Former Mitigates Native Habitat Loss for Endemic Reef Fishes

This article is protected by copyright. All rights reserved. This article isprotected rights by All copyright. reserved. 10.1002/eap.1956doi: lead differences to version between this andthe ofPleasecite article Version Record. this as been and throughtypesetting, proofreadingwhich may thecopyediting, process, pagination AcceptedThis article undergone has for and buthas accepted been not review publication fullpeer experiment andbyrecording willingness of severalendemicfishes reefonurchin kelp non grazing drive have under environments Animals ABSTRACT * Corr Article School Australia ofBioSciences, University Melbourne, Parkville, Victoria of 3010, Luke Dempster Tim T Barrett*, habitat-form A non-native Articletype : Articles STEPHENPROF. E. SWEARER (Orcid ID 0000-0001-6381-9943): LUKEDR. BARRETTT (Orcid ID 0000-0002-2820-0421): -

native canopy - esponding author: [email protected] espondingauthor:

or over

that seaweeds (wakame select , but

- fish util ize

n a n ecological change to util

the

that that d bynative global Undaria pinnatifida Undaria best ava best ize provid

er native vs. decline in natural mitigates native habitat loss for endemic for loss mitigatesreef fishes nativehabitat ilable habitat

e a fauna

nd novel macrophyte habitatnovel macrophyte Stephen E Swearer Stephen ESwearer recruitment to - can createcan grazed insouthern Australia. reefs . wakame

native In temperate coastale waters, ) functions as aviableecological habitat or trap s

are seaweed

kelp kelp evolutionarily unfamiliar habitats

most likely most specially canopy s

and .

via a facilitatedestablishment of the

construct to e

succeed tested whether laboratory habitat choicelaboratoryhabitat utrophication and utrophication ed boulder

in degraded We We assessed a

reef non that may be - s

native native the with f or This article is protected by copyright. All rights reserved. This article isprotected rights by All copyright. reserved. Accepted causing (evolutionary maladaptive decisions make trap: to individuals Robertson history can inalteredenvironments a create outcomes, mismatch between and cues fitness impacted landscapes (Sih andmakein response resources abletopersist tonovel be adaptive in risks will best decisions partially individuals respond altered to dependent that onhow Animals ordegraded habitats. shifts Ecosystems anthropogenic are dramatic undergoing INTRODUCTION ecology; Key persist. benefit from non Articlenon this viable habitatendemic for fis adjacent Fitness metrics infishfrom collected occurred inhigher abundanceand diversity canopy but vs. habitat for before manipulated wakame - degraded - native ofenvironmental habitatsthecontext within change,as fauna endemic may words -

after

native kelpnative kelp canopy;kelp

resident fish, resident

: tobarrenpreferred habitats. both reef - kelp kelp control kelp ecological trap; fitness; habitat fitness; ecological trap; ecosystem - canopy nat canopy -

impact survey impact patches ive habitat ive

rchin barrens;rchin w . compared . . We also. We compared

More broadly, w Endemic fishesdistinguish didnot between et al. .

h and may These findings - 2011 formers in areas where inareasnativeformers cannot counterparts their

fitness of wakame patches ,

Wong and Candolin, 2014), but a lack of evolutionary buta 2014), lack Wong and Candolin, wakame akame play a in role play metrics formetrics e recommend that managerse theroleconsider recommend of where selection indicate thatindicate

fish

patches

On urchin communities seasonal ; fish sustaining

, and to habitat were

the collected from worldwide, withimpactsfauna on wakame canopy was present wakame canopy - comparable grazed non quality assess the quality of wakameassess thequality of

on natural reefs native fauna populations native fauna - native natural natural ;

the HIREC; HIREC;

to those infishfrom to canopy habitats with with habitats native or native reefs,

invasion using using

provides provides fish et wakame

al. a native 2013). .

a in

This article is protected by copyright. All rights reserved. This article isprotected rights by All copyright. reserved. animal invaded in populations ecosystems Accepted(Schaffelke et and2007,Davidson al.2015), Hewitt established Americas in Europe, the Wakame on behavioralby fauna native responses habitat. tothe novel state ofthe ecosystem priortoinvasion,the qualitynativeof habitatfor fauna, thenovel and Dijkstra etbiodiversity onaincluding on al.2017). range Effects conditions, the depend of evidence and(Gribben Pyšekal.animals Wright 2012, particularlyfor isequivocal, et 2006, assumedspeciesreduce thatnon-nativewill biodiversity but the body areas, ininvaded of formers anthropogenic lead habitat-forming stressors native species, todeclines in 2002,Gribbenand Wright shelter animals(Crooks and et 2006,Pyšek for al.2012). by andwith nativehabitat-formers spaceby changing competingavailability for offood the novel andalgae,createNon-native including plants species, habitat-forming can ArticleSievers et al.2018). whereanthropogenic created have novel impacts ecological conditions considered conceptual framework. theecologicaltrap within but 2015). habitats orfail totake advantageunfamiliar of animals attractiveinto either are drawnfrom populationsinks surroundinghigher quality canindividual-level responses trap quality butunattractive habitats high In decisions, maycase this result underutilizing ofhabitat inindividuals the selection maybe : Robertsonand These may take advantagemaytake vacantn of Undaria pinnatifida detected detected processes aredifficultresolve to processes

Hutto 2006, Hutto when measureswhen are preferenceand ofhabitat fitnessoutcomes

is ais habitat-formingkelp to native exacerbate population-level effects of environmental changeexacerbate effects population-level of or selecting (ecological lowquality butattractive habitats

Pattenand and Oceania. and Oceania. iches iches (Raffoet al.2009,2014,Thomsen et al.2009,

Kelly 2010, Kelly (MacDougall 2005). and Turkington using typical habitat assessment approaches assessment habitat typicalusing habitats in degraded in habitats landscapes Despite highaserial its as profile invader very little is known about its impacts on its very isknownabout little

Hale and

This is particularly importantThis is East Asia

Swearer 2016). Such 2016). Swearer (Hale et al.2015, non that has now that -native (Hale et al. ecosystems It often is Where habitat- if This article is protected by copyright. All rights reserved. This article isprotected rights by All copyright. reserved. Acceptedurchinleading barrens tolargeareas of habitats theBay in embayment The studyplace5 at took Study METHODS can ofthe employedassessments be in non responses toestablished nativeand (Q3) assemblages? grazed reefsfish modify non role outcomes. Articleshelter providednative by the fishnon utilize Seasonal 2016). 2003, and and BurridgeandEdgar Johnson Thomsen 1998, Valentine et al.2004,South takes advantage ofbare substrate communities Appendix perennial native such as kelps occurs Irigoyen et 2012). al.2011,Howland -native kelp habitat? -native(Q2) kelp habitat? of the non system on

wakame growthmay wakame

artificial artificial S1 W non in south-eastern Australia (location descriptions: Appendix Appendix (location Australiain south-eastern descriptions:

: Fig.Wakame S1). e (Valentine and Johnson 2003,Edgar(ValentineandLeij et Johnson al.2004,de 2017), et al.

-native -native -native kelp habitat -native kelp employ the ecological trap conceptual frameworkemploy ecologicalconceptual trap the have been degraded by poor water quality been water quality degraded poor have by substrates and degraded reefs where urchin grazing has grazingwherehas reefs andurchin degradedsubstrates canopy for endemic reef fishes: canopy endemicfishes: reef for locations in Port Phillip locationsin Port aBay 1930km 1), (Fig. -nativeecologicalconcept and how trapdemonstrate species the Does seasonal growth ofnon-nativegrowth kelp onurchin- canopy Does seasonal Ecklonia radiata Ecklonia mitigate

is and s?

a weak competitor in undisturbed macroalgal a weakcompetitor In

In is better able topersist ondegradedable betterreefs is effects non-native of

addressing theseaddressing and

declines in fish biodiversitydeclines in south-eastern south-eastern microalgal turf microalgal Are measuresArefitness of -native -native (Kriegisch et al.2016, kelp Australia, seasonal wakamecanopyAustralia, seasonal (Q1) questions, wequestions, and experience good fitnessand experience (Kriegisch et al. 2016, 2019, (Kriegisch et al. Are native fish willing touse the Are native habitat-formers onnative habitat-formers fauna. and to test 3 3 testto

overabundant urchins, urchins, overabundant on comparable between

inform managementinform Carnell etCarnell al.2019, urchin-grazedreefs S1, S1, Section S1). questions about the questions 2

driven marine (Campbell

a but quickly decline in decline Reef

This article is protected by copyright. All rights reserved. This article isprotected rights by All copyright. reserved. to replicatefish the experiment tank for each replicate fish. macroalga linearifolium and offered a simultaneous choicebetween 4 collection Nov 2014 Baynorthern PortPhillip dominated by associated fishes in ( common weedfish ( To Question winter-spring in the northern half. was Ecklonia radiata Carnell and Keough 2019). Odacidae: - chambered

Acceptedpermit assessment of Article investigatewhether 3 introduc

macroalgal habitat cuesmacroalgal habitat ( Habitat choiceHabitat experiment . Nofish were , housed inrecirculatingaquaria shelters, withartificial 1: — Neoodax balteatus ed measured bywater displacement measured Are willing tousethe non nativefish .

cross attached and completelyand senescing We heldWe a fishin transparent , with

in the 1980s in the 1980s

have declining been - shaped tank( shaped Clinidae: the Wakame Wakame macroalga

via a tie cable native reef fishnative

region habitat habitat taken

Native perennial canopy-forming macrophytes such macrophytesasNative the perennial canopy-forming At least and now occurs on reefsthe throughoutB Heteroclinus perspicillatus Heteroclinus . region, this annual form is awinterin

). from wakame patches. from patches. wakame similar Fish were collectedFish from numerous wererocky reef patches cu

specimens, specimens, Theseamong are species common themost McDermott andMcDermott 2006 Shima es

prior to the commencement Theprior of cylinder tothe thetrial. was on theholdfast ly whilewakame(Carnell and for 2019), Keough decades prefer native specim 1 - E. radiata in

sized sized reference (bare urchin rock, an barren) simulating

summer. summer. plastic rocks androcks chambers — ens rock and randomand

of each cylinder inthethe tank centre for of 5min or mixed nativeor macroalgal mixed cover s - ). We providedvolumes equalofeach

o native kelp habitat?native kelp wit ver We placedWe indiv h ) and

non wakame macroalga ize - ;

native 23 Appendix d their positions within the within d their positions random

little weedlittle whiting and , E. radiata ing dense stands during stands ing dense

kelp were used were used iduals inthecentreaiduals of ay ize

, , S1: Fig. S2 with high

we coll

d between within 2weekswithin of seaweed

throughout Sargassum ected densities

) - in Aug

and in k 48 elp - This article is protected by copyright. All rights reserved. This article isprotected rights by All copyright. reserved. at each date. survey recruitment interms of quantified theabundance was and end of the during Wakame isless robustthan canopy onnatural cover reefs 2015). 2015 and recordedrecruitment natural offishes on other local collected from canopy, grid and pattern, randomlyeach reefassigned to 2014, we 1 constructed To complement thelaboratorychoiceexperim be based a decision onmultiple to fish througha holeina small screen. then ra )

be a primarily Accepted Articlewas

i Both at kelpswere stocked equal Oct selected Recruitment to to Recruitment s n = e d by a string constructed 20 replicaconstructed 20 recruitment study - reef fishesreef willingly recruit to Nov boulder 7 with an reef adjacent , and despite these efforts, , and despite the for vision E. radiata

T reefs withmanipulated kelpreefs canopy his metricislikely by influenced both - and large expanse - boulder based decisionbased - pulleyresearcher able theoutof systemwith but toview sight the E. radiata

canopy at locations ourstudy 2

and attached te reefs (1te m reefs cues

vs.

7 . Nofish

of at sandy substrate asuitable depth W 3 and

and , %) e choice recordedboththe initial thefish of and the location mins and of thefish the 20 after densities habitats

n = . wakame coverage lower was than

requir As reefs were fishAs reefs initially devoid of 2 using ) onsandy20 mapart arrayedina 4x5 substrate, chose toremainchose inthe cent 6 as 6 ent, w 1 ed

of this size. of size. this

(75 % coverage) unstocked control of rope andrope ties cable 3

regular replenishment duringgrowing wakame peak season e

occasions throughout ( spring 3 tracked recruitment to tracked recruitment to

treatments ( .

The The

diversity of fish presentdiversity of onthe reef habitat selection Half MoonBayHalf We stockedWe kelp n = 7 n approximating s . ) using kelp Clinids and Clinids

re with

as as

(6 m) of the tank

specially E. radiata t and halli wakame location in Jul , . , expected to

relative During survival specimens kelp Se several senesced , expected - p - Aug .

(

Nov Fig. by Sep . .

the

This article is protected by copyright. All rights reserved. This article isprotected rights by All copyright. reserved. randomly between habitat calm(<15 weather knots) conditions were not southern survey also includeddeploymentsreefrelatively at a pristine to investigate surveys,complement CPUE theUVCa remote and baited underwater (BRUV) survey video beds relevant directly outcompeting co currently E. radiata urchin barrens We patches onurchin fish s seasonalwithout abundance To test whether assemblages?modify fish Question

Accepted- Article occur primarilya in comparisonfish populations focused on of

using pecies

. in ourview

Port Phillip Bay Port Phillip

on rocky the only All

habitats in a in the field, w .

Five Five Does seasonal growth of non growth Does seasonal diver diver survey and collection and survey habitat

rather than rather than habitat conditions preferences inexperimental correspondto patterns wakame -

s location wherelocation grazed reefs catch reef urvey .

- Nonetheless use patterns fishes. inlarger,mobile more use the

native kelps native ,

and

per locations e

Bayfor the potential limited

where

canopy E. radiata types compared

(b) unit

( this invaderthis

Fig. 1

to avoid temporal bias to avoidtemporal dense effort , , w urchin barrens,urchin

, using using were selected

efforts were made making the comparison to makingcomparison to the

e did compare fish populations in fishe populations didcompare

habitat between 1000 fish communities onurchin fish communities )

. E. radiata metric

underwater visual census (UVC) visualunderwater census -

native kelp canopy on urchin on canopy native kelp fill because

(CPUE) s

vacant habitat based onthepresencebased of

wakame was urchin presentbut wakame barrens and - 1600 hours

( a

spatial by . at )

the small size and size rarity ofremainingthe small

the the

patches and

Williamstown same location location replication wakame

barrenmorereefs on degraded reefson degraded .

For com E - grazed reefs fforts fforts researcher

(Governor Reef) habitat habitat wakame dense were , with Williamstown , withWilliamstown parison, t parison,

to target benthic to dense dense -

location grazed reefs

E. radiata

alternated

(L relative to with and

and B) wakame ecologically

rather than he BRUV

under under E. ra , and to of

in beds

fish diata

This article is protected by copyright. All rights reserved. This article isprotected rights by All copyright. reserved. Acceptedwas ofthe driventofacilitate thecentre plot into and algal turf completing wecensus, thefish in situ H.eckloniae,adelaidae, H.wilsoni, macrophthalmus H. distinct observed searchingstructure thereef within and by a diver initiall weight to influencedcharacteristics scale atthis by habitat with Articleby late summer season’ the following was dense most atits surveying close proximity (25 wakameand across 26barren) rugosity Replicate circular 10 , sowere a treatedsingle as y .

Underwater -

herein

by 100 mseparating pl Several ofthe members and multiple times multiple mark plots with and without seasonalwithout and with plots moving in swimming aswimming circular path theplot outside depth

acrossentire the plot autumn ) . .

the middle of middle theplot the

( Mature We We Fig. 1 plots

but differing

visual censusvisual haphazardly

concentric circular during winter after ).

of wakame within theplot, within We employedWe a 12.

the cano ots 6

. visually m Populations ofsmall benthicPopulations and crypticfishes are strongly in the

Heteroclinus undergo a complete aundergo 2 placed

taxonomic unit unit taxonomic

. (2 mradius) 5 - py had Following the initial initial Following the spring

locations

and surveyed l and surveyed

presence among estimated percentcoverage of they were counted as plots path bef

wakame (Jun senesced ore s

on algal coveralgal genus ( that offered from the outerfrom edgecentre ofthe tothe

- - were esta or absenceor Oct after

(Willis and Anderson(Willis 2003) the the wakame forstudy component this ofthe

canopy

2016 arge over summer off . S - senescence H. perspicillatus, H.heptaeolus, H. control mall orcryptic were species - ) ar season repeatseason r winter surveys, blished blished : .

benthic and ‘ wakame and habitats barren I . This was done . Thiswas of of peak f fish of thes f e difficult toreliablye distinguish difficult - impact wakame a singlefish barren - , withnoholdfasts remaining on reefs season’

and benthopelagic (Apr

(BACI) patches

. kelp, kelp, survey

- We surveyed We 51plots May 2017

ame speciesame a short metal stake a

herein with

unless when thecanopy all

. design at each location,

We droppedWe a comparable macroalgae ) and . clearly : Upon

‘off

detected

by then fish were plot

- in

in ,

This article is protected by copyright. All rights reserved. This article isprotected rights by All copyright. reserved. a simultaneouslynumber given ofindividuals species of inthe videofield occurring of view fish,individual we used where a maxN, conservative isthe maximum metric maxN termed abundance ateach ofeach species from20 min when the time theBRUV onthesea relativeassess settled floor. unit To m apart2 at oncomparablesubstrate depthsof reef reef patches inthe thesystems,are spread minimise the bait we used plume but as inBRUV often of wished to 20cmand plastica meshbag placed 20x attachedLarger tothe inend arm. of thebait baits bait armconduit.Two PVC pilchards made 20mm from ( consisted of acamera GoProHero3+ weighted mountedwitha1mlong onplastic crate unit deploymentsat the during with the same were 5locations made UVC visited surveys, The BRUV during conducted peak was survey days =CPUE per Sarga growing onurchin quantification of wa Collection efforts

Accepted Articlekame

species

dro between ssum Baited remote underwater remote Baited video Catch pped

habitat patcheshabitat N fish collected

spp basis onto

24 per .

Collections wereonSCUBA by hand made net , CPUE. CPUE. Oct

with for unit either - B grazed reefsgrazed well between ay are oftenay (10 small very

and and N. balteatus N.

each effort

at Williamstown wakame orurchin = patches14) = (n barrens15). (n locationThe Williamstown containedseasonal a mosaic of / dive 28

collection dive

Nov

duration

2016. , deployment deployment H. perspicillatus

Collection ( Q

treated as asingletreated uestions - defined remnant patches of - while preventi - season only season 100 m). 100 -

4.5 m.Fishwere observations for made and dives

1 and 3) H. heptaeolus D Sardinops sagax Sardinops

alternated between habitatsalternated between eployments w , during Aug ng potential double countingng potentialdouble of were statistical . We calculatedWe timed timed

in - replicate ere made atere least 50 Sep 2016 E. radiata to allow E. radiata E. ) werecut hal) in The CPUE CPUE

where

camera . BRUV

wakame and and

over camera on a

unit unit f 9

This article is protected by copyright. All rights reserved. This article isprotected rights by All copyright. reserved. 4.7 sta perspicillatus I the weight W/W quantified usingrelative the and weightsex ofthe hours of collection, killed coverage of defined E. radiata heptaeolus H comparedWe metrics in body condition habitats? Question Sepioteuthis australis rank (usually possible Family or could beindividual not identified tospecies we level, identifiedtothe lowest it taxonomic counts forsummed themaxN males, ofthat andWhere females species. juveniles an and BabcockIn(Willis thecase 2000). ofsex ndividuals with ndividuals with Accepted . Article perspicillatus exp using clove oil ndard deviations th above

Fish collected natuFish from , where isthe W measured by the dominant kelp speciesby thedominant

3: - habitats

at ( wakame: n = 9; wakame: n= macroalgal speciesmacroalgal estimated visually Are comparablemeasures fitness non of between nativeand -

length individual

K ( wakame: n=11;

rel during Oct wet weightandwet measured totaland length was fish

power

values >1 are heavier than values

before being stomach contents, stomach in the analysis asisfunctionally it fishes. tocarnivorous similar

from

curve fitt E. radiata condition - wakame Nov 2016 e mean) ral reefs Genus). We includedGenus). thesouthern squid calamari placed in sealed plastic bagsan placed insealed in gutted E. radiata ed to

within : n=9 metr

habitat removed was from

. liver . N.

Liver gonad and weight andW weight The habitat occupied was byThe each individual habitat all samples available

ic recommended by balteatus

2 )

ually fishes,dimorphic speciesor we juvenile : n=13 and

collected m ofthecollection average gonad . Fish were c

) (

wakame: and Ogilby'sweedfish

exp s at Williams for .

Overall body condition was Overall bodycondition condition is the

their length ollected usingollected and handnets

(Le 1951) Cren ( n = Appendix gutted

site the

town 22; were

ice slurry , with K dissected todetermine dissected . E. radiata rel predictedby weight

One One

from

quantified usingquantified analysis

S1: Fig.S1: S3 percentage - H. native kelp native kelp H . Within 24 . Within wakame : K eteroclinus : n=23 rel (145 mm

) .

and ) ,

;

This article is protected by copyright. All rights reserved. This article isprotected rights by All copyright. reserved. package for R treatmentsgeneral using Poisson Boulder across the implemented inR Laboratoryc Statistical analys (unstocked)forcomparisonscondition reefs meaningful of radiata identical tho to reefs macrophyte they recruit (n = 20 metrics Q collectedWe Heteroclinus counted =wet gutted organ andGW weight weight). hepatosomatic

Accepted Article1 from , with a ,

Fish collected Fish from fish between stocking

subsamples of reef reef Jan 4 ed to,as

- from 8reefs habitat cues.habitat - dependent reeffish traversedependent to ≥ hoice data much recruit Nov spp.) H. perspicillatus (Bates et al. 2015) et(Bates al. se onnatural reefs,with and gonadosomaticand indices fish from reefsfish from with stocked treatments

i 2015

(R Core Team 2018) s to assess fecundity to assess greater distance tothe nearest reef natural

feeding forays beyond the ‘home’ reeffeeding ‘home’ forayswouldsmall beyond require the a abundance andabundancerichness data species ( ova ( for a for ) Q

1 Individuals

. ) (

boulder

for

There were notenough were tested for habitat preferencewere habitat tested for a using comparison ofcomparison

recruits b ize . We included. We roadcast spawning d linear mixed effectsd linear mixed modelsimplemented inthe lme4

reefs

. were

from , with expected (null) proportions, equally distributed collection effortscollection

respectively where orGSIOW/GW, = (HSI =OW assumed body condition andreproductivebody investment the same the same Forgravid 20 m wakame T reatment ( of sand habitat N. balteatus N. H. perspicillatus

to beresident the to

boulder (n = 11 females, we alternating Q

stocked species kelp on reefs kelp without with and 1) were compared1) kelp across were s

. reefs fish

Collection methodswere )

to or

from 7reefs

constructed for

photographed between between n embryos

eighbouring boulder eighbouring boulder recruits oncontrol X 2

boulder boulder test ofproportions

wakame ( for ) :

or or wakame reef that livebearing and

E. radiata our test of our test

and , . E.

This article is protected by copyright. All rights reserved. This article isprotected rights by All copyright. reserved. usingof canonical principal analysis coordinates ( the associated stronglywiththe observed most differences locations between habitats using and extra ofsquares,rawsums ofand data unrestricted 9999permutations. with permutation 3 model also contained Williamstown, Half MoonBay)and environmental between differences term off dissimilarity between Bray log(x+1) transformed to peak PERMANOVA multivariate Fish community data comparisons ofthe the Treatment term, testedWe for aTreatment withandwithout significant comparingfit ofmodels effect the by random term toavoidpredictiveability overestimating the ofmodel terms Treatment.within was somesowe overdispersion, There included an observation and as repeatedly, reefs werereef identity arandom surveyed radiata - way interactionterm for

Accepted- Article similarity(SIMPER) percentage season season

- - cted diversityusing metrics ( season UVC; off season Curtis similarity resemblanceCurtis matrix Habitat

o r barren) model ANOVA × Location + add s

as a fixed term,fixed as a contained contained 3 while t

- treatments

from UVCandfrom BRUV surveys a samples on - (PERMANOVA) season UVC; season binary binary ) . reduce

(Andersonet al. Th Habitat×Location×Season he R lsmeansfor package e Locatione factor contained 2

factor for Season with complete absences fixed factors,Location,fixed and aninteraction Habitat well as as

the influence of athe influencehighlyabundant few of species

(Lenth 2016) the KelpCover locations locations

function. Finally,function. west ( Diversity combined

model 2008)

Kirk P wit in the

. h (

s function and function

percentage UVC; peak UVC;

. a implemented in implemented (peak Four Four oin dummy variable CAP north (Point Cook, AltonaBay, Cook, north (Point

t) . ( provided

- Q

The model PERMANOVA significant patterns

of theBay. ) plots. (Clarke et al. 2006) (Clarke et or off 2 2 )

coverage ofcanopy levels were - season BRUV. season identified - season)

intercept

Tuke fitted

PRIMER ( s North

The combined The combined of 1 w y’s ere , with a corresponding , with

with species thatwere

models werefitted: models to allow definition of to allow term

pairwise pairwise fitted using Type IIIfitted using Type and and

were 6 withthe . (Harrison 2014) permutational Data were

The

West (ReefID) ) as )

and fitted toa

visual peak post season ) - a covariate , level

We alsoWe reflecting - -

ize

hoc nested and d UVC .

, This article is protected by copyright. All rights reserved. This article isprotected rights by All copyright. reserved. th ( mins than weedfiCommon 1:Are willingQuestion tousethe non nativefish RESULTS ggplot2 package R for A and therelevantmodels with without term. asTreatment, fixed Sex terms and andTreatment/ReefID KelpCover a asrandom kelp treatments metrics for the sequentially hermaphr type (‘ ( a univariate comparedWe f R across Catch per uniteffort H. perspicillatus nd equality of variance andnd equality transformed ofvarianceas necessary. ) ose that chose full Accepted Article with

bar

In all cases, thesignificance we tested of 1.22 list ofmodels list Habitat E. radiata Habitat choiceHabitat experiment ren h abitat as a factorand fixed linear models ×

H. perspicillatus rock, bothinitial

more thanexpected; ’ ) itness metrics , using univariate linear mixed modelsusing mixed linear univariate

macroalgae during their decision initial sh species (‘Species’),

and and H

is providedin data weredata toimprove normality log(x+1)transformed eteroclinus wakame

H. heptaeolus H. (Wickham 2009) (Wickham

implemented in od

itic itic ly recruits

(

Q habitats ( 1.25 N. balteatus N. 3

perspicillatus ) p <0.0001

in Appendix ) × sampling day of the season (‘Day’) oftheday season collected from collected from

native andnative with term. more than expected; thanexpected; more using ausing linear .

. a single model a single

; n=48 Response variableswere for checked normality

included

S d

1 the the were more likelytoselect a : non te te Table S1 effectcomparing ofinterestby fitof the as a ) ( - boulder - native kelp habitat?native kelp

native analysis ofcovariance analysis implemented inlme4 Fig. 2, only We We continuous variable , wakame

and . Habitat andDayterms.Habitat p <0.0001

analysed

Plots werePlots produced using kelp habitats reefs Appendix included terms forincluded kelp terms habitat , and

( was was Q sex sex 3) both ;

preferable to n

were S (‘Sex’)

= 48 1: Table S2 using using macroalga weedfish species

, and included . and

(lm function in compared ) and after20 . a of series compared

Models for intercept

Fitness E. l cover ).

the across across

This article is protected by copyright. All rights reserved. This article isprotected rights by All copyright. reserved. affectdid not amount ofcovermorespecies beimportant than may theproviding thecover canopy 73% E. radiata 1 recruited to A 0. preference p <0.0001 ( Little weed whiting ( were individuals 20 mins, the evenly across distributed radiata 1.16 Fig. 2, ). Therewas forrecruitment noevidence differentialbetweenreefs with stocked 4

Accepted 2.5 Article ; n=21 ; Table 1 × ×

Recruitment to to Recruitment higher abundancehigher cover cover Appendix S1: Table S1: S2 Appendix or

; n=23 Sargassum ( ) ( among p = 0.2 boulder

than expected than Fig. 2, ) species richness (p=species 0.36) covariate . P er area of canopy areaer of ) ( macroalga 1

) Fig. 2, Fig. N Appendix S1: Table S1: S2 Appendix reefs stocked reefs withkelprelativetothose , despite , despite

eoodax ( 2.0 boulder positively

( × p = 0.01 ; Appendix S1: Table S1: S2Appendix

p = 0.0004 and 2.7 l options

wakame balteatus ).

reefs

, recruitment predict ) ×

and

higher rates higher , either initially (p = 0.12

reefs reefs

; also preferred macroalgae bothinitially to barerock, n . 2.4

= 23

). × having recruit abundance( recruit

higher higher ) and after) and 20 mins(

was was , respectively; ). However, we noclear observed

lower lower 1.4× species richness 3

higher macroalgal options canopycover ; n = 20 ; n= p = 0.0 p = 0.015 on unstocked controlsunstocked

1.22 wakame reefswakame

( p = 0.007 ) or after 20mins(p=) or 5

× ) on averageon , indicatin

more more ; n

= 44 . (

p = Canopy cover than expected ) . ), butafter of reef fish 0.9 wakame The The g thatthe ( 42 ; ( Table n

vs.

= 45

or ) ; This article is protected by copyright. All rights reserved. This article isprotected rights by All copyright. reserved. wakame thallus were Gracilaria containalgal any speciesas other such brown ephemeral ± 3 contained 6 comparable depths wakame b observed dissimilarity between ( determined abundance revealed Habitat of survey recordedWe 19fish species assemblages?modify fish of non growth 2:DoesQuestion seasonal 23 arren plots)

Accepted ArticleHabitat ( %dominated by macroalgal cover, %) and generally s ×L Under

plots separation of ocation 5

macroalga Tasmanian blenn Tasmanian

of were wakame

that

± locations .

S H water 2 (

Fig. pecies richnesspecies foun % macroalgal mostly cover, lettuce sea ). eteroclinus eteroclinus weedfish present on present

interaction term

(

3 d in mean ± SD: ±SD: mean v or C e isual censusisual ( , inclu plots plots , Sep b Appendix wakame arren)

Heteroclinus -

spp. Oct wakame

with andwithout ies ding across , Location ,

(2.0×)

Parablennius tasmanianus

habitats 2016) and

2.6

microhabitat Ulva

S1: TableS1: S5 on 25

Diodon ± plots, clinids clinids plots,

and fish communities fish communities ( 0.5

wakame wakame Appendix S1:Appendix Table S3 spp. spp.

(

we (west or north (west or

total abundance m cf. 2. -

edfish

native kelp canopy on urchin on canopy native kelp and ( nicth 28%) wakame

E. radiata (

i.e. i.e. ) and 26 and ( . Gracilaria 58

Barren and emerus 7 Heteroclinus , Clarke’s in %) with some secondary from cover 12/16 fish

± wakame

0.4

(Fig. b Ulva P ( arren

Appendix S1: Table S1: Appendix S4

or ort in m

(1.9×) (

, respectively spp. Sargassum 10%) wakame

3 P spp. threefin wakame

found directlya underneath hillip hillip plots UVC )

spp. and

, andsignificant foundeffect a Wakame

driven primarily were both were W contributed most to most contributed ;

akame B plots threefins

plots Trinorfolkia clarkeiTrinorfolkia

ay plots

spp. Where ) Cristiceps australis Cristiceps

)

and and during . . plots did not did plots

Barren plots plots containedplots 72

- SIMPER analysis wereat placed grazed reefs higher

the and blenn ). peak CAP by a greaterby a on Ulva

- the s

eason eason

ies plots plots other

This article is protected by copyright. All rights reserved. This article isprotected rights by All copyright. reserved. = 0.26 throughout spring,coinciding withwarmerwa of CPUE (CPUE) (total 690min) Heteroclinus heptaeolus Collection efforts 45 provided 1. predicted by 12 Caulerpa abundant interaction ( Habitat, onfishLocation Season and Analysing Table S1: S5 Appendix abundancediffered significantly was present on present provided theHabitat cover. but aamount ofmacroalgal The negligible effectof factor senesced resurveyedWe (9 plots 18 5

Accepted% Article overall , p= 0.24). ) .

, We foundWe noevidence thatoff Diver p = 0.00

, with ( Heteroclinus non

‘ fish communitystructure peak off N. N. Appendix S1: Table S4 Appendix ( peak Appendix - c -

balteatus canopy atch per unit effort atch perunit season

- habitats over 9days greater 7 season ; - Table season covereither of season ’ - forming :

spp. did notdifferspp. did mean mean )

S Apr and off and was .

2 from 12dives 1: Table S

) . wakame - There was no evidence that CPUE ofThere was thatCPUE noevidence May 2017). early Sparse 2.6 cover

Neoodax balteatus - ephemeral macroalga season data revealedseason together ×

between habitats habitats between

higher in

age age , 9 4

). between 24 remained ,

- community as structure,as aHabitat well Off CAP: CAP: season macroalgalseason cover b

( (total 465 min) (total 465 arren) after thearren) after 51 ±12 wakame -

( season Table Table E. radiata Fig.

significant ter andter greater fish activity % Oct

3 2 wakame

, 24 , ) B (F ) during

on . )

16 CPUE CPUE . Neither . Neither and e -

, dominated by stage stage Heteroclinus perspicillatus

than wakame

= 0.5,p= 0. in wakame 28

off

but less wakame and

wakame of wakame Nov - season

significant significant fish N. balteatus N. barren

plots plots on resurveyed plots on resurveyed

canopy

2016 strongly Heteroclinus

spe and 13 dives in and 13dives 5

habitat ) or all macroalgae) or all (F surveys than recruits (<10 cm)recruits wer Ulva plots both contained both plots cies richness nor . Catch per uniteffort Catch had completelyhad

overall effectsoverall of

b , (

than when wakamethan also arren ( plots

Date covariate: Gracilaria (

p = 0.0 ( Fig.

× increased spp. increased Location

and 18 3 E. radiata

4 was D ) , ,

but and 32 ± 16

e R

= 2

This article is protected by copyright. All rights reserved. This article isprotected rights by All copyright. reserved. body condition or radiata W habitats althougheffect of thedirection for metrics reproductive was condition orreproductive fitness metrics differed between proportion and 2.4 N habitats? 3:Are comparableQuestion measures fitness non of between nativeand R TableS1: S6 Table S3 recordedWe 15barren across 28fish species and 14wakame ( deployments to balteatus individual season over time (p = 0.6 eoodax estricting toreef theanalysis e Accepted Articlezero. also in the ×

Fish collected naturalFish from reefs rem Baited

or ( found little ). Fish communities did notdiffer did ). Fish between communities

Table heavier balt (

Appendix wakame in were habiting ), and nor didspecies MaxN richness orcombined eatus northern pa 3 male

) (p = 0.01) (p . ;

reproductive investment betweenreproductive habitat types ote underwater video

individuals collectedindividuals from Table habitats

evidence that

a ( 1: Table S3 E. radiata E. macroalgal microhabitat rt of theBay 2 ).

than those inseasonal experience different In thecourse ofsurveying - associated : 7/23 ) H. perspicillatus . Accor , w ; wakame

e observed only

fish d ingly, E. radiata species did not alter didnot species our interpretation

ial on on : 1/22 CPUE wakame

habitat quality an or wakameand barrens habitats H. heptaeolus ) otherwise plot barren . 26 barren UVC plots 26 barren

W in the barren habitat were 1

E. radiata e found noevidence thatbody clinid habitat generally ( — Appendix

( , with

Table ( a Table

collected from H. perspicillatus

and s 1.3

positive in positive would likelywould be no difference insize, 3 × wakame ) 3

. However, . longer S1: TableS1: S7 ) — , Appendix S1: S1: Appendix

- during and native kelp native kelp and no a higher a higher ( wakame

(p = 0.007) habitats Appendix Appendix

E. peak s . N

the close ).

This article is protected by copyright. All rights reserved. This article isprotected rights by All copyright. reserved. thosecondition in to Acceptedindicate that native kelp patches and testing endemic fish inwinter species create anfor ecological trap native Overall DISCUSSION were unaffectedby k stocked with Hepatosomatic was index Article difference ofstomach inthe weight contents from frequentlymost prey items for identifiable and wakame Dietary 0.003 proportion offertil preferred barren bothto reefs E. radi N. balteatus N. ; kelp Table Q , Fish collected Fish from assessment

these results these and 1 , ata we found that fish foundwe that canopy

fish can can E. radiata 3 wakame ) ) , isopods .

increase increase inhabi

in ize

is lost revealed that revealed almost wakame elp canopy treatment adjacent

indicate that the presenceofthe d eggs canopy

t habitats

ing ( . wakame fish abundance and diversity on 2.0 Furthermore, body

these

boulder was was

× habitats althoughwas were notidentifiable, nosi there

native kelp versus versus - were equally to willing

spring while the canopyspring whilethe ispresent higher in .

Some Some 1.4 . non

only) For fish

× reefs E. radiata -

native higher inweedfish living Q2, ; rather it ; rather individuals

or all H. perspicillatus

beds

( N. balteatus N. decapods fish Table clinids

( kelp Table Table condition andreproductivecondition investment

(Q3).

community canopy may

3 patches ) had also consumedamphipods had consumed shrimp mysid . 3

( ) offer E. radiata non util .

( (p = 0.01) E. radiata ize

- have similar or body similar have better heavily urchin individuals collectedindividuals from reefs native

valuable data

shelter

in indicated that only)

habitat , w , on urchin E. radiata

only)

provided byprovided h hile ot abitat for at least .

Amphipods wereAmphipods the - . - former grazed reefs Animal p her fitness metrics - grazed reefs

habitats

non , both in , bothin

does not either

( - wakame native rey items gnificant metrics

( where

p = some kelp .

This article is protected by copyright. All rights reserved. This article isprotected rights by All copyright. reserved. morphologies supports aabundance similar and diversity ofepifauna tonative kelps Thresher 1991 throughout and thespawning into vitellogenesis period C fishes Wakame kelp species that the be a viable replacement functional Wakame and to larger predator accessiblethat is The functional macroal role of of benefits of 2012 native taxa structure Lloyd 2005, and Martin al. 2007 non populations Non ommon ommon be Accepted Articlehabitat degradation - - native , Wright etal. 2014 native preferred asby shelter macroalgae to the extent that to the extent had climate )

or asource novelor food or seaweed

a habitat is andin local increases biodiversity

habitat relatively minor minor relatively occupied in invaded landscapes

weakly E. radiata

(Howland 2012, Suárez (Howland is highly seasonal , -

- inaccessible spacemacroalgaefilamentous inaccessible 2019) (Wareet than al. Neira driven replacement of one dominant kelpspeciesreplacementdriven with dominant of one by - - associated reefassociated fishes such forming species

- prey but not predators butnot prey competitive avoided

( and on on leading it

, Ramus etal. 2017 , are Rodewald etal. 2010)

native coincides provisioning settlement. reproductive with and larval Sporcic 2002 broadly broadly effects on

(

leading to gaefishes for is to ,

biodiversity.

and

there poor fitness outcomes and fitness outcomes poor non

. if the non

Inan case,(201 analogous et al. Pessarrodona that replace native habitatsthat replace native similar in this regard inthis similar may - native - can becan Jiménez et Jiménez al. 20 some , -

this study) this associated fishesal. (e.g. 2018) et. O’Brien habitat loss influence thereproductiveof loca influence success

(Wareet al.2019) )

- . habitat

key ecosystemkey processes

ameliorative or The presentThe (Crooks 2002, Castilla et 2002,Castilla al.2004,Byers(Crooks et al. as ative habitat ofpoorative is quality, . predicted by the However, whereHowever, clinids and odacidsclinids . - : form Current that evidence wakame indicates Trammell and Butler1995, Valentine et ( 17) late winter , which may predispose wakamewhich may predispose to , ing species

study study . Our an ecological trap . beneficial effect

Tall, a branching kelps provide

can interstitial interstitial highlights data data the invader the invader

negatively to late spring to late

inhabit in mitigating theimpacts also . with comparablewith

a structurally indicate that adults

volume and area the potential wakame adds physical s : whether affect

Remeš 2003, for some : 9 Gunn , and )

l reef . - reported

fauna similar similar patches the tend and l

This article is protected by copyright. All rights reserved. This article isprotected rights by All copyright. reserved. Accepted2002) considerablechallenge. common anecdotalclinids ‘rafting’ of reports in fishlate stageadult juvenileand the potential temporal ecological trapclinid recruits for wakame adults, densities of summer at peak settlement occurri densitiesinthe water column inspring,with settlement preferences larval of assessingrole ofthe the The present focused study Articleand we expect but contain fewanyarefrom conspecifics if and adjacent urchin patches separated barrens by wakame that duringfalling vitellogenesis are a into condition 1969) reduced radiata residing food experiencecomparable availability habitat inwakame innative tothose value of thetime spent

w internal akame . , bywhich time Regardless large numbers

habitats, may this although therefore also population and reflect density lower

competition in wakamecompetition in patches (Gunn and1991,Neira 2002) and Thresher Sporcic . patches. This may reflect maypatches. This mate canopy

Q uantifying movem

wakame

f patches on ertilisation rates were lower

that . Such a l , it isunlikely, it that choose thatindividuals toreside in

this possible Allee possible this effect will

canopy, and wakame may

these these S non oss of ettlement

on juvenile and adult fish, but larval but on juvenileand adult fish, recruit these shortly to habitats b inhabiting the - native degraded are increasing reefs withsuccessive insize seasons ent and mortality of cryptobenthicent a andmortality fishes remains of

thalli have regressed tosporophyll havethalli and and regressed holdfasts cover Heteroclinus on ourand plots it is it

of habitat

likely that N. balteatus N. on unattached unattached - finding difficulty habitat in small that patches

( otherwise barrenotherwise non i.e., an ideal free distribution, Fretwellan free ideal distribution, i.e., in - former. H. perspicillatus

- spp. or native - if driven ecologicaldriven trap. ameliorate boulder

macroalgae peaks later insummer larvae We areWe of notaware

if it increasesif it mortality kelp Neoodax

have

reefs

However, the rapid appearancerapid However, the of reefs efore the summer efore thesummer

. This coincides with peak with . Thiscoincides over time.

and —

balteatus similar habitat preferences habitat similar to in summer

settlement alsoimportant in is warrant suggests that migrationsuggests that is H. heptaeolus

ng during spring , s We didfindevidenceWe wakame

research

but c investigation as a investigation as (Neira and Sporcic —

and outweighs together with die linid larvaelinid are

from and

- habitats on the on the off may

Lukas of E.

- no ,

This article is protected by copyright. All rights reserved. This article isprotected rights by All copyright. reserved. wakameand native kelp fish thannative food or(Zavaleta shelter drive additional biodiversity wherefauna depend loss native onthenon sufficient al. 2009), and restore(Reid thenatural islikely to ecosystemet furthermore, to Where a non presence of its reefsand recruitment stable Inabsence ofs the regionthis oflocal regardless nutrient 2016) ecological change I Management implications macrophyte (Ballal. 2014) et since declines the 1980s(Carnell andwithsimilar Keoughal. 2019)inseagrass et meadows native kelp habitat as adults longer attractive offer Accepted Articlecontrast many non n to winter - Instead,. state domin - also turf clears spring growing seasonspringgrowing and seagrass - wakame (Reeves et al. 2018).W (Reeves et associatedfishe - native specieshasfunctionallynative a replaced native may eradication not species, field manipulations indicate tha manipulations field E. radiata , , butr perhaps ated by sedimentated by (Valentine and Johnson 2003,Edgar and Johnson (Valentine Thomsen et and al.2004,South couring by and shading helps helps

habitat forhabitat recruits. emnant patchesemnant -

, making , it native ecosystem engineers,

habitats. mean terms, thatwakame, inabsolute

et al. through

canopy, trends therelativeabundanceand of current population recovery ofnative kelp

s and their 2001).

(Reeves etal. 2018)

Native kelp coverage in spillover from spillover from - akame a trapping

versatile versatile Although wakameAlthough probably su

or sedimentation or sedimentation are probably still are still probably preservation preservation

Such speciesthe likely disperse into native appears betterappears ableonheavily topersist algal turfalgal thatimpedes kelp subsequent functional replacementfunctional t u areas ofhighinremnant populationdensity kelp thalli rchin grazing drive , but it is unlikely is butit , tohinder it is wakame is . It. a key management levels (Kriegisch et al.levels 2016 (Kriegischet important sources population for remains the Bay the , reefs toa can shift may soon un

unclear whether

has by declined likely pports a lower densitypports of s

for kelp native native kelp decline - native habitatnative for to be aof driver to support alarger support priority non n alternate .

. the - - 59

grazed native , 2019

- during 98 % s

be This article is protected by copyright. All rights reserved. This article isprotected rights by All copyright. reserved. Manuel Juan ValeroO’Connor, Reeves, Rodriguez, Simon Jack Menzies, AkivaNina Gebler,Kevin Kevin Kriegisch, Valeriya Jensen, Komyakova, Seann thank We Dean BenMolly Chia, EmilyFobert, Fredle, Chamberlain, Cleveland, ACKNOWLEDGEMENTS evidence assessment frameworkguide canevidence provide that needed to al. 2017 to non likely toexacerbate declines in aforementioned control should achievinggood for outcomes recommend that are by heavilyrange anthropogenic impacted a stressors of Analogous environmentscases most in exist likely waters. ( protection of urchin urchin culls predators, case ofsouth address the regionin this of number of fish e.g.

Accepted Article established arou - native species management ) - , but nd remnant kelp patches) native nd based management underlying that - , potentially freeing, potentially totarget resources eastern Australia, this studythis isamongfirst the wakame not be a goal itselfandnot bea in only should be on reefs in on reefs in outcomes conservation agenciesconservation biotic and biotic populations populations , for example this embaymentthis approach ecosystem functionecosystem and biodiversity native kelp recovery abiotic stressors that abiotic stressors

( should notautomaticallyshould a management high priority be e.g. .

adopt evidence where a non Zavaleta et al.2001, Zavaleta , and tighter controls, andonnutrient inputs tighter

than and expansion ofurchinexpansion and fisheries . We are not the first to suggest such an areWe notthe firstsuggest to demonstrate nativ

(Schlaepfer et al.2011) - more native highlyand speciesis invasive e kelp will bewill /or - facilitate based

undertaken native biodiversity.

the ecological trap impactful

Kyler Tan, Chris Taylor and João and Tan,Taylor João Kyler Chris patches betterby served

Schlaepferal. et2011 strategies strategies , so

non an outcomes . mor

- when non W native species.native e e broadly, that that - suggest native specie native

it it , especially those aids focus on Non concept greater in strategic areas - focused

that the - to coastal

native we we , Ramuset

approach In the control control as an as s or and

This article is protected by copyright. All rights reserved. This article isprotected rights by All copyright. reserved. Carnell, E.,and P. Keough. M.J. 2019.Reconstructing reveals historical populations marine andCampbell, T.R.Burridge. S. 1998.OccurrenceJ., of ImpactsYeager,Byers, C. 2012. E.Gribben, E.,P. and abundant J. E.Sotka. of an Bates,B. 2015.Fitting Bolker,and D., Walker. M.Maechler, S. effects linear mixed models Ball, and Young. seagrass P. Historical D.,M.Soto-Berelov, mapping 2014.Phillip inPort Anderson, and Clarke. M.,R.Gorley, R. 2008.PERMANOVA+Guide PRIMER: to for CITED LITERATURE gave publication. final approval for LBdata; LB,declare. TD and SS VictorianAssessment Environmental Council. ResearchEndowment,was provided Wildlife bytheHolsworth fisheries and(RP919) u Byers(University ofGeorgia) Teixiera Accepted Article wasWork conducted2 anonymousseful inaccordance comments, as did reviewers. 49:379– Laminariales) Bay, Phillip inPort Victoria, Australia. Invasions 14:2587– introduced Biological the southeasternengineer ecosystemwithin mudflats of US coast. using ofStatisticalSoftware lme4. Journal 67:1– Bay, 18:257– ofCoastal Journal Conservation Australia. Limited. Software Methods. Primer-E and Statistical for assistance with fieldwork. for assistance with led the writingofmanuscript. the led the 381.

institutional animal ethics approvals animal ethics (1413193 institutional conceivedand 2600.

and Chris McKindsey (Fisheries and Oceans Canada) and(Fisheries Oceans Chris McKindsey Members of the Members SALTT and of REEF labs designed the study; LBstudy; analysed designed collected and the the All authors contributed criticallyAll authors andto the drafts

The authorscompeting have to interests no 48. 48. Undaria pinnatifida MarineFreshwater Research and 272. PADI and Foundation,

and1413133).

(Phaeophy (UoM), Jeb

Fund provided provided with ta : ing ing This article is protected by copyright. All rights reserved. This article isprotected rights by All copyright. reserved. AcceptedInvasive T.Wright.Gribben, P.E.,and2006. J. recruitment seaweedenhances ofa native Morton, and R. C. 2004.EffectsEdgar, A.J. Samson. N.S.Barrett, algal G. canopy J., of A.,L.Litterer, Dijkstra, K.Mello,Invasive and A. J. C. Wells, G. Harris, C. 2017. Ware. Davidson, A.D., A.2002.Characterizing J. Crooks, ecosystem-level consequences the invasions: ofbiological Articlegonadweight andseasonalLe length-weight relationship cycle in E.D. 1951.The Cren, Somerfield,Clarke, J. K. R., P. andM.G. Chapman. Lagos, C.,N.A. Castilla, Marine M.Cerda. and ecosystemJ. 2004.engineering alien by the coefficient for ofExperimentalMarine assemblages. denuded Journal Biology and ecological dissimilaritiesBray-Curtis includingtaxonomic and studies, a zero-adjusted Series 268:119– ascidian major declinea kelp of ecosystem42:765– forest Estuaries Australia. in and Coasts Ecology318:177– Series Progress bivalve: choice predation rolesfrom ofrefuge ofrecruits. and the habitat Marine ofExperimental Journal Marine BiologyEcology and312:67– oneasternclearance macroinvertebrate reefs.communities Tasmanian fishand onplant, ofEcologyJournal 105:1668– seaweeds habitat transform structurebiodiversity species. and ofassociated increase Marina 58:55– impacts ofnonindigenous marineupdate macroalgae: ofan currentBotanica knowledge. role ofecosystem engineers.Oikos 97:153–166. theperchcondition in ( Ecology 330:55 Pyura praeputialis M. L. Campbell, C. L. L. B. C. and Assessing Schaffelke.the M. Campbell, Hewitt, 2015. 79. 79. – 130. 130. 80. 80. Perca fluviatilis Perca

on a mid-intertidalrockyEcology Marine shore. Progress 1678. 185.

). Journal of AnimalEcology 20:201–

2006. Onresemblance measures for 87. 87. 219.

778.

This article is protected by copyright. All rights reserved. This article isprotected rights by All copyright. reserved. AcceptedLeij,2017. Thede influence ofnative Brown,Smale. R.,G.Epstein,P. M. A. and D. and S. Ling.Kriegisch,D. R.Johnson, N.,E.Reeves, C. S. and S. Ling.Kriegisch,D. R.Johnson, N.,E.Reeves, C. S. algaeIrigoyen, C.Eyras,and A.J., Alien A.M.Parma. 2011. andimpactsHowland,biodiversity S.2012.Variation on a assemblages: inkelpholdfast Article effects modeloverdispersion to Harrison, in Using observation-levelrandom X. A. 2014. E.Swearer. S. Hale, and consequences R.,E.A.Treml, 2015. Evaluating themetapopulation Hale, current 2016. and E.Swearer. Ecological R., traps: and S. directions. future evidence and E.Thresher. S., R. Gunn, J. Viviparityand thereproductiveclinid 1991. of ecology of ecological ProceedingsLondon traps. Royal ofthe Biological B: Society of Sciences Proceedings SocietyB: ofthe Royal Biological Sciences283:494– 31:323– fishes (Clinidae) from Environmental BiologyFishes temperate Australianwaters. of pinnatifida macroalgal and canopies abundance distribution onthe kelp non-native ofthe enhancement, ofExperimentalMarine Journal Biology and Ecology of stimulation overgrazing kelp overwhelmsbedsdespite bottom-up sediment 11:e0168333. urchin ONEPLOS overgrazing reefs. onnutrified habitat for loss rocky fishes innorthPatagonia. reef BiologicalInvasions 13:17– Thesis,University Melbourne, of comparison the of introduced 2:e616. count evolution. PeerJ dataand inecology 282:20142930. 344.

in natural reef habitats.Biology Marine 164:156.

Undaria pinnatifida

Victoria, Australia.

and theindigenous

2019 2016 Undaria pinnatifida . .

Top-down sea urchinTop-down dynamicsPhase-shift sea of 499. 499. 514 Ecklonia radiata Ecklonia – 515:4

causes Undaria 8 24. – 58

. This article is protected by copyright. All rights reserved. This article isprotected rights by All copyright. reserved. Accepted Pergl,Pyšek, E.Hulme, P. J. Hejda, V.Jarošík, M. P., M. Vilà. U. 2012.A Schaffner,and Pessarrodona,A. Foggo,Can ecosystemD. A. A., Smale. and2019. functioning be F.Patten, M.A.,and Kelly. J. andthe selection perceptual 2010.Habitat Ecological trap. Litterer,O’Brien, A. B. K.Mello, A.Dijkstra. S., and 2018.Seaweed J. structure shapes ArticleI. andNeira,F. M. J., ichthyoplankton 2002.Use toevaluate ecology ecosystem Sporcic. of 2006.Ontogenetic and Shima. J. S. McDermott, inmicrohabitat shifts C.J., preference ofthe Turkington. invasivespeciesMacDougall,R. of the 2005.Are drivers A.S., andchange or Lloyd, D.,and in 2005.Reproductivesuccess longspurs chestnut-collared T.E.Martin. J. of Lenth, Least-squaresStatistical means: lsmeans.of V.2016. package theR Journal R. passengers of change in degraded ecosystems? Ecologydegradedpassengers changeecosystems? in86:42– of native and grassland.The exotic Condor 107:363– Software 69:1– environment.Biology GlobalChange 18:1725– ecosystems: theinteraction of impact measures, invading and species’ traits global ofinvasive assessment plantimpacts species,resident on and communities marine ofEcology forests.Journal 107:91–104. Insightsmaintained composition? species despite shiftsin novel climate-driven from Applications 20:2148– MarineExperimental Biology and Ecology 506:1–8 leveltrophic interactions: fishspecies. study of Acase Journal a using mid-trophic Research 53:339. changes: bay.Australian acase Marine large, a in study semi-enclosed Ecology320:259– Series Progress temperatereef fish 33. 33. Forsterygionlapillum 2156.

266.

: implications for: implications populationlimitation. Marine 1737. 1737. 374. .

55. 55. and Freshwaterand This article is protected by copyright. All rights reserved. This article isprotected rights by All copyright. reserved. AcceptedL.Schaffelke,ImpactsandBotanica B., seaweeds. C. Hewitt. Marina 2007. introduced of Rodewald, shrubsasL. A.D.,D. Shustack, ephemeral P. and2010.Exotic E.Hitchcock. Rehage,Robertson, S. B. A.,J. and 2013.Ecological A.Sih. emergence and novelty the of Robertson, B.L. A.,and for R. Hutto.2006.Aframework ecological understanding traps and habitatofRemeš, V.exotic onnesting 2003.Effects success,density, and territory settlement D.Ling. S. R. Reeves, C. N.Johnson, Kriegisch, S.E., 2018.Reduced resistance tosediment- ArticleRamus,A. P.,B.Thomsen,and M.S. foundation R.Silliman, Z. Long.An invasive T. 2017. LoIntroducedRaffo, V. and Russo, E.Schwindt. M.P., 2014. and native onrocky species Iribarne.Raffo, Eyras, and M.C. O. The M.P., invasionof 2009. CoreR Team. Alanguageand for 2018.R: environment statistical computing. RFoundation shore patterns, macroalgal composition anddiversity. zonation assemblages: Aquatic Marine ofthe BiologicalUnitedKingdom 89:1571– Association Macrocystis pyrifera for Computing, Statistical Vienna, Austria. ecologicalBiologicalInvasionsfor 12:33– trapsnestingbirds. inEcologyevolutionaryand Trends traps. an evidence. evaluationexisting of 87:1075– Ecology patterns intheblackcap ( 188:1239– ofantrappingof kelp.and native exotic Oecologia withestablishment decline kelp turfs Academy ofSciences 114:8580– species enhances inacoastal ecosystem. multifunctionality the National Proceedings of Botany 112:57– 1251. 65. 65.

kelp inPatagoniakelp Atlantic).ofthe south-west Journal (Argentina, Sylvia atricapilla 8585.

). Conservation Biology 17:1127– Evolution 28:552– Evolution 1085.

560. 39. Undaria pinnatifida Undaria 1580. 1580.

1133.

to a This article is protected by copyright. All rights reserved. This article isprotected rights by All copyright. reserved. AcceptedL.I.L.Valentine,B. and Roberts, driving E., N. Schwarzkopf. 2007.Mechanisms avoidance 2003. Establishment and R. P., C. Valentine, of Johnson. theintroducedkelp J. Trammell, L.Butler. M.A.,and plantsonnative J. 1995.ofexotic ungulate Effects of use Evidence 2009.for impactsThomsen, M.S.,T.Wernberg, Silliman. of B. F. and R. Tuya, McLeod, R., L. D.Hepburn,andSuárez-Jiménez, C. R.J. Hyndes, B. C. G.A. Taylor, R. Article M.,and M.S. P. South, Thomsen. 2016.The ecological role ofinvading O.Ferrari,andbehavioural Harris. A.,M.C. responses andSih, D.J. Evolution to 2011. E.Swearer, wetlands canSievers, S. M.,K. 2018.Stormwater M.Parris, and Hale. R. and D.Olden.Sax, 2011.TheSchlaepfer,F. M.A.,J. potentialconservation value D. onnon- function as for ecologicalfrogs. traps urban EcologicalApplications 28:1106– native Biology species. Conservation 25:428– 50:397– of non-native plants by lizards. Journal of Applied Ecology 44:228–237. of non-native ofApplied Journal Ecology plantsbylizards. 44:228–237. MarineExperimental Biology and Ecology 295:63– pinnatifida habitat. ofWildlife Journal 59:808–816. Management Phycology 45:812– of Journal nonindigenousexperimental field of studies. macroalgae: ameta-analysis Series 582:45– tonativesimilar comparable with seaweeds Progress morphologies. MarineEcology Hurd. kelp 2017.The invasive an experimental testofthe driver– human-induced 4:367– change. environmental Evolutionary rapid Applications 417.

in Tasmania depends ondisturbance tonativealgal of assemblages.Journal

55. 55. 819. 819. Undaria pinnatifida passenger models. Marine Biology 163:175. Marine models. Biologypassenger 163:175. 437. 437.

hosts anepifaunalhosts assemblage 90.

Undaria pinnatifida Undaria Undaria 1115. 387.

: This article is protected by copyright. All rights reserved. This article isprotected rights by All copyright. reserved. AcceptedData are DATA AVAILABILITY Hobbs,andZavaleta, Viewing H.A. Mooney.ina removal species R.J. 2001. E.S., invasive L. 2014.Engineering T., E.Byers,orfood? Sotka. Wright, J. E. J. J. and DeVore, E. Wong,B. B.2014.BehavioralCandolin. environments. M.,andchanging U. responses to Article T.andBabcock.Willis, C. R. J., video the underwater 2000.Abaited systemfor cryptic T.andWillis, M.Anderson. 2003.Structurereef fishJ., of relationships assemblages: York. elegant New Wickham, H.2009.ggplot2: data analysis. graphics Springer-Verlag for A.Dijkstra,Ikedo. K.Mello, O’Brien,Ware, A.Stevens,S. B. C.,J. 2019.Anoveland W. 257:209– with habitatcharacteristicsMarine Series and predatorEcology density. Progress macroalgaeaMarine Series refuge. as Ecology 608:93– Progress offunctionalthree-dimensional architecture thatdescribes of theproperties analysis whole-ecosystem context. Trends in Ecology and Evolution 16:454–459. 16:454–459. whole-ecosystemEvolution Trends and Ecology context. in 2706. Mechanisms by offacilitation a habitat Behavioral Ecology 26:665– Research 51:755–763. determinationdensitycarnivorous ofreefFreshwater relativefish. of and Marine available at figshare: https://doi.org/10.6084/m9.figshare.7396964.v1 https://doi.org/10.6084/m9.figshare.7396964.v1 available at figshare: 221.

673.

‐ forming invasiveseaweed. Ecology95:2699– 103. 103. This article is protected by copyright. All rights reserved. This article isprotected rights by All copyright. reserved. E. radiata Wakame Wakame Pairwise comparisons B E. radiata Wakame Treatment pinnatifida 1. Table

Accepted Articlearren

Summary recruitment fish of – –

– , E. radiata Barren

Ecklonia radiata Barren

Kelp cover canopy (%)

73 ±2 42 ±3 5 ± , orleft barren.

(mean ± SE) (mean ±SE)

Abundance (fish z = 3.0,p=z = 2.3,p=z = 1.7,p=z 0.4 ±0.2 1.1 ±0.1 0.9 ±0.1 0.008 0.05 0.21

reef

to mesocosmreefs stocked with

- 1

)

z = 3.3,p=z Species richness z = 2.8,p=z = 1.6,p=z 0.24 (species 0.4 ±0.2 1.1 ±0.1 0.8 ±0.1

reef 0.003 0.02

- 1 )

Undaria surveys 18 89 89 N

This article is protected by copyright. All rights reserved. This article isprotected rights by All copyright. reserved. Accepted Neoodax balteatus Heteroclinus perspicillatus Heteroclinus heptaeolus Heteroclinus ArticleTemporaleffect Neoodax balteatus Heteroclinus perspicillatus Heteroclinus heptaeolus Heteroclinus effect Habitat Negative Cohen’s ratioTerms comparison likelihood models( are tested fitted of byand maximum null ‘Wakame, and over timeeffect’). (‘Temporal given of efforts (Nare Number collection as dives) bycatchand diver uniteffort per (CPUE), inwakame 2. Table Comparison reef of fish relativeabundance E. radiata

spp. spp.

effect sizes indicate metricseffect sizes were in higher ’. N divesdifferall species.’. N as all divestargeted betweennot species

Wakame 1.6 ±0.4 1.5 ±0.4 0.7 ±0.2 0.9 ±0.3

4.1 ±1.0 2.7 ±0.8 1.0 ±0.4 2.0 ±0.6 radiata E. E.

- 0.26 0.03 0.10 0.02 R (mean ± SE) (mean ±SE)

2 E. radiata

N dives 13, 10 13, 12 13, 12 13, 10 13, 12 13, 12 9, 10 9, 10

E. radiata

habitats (‘Habitat effect’),

at Williamstown, estimated at Williamstown,

0.74 0.32 0.04 0.14 0.77 2.1 1.4 3.3 X

h 0.007 abitat. 0.33 0.04 0.73 0.91 0.12 0.87 0.19 p

Cohen’s X - - - - 2 1.08 0.48 0.30 0.74 ). d

This article is protected by copyright. All rights reserved. This article isprotected rights by All copyright. reserved. (*1000) index Gonadosomatic (*1000) index Stomach (*1000) index Hepatosomatic W weight (g) Gutted Length(mm) Heteroclinus (%) fertilisation Egg weight Eggsgutted weight gutted Embryos Eggs Embryos (*100) index Gonadosomatic (*1000) index Stomach (*1000) index Hepatosomatic W weight (g) Gutted Length(mm) Heteroclinus maturityEgg(%) weight Eggsgutted weigh gutted eggs Mature Eggs eggs Mature (*1000) index Gonadosomatic Stomac (*1000) index Hepatosomatic W weight (g) Gutted Length(mm) balteatus Neoodax indicatesizes metrics were higher in tested by modelscomparing andwithout Habitat with fitof term. NegativeCohen’s Half MoonBay (constructed boulder reef wakamefishesand collected from 3. Table

Acceptedrm rm Articlerm

h index (*1000) hindex

Comparison body of condition condition andreproductive metrics

spp. spp.

– – - - – 1 1

natural reefs natural boulder reefs boulder

natural reefs natural -

t - 1

3162 936 ± 3162 516 ± 102 516 ± 128 742 ± 245 789 Wakame 124 ± 124 ± 35 256 ± 0.9 4.1 ± 39 198 ± 0.9 3.9 1.3 ± ± 0.1 1.3 ± 0.3 1.3 102 ± 3 102 ± 1 101 43 ± ± 17 43 12 ± ± 5 12 ± 4 16 ± 4 51 ± 6 60 ± 9 68 ± 2 12 ± 3 24 ± 1 19 ± 5 74 ± 4 26 ± 8 51 ± 2 25 ± 2 30 ± 4 73 E. radiata reefs). N‘Wakame reefs). =

E. radiata

2789 850 ± 2789 E.radiata habitat. 516 ± 213 516 568 ± 176 568 116 ± 29 116 ± 1.7 9.5 1.3 ± ± 0.1 1.3 ± 0.4 2.3 ± 28 126 ± 66 274 ± 33 198 ± 0.3 2.6 48 ± ± 10 48 55 ± ± 19 55 ± 16 92 ± 17 42 ± 3 100 27 ± ± 2 27 ± 2 28 ± 1 99 ± 6 96 15 ± ± 3 15 ± 3 21 ± 4 62 ± 7 81 ± 3 11 ± 3 21 ± 2 65 ± 8 24

habitats atWilliamstown(natural and reefs)

, E.radiata 17, 10 17, 10 17, 10 17, 23 22, 23 22, 23 22, 23 22, 23 22, 23 22, 11, 20 11, 20 11, 20 11, 20 11, 20 11, 20 11, 12 13, 12 13, 12 13, 12 13, 12 13, 22 20, 22 20, 22 20, 22 20, 22 20, 22 20, 10 17, 10 17, N

<0. <0. 0.6 0.5 0.5 0.2 1.0 2.1 4.0 7.2 8.2 0.3 2.4 2.9 0.8 0.6 2.0 0.2 1.6 1 0.3 … … … … … … 11 F 1 1 .3

’. Habitat effect is

<0.1 0.8 5.9 0.3 0.9 0.6 … … … … … … … … … X … … … … … … … … … … … … … (mean ±SE)

0.007 0.003 0.63 0.49 0.49 0.67 0.32 0.15 0.05 0.01 0.37 0.99 0.01 0.58 0. 0.45 0.58 0.14 0.10 0.39 0.45 0.16 0.98 0.63 0.21 0.26 0.93 0.34 p 35

effect +0.59 +0.11 +0.30 +0.07 +0.20 +0.50 +0.08 +0.53 +0.01 +0.81 +0.48 +0.10 +0.12 +0.50 +0.52 +0.06 +0.32 ------in 0.19 0.87 0.97 2.39 0.70 0.71 0.90 0.02 0.52 0.31 0.09 d

This article is protected by copyright. All rights reserved. This article isprotected rights by All copyright. reserved. Acceptedmean anderror. standard surveys surveys; foranalysis (CAP) principalcoordinates of senescence(off-season) wakame canopy of season while ispresent canopycover present (wakame:light Figure3 initially and(light blue) after20min (dark blue N = 48;( Figure 2. Article habitats atWilliamstown. surveys andfitness metric were andatin urchin wakameall5locations. habitats barren done surveys andUnderwaterremote baitedvideo underwater visual census patches kelp ofnative also AltonaReef,Cook, containsremnant Williamstown andBay. Half Moon Williamstown populations Figure1 FIGURE LEGENDS ; . Bay, ofstudy locations PortPhillip in . Map Australia ( ( B D C Representation of reef fish communities reef offish communities Representation Habitat choice trial resultsHabitat for ( choice ) little weed) little ( whiting ) ) .

Wakame and urchin Point andwereKirk barrensPoint, surveyed are present at total abundance total abundance Fish)richness (N abundance and Rich) total (Sp species Ecklonia radiata Ecklonia markers; barren:dark

comparisons were done in in comparisonswere done and species richness for and richness species Neoodax balteatus (peak-season) (peak-season)

in close proximity and wakame habitats. tobarren A ) common weedfish) common ( peak-season peak-season ( B markers), both during the wakame growing markers),the wakame bothduring , ). D

). Individual( panels depict: wakamein surveywithout and with plots ): N= recorded 23.Preference was ( A neighbouring off-season surveys. Bars indicate groupoff-season Bars indicate surveys. , C surveys ) and ) with established wakamekelp established with again again ; Heteroclinus perspicillatus Heteroclinus ( B Diver catch per uniteffort wakame and wakame ) CAP for off-season for CAP after complete after for peak-season of fish populations populations fish of A ) E. radiata canonical