SREL Reprint #0077




TID-21791, U.S. Atomic Energy Commission, Technical Information Division

R. L. Humphries



  1. A study of the movement of the channel catfish (Ictalurus lacustris punctatus) was conducted in the Savannah River at the plant of the U. S. Atomic Energy Commission in Aiken, Barnwell and Allendale Counties, South Carolina. The aim of the study was to determine the extent and nature of the movement of channel catfish in the river and one of its tributary streams, Upper Three Runs.
  2. Data were collected in the field from June to December, 1953 and from April to September, 1954. Seven trapping stations were established, three in the Savannah River and four in Upper Three Runs. At each of these stations fish were captured, marked in a distinctive manner and released. Records of length, weight, and mark applied or previous mark, if any, were kept.
  3. Several marking methods were used. Fish caught in 1953 were fin-clipped in a different manner at each station thereby alloying subsequent recaptures to be identified as to their station of marking. Tattooing vas attempted on a few fish in 1953 but vas discontinued after it proved impractical. In 1954 all fish caught were tagged with serially numbered Petersen-type tags. These tags also bore a legend intended to prompt their return by fishermen who might catch tagged fish.
  4. Trapping success varied markedly between the two years; 1,475 channel catfish being marked in 1953 while only 369 were tagged in 1954. A relationship vas noted between the catches and fluctuations in river level which was assumed to account for the discrepancy in the catches of the two years.
  5. There was apparently complete absence of channel catfish in late summer and fell in that portion of Upper Three Runs above the point where river levels influenced the level of the stream. No catches of channel catfish were made in this portion of Upper Three Runs after August 5, 1953 or July 31, 1954. This absence was substantiated by gill net sets made after these dates. No channel catfish were caught in these nets.
  6. The movements of channel catfish may be classified into three general types. First, movement within limited area during the normal activities of the fish. The size of this area was not definitely determined, but the date indicate that it may include from 0.5 to perhaps as many as 5.0 miles of river.Included in this type of movement was a tendency for fish to move into the lower portions of tributaries during periods of high water. Second, there vas a definite upstream movement into the tributary stream item the river in the spring. This movement occurred in May and June of 1954. In 1953 trapping presumably was not begun until after this movement had occurred. Subsequent to this upstream movement in the tributary, there was downstream movement to the river which occurred in late spring and summer (June and July of both years). Movement of channel catfish out of the tributary stream at this time was substantiated by the previously mentioned apparent absence of this fish in the stream in late summer and fall. It was speculated that this movement was in some way related to spawning, but no evidence for this was available. Third, there was apparently random, long distance movement to other parts of the river. This was evident in 1954 from the return of tags by fishermen. Comparable data were unavailable in 1953. No explanation for this type of movement had been found, nor has it been possible to relate it to any environmental factor. The greatest distances traveled were 67.9 miles downstream and 32.1 miles upstream.
  7. The rate of return of tags by fishermen was very high for a study which involved no large commercial fishery. To date 12.2 percent of the tags applied have been returned by fishermen. This high rate of return may indicate a low population level, a high rate of exploitation, or some combination of the two.

SREL Reprint #0077

Humphries, R.L. 1965. A study of the movements of the channel catfish, Ictalurus lacustris punctatus, in the Savannah River and one of its tributaries within the AEC Savannah River Operations area. U.S. Atomic Energy Commission, Technical Information Division. TID 21791.





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