the same treatment (e.g., nutrient and light limitation of algal productivity, inorganic turbidity, etc.), which can affect a pond's response to fertilization. In particular, the fixed-input treatment did not add carbon to compensate for nonuniform losses in alkalinity, which resulted in relatively high soluble P concentrations in treatment ponds where C availability apparently limited algal productivity. Including C fertilization in the fixed-input treatment would have likely reduced NFY variability and improved P utilization efficiency in those ponds.
Because both PONDCLASS and the ABFS adjusted pond-specific fertilization requirements throughout the study, they provided increased fertilization efficiencies and profitability over the fixed-input strategy. However, the ABFS is more practical than PONDCLASS for rural application because it is far simpler and does not require water chemistry, computers, laboratory equipment, technical expertise, or electricity to implement. Based on this study, the recommended fertilization strategy designed to achieve cost-efficient, consistently high yields is a modified ABFS approach that uses a fixed-input fertilization rate for N, and algal bioassays to determine time-specific and pond-specific fertilization requirements for P and C.
This abstract is excerpted from the original paper, which was published in Aquaculture, 228: 1
CRSP Research Report 03-198
Application of GIS and Remote Sensing for Assessing Watershed Ponds for Aquaculture Development in Nguyen, Vietnam
Dao Huy Giap and Yang Yi
Aquaculture and Aquatic Resources Management
Asian Institute of Technology
Klong Luang, Pathumthani 12120, Thailand
Nguyen Xuan Cuong and Le Thanh Luu
Research Institute for Aquaculture No.1
Tu Son, Bac Ninh, Vietnam
James S. Diana and C. Kwei Lin
School of Natural Resources and Environment
University of Michigan, Ann Arbor, Michigan 48109 USA
This study was conducted in Dai Tu district of Thai Nguyen province during November 2001January 2003 to assess the aquaculture development potential for watershed ponds by integrating socio-economic and environmental data into GIS database, detecting land use change, and identifying and estimating potential areas for aquaculture development in watershed ponds. The socio-economic and environmental data were collected using pre-test questionnaires and field measurements. Three SPOT multi-spectral band satellite images were used to detect land use change during three periods of 19941998, 19942002, and 19982002. For land suitability evaluation, the suitability ratings were established according to FAO classification in terms of suitability of land for defined uses. Aquaculture production and economic returns from interviewed farmers were used to verify the results and comparisons among different land suitability levels.
The present study has predicted that about 4.7% (2,725 ha) of the total land area of 57,618 ha in Dai Tu district are suitable sites for watershed pond construction, compared to the existing 404 ha watershed ponds. The present study has demonstrated the usefulness of integration of remote sensing, GIS and attribute data to select suitable sites for the development of watershed ponds, and the importance to be a useful tool for planners to develop strategic plans for aquaculture development.
This abstract is excerpted from the original paper, which was published online at <http://gisdevelopment.net/application/nrm/water/overview/ma03166.htm>.
Two Phytochemicals, Genistein, and Quercetin as Possible Sex Differentiation-Affecting Agents in Tilapia Nilotica by Dietary Administration.
Kam Silapajarn, Auburn UniversityClaude Boyd, Major Professorfor:
Silapajarn, K. and C. Boyd. Particle Size and Reaction of Agricultural Limestone.
Orawan Silapajarn, Auburn UniversityClaude Boyd, Major Professorfor:
Silapajarn, O. and C. Boyd. Nitrogen and Phosphorus Concentrations and Loads in a Stream Receiving Catfish Farm Effluents.
Elizabeth Trejos-Castillo, Auburn UniversityJoseph Molnar, Major Professorfor:
Trejos-Castillo, E. and J. Molnar. Income, Food Security, and Poverty Reduction: Case Studies of Small-scale Aquaculture Producers in Santa Barbara, Honduras.
Professional Awards Recipients
Suyapa Meyer Triminio for:
Meyer, S., J. Molnar, and D. Meyer. Tilapia Fingerling Producers in Honduras: Characteristics, Practices and Needs.
Christopher Knud-Hansen for:
Knud-Hansen, C., Y. Derun, Y. Yi, and T. Batterson. Potential for Using Clinoptilolite Zeolites for Ammonia-N Transfer and Retention in Integrated Aquaculture Systems.
Ivano Neira for:
Neira, I. and C. Engle. Restaurant Markets for Aquaculture Products in Peru: A Descriptive Analysis.