WSP06495

• File Number: 8240.300.31.J
• Description: San Juan River - Environmental Studies
• Basin: San Juan/Dolores
• Water Division: 7
• Date: 11/1/1999
• Title: San Juan River Fish Health Surveys ‎(1992-1999)‎
• Water Supply Pro - Doc Type: Report/Study

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Table 2. Six-year review of fishery biologists' San Juan river C. lalipillllis and C. discobolus
abnormality data (10/91 - 10197):

Date # of fish sampled % of fish with % of abnormalities that
abnormalilies are lesions
10/91 1606 2.6 54
6/92 3018 3.6 65
10/92 3413 0.3 30
10/93 2959 0.4 55
5/94 1878 3.0 74
10194 9524 0.6 30
5/95 1266 0.] 25
10/95 226] 0.8 25
5/96 2557 3.4 72
10/96 2888 1.6 33
5/97 5270 0.4 19
10/97 7440 0.3 32

Abnormality incidences versus river mile (RM)/Fish health inspection data: During years of high
abnormalities, most were found in sections RM ]2]-156 and RM 76.

Fishery biologist data: Most of the abnormalities observed by fishery biologists consistently were found
on fish in RM 126-156. As with fish health inspection data, fewer abnormalities were found in Ihe Fall
(October) compared to Spring (May) surveys. Few abnormalities were found from Lake Powell (RM 0)
to the head of the canyon (RM 78). However, bite marks caused by fish predalors were common. From
the head of the canyon to Farmington, New Mexico (RM 178), wounds from bird predators were also
common. Both of these wound types were easi ly distinguished from lesions.

Bacterial isolates of San Juan River fish: Bacterial isolates from all survey trips are identified in
Table 3. Bacteremia, as indicated by bacteria] growth from kidney tissue tended to follow the
abnormality trends on each of the surveys.

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