Pacific Ocean

Climate Ecosystem Connections in the Northeast Pacific Ocean:

Linkages between Gulf of Alaska Ichthyoplankton and Physics at the Local and Basin Scales AUTHORSAUTHORS

MiriamMiriam DoyleDoyle –– JISAOJISAO (UW,NOAA/AFSC)(UW,NOAA/AFSC) SusanSusan PicquellePicquelle –– NOAA/AFSCNOAA/AFSC KathyKathy MierMier –– NOAA/AFSCNOAA/AFSC MickMick SpillaneSpillane –– JISAOJISAO (UW,(UW, NOAA/PMEL)NOAA/PMEL PRESENTATIONPRESENTATION OUTLINEOUTLINE ContextContext Exploring Climate-Fisheries Interactions Early Life History Perspective

IchthyoplanktonIchthyoplankton DataData TimeTime--Series:Series: Collections, Dominant Taxa, Seasonal Patterns, Interannual Patterns PhysicalPhysical DataData TimeTime--Series:Series: Basin-Scale and Local-Scale Variables AnalysisAnalysis Methodology:Methodology: Application of Generalized Additive Models ResultsResults andand Conclusions:Conclusions: Emergent Associations between Larval Species Abundance and Physical Variables Potential Mechanisms and Early Life History Strategies ConclusionsConclusions inin Context:Context: UdU d t ddii FFiih i Cli t I t tii Context:Context: FisheriesFisheries--ClimateClimate InteractionsInteractions

TheThe impactimpact ofof climateclimate onon fisheriesfisheries isis highlyhighly variable,variable, indirectindirect andand complexcomplex

LarvalLarval mortalitymortality isis highlyhighly variablevariable andand subjectsubject toto manymany interacting,interacting, highhigh--frequencyfrequency factors,factors, withwith feedbackfeedback andand nonnon--linearitylinearity

Bailey, Hollowed and Wooster, 2004 Given this level of complexity….

Question:Question:

WhatWhat kindkind ofof connectionsconnections areare therethere betweenbetween ourour ichthyoplanktonichthyoplankton datadata timetime--seriesseries andand oceanocean--climateclimate conditionsconditions inin thethe GulfGulf ofof Alaska?Alaska?

InsightInsight intointo potentialpotential environmentalenvironmental controlcontrol ofof recruitmentrecruitment asas mediatedmediated throughthrough thethe EarlyEarly LifeLife HistoryHistory PhasePhase ofof NorthwestNorthwest GOAGOA FishFish Populations?Populations? IchthyoplanktonIchthyoplankton DataData TimeTime--SeriesSeries o IchthyoplanktonIchthyoplankton SamplingSampling GOAGOA Seasonal Pattern Plankton Sampling: Gulf of Alaska, 1972, 1977-2003

2500

2000 Late Spring Time-Series: 1500 1981-2003 on Samples Collected 1000 Plankt of 500 l No. a t o T 0 J JFFMMAAMMJ J J JAASSOONNDD Half Month Ichthyoplankton Data Late Spring Time-Series t la rai u 65°0'0"N s St n ni Bering Sea of Alaska Pe lik 60°0'0"N e Sh Kodi ak Line Island 55°0'0"N 8 Gulf of Alaska

180°0'0"W 170°0'0"W 160°0'0"W 150°0'0"W 140°0'0"W y e ll a a V k as a Al e S

f o k li e h S Favorable Productive Coastal Waters for Fish Larvae

Bathymetry 200 m 500 m Sample size by year

160 140 120 100 80 60 40 20 0 1985 1990 1995 2000 Total no. Plankton Samples Total no. Plankton

• 60 cm Bongo Samples • 23 Sampling Cruises • 21 Years in Time-Series • Date Range May 18 – June 6 • Total of 1706 Plankton Samples MeanMean AbundanceAbundance TotalTotal FishFish LarvaeLarvae RelativeRelative toto SpeciesSpecies Diversity,Diversity, GulfGulf ofof Alaska:Alaska: 1972,19771972,1977--20032003 ) 2 1600 Abundance 2.0 1400 Shannon Diversity Index

1200 y Index 1.5 1000

800 1.0

600

400 0.5

200 Mean Shannon Diversit 0 0.0 Mean abundance total larvae (no./10 m total larvae Mean abundance J JFFMMAAMMJ J J JAASSOONNDD Half month NumericallyNumerically DominantDominant SpeciesSpecies ofof FishFish LarvaeLarvae inin LateLate SpringSpring TimeTime--Series,Series, 19811981--20032003

Mean abundance Species Common name % Occurrence no./10 m2 Theragra chalcogramma Walleye pollock 90.18 362.11 Hippoglossoides elassodon Flathead sole 76.57 50.01 Ammodytes hexapterus Pacific sandlance 75.15 33.38 Bathymaster spp. Ronquils (genus Bathymaster) 66.43 99.42 Gadus macrocephalus Pacific cod 49.78 14.65 Lepidopsetta polyxystra Northern rock sole 35.05 5.29 Stenobrachius leucopsarus Northern lampfish 33.03 5.88 Sebastes spp. Rockfishes 30.99 29.03 Lepidopsetta bilineata Southern rock sole 20.55 2.77 Atheresthes stomias Arrowtooth flounder 18.79 7.32 Platichthys stellatus Starry flounder 18.56 3.24 Hippoglossus stenolepis Pacific halibut 10.00 1.07 Gadids Small Forage Species Flatfish LLarvaarvall FiFisshh SSpecpeciieses

25 30 20 Northern lampfish 25 Arrowtooth 20 15 flounder 15 10 10 5 5 0 0 70 1985 1990 1995 2000 1985 1990 1995 2000 60 Pacific cod 150 Flathead sole 50 120 40 90 30 60 ) 20

2 10 30 0 0 1985 1990 1995 2000 1985 1990 1995 2000 5 2500 Walleye Pollock 4 Pacific halibut 2250 3 750 500 2 250 1 0 0 250 1985 1990 1995 2000 20 1985 1990 1995 2000

200 Rockfish 15 Southern rock sole 150 10 100 5 50 0 0 1985 1990 1995 2000 1985 1990 1995 2000 400 25 Mean abundance (no./10 m Ronquils 20 Northern rock sole 300 15 200 10 100 5 0 0 1985 1990 1995 2000 1985 1990 1995 2000 30 60 Pacific sandlance 25 Starry flounder 20 40 15 10 20 5 TheThe PhysicalPhysical DataData

BasinBasin--ScaleScale VariablesVariables

LocalLocal--ScaleScale VariablesVariables PDO – Pacific Decadal Oscillation Leading pattern of North Pacific SST NP – North Pacific Index Intensity of the mean Winter Aleutian Low Pressure cell AO – Arctic Oscillation Index See-saw pattern of polar-middle latitude Atmospheric Pressure MEI – Multivariate ENSO Index See-saw Pattern of Tropical Sea Level Pressure, East-West Pacific EP-NP – East Pacific-North Pacific Index Leading mode of North Pacific Atmospheric Variability in Spring – Spring Atmospheric Forcing

Monthly mean values Jan – May Relating prevalence of larvae in late May to climate dditiltitthhi gg InfluencingInfluencing LarvalLarval DriftDrift

Alaska

Shelikof Strait k ia od m Bering Sea K a re Unimak C t Pass C S A ka las A

Gulf of Ala ska Sub-surface cross-shelf transport

also importantSub arctic Current DynamicDynamic circulationcirculation featuresfeatures controllingcontrolling ttransportransport aandnd prevalenceprevalence ofof FRESH – GOA River Discharge Total Estimated Freshwater Input from Rivers (Royer et al., 2001) ALONG – Alongshore Wind Index MIXING – Wind Mixing Index (WS3) Calculated from Coastal Wind data for Gore Point (Nick Bond, Stabeno et al., 2004) SST – Sea Surface Temperature For Shelikof Strait, from NOAA-NCEP Reanalysis Data FLOWKL8 Total Flow southern sector Line 8, Kodiak side RI - Shelikof Retention Index (percent particles released in study area, upper 100m, not lost to advection in 15 days) FLOWKL8 and RI computed from the SPEM circulation model (Hermann and Stabeno, 1996) Monthly mean values Jan May AnalysisAnalysis MethodologyMethodology

ConnectingConnecting LarvalLarval FishFish SpeciesSpecies WithWith PhysicalPhysical VariablesVariables

GeneralizedGeneralized AdditiveAdditive ModelingModeling GeneralizedGeneralized AdditiveAdditive ModelingModeling Definition Non-parametric, additive regression technique that models a response variable onto one or more independent variables Advantage of this technique No need for a priori specification of the functional form between the response variable and independent variables Disadvantage Ideally, there should be no interaction between the Independent variables (thus the term additive). Clearly not the case here. GAM remains an “approximation” of the true relationship between the response and independent variables. Application 12 species, 5 basin variables, 6 local variables, 5 months Automated process: Ran each species with all possible combinations of a) basin, b) local variables, for each set of monthly mean values (Jan-May). Best-fit models: chosen according to lowest GCV value, RESULTSRESULTS anandd CONCLUSIONSCONCLUSIONS

EmergentEmergent AssociationsAssociations BetweenBetween LarvalLarval SpeciesSpecies AndAnd PhysicalPhysical VariablesVariables

PotentialPotential MechanismsMechanisms andand EarlyEarly LifeLife HistoryHistory StrategiesStrategies Pacific sandlance Variables Jan Feb Mar Apr May PDO NP Neg AO EP-NP MEI R2(adj) 0.16 0.28 0.35 0.21 0.42 SST ALONG MIXING FRESH Neg Neg FLOWKL8 RI Neg R2(adj) 0.37 0.21 0.65 0.03 0.27

variable contributed significantly to model (P<0.05)

variable contribution not significant (P>0.05)

Pos variable effect positive

Neg variable effect negative

variable absent from model Pacific sandlance Variables Jan Feb Mar Apr May PDO NP Neg AO Most EP-NP Vulnerable MEI During R2(adj) 0.16 0.28 0.35 0.21 0.42 Hatching? SST ALONG MIXING FRESH Neg Neg FLOWKL8 RI Neg R2(adj) 0.37 0.21 0.65 0.03 0.27

Basin-scale climate-forcing seems most important during peak period of larval drift – May. Persistent PDO link (temp). Local conditions – strong connection with peak period of larval (M h) i b t d i t l Starry flounder Variables Jan Feb Mar Apr May PDO NP ELH AO Strategy of EP-NP Resilience MEI R2(adj) to the 0.07 0.04 0.27 -0.01 0.04 SST Pelagic ALONG Environment? MIXING FRESH Pos FLOWKL8 RI R2(adj) 0.18 0.45 0.03 0.05 0.33

Weak overall connection with basin and local variables reflects the limited planktonic stage of this species; short egg incubation and larval duration (transf. 8-10.5mm) Arrowtooth flounder Variables Jan Feb Mar Apr May Vulnerability PDO Neg NP of larval drift AO Neg pattern to EP-NP Pos disruption of MEI cross-shelf R2(adj) 0.01 0.31 0.23 0.69 0.34 and along- SST shelf ALONG Pos transport MIXING Neg (mediated by FRESH Neg FLOWKL8 winds)? RI R2(adj) 0.58 0.06 0.15 0.66 0.03

Winter local conditions winds and river discharge important during spawning and egg/early larval stage (slope) . Spring climate forcing - most important during drift of late larvae to coastal nursery grounds; persistent EP-NP link. Si l l diti iifi tlikithl h id Pattern Emerging:

Larval abundance in late spring is linked to species-specific combinations of environmental variables with seasonal variation in linkages apparent.

Nature of “Connections” between larval abundance and physical variables reflects details of individual species Early Life History Strategies. 20 15 flounder 15 10 10 5 5 0 0 70 1985 1990 1995 2000 1985 1990 1995 2000 60 Pacific cod 150 Flathead sole 50 120 40 90 30 60 ) 20

2 10 30 0 0 1985 1990 1995 2000 1985 1990 1995 2000 5 2500 Walleye Pollock 4 Pacific halibut 2250 3 750 500 2 250 1 0 0 250 1985 1990 1995 2000 20 1985 1990 1995 2000

Arrowtooth flounder Variable Connections Variables Jan Feb Mar Apr May • March-May EP-NP PDO Neg NP • Spring ALONG AO Neg EP-NP Pos MEI ELH Strategies R2(adj) 0.01 0.31 0.23 0.69 0.34 • Winter spawning - deep SST ALONG Pos • Mesopelagic eggs MIXING Neg FRESH Neg • Cross & along-shelf FLOWKL8 larval drift RI 20 15 flounder 15 10 10 5 5 0 0 70 1985 1990 1995 2000 1985 1990 1995 2000 60 Pacific cod 150 Flathead sole 50 120 40 90 30 60 ) 20

2 10 30 0 0 1985 1990 1995 2000 1985 1990 1995 2000 5 2500 Walleye Pollock 4 Pacific halibut 2250 3 750 500 2 250 1 0 0 250 1985 1990 1995 2000 20 1985 1990 1995 2000

Walleye pollock Variable Connections Variables Jan Feb Mar Apr May • Spring EP-NP PDO NP • Mar-AprALONG AO Neg • Winter SST EP-NP Pos Pos MEI ELH Strategies R2(adj) 0.07 0.50 0.02 0.50 0.40 SST Neg • Winter-spring spawning ALONG MIXING • Along-shelf larval drift FRESH • Larval size & duration sim. FLOWKL8 RI Winter temp control? Spring 20 15 flounder 15 10 10 5 5 0 0 70 1985 1990 1995 2000 1985 1990 1995 2000 60 Pacific cod 150 Flathead sole 50 120 40 90 30 60 ) 20

2 10 30 0 0 1985 1990 1995 2000 1985 1990 1995 2000 5 2500 Walleye Pollock 4 Pacific halibut 2250 3 750 500 2 250 1 0 0 250 1985 1990 1995 2000 20 1985 1990 1995 2000

200 Rockfish 15 Southern rock sole 150 10 100 5 50 0 0 1985 1990 1995 2000 1985 1990 1995 2000 400 25 Mean abundance (no./10 m Mean abundance Ronquils 20 Northern rock sole 300 15 200 10 100 5 0 0 1985 1990 1995 2000 1985 1990 1995 2000 30 60 Pacific sandlance 25 Starry flounder 20 40 15 10 20 5 Rockfish Starry flounder Variables Jan Feb Mar Apr May Variables Jan Feb Mar Apr May PDO PDO NP Pos NP AO AO EP-NP EP-NP MEI MEI 2 R2(adj) 0.22 0.05 0.03 0.00 0.53 R (adj) 0.07 0.04 0.27 -0.01 0.04 SST Pos Pos Pos SST ALONG ALONG MIXING MIXING FRESH FRESH Pos FLOWKL8 FLOWKL8 RI RI 2 R2(adj) 0.44 0.38 0.62 0.37 0.50 R (adj) 0.18 0.45 0.03 0.05 0.33 Variable Connections Southern rock sole Variables Jan Feb Mar Apr May • Mar or May EP-NP PDO • May ALONG NP • Mar-Apr SST (RF & SRS only) AO EP-NP MEI ELH Strategies R2(adj) 0.02 -0.03 0.26 0.02 0.09 • RF & SRS late spring-summer SST Pos ALONG spawning (SST+ link) MIXING • Cross-shelf (RF) & along-shelf FRESH Pos Pos (all) larval drift FLOWKL8 Pos RI S i L l T t V i bilit Total Significant Contributions of combined Variables by Months to all Species Best-Fit GAMs

bles 35 a Basin-scale Variables 30

vari Local-scale variables 25 20 15 n combined 10 5 0 Contributio

% Jan Feb Mar Apr May Total Significant Contributions of Variables by Months to 12 Species Best-Fit GAMs

% Contribution Variables Jan Feb Mar Apr May Months combined Ba sin-sca le EP-NP 20447 28.33 AO 23151 20.00 NP 12332 18.33 PDO 24121 16.67 MEI 11010 5.00 % Contribution 13.33 16.67 15.00 25.00 18.34 17.67 Total variables Local-scale ALONG 11464 26.67 FRESH 54511 26.67 SST 13353 25.00 FLOWKL8 no data no data 1 5 0 16.67 MIXING 21221 13.33 RI no data no data 1 2 1 11.11 % Contribution 18.75 18.75 22.22 29.17 13.89 20.83 Total variables overall level of significant contribution to all potential best-fit GAM models.

Variable % Contribution Larval Transport Dynamics EP-NP 28.33 Primarily Spring ALONG 26.67 } Main Source NE of Kodiak FRESH 26.67 Winter “flushing” of larvae SST 25.00 Spawning, larval hatch, AO 20.00 larval growth / survival NP 18.33 PDO 16.67 FLOWKL8 16.67 Shelikof transport and MIXING 13.33 retention less important RI 11.11 to prevalence of larvae in study area late May MEI 5.00 Primacy of “Upstream” Dynamics (Spring) Atmospheric Circulation, Wind Driven Transport, Alaska Stream v Alaska Coastal Current, g combined Variables by Species to all monthly Best-Fit GAMs

40 Basin-scale Variables Local-scale variables 30

% contribution combined variables % contribution t u e e k le od ils ol ol c sh o c u lib s lo c q ance s s fi n d k k ndl ha a ounder pol ounder Ro a roc e Rockfi oc fl aci ific y y P s athe rn rn r ic oth fl e lle Fl to cif Pac rthern lampfish h Starr w rt Wa uthe Pa o o No rro N S A

Gradient of vulnerability of ELH patterns to • Observed patterns of interannual trends in larval abundance – unique to spp. but some commonality • Emmergent species-specific associations between larval abundance and physical variables reflect details of ELH patterns • Species with similar ELH strategies show similar interannual trends in larval abundance that yielded common “connections” with basin- scale and local-scale physical variables • Basin-scale Atmospheric Circulation (EP-NP) and local winds (ALONG) in spring seem to impart the strongest influence on the prevalence of various larval fish species in the favorable productive coastal waters of Shelikof Strait in late May. FRESH and SST ranked highly. Proposed Physical Mechanisms: Winter Transport strongly influenced by River Discharge Spring Larval Transport Dynamics “Upstream” of Shelikof Fisheries-Climate Interactions

This type of ichthyoplankton time-series study shows good potential for identifying levels of resilience or vulnerability of individual species early life history patterns to fluctuating oceanographic conditions Insight into Climate-Mediated Control of ACKNOWLEDGEMENTSACKNOWLEDGEMENTS

NOAANOAA AlaskaAlaska FisheriesFisheries ScienceScience CenterCenter RECRUITMENTRECRUITMENT PROCESSESPROCESSES GROUP:GROUP:

IchthyoplanktonIchthyoplankton Collections,Collections, Taxonomy,Taxonomy, EarlyEarly LifeLife HistoryHistory Information,Information, IchthyoplanktonIchthyoplankton DatabaseDatabase development.development.

NickNick BondBond –– JISAOJISAO (UW,(UW, NOAA/PMEL):NOAA/PMEL): AdviceAdvice onon choicechoice ofof ClimateClimate IndicesIndices andand InformativeInformative discussionsdiscussions onon ClimateClimate ForcingForcing inin GulfGulf ofof AlaskaAlaska