culture followed by a period of collapse.
Interviews were conducted with farmers, head villagers, and other stakeholders. Quantitative data generated through the questionnaire was supplemented by qualitative data obtained through informal questioning during interviews. The distributions of responses were compared statistically to a random distribution using a chi square test (alpha = 0.05), and results with significant values higher or lower than random were considered to demonstrate preference or lack of preference for a response, respectively. Data were compared by informant group within each site, by informant group across sites, across informant group by site, and aggregated as one sample.
An average of 54% of identified shrimp ponds were abandoned or converted to other uses at the time of study. This varied strongly by region, with 87% abandoned or converted at Samut Sakhon, 63% at Chachoengsao, and only 12% at Chanthaburi. Conversion options were numerous, including polyculture (36% of all conversions), fish monoculture (15%), rice culture (9%), and a variety of other changes (40%). Abandoned land was estimated to be 14% of the area occupied by shrimp culture, while 30% was in polyculture, 25% remained in shrimp culture, 17% was in urban development, 9% in fish culture, and 5% in salt pans. Results for housing were inflated by the occurrence of two large developments in Samut Sakhon.
Responses to 11 questions indicated that informants felt their communities had grown and developed in positive ways during the period of the shrimp boom and subsequent bust. A significant majority of respondents agreed there was more opportunity for children, people were happier, and there was less illness than in the past in their community. Over all respondents, these answers indicated positive community development.
Employment preference indicated that land ownership and self-employment were more desirable than off-farm employment. There was very strong statistical agreement among all areas and all groups that people with their own land were less subject
to economic problems and that communities would be better off if more people owned their land.
There was no indication that respondents felt shrimp pond abandonment or land dereliction were problems for their communities. Despite 70% of respondents recognizing that farmers had changed culture practices or left their land, 87% did not feel abandoned ponds were a problem.
We expected to find a linear process of converting from other agriculture to shrimp aquaculture and then to a new use after
collapse occurred. The process was actually cyclic with some farmers opting to rent their land to new farmers after collapse,
or temporarily convert while waiting to return to shrimp when conditions permit.
This study evaluates barriers to converting ponds to shrimp culture. Perhaps the single largest barrier to reclamation the perception locally that there is no problem with abandoned or idle land.
In many cases, intensive shrimp culture results in abandonment of poorly functioning farms. A great deal of research
has been conducted on shrimp aquaculture with abandonment being mentioned as the end result of failed culture (Flaherty and Vandergeest, 1999; Quarto et al., 1996; Ham