U.S. Department of the Interior

U.S. Geological Survey

Nonnative Fish Control Plan: 

Summary of Primary Revisions 

from TWG Review

Prepared for Glen Canyon Dam Adaptive Management Program

TWG Conference call, January 5, 2010

By

Kara Hilwig

USGS, Grand Canyon Monitoring and Research Center

1
Overview

NNF Plan Reviews

 Internal and external

 Science Advisors

 TWG

Input from reviewers enhanced document

 Reviewer efforts appreciated

 Addressed majority of comments

 Added Recommendations for Implementation

 Provides tangibility of direction in nonnative control 

planning

Nonnative Control Plan not static

 Annual input from monitoring, research and 

control recommendations

2
Presentation Goals

 Describe primary TWG review comments

 Identify revision in document

 Page number referenced

 Identify significant factual errors or omissions 

for revision

 Submit for TWG finalization 

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Need for Risk Assess.\ Proj. Priority

 Refinement and completion of risk assessment 

is priority once plan is finalized

 Strategic Approach Identified

 Section added: See Strategic Issues (pg 36)

 Valdez and Speas (2009); Valdez (2008)

 Assessed benefits of TCD to fish spawning, incubation and 

growth in GC

 Extensive review of temperature requirements

 Will be included in bioenergetics modeling

Section added: See Research Recom., Risk Assessment (pg 45)

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Need for Risk Assess.\ Proj. Priority

 Progress in Ecopath/Ecosim modeling 

 Use to simulate invasion of nonnative fish and impacts to 

juvenile humpback chub

 Forcing function to simulate various temp scenarios

 Integrating with foodbase

 Identify information needs

 March 2010 Workshop – outcome presented to TWG in April

Section added: See Implementation Section (pg 64)

 Nonnative Control Ad Hoc (2003) threats:

1. Brown trout 4. Common carp 7. Fathead minnow

2. Rainbow trout 5. Red shiner 8. Black bullhead

3. Channel catfish 6. Yellow bullhead 9. Green sunfish

10. Largemouth bass

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Need for Risk Assess.\ Proj. Priority

 Repeat threats survey from Nonnative Control 

Ad Hoc (2003)

 Identify species of greatest risk

 Best professional judgment in the absence of 

definitive data

 Nonnative Fish project prioritization process

 Address nonnative fish issues of greatest concern

 Upper Basin developed successful prioritization 

protocol

Sections added: See new Implementation Section (pg 64)

And Appx. C – Prioritization Recom. Memo (pg 103)

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Define Agency Roles\ Need for MultiAgency Implementation Doc.

 Not appropriate for GCMRC to assign tasks or 

responsibility to Mgmt. Agencies

 See new Implementation Section (pg 64)

 Develop multi-agency Rapid Response Plan (AMP)

 Develop Desired Future Conditions (AMP)

 Project Prioritization Process/ Repeat Risk Survey (GCMRC)

 GCMRC recommends Response Plan approach 

for AMP Implementation

Section added: See Rapid Response Plan (pg 70) 

and Appx. D Rapid Response Plan Example

7
Mechanical Removal Triggers Questioned

Text added: See Mech Removal 

Recom. (pg 35)

 Lit support for removal of ↑ %

 Projected # of trips to maintain 

RBT abundance in LCR reach 

at 10-20 % Jan. 2003 level 

(Coggins model)

 600 to 1,200 fish in LCR reach

 Low Immigration (50 fish/mo)

 1-2 trips per year

 High Imm. (300 fish/mo)

 2-3 trips per year

 Future Imm. rate unknown

 2008 RBT cohort in Lees Ferry

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Mechanical Removal

 Discussion of certainties and uncertainties 

 Discuss exploring feasibility of removal 

upstream

See Mechanical Removal Recom. (pg 39-42)

 Text indicates complexity of implementing 

nonnative fish management 

 Tribal concerns/consultation

 Environmental compliance

See Regulatory Authority (pg 37) 

Implementation Strategies (pg 66)

9
Clarify Triggers and Response

 Scientist and Manager input

 NNF Workshop (pg 55); examples added

 Response Triggers (pg 59); text added

 Responding to NNF Threats (pg 61); text added

 Most likely scenarios presented

 Require management agency response

 Nonnative fish monitoring needs

See Review of Fish Proj (pg 15); text added

and Monitoring Recom. (pg 37); text added

 Adaptive Management Approach

 Annual evaluation

10
NNF Plan should be a review of Upper Basin efforts

 Plan not intended to be review

 Active interaction with UB Recovery Prog.

 UB NNF Workshops

 Researchers Meetings

 Prioritization Process

 UB participation in GC NNF Workshops

 UB thinks most important part of GC Plan is 

PREVENTION

See Prevention and Public Outreach (pg 57); text added

11
Need all response scenarios developed

 Large # of possible methods/scenarios

 Invading species, #s and sources unknown

 Limited removal methods available for GC

 Use tools and personnel available

 Opted to use NNF Workshop for ‘real time’ 

response plan development

 Identify NNF issue requiring response

 Develop Control Response

 Scenarios presented

See Responding to Perceived Threats (pg 61); text added

12
Conclusions

 Plan is product of multiple reviews

 Requires adaptive management approach

 Implementation plan needed

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Kara Hilwig

USGS Fisheries Biologist

Grand Canyon Monitoring and Research Center

(928)556-7459

khilwig@usgs.gov

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