Two-Year Science Plan

for

Experimental Flow Treatments and Mechanical Removal

Activities in WY's 2002-2004

PREPARED BY THE GRAND CANYON MONITORING AND RESEARCH CENTER

for

Glen Canyon Adaptive Management Program

August 9, 2002
Proposed GCMRC Science Plan for Experimental Flow Treatments

and Mechanical Removal Activities for WY 2002-2004

TABLE OF CONTENTS

Introduction 1

Background 2

Proposed Treatment Scenarios (#1 and #2) 5

Specific Proposed Action 6

Experimental Treatment Scenarios Project Overview 6

Project Descriptions 17

I. PRIMARY SEDIMENT TREA TMENT 17

Project 1. Fine-Sediment Mass Balance, Parts A and B 17

Project 2. FIST - Parts A and B 20

Project 3. Fine-Sediment Dynamics and Terrestrial Vegetation Responses 21

Project 4. State of Primary Productivity, Carbon Flux and Alteration

of Food Base """"""""""""""""""""""""""" 22

Project 5. Near Shore Temperature and Habitat Use Monitoring During

Low Steady Flows 24

II. SECONDARY SEDIMENT TREATMENT (Beach/Habitat-Building Flows) 25

Project 1. Part C - Continuation of Mass Balance for Fine Sediment 25

Project 6. Sediment-Transport Modeling Measurements 26

Project 7. Coarse-Sediment Monitoring (Inputs, Impacts and Reworking) 26

Project 8. Kanab Ambersnail Compliance Monitoring 27

Project 9. Food base Impacts ofBHBF Flows in Glen Canyon Reach 29

Project 10. Water Quality, Hydrology in Glen Canyon Forebay 30

Project 11. Water Quality Monitoring of Jet Tubes 31

Project 12. Mixing Zone and Monitoring of Downstream Water Quality 31

III. POST-BHBF TREATMENT (January to April fluctuating flows) 32

Project 13. Monitoring of Rainbow Trout Adult Stranding and Mortality 33

Project 14. Distribution of Spawning Redds for Rainbow Trout in the Lees

Ferry Reach 34

Project 15. Determination of the Mechanism Accounting for Reduced

Recruitment During Fluctuating Flows in the Lees Ferry

Reach 34

Project 16. Food Base Impacts of Fluctuating Flows 35

Project 1. Part D - Ongoing Mass Balance of Sediment Transport 36

Project 2. Part C - FIST 36
4. NON-FLOW TREATMENT 38

Project 17. Mechanical Removal of Non-Native Salmonids from the

Colorado River Near the Confluence with the

Little Colorado River 38

Project 18. Water Quality Impacts of Trout Removal 40

Project 19. Rainbow Trout Diet Analysis at the LCR Confluence and in

Glen Canyon Reach 41

Project 20. Incidence of Predation on Humpback Chub by Rainbow and

Brown Trout at the Confluence of the Little Colorado River,

Grand Canyon 42

Project 1. Part E - Ongoing Sediment Mass Balance 44

Project. 2. Part D - FIST 44

Socio-Cultural Studies 46

A. Archaeological Studies 46

Project 21. Monitoring for Effects of the Test Flows at

Archaeological Sites , 46

Project 22. Monitoring of Sediment Deposition in Arroyos 46

Project 23. Monitoring of Aeolian Sediment Transport at

Archaeological Sites 47

B. Tribal Resource Studies """"""""".'.""""""""""""""..'" 47

Project 24. Monitoring of Traditional Tribal Resources 47

C. Economic Studies 48

Project 25. Economic Impacts to Whitewater and Angler

Concessionaires and Private Boaters and Anglers 48

Project 26. Economic Impacts to Power Customers 48

D. Recreational Use Studies ""'."""""""""""."".".""' '.." 49

Project 27. Changes in Campable Beach Areas 49

Project 28. Recreational Safety Study 49

Relationship of Proposed Projects to Existing Monitoring Programs ...50

Remotely Sensed Data Collection ..,., , "" ,..,."."."., , 51

Survey Support ' ' '.'...' 51

Logistics , ,.,.., ,.,.." , ,..,.., 51

References 52

APPENDICES

1. Trout Discussion Paper , 55

2. Proposed Fish Experiment LCR Confluence 64

3. Summary of Routine Fisheries Monitoring Program Indicating

when Monitoring Information will be Available Relative to

when Treatment Actions are Conducted 65-67

4. Trip Schedules 68- 72

11
1

Two-Year Science Plan for Experimental Flow Treatments

and Mechanical Removal Activities in WY's 2002-2004

Introduction

This plan describes a conceptual framework, which identifies priority project areas for

research and monitoring related to experimental flows and mechanical removal of nonnaive fishes. It is not intended to provide highly detailed methodologies for

accomplishing the research and monitoring. The plan assumes that nonnal core

monitoring activities conducted by GCMRC as part of the Glen Canyon AMP will be

completed and indeed may provide much of the necessary infonnation to evaluate the

effectiveness of the treatment scenarios.

In response to a motion passed by the Adaptive Management Work Group at their

January 2002 meeting a series of treatment scenarios for WY2002-03 was developed by

the Grand Canyon Monitoring and Research Center in conjunction with the Technical

Work Group (GCMRC, 2002). At their April 24, 2002, meeting, the Adaptive

Management Work Group reviewed these scenarios and made their recommendation for

implementing Experimental Flows and Mechanical Removal of salmonids in the LCR

reach of the Colorado River Ecosystem. The Bureau of Reclamation has forwarded the

AMWG recommendation to the Secretary of the Interior via the Assistant Secretary for

Water and Science. The Secretary's decision on that recommendation is expected during

summer of 2002.

The treatments recommended by GCMRC and adopted by the AMWG for WY 2002 -

2004 are intended to: (1) decrease downstream export of tributary input sediment from

Marble Canyon, (2) increase retention of sediment through Beach/Habitat-Building

Flows (BHBF), (3) improve survival and recruitment ofHBC by reducing competition

and predation from non-native fish (primarily rainbow trout) and (4) improve and

maintain habitat for young native fish.

Within the recommended experimental flow scenario for WY 2002 - 2003 GCMRC is

recommending a series of treatments, depending on the timing of and whether or not one

gets significant sediment inputs, that combine low flows to reduce sediment export,

BHBFs to enhance sediment storage, and high fluctuating flows to disadvantage nonnative fish. This latter flow pattern will potentially improve the growth of salmonids by

reducing density in the Lees Ferry reach and reduce predation or competition by rainbow

and brown trout on the endangered humpback chub in the LCR reach. Integrated science

studies are also being designed to document relationships between terrestrial sand-bar

dynamics and vegetation and impacts to cultural and recreational resources within Grand

Canyon.

In addition, GCMRC has provided a first draft of a larger set of experimental flows that

can serve as a starting point for working with the Science Advisors, the TWG, and other

stakeholders to develop a longer term program of experimental flows. This long term

implementation plan was part of the AMWG motion passed April 24, 2002.

Proposed GCMRC Science Plan for Experimental Flow Treatments and

Mechanical Removal Activities for WY2002-2004

Aul!ust 9. 2002