The View from 60,000 Feet

The View The View

from 60,000 Feetfrom 60,000 Feet

Evolution and DiversityEvolution and Diversity

of Steelheadof 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 AmericaEocene North America 55-30 Million 55-30 Million

Years AgoYears AgoBegan with rapid warmingBegan with rapid warming

Tropical forests in Pacific NorthwestTropical forests in Pacific Northwest

Polar climates similar to Pacific Polar climates similar to Pacific Northwest todayNorthwest today

Large lakes and inland seas; none of existing Large lakes and inland seas; none of existing mountain rangesmountain ranges

British ColumbiaBritish Columbia40-50 Ma 40-50 Ma

Salmonidae Salmonidae already presentalready present

Eosalmo driftwoodensis

IncludedIncluded• ThymallinaeThymallinae• CoregoninaeCoregoninae• SalmoninaeSalmoninae

Start of long-term Start of long-term cooling trend cooling trend

Continued coolingContinued coolingallowed dispersalallowed dispersal

southwardsouthwardLate Miocene Late Miocene (10-5 Ma) (10-5 Ma)

The Sabertooth SalmonOncorhynchyus (Smilodonichthys) rastrosus

Continued coolingContinued coolingallowed dispersalallowed dispersal

southwardsouthward

Plio-Pleistocene Plio-Pleistocene (5-0.1 Ma) (5-0.1 Ma)

Fossil Fossil O. australisO. australisIn Lake Chapala, In Lake Chapala, MexicoMexico

Distribution of western trouts Distribution of western trouts in North America in North America

about 1900 about 1900 ((from Behnke 1992from Behnke 1992))

Diversity of extant Diversity of extant western trouts 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 reflectreflect colonization

to the south

Extant distribution does not Extant distribution does not simply reflect southward simply reflect southward

colonizationcolonization

Formation of mountain ranges

Shaping old rivers & creating new ones

Faulting in Basin & Range

Columbia basalts & Columbia basalts & Snake River flowsSnake River flows

Volcanic lava floods

Glaciation


to the south



Formation of mountain ranges

Shaping old rivers & creating new ones

Faulting in Basin & Range

Columbia basalts & Columbia basalts & Snake River flowsSnake River flows

Volcanic lava floods

Glaciation

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

50,000 years ago


to the south



Eoc

ene

Mio

cene

Olig

ocen

ePleistocenePleistocene

PliocenePliocene

23

5.35.3

34

2.62.6

Species & Subpecies of North American trout

HuchoBrachymystaxSalvelinus

OncorhynchusSalmo

Salmo Oncorhynchus

Two Morphologically Two Morphologically Different Forms of Different Forms of

Steelhead TroutSteelhead Trout

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

Coastal formCoastal form

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


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 Most primitive forms of O. mykiss O. mykiss occur near occur near

Gulf of CaliforniaGulf of California

Primitive TraitsPrimitive Traits

Derived TraitsDerived 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 Earliest O. mykiss O. mykiss evolved evolved around the Gulf of California & around the Gulf of California &

dispersed northdispersed north


SacramentoSacramento

San Joaquin San Joaquin

KlamathKlamath

?Columbia Columbia

Oregon Desert BasinsOregon Desert Basins

Reached Columbia River Reached Columbia River 32-50K years ago32-50K years ago




KlamathKlamath

?Columbia Columbia


Tahoe Glaciation 32K years ago

Glacial Lake Missoula

Upper Fraser

Puget Sound

10-15 K 10-15 K years agoyears ago

C CCCCBB B

G

G

EG

B

EEE

BBBA

A

B

C

AAAAEFFFFFFF

AAAA

CBBCBF

AAA

ADDDDGGGGBBBBBB

CAAAAAAA

BBBBBBB

CE

BBBA

AAA

CB

G

Columbia River

C C

Ca

non

ica

l Va

riat

e 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



KlamathKlamath

?Columbia Columbia



Upper FraserPuget

Sound

Steelhead life-history contributed to greater O. mykiss diversity

than often recognized



KlamathKlamath

?Columbia Columbia



Upper FraserPuget

Sound

Large river systems were more important that glaciation in

diversity of O. mykiss

Ability to Explain Differences



KlamathKlamath

?Columbia Columbia



Upper FraserPuget

Sound

Basins now isolated from large river systems played key roles in

the evolution of steelhead

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

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The View from 60,000 Feet