Sum

mer

Und

ergr

adua

te R

esea

rch

Opt

imal

Gra

in S

ize

Dia

met

ers f

or S

alm

on S

paw

ning

Hab

itat P

rior t

o M

arm

ot D

am R

emov

al o

n th

e Sa

ndy

Riv

er, O

rego

nM

icha

ela

Long

, Uni

vers

ity o

f Ari

zona

Men

tors

: Dr.

Pete

r Wilc

ock,

Chu

ck P

odol

ak, J

ohns

Hop

kins

Uni

vers

ity

N

A

T

I O

N

A

L

C

E

N

T

E R

F O

R

E A

R

T

H

-

S U

R

F

A

C

E

D

Y

N

A

M

I C

S

St.

Ant

hony

Fal

ls L

abor

ator

y

Obj

ectiv

esO

ne o

f the

pri

mar

y pu

rpos

es o

f dam

rem

oval

is to

rest

ore

the

stre

am to

the

natu

ral c

ondi

tion

with

em

phas

is on

aid

ing

natu

ral b

iolo

gica

l hab

itats

. Thr

ough

obs

erva

tion

of se

dim

ent t

rans

port

, one

can

pr

edic

t the

suita

bilit

y of

salm

on sp

awni

ng. A

lthou

gh th

ere

are

seve

ral f

acto

rs th

at c

ontr

ibut

e to

de

term

inin

g op

timal

spaw

ning

hab

itat s

uita

bilit

y, g

rain

-siz

e di

stri

butio

n of

the

rive

rbed

is th

e m

ost

signi

fican

t for

ana

lysis

of r

iver

con

ditio

ns b

efor

e an

d af

ter d

am re

mov

al. T

he d

istri

butio

n of

the

sedi

men

t fol

low

ing

a m

assiv

e lo

ad o

f sed

imen

t tra

nspo

rt w

ill d

eter

min

e th

e su

sten

ance

of t

he sa

lmon

sp

ecie

s dur

ing

dam

rem

oval

and

ulti

mat

ely

dete

rmin

e th

e su

cces

s of d

am re

mov

al p

roje

cts.

Met

hods

To e

valu

ate

pre-

dam

rem

oval

sedi

men

t com

posit

ion,

I ge

nera

ted

faci

esm

aps w

hich

are

map

s of n

umer

ous

patc

hes o

f sed

imen

t with

the

hom

ogen

eous

cha

ract

erist

ics.

I per

form

ed p

ebbl

e co

unts

of t

he a

rea

to

dete

rmin

e th

e gr

ain-

size

dist

ribu

tion

of th

e ri

verb

ed a

cros

s sev

eral

reac

hes d

owns

trea

m. I

took

exi

stin

g fis

h lit

erat

ure

in fi

sher

ies j

ourn

als t

o fin

d sa

lmon

spaw

ning

are

as. T

he lo

catio

ns m

appe

d ou

t in

fishe

ries

jo

urna

ls w

ill p

rovi

de a

foun

datio

n fo

r whi

ch to

nar

row

sear

ch fo

r red

dsfo

r eac

h pa

rtic

ular

spec

ies o

f sa

lmon

ids.

Alth

ough

nei

ther

of t

he sa

lmon

spec

ies w

ere

spaw

ning

at t

he ti

me

of th

e fie

ld w

ork,

I ob

serv

ed

the

grai

n-siz

e di

amet

ers o

f the

gra

vel w

here

redd

sare

exp

ecte

d to

be

foun

d du

ring

spaw

ning

seas

on a

nd I

prod

uced

faci

esm

aps i

n th

ese

area

s.

Abs

trac

tTh

e pu

rpos

e of

the

Mar

mot

Dam

rem

oval

at t

he S

andy

Riv

er is

to im

prov

e ha

bita

t con

nect

ivity

for

salm

onid

popu

latio

n an

d to

rest

ore

natu

ral s

trea

mflo

wdo

wns

trea

m o

f the

dam

. The

nat

ure

of sa

lmon

sp

awni

ng e

ffort

s dep

ends

sign

ifica

ntly

on

sedi

men

t com

posit

ion

of th

e ri

verb

ed. T

he a

ntic

ipat

ed

sedi

men

t tra

nspo

rt in

itiat

ed b

y da

m re

mov

al is

exp

ecte

d to

affe

ct sa

lmon

hab

itat a

cros

s diff

eren

t rea

ches

of

the

rive

r, w

ith th

e de

gree

of s

ever

ity d

epen

ding

on

loca

tion

rela

tive

to th

e da

m a

nd se

dim

ent

com

posit

ion.

How

will

the

mas

sive

amou

nt o

f sed

imen

t tra

nspo

rt a

ffect

salm

on sp

awni

ng? W

hich

gra

in

sizes

are

opt

imal

for s

paw

ning

? How

are

thes

e pa

rtic

ular

gra

in-s

izes

dist

ribu

ted

alon

g th

e ri

ver?

How

w

ill th

is se

dim

ent t

rans

port

follo

win

g da

m re

mov

al?

Dat

a co

llect

ion

cons

ists o

f usin

g W

olm

an’s

pebb

le-

coun

t met

hod

to d

eter

min

e th

e gr

ain-

size

dist

ribu

tion

(GSD

) acr

oss s

ever

al ri

ver r

each

es. C

ompa

riso

ns

of g

rain

-siz

e di

amet

ers t

o sa

lmon

hab

itat w

ill d

eter

min

e th

e op

timal

gra

in-s

ize

for s

alm

on sp

awni

ng

effo

rts.

Res

ults

show

that

the

aver

age

grai

n-siz

e of

are

as w

ith g

reat

er sa

lmon

spaw

ning

act

ivity

is a

gr

avel

and

cob

ble

com

posit

ion

with

dia

met

ers r

angi

ng b

etw

een

16m

m a

nd 4

5mm

. The

se re

sults

will

fu

rthe

r be

used

to d

etec

t cha

nge

in ri

verb

ed c

ompo

sitio

n ov

er th

e co

urse

of t

he n

ext 5

-10

year

s and

how

da

m re

mov

al a

ffect

s sal

mon

idha

bita

t.

Dam

rem

oval

will

aid

the

salm

on p

opul

atio

ns b

y sig

nific

antly

rest

orin

g th

e st

ream

to it

s nat

ural

co

nditi

ons.

Theo

retic

ally

, the

rive

r may

nev

er re

turn

to it

s nat

ural

, pri

stin

e co

nditi

ons d

ue to

the

long

-ter

m a

dver

se e

ffect

s of d

am c

onst

ruct

ion

on th

e st

ruct

ure

and

natu

ral f

unct

ions

of t

he ri

ver

ecos

yste

m. H

owev

er, d

am re

mov

al o

ffers

the

best

att

empt

at s

alva

ging

the

num

erou

s eco

logi

cal

com

mun

ities

. Im

med

iate

ly fo

llow

ing

dam

rem

oval

, the

con

ditio

ns o

f the

bed

cha

nnel

is e

xpec

ted

to

be d

isast

rous

for f

ish p

opul

atio

ns d

ue to

the

rela

tivel

y m

assiv

ese

dim

ent t

rans

port

dow

nstr

eam

. The

di

ssol

ved

load

, con

sistin

g of

mat

eria

l tha

t is t

rans

port

ed in

solu

tion,

is p

redi

cted

to b

e hi

ghly

un

suita

ble

to sa

lmon

bio

logi

cal f

unct

ions

ulti

mat

ely

caus

ing

mor

talit

y. In

add

ition

, the

bed

cha

nnel

is

expe

cted

to b

e hi

ghly

uns

tabl

e fo

r sev

eral

yea

rs fo

llow

ing

dam

rem

oval

dir

ectly

impa

ctin

g sa

lmon

ha

bita

t. Ev

entu

ally

, the

bed

cha

nnel

will

flat

ten

out o

ver t

ime

and

mak

e th

e be

st a

ttem

pt to

rest

ore

to p

re-d

am c

ondi

tions

supp

ortin

g aq

uatic

eco

syst

ems.

Paci

fic sa

lmon

idsa

re c

ritic

al to

mai

ntai

ning

nut

rien

ts in

the

rive

r eco

syst

em. T

hey

are

anad

rom

ous;

they

sp

end

the

begi

nnin

g of

thei

r liv

es in

fres

hwat

er a

nd m

igra

te to

the

sea

whe

re th

ey sp

end

a m

ajor

ity o

f th

eir a

dult

lives

. Eve

ntua

lly, t

hey

retu

rn to

the

exac

t str

eam

s whe

re th

ey w

ere

hatc

hed

in fr

eshw

ater

to

repr

oduc

e an

d di

e. T

hus,

mig

ratio

n pa

ssag

es a

re h

ighl

y sig

nific

ant t

o sa

lmon

dev

elop

men

t and

re

prod

uctio

n. D

urin

g th

eir p

erio

d in

saltw

ater

, the

y ea

t rav

enou

sly to

stor

e fa

t and

no

long

er fe

ed in

the

rive

r. W

hen

the

fem

ale

spaw

ns, s

he b

urie

s red

ds, o

r nes

ts in

the

grav

el. S

alm

on ty

pica

lly d

epos

it up

to a

th

ousa

nd e

ggs i

n ea

ch re

dd. U

pon

fert

iliza

tion,

the

fem

ale

then

cov

ers e

ach

redd

with

gra

vel a

nd

dete

rior

ates

whi

le g

uard

ing

the

nest

. Sal

mon

cor

pses

pro

vide

ple

ntifu

l nut

rien

ts to

the

rive

r.

Ther

e ar

e se

vera

l spe

cies

that

inha

bit t

he S

andy

Riv

er. T

he c

oho

salm

on (O

ncor

hync

husk

isutc

h) is

the

spec

ies u

nder

inve

stig

atio

n in

th

e fie

ld d

ue to

its h

igh

popu

latio

n. T

he S

andy

rive

r con

sists

of

salm

on th

at h

ave

been

raise

d at

the

fishe

ries

and

then

rele

ased

into

th

e ri

ver;

wild

salm

on a

re n

ot u

nder

exp

erim

enta

tion.

The

spri

ngCh

inoo

k, su

mm

er S

teel

head

, and

Coh

o sa

lmon

spaw

n up

stre

am

rela

tive

to th

e da

m a

cros

s sev

eral

reac

hes o

f the

rive

r. Th

e Fa

ll Ch

inoo

k sp

awn

dow

nstr

eam

rela

tive

to th

e da

m. W

inte

r Ste

elhe

ad

spaw

n bo

th u

pstr

eam

and

dow

nstr

eam

of t

he ri

ver r

elat

ive

to th

e da

m. A

ll sa

lmon

idss

paw

n fa

r ups

trea

m a

nd d

owns

trea

m fr

om th

e M

arm

ot d

am. H

owev

er, t

he C

hino

ok sa

lmon

hav

e se

cond

ary

spaw

ning

are

as ju

st a

bove

the

Mar

mot

dam

, thu

s the

se sp

ecie

s may

be th

e m

ost a

ffect

ed a

s a re

sult

of th

e se

dim

ent t

rans

port

in th

e re

serv

oir.

Gra

in S

ize

Dis

trib

utio

n

0102030405060708090100 0.

010.

11

1010

010

0010

000

diam

eter

(mm

)

% finer

A B1 B2 OB

Tota

l

Res

ults

Follo

win

g 3

wee

ks o

f fie

ld o

bser

vatio

ns a

nd st

udy

at th

e Sa

ndy

Riv

er, O

rego

n, th

e na

ture

and

su

itabi

lity

of sa

lmon

spaw

ning

hab

itat w

as e

valu

ated

and

map

ped

acro

ss se

vera

l rea

ches

do

wns

trea

m o

f Mar

mot

Dam

. The

opt

imal

gra

in si

ze d

iam

eter

for s

alm

on sp

awni

ng e

ffort

s in

the

Sand

y R

iver

was

det

erm

ined

to ra

nge

betw

een

the

diam

eter

s of2

0mm

and

47m

m. T

he

idea

l are

as fo

r spa

wni

ng h

abita

t was

bas

ed o

n ex

istin

g fis

h lit

erat

ure

gath

ered

by

the

fore

st

serv

ices

. The

re w

as c

onsid

erab

le fo

cus o

n sid

e ch

anne

ls an

d ar

eas w

ith m

inim

al h

uman

ac

tivity

and

low

disc

harg

e.

Ack

now

ledg

emen

tsI w

ould

like

to th

ank

Dr.

Pete

r Wilc

ock

and

Chuc

k Po

dola

kat

John

s Hop

kins

U

nive

rsity

. I w

ould

also

like

to th

ank

Kar

en H

ill a

nd Je

ff M

arr f

or th

e th

eir i

nval

uabl

e gu

idan

ce. I

wou

ld li

ke to

than

k th

e N

atio

nal C

ente

r for

Ear

th-S

urfa

ce D

ynam

ics (

NCE

D)

and

St. A

ntho

ny F

alls

Labo

rato

ry (S

AFL

).Disc

ussio

nTh

e M

arm

ot D

am re

mov

al re

sear

ch p

roje

ct w

ill c

ontin

ue in

to n

ext y

ear.

Furt

her r

esea

rch

will

be

cond

ucte

d to

det

erm

ine

chan

ge d

etec

tion

in th

e ri

ver b

edfo

llow

ing

a m

assiv

e lo

ad o

f se

dim

ent t

rans

port

dow

nstr

eam

from

the

dam

. Thi

s map

ping

effo

rt w

as c

ondu

cted

to e

nsur

e a

deep

er u

nder

stan

ding

of t

he b

iolo

gica

l im

pact

of s

trea

m re

stor

atio

n. In

effo

rt to

det

erm

ine

the

optim

al g

rain

size

for s

paw

ning

hab

itat,

the

dow

nstr

eam

reac

h of

the

rive

r was

m

etic

ulou

sly m

appe

d ev

en in

are

as w

ith n

o sp

awni

ng su

itabi

lity.

Thi

s dat

a w

ill p

rovi

de a

ba

sis to

det

ect t

he e

xact

cha

nge

in th

e ge

omor

phol

ogy

of th

e ri

ver a

nd c

an b

e us

ed in

futu

re

dam

con

stru

ctio

n an

d re

mov

al p

roje

cts.

Mar

mot

Dam

bef

ore

rem

oval

.Th

e Sa

ndy

Riv

er a

t Oxb

ow P

ark,

just

one

hou

r eas

t of P

ortla

nd.

Coho

Sal

mon

Red

dsem

bedd

ed in

gra

vel.

Faci

esM

aps a

t Oxb

ow P

ark

whe

re si

gnifi

cant

spaw

ning

act

ivity

occ

urs i

n th

e fa

ll.

Pebb

le C

ount

ing

alon

g th

e ri

verb

ank.

Back

grou

ndTh

e co

nstr

uctio

n of

the

Mar

mot

Dam

forc

es se

vera

l disa

dvan

tage

s to

the

salm

onid

popu

latio

n of

the

Sand

y R

iver

. Dam

s alte

r the

nat

ural

m

igra

tion

pass

ages

in th

e up

stre

am d

irec

tion.

Dam

s neg

ativ

ely

mod

ify u

pstr

eam

and

dow

nstr

eam

aqu

atic

env

iron

men

ts, i

nclu

ding

: th

erm

al st

ratif

icat

ion

of th

e re

serv

oir;

dow

nstr

eam

flow

alte

ratio

n an

d te

rmin

atio

n of

inun

datio

n of

dow

nstr

eam

floo

dpla

ins;

sedi

men

t an

d nu

trie

nt tr

appi

ng in

rese

rvoi

rs.