Food Base Enhancement Proposal for the biannual budget 2015‐2016 and to start the discussion

towards a more detailed plan:

Numerous published articles and presentations have referenced the importance of an adequate food

base for the health and growth of native and non‐native fish in the Colorado River.  Colton Finch in his

Thesis points out the importance of flow to the drift of invertebrate.  ECOSYSTEM ECOLOGY MEETS

ADAPTIVE MANAGEMENT: FOOD WEB RESPONSE TO A CONTROLLED FLOOD ON THE COLORADO RIVER,

GLEN CANYON, points out Midges (Chironomidae), Black Flies (Simuliidae), and Scuds (Gammarus

lacustris) represent most all of the insect food base.  David Ward has pointed out the HBC’s over 60 – 70

mm have a greater chance of survival.  A greater food base can improve their opportunity.  Recently

released in a preprint version the following article gives direct linkage to the food availability for the HBC

and density limitations referenced by Carl Waters in past Knowledge Assessments.  FOODWEB

DYNAMICS IN A LARGE RIVER DISCONTINUUM, Cross et al  Taxon‐specific comparisons of the four most

productive invertebrate taxa showed that fish consumed nearly all of the available Simulium,

Chironomidae, Gammarus, and Potamopyrgus production at most site‐year combinations downstream

of the LCR.   

Ted Kennedy has done extensive research on the drift of these insects.  In his recent WebEx he

suggested habitat improvements could be effective.  This is supported by “Driftwood: an alternative

habitat for macro invertebrates in a large desert river”, G. Allan Haden et all.  Though the following

article was in reference to salmonids it does demonstrate the impact of habitat augmentation on food

base, “Do In‐stream restoration structures enhance salmonid abundance?  A meta‐analysis”, Sarah L.

Whiteway et all, the placement of large boulders and large woody debris is supported to restore and

support high biomass of invertebrates in the rivers.  

During the on river review by the Protocol Evaluation Panel, early last year, one member mentioned this

very fact and suggested the key role that filter feeders play in the food base above the dam has been

precluded from these canyons because the host colonies are above the damn and can no long support

localized populations. Also mentioned was the dam not only is a barrier to sediment transportation but

also that of drift wood, key to invertebrate production in rivers and streams.  The specific insect

mentioned was the Caddis (Trichoptera) which is found in many of the tributaries. During the January,

2013 Annual Report meeting Brian Healy reported that Caddis are present in lower tributaries.  Those

mentioned were Bright Angel and Havasu. Another insect found is the Mayfly (Baetidae).   

The great work done by all of these scientists has established a large base of basic research on the food

base types currently available, their densities, drift, impact of seasonal‐light variations, aquatic

vegetation variation, etc.  It seems only timely and correct to move into an applied research mode to

use this data to enhance food base in specific areas to benefit existing and planned aggregations, reduce

possibilities for density limitations, and establish host colonies for speedier redevelopment of aquatic

invertebrate production following detrimental events reducing available food.  Such a program is

consistent with the draft Performance Criteria for Glen Canyon Dam Long‐Term Experimental and

Management Plan Environmental Impact Statement in sections related to Natural Processes, Humpback

Chub Recovery Goals, etc.
Thus as we move forward with the planning for the 2015‐2016 budget we should include a project to

Enhance Food Base in Specific areas of the River.  The following is a very basic outline for such a

program.  

Food Base Enhancement to include:

a) A review/develop data on flows and Temperature to determine what flow regimes are most

positive to higher densities of aquatic invertebrate,

b) Test stream habitat augmentation to improve colonization and establish host colonies of

invertebrate.  Such augmentation can include movement of rocks and boulders as well as introduction

of wood and logs.  Consideration should also be given to nutrient supplementation.

c) Translocation of native insect taxa to establish colonies in the main stream

Such a project should not be limited to the above considerations.  During the 2015‐2016 budgeting

process the GCMRC could schedule a workshop to develop a project in coordination with responsible

agencies.  A good foundation may be data collected in the tail water synthesis project.  By introducing a

basic outline at this time the TWG, scientists of the GCMRC and constituents parties have the

opportunity to utilize their understanding of the basic research at hand and organize a logical

investigative approach for an applied application to address the issued discussed here.

  
Food Base Enhancem

It is well established that rainbow trout and na

populations in Glen and Grand Canyon are lim

the availability of high quality invertebrate pre

KT2
Slide 3

KT2 The foodbase project from 2006-2009 investigated sites throughout the CRE and came to basically the sam

(2001) arrived at for rainbow trout in Glen Canyon....fish populations are limited by the availability of high qKennedy, Theodore, 1/8/2014
The scientists have provided us with a wealth 

research on food base:

 Types currently available Their densities Drift Impact of seasonal light variations Aquatic vegetation, etc

It is time to move to an applied management 

improve the health of the invertebrate assem

KT8
Slide 4

KT8 modified and shortened text

Kennedy, Theodore, 1/8/2014
A FY15‐16 Food Base Enhancement project would include bu

limited to some of the following elements:

A review of the data collected in the Tail Wat

Synthesis project

Determine what flow regimes are most posit

higher densities of aquatic invertebrates

Translocation of native insect taxa from othe

of the Colorado River

Habitat augmentation to improve colonizati

establishment of host colonies of invertebrat

KT6
Slide 5

KT6 shortened text. The points you were making were all 

Kennedy, Theodore, 1/8/2014
A project of Food Base Enhancement would suppor

of the Desired Future Conditions:

CRE Aquatic DomainNative SpeciesRainbow troutNonfish Biotic Communities

Blue Ribbon Trout Fishery in Glen Canyon

National Recreation Area
The problem is 

have, in most all 

River, to many ch

fish of all specie
Which has 

Mother Hcupboard The answ

the childr