The presence of multiple anomalies should be recorded. For example, if a fish has a skeletal deformity, lesions, and unidentified external parasites, then "DE, LE, PA" should be recorded in the "ANOMALIES" column. For each fish that is measured for length (total and standard), weighed, and examined for external anomalies, a "1" is entered in the "NUMBER" column. When 30 individuals of a species have been measured, weighed, and examined for external anomalies, the remaining number of individuals of th at species are counted. The species name is entered and the total number of remaining individuals is entered in the "NUMBER" column. For example, if 42 bluegill (Lepomis macrochirus) are collected, 30 individuals representing the range of sizes present in the sample are individually measured, weighed, examined for external anomalies, and a "1" is recorded in the "NUMBER" column for each individual. An additional entry for Lepomis macrochirus is made, with all columns except for the "NUMBER" column left blank. The number "12" is then entered in the "NUMBER" column.
Table 2.--Two-letter codes used to record external anomalies
The National Water-Quality Assessment Program is designed to assess status of and trends in the Nation's water quality and to develop an understanding of the major factors that affect observed water-quality conditions and trends. Characterization of fish community structure is conducted as part of NAWQA to relate fish community characteristics to physical, chemical, and other biological factors as part of an integrated assessment of the Nation's water-quality conditions. To accomplish this, fish community structure is described at sites representing selected environmental settings. In addition,