THREATS TO ATLANTIC SALMON SUSTAINABILITY IN NEW ENGLAND

Stephen D. McCormick

USGS, Conte Anadromous Fish Research Center, Turners Falls, MAUniversity of Massachusetts, Amherst

ATLANTIC SALMON LIFE HISTORY

THE ENDANGERED ATLANTIC SALMON

• COMPARATIVE PHYSIOLOGY: THE KROGH PRINCIPLE– OSMOREGULATION AND MIGRATION

COMMERCIAL & SOCIAL IMPORTANCE FISHERIES AND AQUACULTURE

WILD SALMON ARE DECLINING WORLDWIDE DUE TO HABITAT LOSS, DAMS, POLLUTION,

OVEREXPLOITATION

SALMON RIVERS OF NEW ENGLAND

• RIVERS IN SOUTHERN NEW ENGLAND EXTIRPATED IN THE 1800’S DUE TO DAM CONSTRUCTION & HABITAT LOSS

• SALMON IN DOWNEAST MAINE RIVERS DECLINED IN THE 1970’s.

VERMONT

NEW HAMPSHIRE

RHODE RHODE

ISLANDISLAND

RHODE RHODE

ISLANDISLAND

MASSACHUSETTS

CONNECTICUT

THE CONNECTICUT RIVER

• 40,000 SQ KM WATERSHED

• LARGEST RIVER IN NEW ENGLAND

• PROBABLY HELD THE LARGEST SALMON POPULATIONS IN NEW ENGLAND (10,000-50,000)

1850 Present

DAMS ON THE CONNECTICUT RIVER

1850

HISTORY OF ATLANTIC SALMON ON THE CONNECTICUT RIVER

1798: Turners Falls Dam built – led to salmon declines

1850: Holyoke dam enlarged – led to salmon extirpation

1869-1888: First salmon restoration attempt

1965: Anadromous Fisheries Conservation Act

1967: Current salmon restoration program initiated

TurnersFalls

Holyoke

SALMON RESTORATION ON THE CONNECTICUT RIVER

FRY STOCKINGSMOLT STOCKING

Smolts Stocked into the Connecticut River

050

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Fry Stocked into the Connecticut River

Adult Atlantic salmon returns to the Connecticut River

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Summary of Total Atlantic Salmon Returns (186) By

Location in 2005

Holyoke71%

Westfield15%

Rainbow8%

Leesville6%

INITIAL SUCCESS OF STOCKING ATLANTIC SALMON IN THE CONNECTICUT RIVER,

BUT…

WHAT FACTORS ARE LIMITING A MORE COMPLETE RESTORATION?

RESEARCH IN SUPPORT OF SALMON RESTORATION ON THE CONNECTICUT RIVER

• HOW MANY SMOLTS ARE PRODUCED FROM FRY STOCKING?

• WHEN DO THEY MIGRATE DOWNSTREAM, AND WHAT CAUSES THEM TO MIGRATE?

• WHAT ARE THE IMPACTS OF DAMS ON SMOLT SURVIVAL AND MIGRATION?

• Labor intensive• Expensive• Variable and low efficiencies• Prone to wash out

PREVIOUS TECHNOLOGY FOR ASSESSING SMOLT MIGRATION:

- COUNTING FENCES- BYPASS STRUCTURES- RADIO/ACOUSTIC TAGS- MARK-RECAPTURE

COMPUTER CHIPS IN FISH

(Get it, fish & chips?)

WIRING THE STREAM

ANTENNA12 guage wire in PVC

TUNING BOX

CABLE READERS,PALMTOPCOMPUTERS,DEEP CYCLEBATTERIES

PIT TAGGING OF JUVENILE ATLANTIC SALMON

TIMING OF SPRING SMOLT MIGRATION IN RELATION TO TEMPERATURE

TIMING OF SPRING SMOLT MIGRATION

Over 6 years, only a 6 day difference in median migration date-indirect evidence for role of daylength in controlling

migration

ANTENNA READ DATE

3/18 4/01 4/15 4/29 5/13 5/27

CU

MU

LA

TIV

E %

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1998 T= 23 6.45 deg/day april1999 T= 79 6.10 deg/day april2000 T= 43 5.50 deg/day april2001 T= 156 2.27 deg/day april2002 T= 77 6.58 deg/day april2003 T= 72 4.57 deg/day april

EFFECT OF PHOTOPERIOD ON DOWNSTREAM MOVEMENTS IN ATLANTIC SALMON SMOLTS

LDNLONG DAYS

SHORT DAYS

APRIL MAY

DO

WN

ST

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AM

MO

VE

ME

NT

TIMING OF SPRING SMOLT MIGRATION

Over 6 years, only a 6 day difference in median migration date-indirect evidence for role of daylength in controlling

migration

ANTENNA READ DATE

3/18 4/01 4/15 4/29 5/13 5/27

CU

MU

LA

TIV

E %

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1998 T= 23 6.45 deg/day april1999 T= 79 6.10 deg/day april2000 T= 43 5.50 deg/day april2001 T= 156 2.27 deg/day april2002 T= 77 6.58 deg/day april2003 T= 72 4.57 deg/day april

TIMING OF SPRING SMOLT MIGRATION IN RELATION TO TEMPERATURE

CUMULATIVE DEGREE DAYS IN APRIL WAS A BETTER PREDICTOR OF MIGRATION TIMING THAN DATE AT 10 oC - SUGGESTS FISH ARE ‘SUMMING’ TEMPERATURE RATHER THAN RESPONDING TO A THRESHOLD TEMPERATURE

OVERWINTER SURVIVAL OF JUVENILE ATLANTIC SALMON (> 11.5 cm; October to May)

1998-99 44.5 %

1999-00 27.6 %

2000-01 68.2 %

2001-02 35.1 %

2002-03 64.1 %

2003-04 41.6 %

Winters are tough!

Turners Falls Dam

Vernon Dam

Holyoke Dam

Acoustic tag

receivers

SMOLT MIGRATION ON THE MAINSTEM OF THE CONNECTICUT RIVER

Tagging salmon smoltswith acoustic tags

River Kilometer

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SMOLT MIGRATION ON THE MAINSTEM OF THE CONNECTICUT RIVER

DAMS ARE TOUGH ON SMOLTS - HIGHER MORTALITY - SLOWER MIGRATION

PHYSIOLOGICAL CHANGES DURING SMOLTING

INFLUENCE OF TEMPERATURE ON SMOLT PHYSIOLOGY

HIGHER TEMPERATURES AND TIME RESULT IN LOSS OF SEAWATER PREPAREDNESS - DAMS THAT RESULT IN DELAYS WILL DECREASE SMOLT SURVIVAL

RECENT DECLINES IN ATLANTIC SALMON POPULATIONS IN MAINE

• ATLANTIC SALMON IN EASTERN MAINE MAINE WERE STABLE UNTIL RECENTLY

• DECLINES BEGAN IN 70’S• LISTED AS ENDANGERED SPECIES IN 2000

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1960 1965 1970 1975 1980 1985 1990 1995 2000

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NARRAGUAGUS RIVER

HYPOTHESIZED CAUSES OF MAINE ATLANTIC SALMON POPULATION DECLINES

• ACID PRECIPITATION AND ASSOCIATED ALUMINUM TOXICITY

• ENDOCRINE DISRUPTORS (CONTAMINANTS THAT ACT AS HORMONES, AFFECT DEVELOPMENT AND SURVIVAL)• HERBICIDES AND PESTICIDES FROM

AGRICULTURE AND FORESTRY

• IMPACTS OF SALMON FARMING• DISEASE

• OCEAN CONDITIONS

ACID/ALUMINUM AND ENDOCRINE DISRUPTORS MAY SPECIFICALLY IMPACT SMOLTS

ENVIRONMENTAL PROBLEM OF ACID RAIN

(United States Geological Survey)

• Anthropogenic acidification results in episodic pulses of acidity during spring snowmelts and fall storms

TRIPLE WHAMMY OF ACID RAIN:• MORE ACID IN STREAMS• REMOVAL OF NATURAL BUFFERING (Ca and Mg) •MORE ALUMINUM LEACHED FROM SOIL; BECOMES

TOXIC AT LOW pH

SENSITIVITIES OF SALMON LIFE STAGES TO ACID & ALUMINUM

Eggs• delayed hatching• increased mortality

Fry• increased mortality• decreased ion content

Smolt• increased mortality • plasma ion loss in FW• loss of SW tolerance

Parr• smaller parr more sensitive than larger parr• decreased plasma ions

Alevins• impaired ion uptake• decreased growth and yolk reabsorption

PHYSIOLOGICAL CHANGES DURING SMOLTING

• ACID AND ALUMINUM INTERACT TO CAUSE MORTALITY OF ATLANTIC SALMON

• THE CAUSE OF MORTALITY IS COMPROMISED ION REGULATION (LOSS IN FW, GAIN IN SW)

IMPACT OF ACID & ALUMINUM ON SMOLT SURVIVAL

PE

RC

EN

T M

OR

TA

LIT

Y

(ug./l)

MAINE RIVER WATER CHEMISTRY (NOAA Fisheries, 2003)

5. Dennys 8. Pleasant 9. Narraguagas11. Penobscot

9 85

11

= Dennys= Narraguagas= Pleasant= Penobscot

STREAM-SIDE REARING OF SMOLTS IN MAINE RIVERS

HOLD SMOLTS IN NATURAL WATERS FOR 6 DAYS DURING NORMAL SPRING MIGRATION, MONITOR SURVIVAL AND PHYSIOLOGY

NO MORTALITY, BUT A CLEAR pH-RELATED COMPROMISE OF ION REGULATION.

CONTAMINANTS THAT ACT AS ENDOCRINE DISRUPTORS

Sm

olt-

to-A

dult

Sur

viva

l (%

)

Percent of Basin Sprayed (Fairchild et al., 1999)

INCREASED SPRAYING OF MATACIL (CONTAINING 2% NONYLPHENOL)IS CORRELATED WITH POORER SMOLT-TO-ADULT SURVIVAL OF ATLANTIC SALMON IN NEW BRUNSWICK RIVERS

ENDOCRINE DISRUPTION OF THE PARR-SMOLT TRANSFORMATION IN ATLANTIC

SALMON

• EXPOSURE TO NONYLPHENOL CAUSED LOSS OF SEAWATER TOLERANCE.

• BUT THIS ONLY OCCURRED AT RELATIVELY HIGH CONCENTRATIONS, HIGHER THAN THOSE SEEN IN NATURE.

• ARE OTHER LIFE STAGES MORE

SENSITIVE?

Exposure to nonylphenolAs yolk-sac larvae (21 days)

Smolts-sampling

1 Year, inclean water

Freshwater Seawaterchallenge

Stress Seawater preference

ENDOCRINE DISRUPTION OF THE PARR-SMOLT TRANSFORMATION IN ATLANTIC SALMON

EFFECT OF NONYLPHENOL ON SURVIVALOF ATLANTIC SALMON YOLK-SAC LARVAE

NP

MORTALITY OCCURRED AT HIGH NP CONCENTRATIONS(THIS DOSE DID NOT KILL SMOLTS)

DELAYED MORTALITY 30 DAYS AFTER EXPOSURE AT LOW NP

• Gill Na+, K+-ATPase and seawater tolerance are significantly reduced in smolts 1 year after exposure to NP as larvae.

p = 0.0030

VC E2 NP

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Estradiol2 g l-1

p = 0.0056 p = 0.0002

VC E2 NPVEH

VEH

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E2

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NP

EFFECT OF NONYLPHENOL AND ESTRADIOL ON SMOLT DEVELOPMENT, ONE YEAR AFTER EXPOSURE

FACTORS AFFECTING RESTORATION & CONSERVATION OF ATLANTIC SALMON

• SOUTHERN NEW ENGLAND • LOSS OF ORIGINAL GENETIC STOCKS• DAMS HAVE IMPACTED AND CONTINUE TO IMPACT

ATLANTIC SALMON IN SOUTHERN NEW ENGLAND

• DOWNEAST MAINE• CONTAMINANTS SUCH AS ACID RAIN AND

PESTICIDES MAY HAVE PLAYED A ROLE IN SALMON DECLINES IN MAINE

• EFFECTS CAN BE SUBTLE, AFFECTING SPECIFIC LIFE STAGES, AND CAUSING INDIRECT MORTALITY THROUGH COMPROMISED SEAWATER TOLERANCE, DISEASE RESISTANCE AND OTHER PATHWAYS.

REASONS FOR OPTIMISM FOR THE FATE OF ATLANTIC SALMON

• DAM REMOVAL (PENOBSCOT RIVER)

• INNOVATIONS IN FISH PASSAGE: - UPSTREAM AND DOWNSTREAM

• CONTINUED DEVELOPMENT OF A ‘CONNECTICUT RIVER’ STOCK OF ATLANTIC SALMON

• CONTINUED RESEARCH WILL ALLOW US TO MORE CLEARLY DEFINE FACTORS THAT AFFECT SALMON SURVIVAL

• CONTINUED PUBLIC SUPPORT

ATLANTIC SALMON LIFE HISTORY

SEAWATER(1000 mOsm)

325 mOsm

OSMOREGULATORY PHYSIOLOGY OF TELEOST FISH

WATER IONS

300 mOsm

FRESH WATER (5 mOsm)

WATER IONS

ION UPTAKE DILUTE URINE

ION SECRETION

DRINK

ISOOSMOTIC URINE