Improving methods to accurately age rainbow smelt (Improving methods to accurately age rainbow smelt (Osmerus mordax)Osmerus mordax)

Scott Elzey, Massachusetts Division of Marine FisheriesScott Elzey, Massachusetts Division of Marine FisheriesClaire Enterline, Maine Department of Marine ResourcesClaire Enterline, Maine Department of Marine Resources

Jessica Fischer, New Hampshire Department of Fish and GameJessica Fischer, New Hampshire Department of Fish and Game

American Fisheries Society 2010 Meeting, Pittsburgh, PAAmerican Fisheries Society 2010 Meeting, Pittsburgh, PA

Anadromous Rainbow SmeltAnadromous Rainbow Smelt

Eat plankton, small shrimp and fishEat plankton, small shrimp and fish

SpringSpringSpawn at head of tideSpawn at head of tide

SummerSummerYoung of the year in estuaries, adults Young of the year in estuaries, adults

in coastal watersin coastal watersFallFall

Open bays, moving towards shoreOpen bays, moving towards shoreWinterWinter

Sheltered bays, large tidal riversSheltered bays, large tidal rivers

May spawn in different streams each year May spawn in different streams each year within the same river systemwithin the same river system

Variation in genetic structure of Variation in genetic structure of populations > four distinct regionspopulations > four distinct regions

Sources: Kendall, 1926; Buckley, 1989; Sources: Kendall, 1926; Buckley, 1989; MurawskiMurawski

et. al. et. al. 19801980

Can live up to 6 years and 10Can live up to 6 years and 10””, but more typically 2, but more typically 2--3 years and 63 years and 6””

Rainbow Smelt: Species of ConcernRainbow Smelt: Species of Concern

Possible threats to adults:Possible threats to adults:

Historical commercial fisheryHistorical commercial fishery

Rising ocean temperatureRising ocean temperature

Marine predationMarine predation

Threats to spawning:Threats to spawning: ObstructionsObstructions pH (acid rain, land use)pH (acid rain, land use) Habitat alterationHabitat alteration EutrophicationEutrophication

Sources: Fuda

et. al., 2007; Geffen, 1990

Ageing Objectives and Current ResearchAgeing Objectives and Current Research

Smelt in stressed populations may mature at smaller sizesSmelt in stressed populations may mature at smaller sizes

Genetic work shows lack of allelic diversity in rivers where smaGenetic work shows lack of allelic diversity in rivers where smallest llest average length at age 1 is observed, southern edge of rangeaverage length at age 1 is observed, southern edge of range

University of New Hampshire, D. Berlinsky

Ageing Objectives and Current ResearchAgeing Objectives and Current Research

Monitoring year class strengthMonitoring year class strength

Small Age 1 year class in 2009 is seen as small age 2 year classSmall Age 1 year class in 2009 is seen as small age 2 year class

in 2010in 2010

Age 1

Age 2

Age 3

0

5

10

15

20

25

30

11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26

Length (CM)

Per

cent

of P

opul

atio

n at

Len

gth

Age 1 Age 2 Age 3 Age 4 Age 5 Age 6

2009

Age 1

Age 2Age 3

0

5

10

15

20

25

30

10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27

Length (CM)

Perc

ent o

f Pop

ulat

ion

at L

engt

h

Age 1 Age 2 Age 3 Age 4 Age 5

2010

Massachusetts Division of Marine Fisheries, Spring Fyke Net Survey Massachusetts Division of Marine Fisheries, Spring Fyke Net Survey

Develop mortality estimatesDevelop mortality estimatesConservation plan based on findingsConservation plan based on findings

OtolithsOtoliths, , FinraysFinrays, or Scales?, or Scales?

Short life span > outer annuli are easily visible on scalesShort life span > outer annuli are easily visible on scales

Rainbow smelt spawning is not violent > fewer regenerated scalesRainbow smelt spawning is not violent > fewer regenerated scales

Whole and sectioned smelt Whole and sectioned smelt otolithsotoliths

and and finraysfinrays: unclear and open : unclear and open to more interpretationto more interpretation

OtolithOtolith

collection is lethalcollection is lethal

Existing KnowledgeExisting Knowledge

Scar forms at the scale edge at the end of each Scar forms at the scale edge at the end of each growing season, the growing season, the ““shiny lineshiny line””

Females have a faster growth rate than malesFemales have a faster growth rate than males

Average length at age decreases through the Average length at age decreases through the spawning season for all agesspawning season for all ages

Existing keys and assumptions are site specific Existing keys and assumptions are site specific ((MiramichiMiramichi

River, Lake Superior)River, Lake Superior)

Discrepancies: when the annuli are formed Discrepancies: when the annuli are formed and characteristics of the first annulusand characteristics of the first annulus

Sources: Bailey, 1964; McKenzie, 1958Sources: Bailey, 1964; McKenzie, 1958

Age 2

Age 1

Age 3

There are currently no regionThere are currently no region--wide reference collections wide reference collections or comparisons of age at length keysor comparisons of age at length keys

Traditional MethodsTraditional Methods

Projected Image Projector Scope

Cleaned with brush:Damaged circuli and possible annulus

Uncleaned

scale

Improved Cleaning MethodsImproved Cleaning Methods

5% diluted solution of 5% diluted solution of pancreatinpancreatin

to digest mucus to digest mucus

15 minute bath in a high15 minute bath in a high--frequency sonic cleaner frequency sonic cleaner

Toothbrush removes any excess mucusToothbrush removes any excess mucus

==

Source: Whaley, 1991

Process multiple batches simultaneously Process multiple batches simultaneously Fewer remounts Fewer remounts

(28% using brush method, 14% using (28% using brush method, 14% using sonicatorsonicator, Maine DMR), Maine DMR)

Higher agreement ratesHigher agreement rates

Digital MicroscopeDigital Microscope

Image Pro (V6.2) drives a digital video camera mounted atop a Image Pro (V6.2) drives a digital video camera mounted atop a dissecting microscope with transmitted lighting dissecting microscope with transmitted lighting

Emphasize true and false annuli Emphasize true and false annuli

Image enhancementImage enhancement

Digitally archives images, ages, and measurementsDigitally archives images, ages, and measurementsFalse 2nd

annulus does not have “shiny line”

Image Pro InterfaceImage Pro Interface

Image Enhancement

Records age and measurements

Digital Reference CollectionsDigital Reference Collections

Quality Assurance: agers review collections periodicallyQuality Assurance: agers review collections periodically

Agreement has increased from 80% to over 90% (MA DMF)Agreement has increased from 80% to over 90% (MA DMF)

River specific: growth rates and false markings varyRiver specific: growth rates and false markings vary

Compiled from preceding four years of scalesCompiled from preceding four years of scales

Updated annually to reflect current growth ratesUpdated annually to reflect current growth rates

River specific collections are combined into regional setRiver specific collections are combined into regional set

Future studies better informedFuture studies better informed

Collections are currently consensus aged, will be Collections are currently consensus aged, will be validated by OTC marking and taggingvalidated by OTC marking and tagging

ValidationValidation

Age 1:Age 1:

YolkYolk--sac larvae are marked with sac larvae are marked with oxytetracyclineoxytetracycline

hydrochloride (OTC) and hydrochloride (OTC) and released as part of stock enhancement in an annual survey sitereleased as part of stock enhancement in an annual survey site

14 OTC marked smelt recaptured year after released, scales indep14 OTC marked smelt recaptured year after released, scales independently given age 1endently given age 1

Age 2 and up (not tested):Age 2 and up (not tested):

Mark captured spawning adults with OTC through osmotic inductionMark captured spawning adults with OTC through osmotic induction, OTC , OTC mark would be visible on the scalesmark would be visible on the scales

Implant adults with coded wire tags Implant adults with coded wire tags --

may be less accurate because comparing may be less accurate because comparing scales to scalesscales to scales

Preliminary ResultsPreliminary Results

Age can be predicted by length and sex.Age can be predicted by length and sex.(Linear Regression: R(Linear Regression: R²²=0.74, age Std =0.74, age Std CoefCoef=0.84, sex Std =0.84, sex Std CoefCoef=0.12; p=0.000<0.005; Fore River, all =0.12; p=0.000<0.005; Fore River, all

years combined)years combined)

0 1 2 3 4 5 6 7AGE

100

150

200

250

300LE

NG

TH

MF

SEX

Length at age separated by sex. Data combined 2005-2010. Fore River, MA.

Preliminary Results: Age CohortsPreliminary Results: Age Cohorts

AgeAge--2 individuals compose a smaller proportion of the sampled 2 individuals compose a smaller proportion of the sampled population over the sample period.population over the sample period.

Average length of AgeAverage length of Age--2 increases for both sexes 20062 increases for both sexes 2006--2010.2010.(Linear Regression: R(Linear Regression: R²²=0.27, year Std =0.27, year Std CoefCoef=0.34, sex Std =0.34, sex Std CoefCoef=0.35; p=0.000<0.005; Fore River)=0.35; p=0.000<0.005; Fore River)

0

10

20

30

40

50

60

70

2006 2007 2008 2009 2010

Year

Prop

ortio

n of

Sam

pled

Pop

ulat

ion

2004 2005 2006 2007 2008 2009 2010 2011YEAR

100

150

200

250

LEN

GT H

MF

SEX

Proportion of sampled population composed of age-2 individuals. Fore River, MA DMF.

Average length of age-2 males and females increases over the sample period. Fore River, MA DMF.

In sumIn sum……Standardizing and updating cleaning and ageing Standardizing and updating cleaning and ageing

procedures increases precision procedures increases precision

Digital archiving allows reference collections to be easily Digital archiving allows reference collections to be easily shared and updatedshared and updated

Reference collections need to be updated through time as Reference collections need to be updated through time as growth rates changegrowth rates change

Compiling reference collections for the entire region Compiling reference collections for the entire region informs future studiesinforms future studies

Standard ageing protocols allow regional data to be Standard ageing protocols allow regional data to be analyzed to understand population trendsanalyzed to understand population trends

Project partnersProject partnersMaine Department of Marine ResourcesMaine Department of Marine Resources

New Hampshire Department of Fish and GameNew Hampshire Department of Fish and GameGreat Bay National Estuarine Research ReserveGreat Bay National Estuarine Research ReserveMassachusetts Division of Marine FisheriesMassachusetts Division of Marine Fisheries

University of New HampshireUniversity of New HampshireUSGS Conte Anadromous Fish Research LaboratoryUSGS Conte Anadromous Fish Research Laboratory

Funding through NOAA, NMFS Office of Protected SpeciesFunding through NOAA, NMFS Office of Protected Species

Questions?Questions?Scott ElzeyScott Elzey

, Massachusetts Div. of Marine Fisheries, , Massachusetts Div. of Marine Fisheries, AnnisquamAnnisquam

River Marine Fisheries Station, 30 River Marine Fisheries Station, 30 Emerson Avenue, Gloucester, MA 01930Emerson Avenue, Gloucester, MA 01930Email: Email: Scott.Elzey@state.ma.usScott.Elzey@state.ma.us

Claire Enterline, Maine Dept. of Marine Resources, PO Box 8, W. Claire Enterline, Maine Dept. of Marine Resources, PO Box 8, W. Boothbay Harbor, ME 04575Boothbay Harbor, ME 04575Email: Email: Claire.Enterline@maine.govClaire.Enterline@maine.gov

Jessica Fischer, New Hampshire Department of Fish and Game, 225 Jessica Fischer, New Hampshire Department of Fish and Game, 225 Main Street, Durham, NH 03824Main Street, Durham, NH 03824Email: Email: Jessica.Fischer@wildlife.nh.govJessica.Fischer@wildlife.nh.gov

References:References:Bailey, MM. 1964. Age, Growth, Maturity, and Sex Composition of Bailey, MM. 1964. Age, Growth, Maturity, and Sex Composition of the American Smelt, the American Smelt, OsmerisOsmeris

mordaxmordax

((MitchillMitchill), of Western Lake Superior. Trans. Am. Fish. Soc. ), of Western Lake Superior. Trans. Am. Fish. Soc. VolVol

93(4). pp. 38293(4). pp. 382--395.395.Buckley, JL. 1989. Species Profiles: Life Histories and EnviroBuckley, JL. 1989. Species Profiles: Life Histories and Environmental Requirements of Coastal Fishes and Invertebrates (North nmental Requirements of Coastal Fishes and Invertebrates (North Atlantic); Rainbow Smelt. US Fish and Wildlife Service Biol. ReAtlantic); Rainbow Smelt. US Fish and Wildlife Service Biol. Rep. 82(11.106). US Army p. 82(11.106). US Army

Corps of Engineers, TR ELCorps of Engineers, TR EL--8282--4. 11pp.4. 11pp.FudaFuda, KM, BM Smith, MP Lesser, BJ , KM, BM Smith, MP Lesser, BJ LegareLegare, HR , HR BreigBreig, RB Stack, DL , RB Stack, DL BerlinksyBerlinksy. 2007. The effects of environmental factors on rainbow smelt . 2007. The effects of environmental factors on rainbow smelt Osmerus mordaxOsmerus mordax

embryos and larvae. Journal of Fish Biology. Vol. 71:539embryos and larvae. Journal of Fish Biology. Vol. 71:539--

549.549.Geffen, AJ. 1990. Response of rainbow smelt, Geffen, AJ. 1990. Response of rainbow smelt, Osmerus mordaxOsmerus mordax

((MitchillMitchill), eggs to low pH. Journal of Fish Biology. Vol. 37: 865), eggs to low pH. Journal of Fish Biology. Vol. 37: 865--871.871.Kendall, WC. 1926. The Smelts. Bulletin of the US Bureau of FiKendall, WC. 1926. The Smelts. Bulletin of the US Bureau of Fisheries. Dept. of Commerce. Vol. XLII. Document No. 1015. pp.2sheries. Dept. of Commerce. Vol. XLII. Document No. 1015. pp.21717--375.375.McKenzie, RA. 1958. Age and Growth of Smelt McKenzie, RA. 1958. Age and Growth of Smelt Osmerus mordaxOsmerus mordax

((MitchillMitchill) of the ) of the MiramichiMiramichi

RiverRiver, New Brunswick, New Brunswick. Fish. Res. Bd. Canada. . Fish. Res. Bd. Canada. VolVol

15:6. pp. 131315:6. pp. 1313--1327.1327.MurawskiMurawski, SA, GR Clayton, RJ Reed, CH Cole. 1980. Movements of Spawnin, SA, GR Clayton, RJ Reed, CH Cole. 1980. Movements of Spawning Rainbow Smelt, g Rainbow Smelt, Osmerus mordaxOsmerus mordax, in a Massachusetts Estuary. Estuaries. Vol. 3(4): 308, in a Massachusetts Estuary. Estuaries. Vol. 3(4): 308--314.314.Whaley, RA. 1991. An Improved Technique for Cleaning Fish ScalesWhaley, RA. 1991. An Improved Technique for Cleaning Fish Scales. N. American Journal of Fisheries Management. Vol. 11. pp. 236. N. American Journal of Fisheries Management. Vol. 11. pp. 236--239.239.