A SURVEY OF CATFISH POND WATER CHEMISTRY PARAMETERS FOR COPPER TOXICITY MODELLING  

Water samples were collected from 20 catfish ponds in 2015 to obtain data useful in predicting copper toxicity and chemical behavior.  Ponds were located in major catfish producing areas of west Alabama, east Arkansas, and Mississippi.  Pond types included traditional levee ponds, split-ponds, watershed ponds, and one intensively aerated levee pond.  Ponds were sampled monthly to measure alkalinity, hardness, pH, chemical oxygen demand (COD), filtered COD, dissolved organic carbon (DOC) and total organic carbon (TOC).  These variables affect metal toxicity and can be used to predict metal speciation in computer modeling for regulatory purposes.  Result ranges are as follows: alkalinity = 64 - 437 mg/L, hardness = 50 - 534 mg/L, COD = 21 - 150 mg/L, DOC = 5 - 35 mg/L, and TOC = 9 - 54 mg/L.  These results and trends will be discussed.

Information gathered in this study will eventually be used to model copper toxicity to fish in ponds, which is important because copper sulfate is one of the most commonly used and important chemicals in catfish farming.  During the process of gaining approval to use copper sulfate as a therapeutant in aquaculture, an environmental assessment of the impact to ponds was prepared.  Data from this survey will contribute greatly to understanding such environmental impacts.