Characteristics of pond water and bottom soil quality in channel catfish ponds in west-central Alabama.

摘要

Water samples were collected from 223 channel catfish ponds in west-central Alabama during 2000. In 2001, bottom soil samples were taken from 58 of the ponds. This study area extended over 10 counties and included three major soil areas (Blackland Prairie; Coastal Plain; Major Flood Plains and Terraces). Most ponds were filled primarily by surface runoff, but some were supplied water from wells. Wells were developed in several aquifers, and pond water quality sometimes reflected the quality of well water. This was especially true where ponds were filled with saline well waters or well waters with high hardness and low alkalinity. There was wide variation in the concentrations of all bottom soil and water quality variables. Moreover, several basic soil and water quality problems were identified. These included low total alkalinity, high total alkalinity and low hardness, low total dissolved solids (TDS), and saline conditions (above 1,000 mg/L TDS) in pond waters. Acidic conditions, low clay content, low dry bulk density (soft sediment), and apparent anaerobic conditions were found in some pond bottom soils. Although soil and water quality exhibited trends with respect to the soil area in which ponds were located, there was so much variation that concentrations of variables overlapped among soil areas. Thus, pond soil and water quality cannot be accurately predicted based on soil area.; The geometric coordinates of ponds were established by GPS and recorded in the database. The coordinates of a "non-database" pond could be determined by GPS and used to locate the nearest pond for which soil and water quality data were collected and recorded in the database. We recommend that the database provided by this study be used in this manner. We also are evaluating the possibility of applying geostatistics of GIS to the data. This approach might allow more accurate predictions than could be obtained by comparing a "non-database" pond to the nearest "database" pond.; Specific conductance was strongly correlated with several other water quality variables. The measurement of specific conductance can be made rapidly in the field with a portable conductivity meter. Thus, specific conductance could be a useful tool in pond management.