1106

• UCREFRP Catalog Number: 1106
• Author: Gosse, J.
• Title: Microhabitat of Rainbow and Cutthroat Trout in the Green River Below Flaming Gorge Dam.
• USFW Year: 1982.
• USFW - Doc Type: Logan, UT.
• Copyright Material: NO

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face for recording. Velocity and light readings were made by the

surface personnel after the diver had placed the respective probe

ln the proper location.

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An exhaust system vented air bubbles away and downstream
from the diver to avoid frightening the fish. Under nonnal cir-

cumstances, fish were not frightened by the diver. Occasionally,

fish were attracted to the diver when he had dislodged inverte-
brates from the substrate. Data were not taken for fish that

were disturbed (either attracted or frightened). Fish that were

traveling through an area were also not used for data, since they
were not truly choosing microhabitat locations. Fish can and

will travel through nearly all portions of the river, but they

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will occupy only certain areas; i.e., their microhabitat.

A modified dry suit and full face mask protected the diver

from cold water. The risks posed from the modified diving proce-

dures were reduced with special training dives and safety proce-

dures including: multiple buoyancy systems, a separate emergency
atr supply, and surface tenders in radio communication with the

diver.

Variable measurements were made as nearly as possible to

each fish's precise location. When several fish were observed in

the same microhabitat, measurements were made in a location re-

presentative of the entire area, usually near the middle of the

group.

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