Long-term patch Long-term patch dynamics in the dynamics in the

community shaped by community shaped by bivalves, barnacles, bivalves, barnacles,

ascidians and red algae: ascidians and red algae: multiple foundation multiple foundation

species in the White Sea species in the White Sea shallow subtidalshallow subtidal

EugeneEugene Yakovis Yakovis Anna ArtemievaAnna Artemieva

MichaelMichael FokinFokin Marina Varfolomeeva Marina Varfolomeeva

Natalia ShunatovaNatalia Shunatova

St.-Petersburg StateUniversity, Russia

Facilitation by foundation species shapes Facilitation by foundation species shapes many terrestrial and benthic communitiesmany terrestrial and benthic communities

Communities with multiple functionally differentCommunities with multiple functionally differentfoundation species are poorly studiedfoundation species are poorly studied

Locations: 12 m deep Site 1 and 15 m deep Site 2Locations: 12 m deep Site 1 and 15 m deep Site 2

Site 165° 01.2’N35° 39.7’E

The WhiteThe WhiteSeaSea

Site 265° 00.7’N35° 41.7’E

Epibenthic patches (EPs) on the unstructured sedimentEpibenthic patches (EPs) on the unstructured sediment

Mean density of EPs Mean density of EPs (m–2): 21±2 (Site 1), 6±1 (Site 2)

Species diversity in and around EPsSpecies diversity in and around EPs

epibenthic patches

H’ = 2.28±0.04(24±1 cm2 patches)

119 mobile species(72 polychaetes)

111 sessile species(64 bryozans)

unstructured sediment

H’=2.62±0.02 (55 cm2 cores)

101 mobile species(78 polychaetes)

Biomass in and around EPsBiomass in and around EPs

epibenthic patches

wet weightof macrobenthic

organisms745 g/m2

unstructured sediment

wet weightof macrobenthic

organisms91 g/m2

Overall species diversityOverall species diversity

H’ = 3.36±0.06

250 speciesin total

(16 x 1 m2 frame)

117±7 species per 1 m2 frame

Epibenthic patches by primary substrate typeEpibenthic patches by primary substrate type

Primary substrate types by total areaPrimary substrate types by total area

Total weight of epibenthic organisms within the patchesTotal weight of epibenthic organisms within the patchesbased on different substrate typebased on different substrate type

Live Live Serripes groenlandicusSerripes groenlandicus stays under the sediment stays under the sediment surface and never has sessile organisms attachedsurface and never has sessile organisms attached

Sessile organisms can utilize a shell only Sessile organisms can utilize a shell only when a clam dieswhen a clam dies

Sessile organisms can utilize a shell only Sessile organisms can utilize a shell only when a clam dieswhen a clam dies

Site 1: 6.7±2.9 live individualsof Serripes groenlandicus

per m2

Site 1: 1.8±0.4 unfouled valvesof Serripes groenlandicus

per m2 on the sediment surface

Most sessile organisms live on secondary biogenicMost sessile organisms live on secondary biogenicsubstrates (% individuals)substrates (% individuals)

Principal secondary space providers are barnacles andPrincipal secondary space providers are barnacles andtheir empty shells, ascidians and red algaetheir empty shells, ascidians and red algae

These are 15 top frequent associations between sessileThese are 15 top frequent associations between sessileorganisms and substrates … organisms and substrates …

… … and these are top 50and these are top 50

Most live barnacles Most live barnacles Balanus crenatus Balanus crenatus are found on are found on primary substrate and conspecificsprimary substrate and conspecifics

Most ascidians Most ascidians Styela spp.Styela spp. are found on barnacles and are found on barnacles andtheir empty shellstheir empty shells

As a result, epibenthic patches with following structureAs a result, epibenthic patches with following structuretypes are frequent:types are frequent:

Some of them look like thisSome of them look like this

The observed variation in structure of epibenthic The observed variation in structure of epibenthic patchespatches::

(i)(i) results from patch dynamicsresults from patch dynamics or or

(ii)(ii) is is just a product of spatial just a product of spatial heterogeneity and variable recruitmentheterogeneity and variable recruitment

??

predictions from predictions from (ii)(ii)::

>> the structure of patches would not depend much on the structure of patches would not depend much on their agetheir age

>> the age-dependent variation of structure would not the age-dependent variation of structure would not match one observed in EPsmatch one observed in EPs

Number of initially empty Number of initially empty SerripesSerripes shells exposed shells exposed

Exposure (yrs)

1998 1999 2000 2003 2006 2007 2008 Total

1 2 8 10 12 12 44

2 13 13

3 10 10

4 8 4 12

5 12 4 16

6 9 9

7 10 10

8 12 12

9 10 10

10 18 18

Installed in (yr)

S = 34.4 ± 0.8 cm2

1-2 yrs1-2 yrs

Serripesshell

Heteranomiasquamula

Balanuscrenatus

live

Balanuscrenatus

dead

PoriferaSpirorbide and serpulide worms

other bryozoans

Dendrobeania fruticosaEscharella sp.

Scrupocellaria arcticaStomachetosella cruenta

red algaebryozoans

3-4 yrs3-4 yrs

Serripesshell

Heteranomiasquamula

Balanuscrenatus

live

Balanuscrenatus

dead

PoriferaDendrobeania fruticosaSchizomavella lineata

Stomachetosella cruenta

bryozoansPorifera

red algae

red algae

5-6 yrs5-6 yrs

Serripesshell

Balanuscrenatus

live

Balanuscrenatus red algae

red algaebryozoans

Porifera

other bryozoans

Verruca stromiaDendrobeania fruticosaSchizomavella lineata

HeteranomiasquamulaStyela spp.

dead

7-8 yrs7-8 yrs

Serripesshell

Balanuscrenatus

live

Balanuscrenatus red algae

red algaehydrozoansbryozoans

Verruca stromiaDendrobeania fruticosa

Escharella spp.other bryozoans

dead

HeteranomiasquamulaStyela spp.

9-10 yrs9-10 yrs

Serripesshell

Balanuscrenatus

live

Balanuscrenatus red algae

red algae

Verruca stromiaHeteranomia squamulaDendrobeania fruticosaSchizomavella lineata

Escharella spp.

Styela coriaceaStyela rustica

dead

Relative areas of principal substrates: Relative areas of principal substrates: shellsshells, , live barnacleslive barnacles, , dead barnaclesdead barnacles, , ascidiansascidians and and

red algaered algae by exposure term (shell area as 1) by exposure term (shell area as 1)

0

2

4

6

8

1 0

1 2

1 4

1-2 yrs1-2 yrs 3-4 yrs3-4 yrs 5-6 yrs5-6 yrs 7-8 yrs7-8 yrs 9-10 yrs9-10 yrs

Relative abundance of sessile organisms (% ind.) on Relative abundance of sessile organisms (% ind.) on shellsshells, , live barnacleslive barnacles, , dead barnaclesdead barnacles, , ascidiansascidians,,

red algaered algae and and otherother substrates by exposure term substrates by exposure term

1-2 yrs1-2 yrs 3-4 yrs3-4 yrs 5-6 yrs5-6 yrs 7-8 yrs7-8 yrs 9-10 yrs9-10 yrs

MeanMean LogE Shannon diversity of epibenthic assemblages LogE Shannon diversity of epibenthic assemblageson on shellsshells, , live barnacleslive barnacles, , dead barnaclesdead barnacles, , ascidiansascidians,,

red algaered algae and and otherother substrates by exposure term substrates by exposure term

1-2 yrs1-2 yrs 3-4 yrs3-4 yrs 5-6 yrs5-6 yrs 7-8 yrs7-8 yrs 9-10 yrs9-10 yrs

nMDS of natural and experimental EPs on weights of nMDS of natural and experimental EPs on weights of ascidians, live and dead barnacles, red algae and ascidians, live and dead barnacles, red algae and

Shannon diversity (stress=0.08)Shannon diversity (stress=0.08)

w/o substrate

on Serripes shells

on other substrates

on live snails

nMDS of natural and experimental EPs on weights of nMDS of natural and experimental EPs on weights of ascidians, live and dead barnacles, red algae and ascidians, live and dead barnacles, red algae and

Shannon diversityShannon diversity1-2 yrs1-2 yrs

nMDS of natural and experimental EPs on weights of nMDS of natural and experimental EPs on weights of ascidians, live and dead barnacles, red algae and ascidians, live and dead barnacles, red algae and

Shannon diversityShannon diversity3-4 yrs3-4 yrs

nMDS of natural and experimental EPs on weights of nMDS of natural and experimental EPs on weights of ascidians, live and dead barnacles, red algae and ascidians, live and dead barnacles, red algae and

Shannon diversityShannon diversity5-6 yrs5-6 yrs

nMDS of natural and experimental EPs on weights of nMDS of natural and experimental EPs on weights of ascidians, live and dead barnacles, red algae and ascidians, live and dead barnacles, red algae and

Shannon diversityShannon diversity7-8 yrs7-8 yrs

nMDS of natural and experimental EPs on weights of nMDS of natural and experimental EPs on weights of ascidians, live and dead barnacles, red algae and ascidians, live and dead barnacles, red algae and

Shannon diversityShannon diversity9-10 yrs9-10 yrs

nMDS of natural and experimental EPs on weights of nMDS of natural and experimental EPs on weights of ascidians, live and dead barnacles, red algae and ascidians, live and dead barnacles, red algae and

Shannon diversityShannon diversity1-10 yrs1-10 yrs

1-21-23-43-45-65-67-87-8

9-109-10

The observed variation in structure of epibenthic The observed variation in structure of epibenthic patchespatches::

(i)(i) results from patch dynamicsresults from patch dynamics or or

(ii)(ii) is is just a product of spatial just a product of spatial heterogeneity and variable recruitmentheterogeneity and variable recruitment

??

predictions from predictions from (ii)(ii)::

>> the structure of patches would not depend much on the structure of patches would not depend much on their agetheir age

>> the age-dependent variation of structure would not the age-dependent variation of structure would not match one observed in EPsmatch one observed in EPs

The observed variation in structure of epibenthic The observed variation in structure of epibenthic patchespatches::

(i)(i) results from patch dynamicsresults from patch dynamics or or

(ii)(ii) is is just a product of spatial just a product of spatial heterogeneity and variable recruitmentheterogeneity and variable recruitment

??

predictions from predictions from (ii)(ii)::

>> the structure of patches would not depend much on the structure of patches would not depend much on their agetheir age

>> the age-dependent variation of structure would not the age-dependent variation of structure would not match one observed in EPsmatch one observed in EPs

The observed variation in structure of epibenthic The observed variation in structure of epibenthic patchespatches::

(i)(i) results from patch dynamicsresults from patch dynamics or or

(ii)(ii) is is just a product of spatial just a product of spatial heterogeneity and variable recruitmentheterogeneity and variable recruitment

??

predictions from predictions from (ii)(ii)::

>> the structure of patches would not depend much on the structure of patches would not depend much on their agetheir age

>> the age-dependent variation of structure would not the age-dependent variation of structure would not match one observed in EPsmatch one observed in EPs

The observed variation in structure of epibenthic The observed variation in structure of epibenthic patchespatches::

(i)(i) results from patch dynamicsresults from patch dynamics or or

(ii)(ii) is is just a product of spatial just a product of spatial heterogeneity and variable recruitmentheterogeneity and variable recruitment

??

predictions from predictions from (ii)(ii)::

>> the structure of patches would not depend much on the structure of patches would not depend much on their agetheir age

>> the age-dependent variation of structure would not the age-dependent variation of structure would not match one observed in EPsmatch one observed in EPs

CCrreeddiittss

Funding: RFBR grants Funding: RFBR grants № № 02-04-50020-a, 05-04-48927-a, 05-04-02-04-50020-a, 05-04-48927-a, 05-04-63041-k, 06-04-63077-k, 06-04-58536-z, 06-04-58537-z, 07-04-63041-k, 06-04-63077-k, 06-04-58536-z, 06-04-58537-z, 07-04-10075-k, 07-04-08366-z, 08-04-01373-a, 08-04-10109-k, 09-04-10075-k, 07-04-08366-z, 08-04-01373-a, 08-04-10109-k, 09-04-

10092-k, 10-04-08011-z10092-k, 10-04-08011-z

Alexander TcherenkovAlexander TcherenkovNadezhda TcherenkovaNadezhda Tcherenkova

Alexey GrishankovAlexey GrishankovAlexandra YakovisAlexandra Yakovis

Dmitry TomanovskyDmitry Tomanovsky

BBoonnuuss ttrraacckk

a shellexposed for

9 yrs