inter-site and inter-specific differences in rates of survival and growth of c. ariakensis and c....
TRANSCRIPT
Inter-site and inter-specific differences in rates of survival and growth of C. ariakensis and C. virginica:
A collaborative on-bottom study in Virginia and Maryland
Kingsley-Smith, P. R., Harwell, H. D, Kellogg, M. L., Allen, S. K. Jr., Meritt, D. W.,
Paynter, K. T. Jr. & Luckenbach, M. W.
9th International Conference on Shellfish Restoration Charleston, South Carolina, USA
November 15th-19th 2006
FUNDING SOURCES
COLLABORATORS
University of Maryland Center for Environmental Science (UMCES)
Horn Point Laboratory
• Current knowledge of C. ariakensis survival and growth rates is based upon 1) field trials using triploids in off-bottom, caged aquaculture, and 2) quarantined studies using diploids.
• Predicting rates of survival and growth of C. ariakensis in natural bottom habitats is critical to a pending decision on an intentional introduction.
• Accurate determination of these rates will improve parameterization of a developing demographic model.
• This study is the first to grow C. virginica and C. ariakensis (in VA and MD) side-by-side on the bottom in an effort to gather survival and growth data in a more naturalistic setting.
I. INTRODUCTION
Triploid Triploid C. ariakensisC. ariakensis and and C. virginica C. virginica werewere set on shell in May 2005 andset on shell in May 2005 and planted at ~400 oysters mplanted at ~400 oysters m-2-2 in late Oct–Nov 2005 at 4 sites in VA and MD. in late Oct–Nov 2005 at 4 sites in VA and MD.
II. METHODS
Oysters were planted in 2’ x 2’ bread trays in 5 x 5 arrays in late Oct-Nov 2005.
II. METHODS
Cages were placed around the trays to prevent disturbances by large epibenthic predators (e.g., cownose rays) and humans, while allowing access
to small predators (e.g., xanthid crabs).
II. METHODS Machipongo River Virginia
Treatments (single treatment per cage):Treatments (single treatment per cage):
• C. virginicaC. virginica only only
• C. ariakensisC. ariakensis only only
• C. virginicaC. virginica and and C. ariakensis C. ariakensis in a 50 : 50 mixin a 50 : 50 mix
• Shell only (no live oysters)Shell only (no live oysters)
Experimental design:Experimental design:
• 2 replicate cages (blocks 1 and 2) per treatment (4) at each field site.
• 4 sites (2 sites in Virginia; 2 sites in Maryland).
• Sites were chosen to cover a range of salinities, water depths, disease pressures and relative predator abundances.
II. METHODS
Atlantic Ocean
Delaware
Bay
Chesapeake
Bay
25 km
Patuxent River
York River
Severn River
Machipongo River
II. METHODS
MACHIPONGO RIVER, VAMACHIPONGO RIVER, VA
Intertidal Intertidal Salinity: ~30 psuSalinity: ~30 psuPredation pressure: HighPredation pressure: HighHigh Dermo & High MSXHigh Dermo & High MSX
II. METHODS
YORK RIVER, VAYORK RIVER, VA Subtidal (1-2m)Subtidal (1-2m)Salinity: 20-25 psuSalinity: 20-25 psuPredation pressure: HighPredation pressure: HighHigh Dermo & High MSXHigh Dermo & High MSX
II. METHODS
PATUXENT RIVER, MDPATUXENT RIVER, MD
Subtidal (3-4m) Subtidal (3-4m) Salinity: 8-10 psuSalinity: 8-10 psuPredation pressure: ModeratePredation pressure: ModerateLow Dermo & No MSXLow Dermo & No MSX
SEVERN RIVER, MDSEVERN RIVER, MD
Subtidal (3-4m)Subtidal (3-4m)Salinity: 5-8 psuSalinity: 5-8 psuPredation pressure: LowPredation pressure: LowNo Dermo & No MSXNo Dermo & No MSX
II. METHODS
Courtesy of Paynter Lab
Courtesy of Paynter Lab
• Sampling = removal of 3 trays from each cage and replacement of sampled trays with those containing only clean shell.
• Cages were sampled one month after deployment (i.e., Nov-Dec 2005) to assess handling and early post-deployment mortality.
• Quarterly sampling thereafter:
Apr 2006, July 2006 and Oct 2006.
• Future sampling: Apr 2007, July 2007 and Oct 2007.
II. METHODS
This study will provide data on the following parameters:
oyster survival (# live oysters)oyster growth (shell height mm)oyster biomass (ash-free dry weight)ploidy/reversion (biosecurity)disease (RFTM & histology)gametogenesis (histology)
comparisons of habitat complexity between treatments (spp.) and its relationship to associated free-living and attached faunal assemblages.
(Poster by Heather Harwell et al.).
II. METHODS
This study will provide data on the following parameters:
oyster survival (# live oysters)oyster growth (shell height mm)oyster biomass (ash-free dry weight)ploidy/reversion (biosecurity)disease (RFTM & histology)gametogenesis (histology)
comparisons of habitat complexity between treatments (spp.) and its relationship to associated free-living and attached faunal assemblages.
(Poster by Heather Harwell et al.).
II. METHODS
July 2006
III. RESULTS – SURVIVALSURVIVAL
MACHIPONGO RIVER YORK RIVER
PATUXENT RIVER SEVERN RIVER
140
120
100
80
60
40
20
0
140
120
100
80
60
40
20
0
140
120
100
80
60
40
20
0
140
120
100
80
60
40
20
0
Oct Nov Dec Jan Feb Mar Apr May Jun Jul Oct Nov Dec Jan Feb Mar Apr May Jun Jul
Oct Nov Dec Jan Feb Mar Apr May Jun Jul Oct Nov Dec Jan Feb Mar Apr May Jun Jul
20062005 20062005
2006200520062005
Mea
n no
. oy
ster
tra
y -1
C. virginicaC. ariakensis
Single spp. cages onlySingle spp. cages onlyError bars are S.D.sError bars are S.D.s
(n = 6)(n = 6)
Error bars are S.E.sIII. RESULTS – SURVIVAL - Within site comparisons
100
80
60
40
20
0
Mea
n #
live
oyst
ers
per
tray
1 2 1 2 1 2 1 2
Machipongo York Patuxent Severn
C. virginicaC. ariakensis
100
80
60
40
20
0
Mea
n #
live
oyst
ers
per
tray
1 2 1 2 1 2 1 2
Machipongo York Patuxent Severn
C. virginicaC. ariakensis
BLOCKS & SPP. NOT SIGNIFICANTLY
DIFFERENT
SIGNIFICANT BLOCK & SPP.
EFFECTS
III. RESULTS – SURVIVAL - Within site comparisons
100
80
60
40
20
0
Mea
n #
live
oyst
ers
per
tray
1 2
Machipongo York Patuxent Severn
C. virginicaC. ariakensis
III. RESULTS – SURVIVAL - Within site comparisons
combined combined combined
Error bars are S.E.s
100
80
60
40
20
0
Mea
n #
live
oyst
ers
per
tray
1 2
Machipongo York Patuxent Severn
C. virginicaC. ariakensis
III. RESULTS – SURVIVAL - Within site comparisons
combined combined combined
ns
Error bars are S.E.s
100
80
60
40
20
0
Mea
n #
live
oyst
ers
per
tray
1 2
Machipongo York Patuxent Severn
C. virginicaC. ariakensis
Intertidal
Subtidal
ns
III. RESULTS – SURVIVAL - Within site comparisons
combined combined combined
Error bars are S.E.s
100
80
60
40
20
0
Mea
n #
live
oyst
ers
per
tray
1 2
Machipongo York Patuxent Severn
C. virginicaC. ariakensis
MLW
MLW + 1ft
Intertidal
Subtidal
ns
III. RESULTS – SURVIVAL - Within site comparisons
combined combined combined
Error bars are S.E.s
Machipongo River Virginia
Machipongo River Virginia
BLOCK 1
BLOCK 2
Machipongo River Virginia
100
80
60
40
20
0
Mea
n #
live
oyst
ers
per
tray
1 2
Machipongo York Patuxent Severn
C. virginicaC. ariakensis
MLW
MLW + 1ft
Intertidal
Subtidal
(p = 0.06)
ns
III. RESULTS – SURVIVAL - Within site comparisons
combined combined combined
MSX?predation?
Error bars are S.E.s
100
80
60
40
20
0
Mea
n #
live
oyst
ers
per
tray
Machipongo York Patuxent Severn
C. virginicaC. ariakensis
III. RESULTS – SURVIVAL – Across site comparisons
combined combined combined combined
Error bars are S.E.s
III. RESULTS – SURVIVAL – Across site comparisons
100
80
60
40
20
0
Mea
n #
live
oyst
ers
per
tray
Machipongo York Patuxent Severn
A AB BC C
C. virginica across site comparisons
combined combined combined combined
Error bars are S.E.s
III. RESULTS – SURVIVAL – Across site comparisons
100
80
60
40
20
0
Mea
n #
live
oyst
ers
per
tray
Machipongo York Patuxent Severn
A AB BC C
C. virginica across site comparisons
combined combined combined combined
Error bars are S.E.s
III. RESULTS – SURVIVAL – Across site comparisons
100
80
60
40
20
0
Mea
n #
live
oyst
ers
per
tray
Machipongo York Patuxent Severn
A AB BC C
C. virginica across site comparisons
combined combined combined combined
Error bars are S.E.s
III. RESULTS – SURVIVAL – Across site comparisons
100
80
60
40
20
0
Mea
n #
live
oyst
ers
per
tray
Machipongo York Patuxent Severn
A AB BC C
C. virginica across site comparisons
combined combined combined combined
increasing survival
decreasing salinity
Error bars are S.E.s
III. RESULTS – SURVIVAL – Across site comparisons
100
80
60
40
20
0
Mea
n #
live
oyst
ers
per
tray
Machipongo York Patuxent Severn
C. virginica across site comparisons
combined combined combined combined
Machipongo represents suitable
habitat for C. virginica (survival comparable with York River)….
A AB BC C
Error bars are S.E.s
100
80
60
40
20
0
Mea
n #
live
oyst
ers
per
tray
Machipongo York Patuxent Severn
a
b
C. ariakensis across site comparisons
bb
III. RESULTS – SURVIVAL – Across site comparisons
combined combined combined combined
…but less suitable habitat for C. ariakensis
Error bars are S.E.s
MACHIPONGO RIVER, VA JULY 5MACHIPONGO RIVER, VA JULY 5THTH 2006 2006 YORK RIVER, VA JULY 24YORK RIVER, VA JULY 24THTH 2006 2006
PATUXENT RIVER, MD JULY 10PATUXENT RIVER, MD JULY 10THTH 2006 2006 SEVERN RIVER, MD JULY 17SEVERN RIVER, MD JULY 17THTH 2006 2006
Shell height (mm)Shell height (mm)
# # oy
ster
soy
ster
s
C. virginicaC. ariakensis
0
25
50
75
0- 10- 20- 30- 40- 50- 60- 70- 80- 90- 100- 110-0
25
50
75
0- 10- 20- 30- 40- 50- 60- 70- 80- 90- 100- 110-
0
25
50
75
0- 10- 20- 30- 40- 50- 60- 70- 80- 90- 100- 110-
0
25
50
75
0- 10- 20- 30- 40- 50- 60- 70- 80- 90- 100- 110-
III. RESULTS – GROWTHGROWTH
(Data include oysters from both single and mixed spp. cages.)
• Survival and growth data are now available for triploid C. ariakensis and C. virginica from several bottom habitats ranging in salinity, depth, disease pressure and relative predator abundance.
• Significant interactions were observed between sites and species for both survival and growth.
• Lowest survival of both species was observed at the intertidal Machipongo River site, with C. ariakensis survival especially low.
• Highest growth rates of C. ariakensis were observed at the York River (site characteristics: subtidal & high salinity).
• Both species (particularly C. virginica) show a trend of increased survival with decreasing salinity across sites.
• Growth rates of C. virginica and C. ariakensis were most similar at the low salinity Severn River site.
IV. CONCLUSIONS
Eastern Shore Lab
Reade Bonniwell
PG Ross
Sean Fate
Alan Birch
Edward Smith
Jamie Wheatley
Al Curry
Stephanie Bonniwell
Rochelle Brown
University of Maryland (sampling help)
Jake Goodwin
Mark Sherman
Steve Allen
Marcy Chen
Nancy Ward
VIMS ABC
Shane Bonnot
Ryan Gill
Karen Hudson
ESL Summer aides
Raija Bushnell
Sarah Mallette
Matt Foley
Andrew Wilson
Andrew Matkin
VIMS Shellfish Pathology Lab
Ryan Carnegie
Rita Crockett
Susan Denny
V. ACKNOWLEDGEMENTS
2
4
6
8
10
% f
requ
ency
shell height (mm)
5 10 15 20 25 30 35 40
Pre-deployment shell height distributions
C. ariakensis (mean SH = 13.85mm, n = 1272)C. virginica (mean SH = 12.80mm, n = 1362)