WSP00892

• File Number: 8240.300.03
• Description: San Juan River - Recovery Implementation Program - General Info
• Basin: San Juan/Dolores
• Water Division: 7
• Date: 2/4/1992
• Title: San Juan River Seven Year Research Plan ‎(Fiscal Year 1992)‎
• Water Supply Pro - Doc Type: Report/Study

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San Juan Seven Year Research Plan

WORK S~A~EMENT/PRO~OCOL

TRI:BUTARY I:CHTHYOFAUNAL SURVEYS - NMGF, ODWR

Background:
The San Juan River has comparatively few perennial tributaries. Among these, the
Los Pinos, Piedras, Navajo, Animas, La Plata, and Mancos rivers ~eadwater in
Colorado and New Mexico and are confluent with the San Juan River in New Mexico.
Within Utah Recapture Creek, Montezuma Creek and Chinlee Wash are the major
drainages feeding the San Juan. They, however, contribute little flow to the
river. Discharge of tributary streams is variable seasonally and annually. The
flow contribution of each to the San Juan River is likewise variable; ranging
from less than 1.0 m3/sec to the Animas River, which is seasonally almost equal
in discharge to that of the San Juan River. Three rivers (Los Pinos, Piedras,
and Navajo) enter Navajo Reservoir and the remaining join the San Juan downstream
of Navajo Reservoir. Tributaries downstream of the reservoir contribute to the
restoration of a more natural, seasonally variable.hydrograph in the San Juan
River's lower reaches.

The historic fish community of each tributary is poorly documented, and is based
primarily on reports in the 1890's by Jordan (1891). Several recent cursory
inventories have been conducted on the Mancos River (Jensen, 1975 ; Robertson 1977)
La Plata River (Smith 1976), and Animas River (Platania and Young 1990).
Investigators have reported 17 native and non-native fish species occurring in
one or more of these streams. The ichthyofauna of the Los Pinos, Piedras and
Navajo rivers and Recapture Creek, Montezuma Creek and Chinlee wash are les8
well-known. None of these tributaries has been systematically inventoried to
accurately define the species present, their longitudinal distribution or
relative abundance.

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Although use of tributary streame by target species has been suspected and in
some cases documented, deter.mination of the relative importance of these streams
to target species in needed. The Animas River, for example may be important for
maintenance of the roundtail chub population in the San Juan drainage. A
detailed ichthyofaunal characterization of streams tributary to the San Juan
river is essential to understanding the dynamics of mainstem San Juan River fish
communities.

Objectives:
To deter.mine fish species composition, distribution and relative abundance
in the warmwater reaches of Los Pinos, Piedr~s, Navajo, Animas, La Plata,
and ManCos rivers in New Mexico and Colorado, and Recapture Creek,
Montezuma Creek, and Chinlee Wash in Utah.

Methods:
A series of sampling sites will be located at 3-5 kilometer intervals from the
downstream terminus of each stream to upstream areas supporting only salmonids.
Site placement and frequency will be somewhat dependant upon access. Where
possible hiscoric collection sites will be sampled.

Each study site will be of sufficient length (100-300 meters) to include all
macrohabitat types (e.g. run, riffle, pool, glide) present within the general
stream reach. Collection of specimens will be with electrofishing gear, trammel
and gill nets, and seines. Specific sampling techniques used at a'site will be
at the discretion of the investigator and will depend upon habitats present and
species likely to occur. Sampling will be segregated by macrohabitat type.

A species voucher collection of various sized specimens collected will be made
for each sample site. In addition, specimens less than 150 mm that cannot be
easily identified will be preserved for laboratory identification. Specimens

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