ARS | Publication request: FOOD HABITS OF LESSER SCAUP AYTHYA AFFINIS OCCUPYING BAITFISH FACILITIES IN ARKANSAS

Submitted to: Journal of the World Aquaculture Society
Publication Type: Abstract Only
Publication Acceptance Date: November 4, 2000
Publication Date: March 1, 2004
Citation: Wooten, D.E., Werner, S.J. 2004. Food habits of lesser scaup aythya affinis occupying baitfish facilities in arkansas. Journal of the World Aquaculture Society. v.35 (1). p.70.

Technical Abstract: Arkansas has the largest bait fish industry in the United States. Producers have suspected depredation by scaup for many years. The purpose of this study was to determine the food habits of scaup inhabiting baitfish ponds in order to test the producers hypothesis. Ninety-five scaup were collected from baitfish facilities during the winter of 1999-2000. Specimens were placed into one of three categories; Nov-Dec (n=33), Jan-Feb (n=40), and March-April (n=22). Gastrointestinal contents were removed, weighed, and washed through U.S. standard sieves. Gizzard contents were included in the sieved sample but were not weighed. Microscopy was used to sort the sieved contents. Weights were used to determine the proportion of each food item in the diet. Fish otoliths were used to identify the species of fish consumed, but not to relate to overall biomass. Only 7 out of 95 (7.4%) of Scaup contained fish remains. No fish remains were recovered from the Jan-Feb specimens despite it having the largest sample size. The highest incidences (15.1%) of fish remains were from Scaup collected during Nov-Dec. Twenty-eight fish were recovered during the study with an accumulated weight of 26.7 grams. Chironomids were the primary food item. Other food items listed in order by weight were snails, oligochaets, fish, and crayfish. This study indicates that very little depredation is avoided by removing Scaup. Scaup could be a benefit to bait fish producers by removing oligochaets and snails, which are vectors of diseases and parasitic trematodes.