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