AMWG Desired Future Condition€¦ · AMWG Desired Future Condition A high quality,self-sustaining, trout fishery in GCNRA, as further described in the Recreation DFC that does not

AMWG Desired Future Condition

A high quality,self-sustaining, trout fishery in GCNRA, as further described in the Recreation DFC that does not adversely affect the native aquatic community in GCNP

Shared Fishery Goals for the lower Colorado River – NPS/AGFD

1. Maintaining a quality recreational Rainbow Trout fishery in Lees Ferry

2. Maintaining healthy populations of all native fish (including Humpback Chub and Razorback Sucker) populations in the lower Colorado River

History of Trout in Lees Ferry

020,00040,00060,00080,000

100,000120,000140,000160,000180,000

AZGFD TROUT STOCKINGRainbow Trout Stocking Cutthroat Trout Brook Trout Coho Salmon

Rainbow Trout = 2,122,442Cutthroat Trout = 60,857Brook Trout = 391,562Coho Salmon = 20,000

History of Trout in Grand Canyon

0

50000

100000

150000

200000

250000

NPS/USFWS TROUT STOCKINGRainbow Trout Brown Trout Brook Trout

Rainbow Trout = 427,007Brown Trout = 249,000Brook Trout = 108,000

Rainbow Trout Population Trends in Lees Ferry

Year

1991 1993 1995 1997 1999 2001 2003 2005 2007 2009 2011 2013 2015 2017

Rai

nbow

trou

t CPU

E (f

ish/

min

)

0

2

4

6

8

10

4 fold decline in CPUE from 2012 - 2016

Catch rates < 1 fish per hour – 2014 -2017

Year

1975 1980 1985 1990 1995 2000 2005 2010 2015A

ngle

r CPU

E (f

ish/h

our)

0.00

0.25

0.50

0.75

1.00

1.25

1.50

1.75

2.00

2.25

2.50Boat angler CPUE Walk-in angler CPUE

Angler catch rates mirror electrofishing trends

Year

1992 1995 1998 2001 2004 2007 2010 2013 2016R

ainb

ow tr

out C

PUE

(fis

h/m

inut

e) s

tand

ard

elec

trof

ishi

ng

0

2

4

6

8

10

Rai

nbow

trou

t CPU

E (f

ish/

hour

) for

boa

t ang

lers

-0.5

0.0

0.5

1.0

1.5

2.0

2.5

3.0Electrofishing Boat anglers Walk-in anglers

11.2

11.0

~ c 0.8 :2

·:E :!=

:~ 0.6 •C QI "Cl •C ::::,

~ OA

0.2

0.0

2012

High reuu itment in 2011 due to higll & steady flows over spri ng-sum mer

Limited recru itment

Higher mortality for larger s1 ze classes (die-off)

I I

2013 2014 2015 2016

S ize Cllass (rnm}

• ::,,: 275

• 225-274 D H5-224 D 125-174 • 75-1124

Recru itme 11t increases

2017

<152 mm TL

1990 1995 2000 2005 2010 2015

CPUE

(fish

/min

)

0

3

6152-305 mm TL

1990 1995 2000 2005 2010 20150

3

6

306-405 mm TL

Year

1990 1995 2000 2005 2010 2015

CPUE

(fish

/min

)

0

1

2>405 mm TL

Year

1990 1995 2000 2005 2010 20150

1

A

DC

B

“Catchable” population of Rainbow Trout is still depressed

Poor catch rates = less angler use (>35% decline)

Year

1980 1984 1988 1992 1996 2000 2004 2008 2012 2016 2020

Yea

rly re

lativ

e ang

ler u

se

0

2500

5000

7500

10000

12500

15000

17500

20000

boat anglers walk-in anglers

2015 Lees Ferry Management PlanOBJECTIVE – Provide a quality trout fishing experience with catchfrequency commensurate with the Blue Ribbon status of the fishery.

Angler CatchRate

Angler catch rate ≥ 1 RainbowTrout per hour

• Stocking• HFEs• Change in regulations

AGFD plans to stock 16,000 triploid Rainbow Trout with focus timeframe between April 1st and October 15th

AZGFD/USFWS Approach

2018/2019 – Two year research project to evaluate project

2019 – 2038 – Nonnative stocking procedures manual, consistent with Upper Basin Program

4 Lenses to evaluate “Take” using Grand Canyon and Western U.S. big river Published Literature 1. What is the estimated survival rate of triploid Rainbow

Trout stocked into Lees Ferry?

2. How many stocked triploid Rainbow Trout are expected to out-migrate downstream to habitats occupied by Humpback Chub?

3. How many Humpback Chub would be ingested by the out-migrating stocked triploid Rainbow Trout?

4. What will be the effect of this stocking on the Humpback Chub population?

1) What is the estimated survival rate of triploid Rainbow Trout stocked into Lees Ferry? • Studies have shown stocked

catchable trout in rivers and streams experience greater than 95% mortality rate, and persist less than three months post-stocking (Miller 1952, Walters et al. 1997; Bettinger and Bettoli 2002, High and Meyer 2009, Quinn and Kwak 2011).

Assumption made: 95% mortality over 90 days

2) How many stocked triploid Rainbow Trout are expected to out-migrate downstream to habitats occupied by Humpback Chub?

Assumption made: 0.11% out-migration to reaches II-III and 0.02% out-migration to reaches IVa and IVb over a 90 day period

Korman et. al. 2016

3) How many Humpback Chub would be ingested by the out-migrating stocked triploid Rainbow Trout? Yard et al. 2011, estimated a piscivory rate for Rainbow Trout upstream and downstream of the LCR of 4 fish and 10 fish ingested per year respectively. Of those fish, 27.3% were documented to be Humpback Chub.

David Ward, USGS study results indicate between a 47% and 22% reduction in predation by hatchery raised triploid Rainbow Trout versus wild diploid Rainbow Trout.

Assumption Made: A correction factor of 22% was used resulting in an annual estimated annual piscivory of 3.12 and 7.8 fish ingested per Rainbow Trout upstream and downstream of the LCR respectively. Of those fish, 27.3% are assumed to be Humpback Chub.

4) What will be the effect of this stocking on the Humpback Chub population?

Humpback Chub abundance exceeds 10,000 adults!

Requisite Level of Impact

District Court (E.D. Cal, 2010) says that 9th Circuit cases say that harm by habitat modification requires proof of a population-level impact to listed species

Presenter

Presentation Notes

Coalition for a Sustainable Delta v. John McCamman, 725 F.Supp.2d 1162, 1168 (E.D. Cal 2010) has said that where direct harm and harm via habitat modification appear to differ is in their need for proof of a population-level effect. Take can result from direct harm to a single individual animal.” Whereas harm via habitat modification requires population-level impacts. The problem with the population proposition is that the 9th Circuit cases don’t support it, they cut the opposite direction, but that doesn’t mean that it isn’t defensible. The proposition is supportable on the basis of the requirement of the “impairment of essential behavior patterns” (breeding, feeding, or sheltering) in the definition of harm. Center for Environmental Science Accuracy and Reliability v. National Park Service United States District Court, E.D. California.August 29, 2016Slip Copy2016 WL 4524758 To prevail on a Section 9 claim, a plaintiff must prove by a preponderance of the evidence that a “reasonably certain threat of imminent harm to a protected species” exists. Marbled Murrelet v. Babbitt, 83 F.3d 1060, 1066 (9th Cir. 1996). Thus, Plaintiffs have the burden of proving that the City's diversions will harm one of the five listed fish species identified in the complaint “by killing or injuring it.” Protect Our Water v. Flowers, 377 F. Supp. 2d 844, 880 (E.D. Cal. 2004) (citing Defs. of Wildlife v. Bernal, 204 F. 3d 920, 925 (9th Cir. 2000)). Habitat modification may constitute “harm” to a listed species, but only if it “actually kills or injures wildlife.” Babbitt v. Sweet Home Chapter of Communities for a Great Oregon, 515 U.S. 687, 691 (1995) (quoting and affirming the definition in 50 C.F.R. § 17.3). A “potential” injury to the species is “inadequate to establish Section 9 liability.” Swinomish Indian Tribal Cmty. v. Skagit Cnty. Dike Dist. No. 22, 618 F. Supp. 2d 1262, 1270 (W.D. Wash. 2008) (quoting Forest Conservation Council v. Rosboro Lumber Co., 50 F.3d 781, 784 (9th Cir. 1995)). Take can result from direct harm to a single, individual animal. See, e.g., United States v. Nuesca, 945 F.2d 254 (9th Cir. 1991) (affirming criminal convictions under the ESA for the direct take by hunting of a single Hawaiian monk seal and two green sea turtles). In contrast, “the balance of the authority suggests that a population level effect is necessary for harm resulting from habitat modification to be considered a take.” Coal. for a Sustainable Delta, 725 F. Supp. 2d at 1170 (collecting cases).

Over 1 million diploid Rainbow Trout

Korman et. al. 2016

Adding 16,000 triploid Rainbow Trout to the existing diploid Rainbow Trout population does not constitute a habitat modification to the environmental baseline or population level effect

Conservation Measures1. AGFD will host annual reporting meeting

2. AGFD will not stock more than 5,000 Rainbow Trout per month

3. All stocked trout will be left pelvic fin clipped If funding and compliance is available PIT tags will be used and a PIT tag array will

be placed in the Grand Canyon

4. The Department will assist the Service in monitoring 30 mile spring for Humpback Chub

5. Off ramp stockings at between 8000-9500 individuals (rates still TBD)

6. Monitor Lees Ferry Rainbow Trout Objectives via creel and electrofishing trend survey

7. Monitor downstream under existing planned surveys – any suspected stocked trout will be evaluated for triploidy or PIT tags

Implementation Approach1. Finalize Biological Opinion with USFWS for 2018

2. Section 106 if federal funding used

3. Public Meeting March 5th in Marble Canyon

4. Stocking for 2018 to begin Spring

5. Begin nonnative stocking procedures manual for the State of Arizona

6. Initiate EA and Section 7 on Arizona specific nonnative stocking procedures manual

It’s all about balance!Questions?

Documents

AMWG Desired Future Condition€¦ · AMWG Desired Future Condition A high quality,self-sustaining, trout fishery in GCNRA, as further described in the Recreation DFC that does not