APPENDIX 1

In 1996, the University of Arkansas at Pine Bluff has studied depletion as a technique to estimate commercial pond inventories of channel catfish (Engle at al. 1998). A series of 17 different commercial catfish ponds that ranged in size from 10 to 20 acres were each seined three to five times by commercial seining firms. The ponds were then drained, and all remaining fish were removed and weighed. A minimum of three seine hauls are required to accurately estimate the inventory of a pond using the depletion model technique. However, unpublished results from the study suggest that on average 88% of the fish were caught after two seine hauls (Table App-1).

Appendix 1. Fraction of the fish inventory of seventeen commercial catfish ponds harvested after one to five seine hauls. Unpublished results from a study conducted in commercial pond (Engle at al. 1998)

  Weight harvested per seine haul   Cumulative weight harvested
(lb)   (% of total fish inventory)
Pond SH1 SH2 SH3 SH4 SH5 Scrap   SH1 SH2 SH3 SH4 SH5
1   15,610     2,600        170 n/a n/a        500   83 96 97 n/a n/a
2   22,410   20,960     3,075        300 n/a     3,000   45 87 93 94 n/a
3   21,370     2,506        200 n/a n/a     1,000   85 95 96 n/a n/a
4   35,200   19,625     2,385 n/a n/a     1,000   60 94 98 n/a n/a
5   20,990     4,975        750 n/a n/a     1,000   76 94 96 n/a n/a
6   16,500     3,350        150 n/a n/a     3,000   72 86 87 n/a n/a
7   45,243   11,570     9,400     4,250     2,275     4,000   59 74 86 92 95
8     3,100     2,400        150 n/a n/a     2,000   41 72 74 n/a n/a
9   70,375   14,335     1,250        450 n/a     1,000   81 97 98 99 n/a
10   57,615        700     2,550         25 n/a     1,000   93 94 98 98 n/a
11   10,460        775        800 n/a n/a     1,000   80 86 92 n/a n/a
12   19,580   11,225        550 n/a n/a     2,000   59 92 94 n/a n/a
13   42,510   25,710   14,050     2,100 n/a     4,000   48 77 93 95 n/a
14     2,325        150        150 n/a n/a     1,000   64 68 72 n/a n/a
15   81,075     6,805        680 n/a n/a     1,500   90 98 98 n/a n/a
16   29,175        600        550 n/a n/a     5,000   83 84 86 n/a n/a
17   23,865     7,720        450 n/a n/a     2,300   70 92 93 n/a n/a
Average               70 88 91 96 95
Min.               41 68 72 92 95
Max.               93 98 98 99 95
SD               16 9 8 3 n/a