WSP06389

• File Number: 8220.102.01.I
• Description: Aspinall ‎(AKA Curecanti)‎
• State: CO
• Basin: Gunnison
• Water Division: 4
• Date: 1/1/1994
• Title: Scopes of Work - Endangered Fish Program as Related to Aspinall
• Water Supply Pro - Doc Type: Report/Study

. .

NO: Asoinall - G

RECOVERY IMPLEMENTATION PROGRAM
FOR THE ENDANGERED FISH SPECIES
IN THE UPPER COLORADO RIVER BASIN

FY-1994
SCOPE-OF-VORK
RESEARCH PROPOSAL

Submitted by:

Frank K. Pfeifer, Project Leader

CateEorv (check one):
x Expansion of
Ongoing project
Requested new start
Unsolicited project
Outside funding

Lead Agency:

U.S. Fish & Wildlife Service
Colorado River Fishery Project

Address:

529 25 1/2 Road, Suite B-110
Grand Junction, Colorado 81505

Phone:

303-245-9319

Date:

April 30, 1993

I. Title of Proposal:

ASPINALL STUDY--Spawning period, reproductive success, and population
size of humpback chub in Black Rocks (addition to ongoing project)

II. Relationship to Recovery Program/Ranking Factors:

This study will be conducted as part of the studies to assess the
opportunities to re-regulate the Aspinal Unit to benefit endangered
fishes in the Gunnison and Colorado rivers. The study focuses on the
Black Rocks population of humpback chubs in the Colorado River about 35
miles below the Gunnison River confluence. It is designed to
specifically address the effect of high spring flows on successful
reproduction and recruitment of humpback chub, as well as the effect of
seasonal flow events on the formation of critical habitat and the
invasion/proliferation of non-native species. The study will also assess
the effects of flows on the invasion of roundtail chubs into Black Rocks
and the potential impact of hybridization.

III. Study Goals, Objectives, End Product:

The goal of this investigation is to develop flow recommendations for the
Colorado River to protect spawning and nursery habitat of humpback chub
in Black Rocks. Currently, there are no flow recommendations for
humpback chub in the Colorado River. Maintenance of the populations in
the upper Colorado River is vital since these areas support the largest
numbers of the species in the upper basin. The objectives of the study
are to: (1) Determine spawning and nursery requirements, (2) Determine
the extent of larval drift, (3) Identify and describe reproductive
isolating mechanisms, and (4) Assess recruitment. The end product will
be flow recommendations for spawning and nursery habitat as well as
recruitment of humpback chub in Black Rocks.