ecological considerations for oyster restoration: interactions between oyster larvae and...
TRANSCRIPT
Ecological considerations for Ecological considerations for oyster restoration: interactions oyster restoration: interactions between oyster larvae and reef-between oyster larvae and reef-
associated faunaassociated fauna
Brian B. Barnes*, Mark W. Brian B. Barnes*, Mark W. Luckenbach, Peter R. Kingsley-Luckenbach, Peter R. Kingsley-
Smith Smith
Co
mm
erci
al o
yste
r la
nd
ing
s (m
illio
ns
of
po
un
ds)
1880 1900 2000
120
90
60
30
Virginia landings
Maryland landings
1920 1940 1960 1980
Plight of oysters in Chesapeake Bay
Current Crassostrea virginica population levels in
Chesapeake Bay are < 1% biomass of those at the start of the last century (Newell,
1988)
chesapeakebay.noaa.gov
Shells are limiting to Shells are limiting to epibenthic fauna epibenthic fauna AND restoration AND restoration managersmanagers
Substrate additions areSubstrate additions areoften done without often done without regard for how regard for how substrate colonization substrate colonization affects oystersaffects oysters
Epifaunal interactions research is often Epifaunal interactions research is often conducted using artificial substratesconducted using artificial substrates
Supplementing shell substrateSupplementing shell substrate
Shell planting on Rappahannock River
Research ObjectivesResearch Objectives Investigate the effects of single-Investigate the effects of single-
species epifaunal populations on species epifaunal populations on the recruitment of oyster larvae the recruitment of oyster larvae using natural substratesusing natural substrates
Effect of water soluble cuesEffect of water soluble cues
Effect of clamworms (Effect of clamworms (Neanthes Neanthes succineasuccinea))
Collection sitesCollection sites
a
Rappahannock River site
b
Pungoteague Creek site
VIMS ESL
Images from maps.google.com
a b
Experimental treatmentsExperimental treatments
Cliona sp.No fouling
Balanus improvis
us
Membranipora tenuis
Dead BarnacleBarnacle Mould
... .. .. .. ....... . .
....
50 ml adult oyster
bathwater
~ 75 larvae
Combusted very fine sand (63 – 125 μm)
Test shell (~3 cm x ~3
cm)
Microcosm design – Effect of Microcosm design – Effect of epifaunaepifauna
5.7 cm
4.3 cm
Overall layoutOverall layout
... .. .. .. .. ..
... . .....
=
x 16
Results – Effect of epifauna on Results – Effect of epifauna on oysters: Settlement rate, oysters: Settlement rate, Experiment 1 (Experiment 1 (C. a.C. a.))
0
0.1
0.2
0.3
0.4
0.5
0.6
Pos Control Low Barnacle Med Barnacle High Barnacle Bryozoan Cliona
Treatment
La
rva
l Se
ttle
me
nt
(%) *
Results – Effect of epifauna on Results – Effect of epifauna on oysters: Settlement Rateoysters: Settlement Rate
Experiment SpeciesLow
BarnaclesMedium
BarnaclesHigh
BarnaclesBryozoans Cliona
Dead Barnacles
Barnacle Moulds
1C. virginica
+ + + - p = 0.0254 p = 0.0184
C. ariakensis+ + + p = 0.0093
2 C. virginica+ + + - - p = 0.0282
3 C. ariakensis + - -
4 C. virginica- - -
p = 0.0003
5 C. virginica+ + + +
p = 0.0001 p < 0.0001 p = 0.0001
6 C. ariakensis + + + - p = 0.0034 p = 0.0412
7 C. virginica + + + p = 0.0147
Results – Effect of epifauna on Results – Effect of epifauna on oysters: Mortalityoysters: Mortality
Experiment SpeciesLow
BarnaclesMedium
BarnaclesHigh
BarnaclesBryozoans Cliona
Dead Barnacles
Barnacle Moulds
1C. virginica
+ + + + p = 0.0066
C. ariakensis- + +
2 C. virginica+ + +
p = 0.0195
3 C. ariakensis+ + + +
p = 0.0012
4 C. virginica+ + + + +
p = 0.0001
5 C. virginica+ + - -
6 C. ariakensis+ + + + +
7 C. virginica+ + + +
p = 0.0047 p < 0.0001 p < 0.0001
... .. .. .. ....
... . ...
..
50 ml adult bathwater
~ 75 larvae
Microcosm design – Effect of Microcosm design – Effect of bathwatersbathwaters
5.7 cm
4.3 cm
Results – Bathwater Results – Bathwater experimentsexperiments
0
0.02
0.04
0.06
0.08
0.1
0.12
0.14
Control Oyster Barnacle Clamworm
Bathwater Treatment
Lar
val S
ettle
men
t (%
)
0
0.05
0.1
0.15
0.2
0.25
Control Oyster Barnacle Oyster + Barnacle
Bathwater Treatment
Lar
val S
ettle
men
t (%
)
** *
0
0.1
0.2
0.3
0.4
0.5
0.6
Control Oyster Barnacle Clamworm
Bathwater Treatment
Lar
val M
ort
ality
(%)
*
*
*
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
Control Oyster Barnacle Oyster + Barnacle
Bathwater Treatment
Lar
val M
ort
ality
(%)
*
* *
ConclusionsConclusions No clear differences between No clear differences between C. virginicaC. virginica and and C. ariakensisC. ariakensis larvae larvae Balanus improvisusBalanus improvisus presence likely affects presence likely affects
settling oyster larvaesettling oyster larvae Increased structure likely not importantIncreased structure likely not important Water soluble cue causes mortality, increased Water soluble cue causes mortality, increased
settlementsettlement Membranipora tenuisMembranipora tenuis largely inert to largely inert to
mortality and settlement rate of oyster larvaemortality and settlement rate of oyster larvae ClionaCliona sp. causes mortality to oyster larvae sp. causes mortality to oyster larvae
and deters settlementand deters settlement
Conclusions (continued)Conclusions (continued) Clamworms (Clamworms (Neanthes succineaNeanthes succinea) are voracious ) are voracious
predators on oyster larvae; their bathwater also predators on oyster larvae; their bathwater also causes mortality causes mortality Average predation rate = ~11 larvae dayAverage predation rate = ~11 larvae day-1 -1 wormworm-1-1
Field population abundance = ~10,000 clamworms mField population abundance = ~10,000 clamworms m-2-2
Oyster bathwater causes mortality to conspecificsOyster bathwater causes mortality to conspecifics Effect significant after 2 daysEffect significant after 2 days
Reef-associated invertebrates certainly influence Reef-associated invertebrates certainly influence settling oyster larvaesettling oyster larvae Effect is not uniform or easily predictableEffect is not uniform or easily predictable Interactions should inform the location and timing of Interactions should inform the location and timing of
shell planting projectsshell planting projects
AcknowledgementsAcknowledgements VIMS – Eastern Shore LabVIMS – Eastern Shore Lab
Steph Bonniwell, Lynn Steph Bonniwell, Lynn Walker, Heather Harwell, Walker, Heather Harwell, Edward Smith, Roshell Edward Smith, Roshell Brown, Alan Birch, Sean Fate, Brown, Alan Birch, Sean Fate, Reade Bonniwell, Al Curry, Reade Bonniwell, Al Curry, Jamie Wheatley, Linda Ward, Jamie Wheatley, Linda Ward, Summer AidesSummer Aides
VIMS – Gloucester PointVIMS – Gloucester Point Roger Mann, John Brubaker, Roger Mann, John Brubaker,
Missy Southworth, Juli Missy Southworth, Juli Harding, Harding,
Peter van Veld Peter van Veld UMD – CBLUMD – CBL
Mario TamburriMario Tamburri FundingFunding
Kelley Watson Fellowship, Kelley Watson Fellowship, Eastern Shore Lab Research Eastern Shore Lab Research Grants, GSA Mini-Grant, Grants, GSA Mini-Grant, VIMS AssistantshipVIMS Assistantship
