The View

from 60,000 Feet

Evolution and Diversity

of Steelhead

Ken CurrensPacific Coast Steelhead Management Meeting 2010

West Africa, 1930

Things weren’t always as they are now

The present is often more interesting if we know something about the past

Eocene North America 55-30 Million

Years AgoBegan with rapid warming

Tropical forests in Pacific Northwest

Polar climates similar to Pacific Northwest today

Large lakes and inland seas; none of existing mountain ranges

British Columbia40-50 Ma

Salmonidae already present

Eosalmo driftwoodensis

Included• Thymallinae• Coregoninae• Salmoninae

Start of long-term cooling trend

Continued coolingallowed dispersal

southwardLate Miocene (10-5 Ma)

The Sabertooth SalmonOncorhynchyus (Smilodonichthys) rastrosus

Continued coolingallowed dispersal

southward

Plio-Pleistocene (5-0.1 Ma)

Fossil O. australisIn Lake Chapala, Mexico

Distribution of western trouts in North America

about 1900 (from Behnke 1992)

Diversity of extant western trouts

Coastal cutthroat

Westslope cutthroat

Yellowstone cutthroat

Rio Grande cutthroat

Colorado River cutthroat

Greenback cutthroat

Mexican golden trout& undescribed trout

Apache trout

Gila trout

Rainbow trout O. mykiss

Bonneville cutthroat

Humboldt cutthroat

Lahontan cutthroat

Paiute cutthroat

Whitehorse & Alvord cutthroats

California,& Kern golden trouts

Extant distribution does not simply reflect colonization

to the south

Extant distribution does not simply reflect southward

colonization

Formation of mountain ranges

Shaping old rivers & creating new ones

Faulting in Basin & Range

Columbia basalts & Snake River flows

Volcanic lava floods

Glaciation

Extant distribution does not simply reflect colonization

to the south

Extant distribution does not simply reflect southward

colonization

Formation of mountain ranges

Shaping old rivers & creating new ones

Faulting in Basin & Range

Columbia basalts & Snake River flows

Volcanic lava floods

Glaciation

No O. mykiss in the Columbia River as recently as 70,000-

50,000 years ago

Extant distribution does not simply reflect colonization

to the south

Extant distribution does not simply reflect southward

colonization

Eoc

ene

Mio

cene

Olig

ocen

ePleistocene

Pliocene

23

5.3

34

2.6

Species & Subpecies of North American trout

HuchoBrachymystaxSalvelinus

OncorhynchusSalmo

Salmo Oncorhynchus

Two Morphologically Different Forms of

Steelhead Trout

Inland or fine-scale form with redband trout-like characteristics

Coastal form

Landlocked “redband” trout with cutthroat-like characteristics (Oncorhynchus sp.)

Extant distribution does not simply reflect colonization

to the south

Coastal & Inland forms thought to reflect dispersal after isolation & differentiation in glacial refuges

Mexican golden trout& undescribed trout

Most primitive forms of O. mykiss occur near

Gulf of California

Primitive Traits

Derived Traits

California & Kern golden trouts

McCloud redband

Upper Klamath redband

Goose Lake, Warner,& Chewaucan redbands

Fort Rock redband

Catlow Valley redband

Columbia River redbands

Coastal rainbow trout & steelhead

White River redband

Earliest O. mykiss evolved around the Gulf of California &

dispersed north

Gulf of California

Sacramento

San Joaquin

Klamath

?Columbia

Oregon Desert Basins

Reached Columbia River 32-50K years ago

Gulf of California

Sacramento

San Joaquin

Klamath

?Columbia

Oregon Desert Basins

Tahoe Glaciation 32K years ago

Glacial Lake Missoula

Upper Fraser

Puget Sound

10-15 K years ago

C CCCCBB B

G

G

EG

B

EEE

BBBA

A

B

C

AAAAEFFFFFFF

AAAA

CBBCBF

AAA

ADDDDGGGGBBBBBB

CAAA

A AAABB

BBBBB

CE

BBBA

AAA

CB

G

Columbia River

C C

Ca

non

ica

l Va

ria

te II

I

K

H

H

IHH

K

HIntermediates?Harney (H), Catlow (I)Fort Rock (K)

N

NMN

M

NN

NQ

Q

MM

M

M

M

M

MMMM

M

MN N

NNN N

Klamath:Upper Klamath headwater (M), Upper Klamath Lake (N)Coastal Klamath mountains (Q)

-30 -20-25 5-15 -10 -5 0

-10

-5

0

5

-15

Canonical Variate I

L

L

L

J

J

JJJ

OO O

OO

Sacramento:Goose Lake (L), Warner Lakes (O)Chewaucan (J)

L

Are Extant Distributions Always About Geology?

Life-history (e.g, ability to migrate, environmental tolerance) makes a difference

What about biotic interactions?

Lower Klamath River

Iron Gate Dam

Jenny Creek Falls

Upper Klamath Lake

Williamson River

Sprague River

Sycan River

Trout Creek

Coast steelhead(O. mykiss irideus)

Klamath redband(O. mykiss newberrii)

Klamath River Basin

Lower Klamath River

Iron Gate Dam

Jenny Creek Falls

Upper Klamath Lake

Williamson River

Sprague River

Sycan River

Trout Creek

Klamath BasinOncorhynchus mykiss

sAH*112 allele

sAH* alternate alleles

Ancestral Klamath redband( unnamed subspecies)

• Isolated above barriers formed before dispersal

of coastal steehead from glacial refugia• More primitive morphology

Lower Klamath River

Iron Gate Dam

Jenny Creek Falls

Upper Klamath Lake

Williamson River

Sprague River

Sycan River

Trout Creek

Why Don’t the Ancestral Redband Still Occur Throughout Upper Klamath Lake Basin?

Lower Klamath River

Iron Gate Dam

Jenny Creek Falls

Upper Klamath Lake

Williamson River

Sprague River

Sycan River

Trout Creek

100% Resistant

100% Resistant

100% Susceptible

100% Susceptible

Intermediate resistance

Co-evolution with Diseases & Parasites

Ceratomyxa shasta

Lower Klamath River

Iron Gate Dam

Jenny Creek Falls

Upper Klamath Lake

Williamson River

Sprague River

Sycan River

Trout Creek

Reconnection of Upper Klamath Basin to the Pacific allowed invasion C. shasta and C. shasta resistant O. mykiss displacing earlier form

Sacramento

San Joaquin

Klamath

?Columbia

Oregon Desert Basins

Glacial Lake Missoula

Upper FraserPuget

Sound

Steelhead life-history contributed to greater O. mykiss diversity

than often recognized

Sacramento

San Joaquin

Klamath

?Columbia

Oregon Desert Basins

Glacial Lake Missoula

Upper FraserPuget

Sound

Basins now isolated from large river systems played key roles in

the evolution of steelhead

Sacramento

San Joaquin

Klamath

?Columbia

Oregon Desert Basins

Glacial Lake Missoula

Upper FraserPuget

Sound

Large river systems were more important than glaciation in

diversity of O. mykiss

Glacial refuges & dispersal

Persistence in large river systems

37%

67%

Ability to Explain Differences

Sacramento

San Joaquin

Klamath

?Columbia

Oregon Desert Basins

Glacial Lake Missoula

Upper FraserPuget

Sound

Co-evolution with diseases & parasites may help explain some

unexpected distributions of trout

Fishing for Ancestral Steelhead in the Oregon Desert Basins, 1985

Things weren’t always as they are now

The present is often more interesting if we know something about the past