SEASONALITY AND SIZE OF SEASONALITY AND SIZE OF BOONEA IMPRESSABOONEA IMPRESSA POPULATIONS ON RESTORED AND NATURAL POPULATIONS ON RESTORED AND NATURAL
OYSTER REEFS: DOES ‘SIZE’ MATTER?OYSTER REEFS: DOES ‘SIZE’ MATTER?
Loren CoenLoren Coen**, Andrew Hollis, Andrew Hollis**, Steve , Steve RothRoth**, and Rachel Kalisperis, and Rachel Kalisperis++ *Marine Resources Research Institute, SCDNR *Marine Resources Research Institute, SCDNR
++SC Aquarium, Charleston, SCSC Aquarium, Charleston, SC
SEASONALITY AND SIZE OF SEASONALITY AND SIZE OF BOONEA IMPRESSABOONEA IMPRESSA POPULATIONS ON RESTORED AND NATURAL POPULATIONS ON RESTORED AND NATURAL
OYSTER REEFS: DOES ‘SIZE’ MATTER?OYSTER REEFS: DOES ‘SIZE’ MATTER?
Loren CoenLoren Coen**, Andrew Hollis, Andrew Hollis**, Steve , Steve RothRoth**, and Rachel Kalisperis, and Rachel Kalisperis++ *Marine Resources Research Institute, SCDNR *Marine Resources Research Institute, SCDNR
++SC Aquarium, Charleston, SCSC Aquarium, Charleston, SC
Van Gundy vs. Yao Ming
Emeryville, CA shell mound, originally Emeryville, CA shell mound, originally reportedreported
as over 60’ high >350’ in diameteras over 60’ high >350’ in diameterhttp://sscl.berkeley.edu/arf/publications/54.htmlhttp://sscl.berkeley.edu/arf/publications/54.html
Shell Ring, North Edisto, SCShell Ring, North Edisto, SC(from ~500’ elevation, false color IR)(from ~500’ elevation, false color IR)
(2-3,000 BP, 200’ diameter, 5’ high, 375,000 (2-3,000 BP, 200’ diameter, 5’ high, 375,000 bu)bu)
Oysters Have Been Consumed for 1000s of Oysters Have Been Consumed for 1000s of YearsYears
photo by Anne Shaffer
Olympia Oyster Shell moundsOlympia Oyster Shell mounds
Subtidal Oysters, Most Well Known
Kent, B.W., 1992.Kent, B.W., 1992. Making dead oysters Making dead oysters talk: techniques for analyzing oysters talk: techniques for analyzing oysters
from archaeological sites. MD Historical from archaeological sites. MD Historical TrustTrust
Oysters “plastic growth” reflected in Oysters “plastic growth” reflected in different shell ‘shapes’: different shell ‘shapes’: A) On hard gravelA) On hard gravel B) On soft sedimentsB) On soft sediments C) Crowded on muddy/shellC) Crowded on muddy/shell
Large % oysters in clusters dead shell, 5-Large % oysters in clusters dead shell, 5-95%! 95%!
(Bahr & Lanier 1981, Russo & Saunders (Bahr & Lanier 1981, Russo & Saunders 1989)1989)
Above Photo from K. Paynter, UMDAbove Photo from K. Paynter, UMD
Land Snails alsoLand Snails also
Oysters & Middens in an Oysters & Middens in an Archaeological ContextArchaeological Context
Since the 1800s, archaeologists have know that intertidal oysters (se US) Since the 1800s, archaeologists have know that intertidal oysters (se US) were an important subsistence resource in prehistoric coastal societieswere an important subsistence resource in prehistoric coastal societies
Observed shells scattered, heaped or mounded, often >10 m middensObserved shells scattered, heaped or mounded, often >10 m middens
However, their importance the subject of great debate (no direct tests) However, their importance the subject of great debate (no direct tests) Some: argue low nutritional value and other assumptions support a lower ‘value’ for oysters, Some: argue low nutritional value and other assumptions support a lower ‘value’ for oysters,
suggesting seasonal movements and therefore an assumed cold weather resourcesuggesting seasonal movements and therefore an assumed cold weather resource
Summer months Dermo (20Summer months Dermo (20thth century phenomenon?), lower nutritional yield (notions stem from century phenomenon?), lower nutritional yield (notions stem from modern obs.)modern obs.)
Others: year round resource, not a subsistence item only (e.g., Russo)Others: year round resource, not a subsistence item only (e.g., Russo)
Seasonal models cannot use ‘growth checks’ for oysters vs. other intertidal Seasonal models cannot use ‘growth checks’ for oysters vs. other intertidal bivalves in SE vs. subtidal NE pop. (Kent 1988, Russo 1991, others), clusters bivalves in SE vs. subtidal NE pop. (Kent 1988, Russo 1991, others), clusters large % dead shell, fast growth (cf., x.s. hard clams)large % dead shell, fast growth (cf., x.s. hard clams)
Focused excavations in oyster middens have found Focused excavations in oyster middens have found BooneaBoonea to be to be the most the most abundant gastropodabundant gastropod! !
Amazingly, most sampling of natural or constructed oyster reefs, regardless Amazingly, most sampling of natural or constructed oyster reefs, regardless of location/type have not quantified of location/type have not quantified BooneaBoonea let alone measured them! let alone measured them!
ASSUMPTION-ASSUMPTION- “If seasonal size patterns for “If seasonal size patterns for BooneaBoonea can be established, the can be established, the collection period for oysters in middens can also be established” (Russo 1991)collection period for oysters in middens can also be established” (Russo 1991)
““It is imperative that ecologists and archaeologists It is imperative that ecologists and archaeologists work more closely together, creating a truly cross-work more closely together, creating a truly cross-disciplinary alliance that will help to advance both disciplinary alliance that will help to advance both
fields.”fields.”
Briggs et al. 2006: Why ecology needs archaeologists and archaeology needs Briggs et al. 2006: Why ecology needs archaeologists and archaeology needs ecologists. Frontiers Ecol 4:180-188.ecologists. Frontiers Ecol 4:180-188.
Kent, B.W., 1992. Making dead oysters talk: techniques for analyzing oysters Kent, B.W., 1992. Making dead oysters talk: techniques for analyzing oysters from archaeological sites. MD Historical Trustfrom archaeological sites. MD Historical Trust
Overview of Talk
Sampling a natural reef populations (n = 3 reps/mo.)Sampling a natural reef populations (n = 3 reps/mo.)o BooneaBoonea live:dead ratios live:dead ratioso Measured individual live and dead Measured individual live and dead BooneaBoonea using digitized images and measuring using digitized images and measuring
softwaresoftwareo Measured all live oystersMeasured all live oysterso Recorded other physical dataRecorded other physical data
Re-examined other SC Re-examined other SC BooneaBoonea data from natural and constructed reef data from natural and constructed reef populationspopulations
Address the validity of Address the validity of BooneaBoonea size in archaeological research across the size in archaeological research across the southeastern U.S. as an indicator of harvesting ‘season’ by indigenous peoplessoutheastern U.S. as an indicator of harvesting ‘season’ by indigenous peoples
Utility for other current intertidal/subtidal reef restoration efforts Utility for other current intertidal/subtidal reef restoration efforts
Noting that few if any have quantified or even noted Noting that few if any have quantified or even noted BooneaBoonea in their resident in their resident sampling efforts!sampling efforts!
Since January 2006, we have been sampling Since January 2006, we have been sampling at monthly intervals (9 analyzed to date) at a at monthly intervals (9 analyzed to date) at a natural intertidal oyster reef:natural intertidal oyster reef:
Brumbaugh, Beck, Coen, Craig Brumbaugh, Beck, Coen, Craig and Hicks, 2006. TNC, 28pp.and Hicks, 2006. TNC, 28pp.
Developed Design & Monitoring Manuals, Developed Design & Monitoring Manuals, Working Groups, WebsitesWorking Groups, Websites
Oyster Restoration Working GroupOyster Restoration Working Group http://www.coastal.edu/marine/sgoysterhttp://www.coastal.edu/marine/sgoyster
Coen, Wilber, Walters, Hadley, Coen, Wilber, Walters, Hadley, 2006. SC Sea Grant2006. SC Sea Grant
Burrows et al. 2005. Ch. 4, Vol. Burrows et al. 2005. Ch. 4, Vol. 2, Restoration Monitoring of 2, Restoration Monitoring of
Oyster Reefs, NOAAOyster Reefs, NOAA
Mussel densities can exceed 1,300 per mMussel densities can exceed 1,300 per m22
Little Understood Reef ‘Players’Little Understood Reef ‘Players’
Boonea impressa,Boonea impressa,an ectoparasite of an ectoparasite of
oysters, Dermo vectors, otheroysters, Dermo vectors, otherrelevance?relevance?
SC over-winters over 33% of the eastern race of SC over-winters over 33% of the eastern race of oyster catchers (forage & breeding sites)oyster catchers (forage & breeding sites)
Boonea impressa, Boonea impressa, 1-6 mm 1-6 mm longlong
What We Know in General About What We Know in General About BooneaBoonea
Ectoparasite of bivalves, including, but not limited to Ectoparasite of bivalves, including, but not limited to Crassostrea Crassostrea virginica virginica (e.g.,(e.g., 36 spp. incl.36 spp. incl. Crepidula Crepidula, , GeukensiaGeukensia,, Urosalpinx Urosalpinx))
Reproduction all year, with peaks spring-summer; Reproduction all year, with peaks spring-summer; spermatophore, small eggs (<240 µm), 20-250 hatch 3-5 days, spermatophore, small eggs (<240 µm), 20-250 hatch 3-5 days, larval duration <7 days, some debate whether planktotrophic vs. larval duration <7 days, some debate whether planktotrophic vs. lecithotrophic developmentlecithotrophic development
Feeds on hemolymph from mantle or gill with proboscisFeeds on hemolymph from mantle or gill with proboscis
One of the mechanisms purported toOne of the mechanisms purported to be a mode of Dermobe a mode of Dermo ((P. P. marinusmarinus) dispersal and transmission among oysters, along with ) dispersal and transmission among oysters, along with water borne transmissionwater borne transmission
Can depress host growth rates (by stress or parasite load?), but Can depress host growth rates (by stress or parasite load?), but effects termed by most ‘short-term’?effects termed by most ‘short-term’?
Boonea cont.Boonea cont.
Can reach densities >100 individuals/oyster, 20-40 more typical Can reach densities >100 individuals/oyster, 20-40 more typical for large oysters, 4-5/oyster common for VA-NJ sitesfor large oysters, 4-5/oyster common for VA-NJ sites
Gregarious behavior, often moving daily (‘density-vague’, Wilson Gregarious behavior, often moving daily (‘density-vague’, Wilson et al. 1988)et al. 1988)
Dredged (=subtidal?) samples often yield few individuals Dredged (=subtidal?) samples often yield few individuals
Snails use an attachment thread to help them maintain their Snails use an attachment thread to help them maintain their position if dislodged, sensitive to vibrationposition if dislodged, sensitive to vibration
Live approx. one year, peak reproduction May-July; July-Aug., 1 Live approx. one year, peak reproduction May-July; July-Aug., 1 mm or smaller; Fall, >3-5 mm; often gregariousmm or smaller; Fall, >3-5 mm; often gregarious
In FL, recruiting hermit crabs use dead In FL, recruiting hermit crabs use dead BooneaBoonea shells as they settle shells as they settle out of plankton (P. Wilber pers. obs.)out of plankton (P. Wilber pers. obs.)
We have an We have an extensive and unique datasetextensive and unique dataset quantifying live:dead quantifying live:dead Boonea Boonea
Long-term studies in SC on natural and constructed intertidal oyster reefs have pointed Long-term studies in SC on natural and constructed intertidal oyster reefs have pointed to the ectoparasitic gastropod,to the ectoparasitic gastropod, Boonea impressa Boonea impressa (Pyramidelidae) as an ‘important’ (Pyramidelidae) as an ‘important’ constituent of reef resident faunasconstituent of reef resident faunas
PreviousPrevious B. impressa B. impressa work in SC and elsewhere has focused on:work in SC and elsewhere has focused on: Systematics, host energetic costs, host-to-host (bivalves) transmission of Systematics, host energetic costs, host-to-host (bivalves) transmission of
Perkinsus marinusPerkinsus marinus, effects on host growth and filtration rates, and to a lesser , effects on host growth and filtration rates, and to a lesser extent snail population ecology extent snail population ecology
Since the early 1990s, archaeologists (e.g., M. Russo, Nat. Park Service) have usedSince the early 1990s, archaeologists (e.g., M. Russo, Nat. Park Service) have used Boonea Boonea to derive prehistoric seasonal oyster foraging patterns from midden collections to derive prehistoric seasonal oyster foraging patterns from midden collections in the southeastern U.S. based on their presence/modal size. in the southeastern U.S. based on their presence/modal size.
Since 1995, we have separated live and dead Since 1995, we have separated live and dead Boonea,Boonea, assessed live:dead ratios (% assessed live:dead ratios (% live), live), but never measured individuals, nor collected monthly samplesbut never measured individuals, nor collected monthly samples
However, we did observe seasonal, reef ‘age’ and tidal height variations However, we did observe seasonal, reef ‘age’ and tidal height variations
GOALSGOALS: 1) to look at our : 1) to look at our Boonea Boonea information from numerous sites collected since 1990s; information from numerous sites collected since 1990s; 2) to assess the validity of their assumptions using extant populations, given that 2) to assess the validity of their assumptions using extant populations, given that archaeologists archaeologists cannotcannot tease apart live vs. dead animals as we can. tease apart live vs. dead animals as we can.
Background and Study GoalsBackground and Study Goals
From: H.W. Wells, 1959. NautliusFrom: H.W. Wells, 1959. Nautlius Followed sizes for 18 mo. in NCFollowed sizes for 18 mo. in NC
Presumably measured only live animals?Presumably measured only live animals?
JulyJuly JulyJuly
NC
FL
Closest fit between extant and Closest fit between extant and midden midden BooneaBoonea collections, collections,
springspring
Xanth
idae
O. t
au
G. b
osc
B. im
pres
sa
A. het
eroc
hael
is
0
200
400
600
800
1000
1200
On-bottom off-bottom Intertidal
Past SC Inlet Creek Work on Past SC Inlet Creek Work on Boonea Boonea
AbundanceAbundance
From: R. Kalisperis (Giotta), 1999From: R. Kalisperis (Giotta), 1999Trays = 76 cm x 53 cm x 13 cm, 0.418 mTrays = 76 cm x 53 cm x 13 cm, 0.418 m22, n = 5, n = 5June 12, 1997- June 12, 1998June 12, 1997- June 12, 1998
Adj. Adj. ~700/m~700/m22,,
Jan. 1998Jan. 1998
Inlet Creek Long-Term Inlet Creek Long-Term Study SiteStudy Site
Mea
n N
o. P
er 0
.42
mM
ean
No
. Per
0.4
2 m
22 (+
1SE
) (
+1S
E)
Long-Term Sampling Results Long-Term Sampling Results From Our Two SC ORP SitesFrom Our Two SC ORP Sites
Mean Mean BooneaBoonea abundance adj./m abundance adj./m22 on natural and on natural and experimental (constructed) reefs (n = 9) at our experimental (constructed) reefs (n = 9) at our
two Charleston study sites over six yearstwo Charleston study sites over six years
Interestingly, densities on six Interestingly, densities on six constructed reefs were constructed reefs were consistently consistently lowlow for 6 years of for 6 years of sampling, regardless of time of sampling, regardless of time of yearyear
July natural July natural reef densities werereef densities were consistently lowconsistently low, whereas , whereas January January natural natural reef densities werereef densities were high high..
ACE Basin Constructed Reefs ACE Basin Constructed Reefs Boonea Boonea - Oyster January 2005 Patterns- Oyster January 2005 Patterns
Reefs constructed, 6/2000Reefs constructed, 6/2000w/variety of shellw/variety of shell
Sampled 1/7/05Sampled 1/7/05w/replicate 0.25 mw/replicate 0.25 m2 2
quadratsquadrats~4.5 yr old~4.5 yr old
2005 Live and Dead Boonea
Adjusted to Per m2 Two Sisters Creek, ACE
0
500
1000
1500
2000
2500
Recyc
led S
hell
Whe
lk She
ll
Gulf S
hell
Seed
Shell
Mea
n N
um
ber
of
Bo
on
ea p
er m
2 (+
1SE
)
Live Boonea
Dead Boonea
90.2%
94.5%
94%
73.3%n = 6 n = 3n = 6
n = 4
% Mean Live % Mean Live BooneaBoonea above bars above barsn = sample sizen = sample size
2005 Total Live and Dead Boonea at Two Sisters
0
500
1000
1500
2000
2500
3000
Recycled Shell Whelk Shell Gulf Shell Seed Shell
Mea
n B
oo
nea
(L
+D
) /m
2 +
1 S
E
Aerial of Fort Johnson
Year-Long Study Site Near Our Year-Long Study Site Near Our Lab Lab
(9 of 13 months to date)(9 of 13 months to date)
Study site near Fort Johnson Study site near Fort Johnson
N 32N 32oo.74579’, W 79.74579’, W 79oo.90356’.90356’
Boonea Boonea Sampling, Dog House Sampling, Dog House CreekCreek
Three oyster samples (0.125 m2/mo.), sieved over 0.5 mm mesh
Boonea Boonea Monthly Monthly CollectionsCollections
(both live and dead)(both live and dead)
The 3 replicate, 0.125 mThe 3 replicate, 0.125 m2 2
samples sorted samples sorted
Photos using a Nikon Photos using a Nikon Coolpix 995 grids on a Coolpix 995 grids on a
Nikon SMZ645 Nikon SMZ645 dissecting microscopedissecting microscope
Grid is 2 x 2 Grid is 2 x 2 cmcm
Prep for BPrep for Boonea oonea ImagingImaging
Boonea Boonea Separated into Live & Dead Categories Separated into Live & Dead Categories & then Oriented for Image Capture & & then Oriented for Image Capture &
MeasurementMeasurement
Measuring Live and Dead Measuring Live and Dead BBooneaoonea
Claudia using SigmaScan Pro Ver. 5Claudia using SigmaScan Pro Ver. 5
Measured shell lengths (green lines) Measured shell lengths (green lines) from from
apex to abapical end for each individual apex to abapical end for each individual (up to 500/sample)(up to 500/sample)
General Monthly Patterns: % Live, General Monthly Patterns: % Live, SizeSize
Densities of live Densities of live BooneaBoonea fell off fell off precipitously until July ’06, when precipitously until July ’06, when new recruits arrive (<2 mm TL)new recruits arrive (<2 mm TL)
Within two months, new recruits Within two months, new recruits have nearly doubled in sizehave nearly doubled in size
Populations once again reached Populations once again reached maximum densities in 2-3 maximum densities in 2-3 monthsmonths
0
2000
4000
6000
8000
10000
12000
14000
Jan Feb Mar Apr May Jun Jul Aug Sep
2006
DeadLive
Tot
al n
umbe
r/m
2
0
20
40
60
80
100Ja
n
Feb Mar
AprM
ay Jun Jul
Aug Sep
2006
LiveDead
% L
ive
Boonea
Compared to above Russo Compared to above Russo (1991) data, very similar for 9 (1991) data, very similar for 9 months we havemonths we have
JulyJuly
0102030405060708090
100
2006
Mea
n Pe
rcen
t Liv
e (+
SE
)
****
Jan July
Jan July
Sampling Results From Our Two Long-Term Sampling Results From Our Two Long-Term Oyster Restoration (ORP) SitesOyster Restoration (ORP) Sites
Mean Mean BooneaBoonea abundances for natural & constructed reefs abundances for natural & constructed reefs (n = 9) at 2 sites over 6 years. Note: for 1995 & 1996, sampling also occurred(n = 9) at 2 sites over 6 years. Note: for 1995 & 1996, sampling also occurred
in March (95), May (95), Sept. (95), Nov. (95), April (96), & Oct. (96)in March (95), May (95), Sept. (95), Nov. (95), April (96), & Oct. (96)
Low July densities Low July densities relative to the relative to the January natural reef January natural reef numbers perhaps numbers perhaps from turnover of from turnover of new very small new very small recruits?recruits?
March, Sept. & Nov. March, Sept. & Nov. 1995, Oct. 96, 1995, Oct. 96, densities high alsodensities high also
0
500
1000
1500
2000
2500
2005 2006 2005 2006 2005 2006 2005 2006
Experimental Reefs Natural Reefs Experimental Reefs Natural Reefs
TOLER'S COVE INLET CREEK
Mea
n B
oo
nea
per
m2
(+1S
E)
Live Boonea
Dead Boonea
89.6%77.7%
57.6%
69.5%
37.8% 36.0%
66.9%
73.2%
% Live Boonea shown above bars
May 05
Two Long-Term Oyster Restoration Two Long-Term Oyster Restoration Sites March & May 2005 & January Sites March & May 2005 & January
20062006
41.2% 41.5%
83.6%
66.9%
88.8%
46.5%
73.8%
Natural Reefs on 3/3/05 and Exp Reefs on 5/4/05;Natural Reefs on 3/3/05 and Exp Reefs on 5/4/05; % Live above% Live above
Mar 05Mar 05Mar 05Mar 05May 05
Jan 06Jan 06
May 05 May 05
Mar 05Mar 05Mar 05Mar 05
Jan 06Jan 06
Jan 06Jan 06
Jan 06Jan 06Jan 06Jan 06
NumbersNumbers
Mea
n B
oone
a pe
r m2
(+1S
E)
Dog House Creek, Live Dog House Creek, Live BooneaBoonea x Oysters x Oysters All Monthly (9) Samples All Monthly (9) Samples
5/06
9/06
8/06
7/06
6/06
1/06
3/06
4/06
2/06
Past efforts have found little or no Past efforts have found little or no relationship between ‘oyster size’ relationship between ‘oyster size’
and ‘and ‘Boonea Boonea ‘ densities (all 27 ‘ densities (all 27 samples)samples) Monthly Means for nine samplesMonthly Means for nine samples
Dog House CreekDog House Creek, Boonea , Boonea Size-Freq., April ’06Size-Freq., April ’06Combined, Reps 1-3Combined, Reps 1-3
Mean size of Live Boonea: 4.75 mm Mean size of Dead Boonea: 3.88 mm
86% (range, 76-91%) total individuals liveLive/Dead sizes overlap
0
5
10
15
20
25
30
35
40
0 0.4 0.8 1.2 1.6 2 2.4 2.8 3.2 3.6 4 4.4 4.8 5.2 5.6 6 6.4 6.8
Size class (mm)
Live Boonea
Dead Boonea
Num
ber
of I
ndiv
idua
ls
Apr 2006Rep #1
Total Live = 177Total live measured = 177Mean size = 4.74 mmPercent Live = 76%
Total Dead = 56Total dead measured = 28Mean size = 3.79 mm
0
20
40
60
80
100
120
0 0.4 0.8 1.2 1.6 2 2.4 2.8 3.2 3.6 4 4.4 4.8 5.2 5.6 6 6.4 6.8
Size class (mm)
Live Boonea
Dead Boonea
Num
ber
of I
ndiv
idua
ls
Apr 2006Rep #2
Total Live = 583Total live measured = 492Mean size = 4.74 mmPercent Live = 83%
Total Dead = 116Total dead measured = 60Mean size = 3.88 mm
0
20
40
60
80
100
120
0 0.4 0.8 1.2 1.6 2 2.4 2.8 3.2 3.6 4 4.4 4.8 5.2 5.6 6 6.4 6.8
Size class (mm)
Live Boonea
Dead Boonea
Num
ber
of I
ndiv
idua
ls
Apr 2006Rep #3
Total Live = 843Total live measured = 500Mean size = 4.76 mmPercent Live = 91%
Total Dead = 82Total dead measured = 42Mean size = 3.96 mm
0
50
100
150
200
250
300
0 0.4 0.8 1.2 1.6 2 2.4 2.8 3.2 3.6 4 4.4 4.8 5.2 5.6 6 6.4 6.8
Size class (mm)
Live Boonea
Dead Boonea
Num
ber
of I
ndiv
idua
ls
April 2006Combined, Reps 1-3
Total Live = 1,594Total live measured = 1,169Mean size = 4.75 mmPercent Live = 86%
Total Dead = 254Total dead measured = 131Mean size = 3.88 mm
0
10
20
30
40
50
60
70
80
0 0.4 0.8 1.2 1.6 2 2.4 2.8 3.2 3.6 4 4.4 4.8 5.2 5.6 6 6.4 6.8
Size class (mm)
Live Boonea
Dead Boonea
Num
ber
of I
ndiv
idua
ls
July 2006Rep #3
Total Live = 216Total live measured = 195Mean size = 1.57 mmPercent Live = 70%
Total Dead = 93Total dead measured = 58Mean size = 3.60 mm
0
50
100
150
200
250
300
350
400
0 0.4 0.8 1.2 1.6 2 2.4 2.8 3.2 3.6 4 4.4 4.8 5.2 5.6 6 6.4 6.8
Size class (mm)
Live Boonea
Dead Boonea
Num
ber
of I
ndiv
idua
ls
July 2006Rep #2
Total Live = 1,027Total live measured = 992Mean size = 1.53 mmPercent Live = 58%
Total Dead = 729Total dead measured = 302Mean size = 3.38 mm
0
100
200
300
400
500
600
0 0.4 0.8 1.2 1.6 2 2.4 2.8 3.2 3.6 4 4.4 4.8 5.2 5.6 6 6.4 6.8
Size class (mm)
Live Boonea
Dead Boonea
Num
ber
of I
ndiv
idua
ls
Jul 2006Rep #1
Total Live = 1,605Total live measured = 1,533Mean size = 1.68 mmPercent Live = 90%
Total Dead = 170Total dead measured = 105Mean size = 2.28 mm
Dog House Creek, New Dog House Creek, New Recruits in July ’06Recruits in July ’06
Combined, Reps 1-3Combined, Reps 1-3
Mean size of Live Boonea: 1.62 mm Mean size of Dead Boonea: 3.20 mm
74% (range, 58-90%) total individuals liveLive/Dead sizes do not overlap
0
100
200
300
400
500
600
700
800
900
1000
0 0.4 0.8 1.2 1.6 2 2.4 2.8 3.2 3.6 4 4.4 4.8 5.2 5.6 6 6.4 6.8
Size class (mm)
Live Boonea
Dead Boonea
Num
ber
of I
ndiv
idua
ls
July 2006Combined, Reps 1-
3Total Live = 2,852Total live measured = 2,724Mean size = 1.62 mmPercent Live = 74%
Total Dead = 992Total dead measured = 465Mean size = 3.20 mm
Dog House Creek, All Dog House Creek, All Boonea Boonea (Live + (Live + Dead) Dead)
Monthly (9) SamplesMonthly (9) Samples
0
100
200
300
400
500
600
700
800
900
0 0.4 0.8 1.2 1.6 2 2.4 2.8 3.2 3.6 4 4.4 4.8 5.2 5.6 6 6.4 6.8
Size class (mm)
Dead
Live Total collected = 3844Mean size = 1.84
Total Live = 2852Total live measured = 2724Mean size = 1.62Percent Live = 74
Total Dead = 992Total dead measured = 465Mean size = 3.20
Num
ber
of I
ndiv
idua
ls
Jul 2006
0
100
200
300
400
500
600
700
800
900
0 0.4 0.8 1.2 1.6 2 2.4 2.8 3.2 3.6 4 4.4 4.8 5.2 5.6 6 6.4 6.8
Size class (mm)
Dead
Live Total collected = 1848Mean size = 4.66
Total Live = 1594Total live measured = 1169Mean size = 4.75Percent Live = 86
Total Dead = 254Total dead measured = 131Mean size = 3.88
Num
ber
of I
ndiv
idua
ls
Apr 2006
0
100
200
300
400
500
600
700
800
900
0 0.4 0.8 1.2 1.6 2 2.4 2.8 3.2 3.6 4 4.4 4.8 5.2 5.6 6 6.4 6.8
Size class (mm)
Dead
Live
Total collected = 2258Mean size = 4.39
Total Live = 2079Total live measured = 2075Mean size = 4.41Percent Live = 90
Total Dead = 242Total dead measured = 183Mean size = 4.14+/-0.067 SE
Num
ber
of I
ndiv
idua
ls
Jan 2006
Dog House Modal Data Analyzed Dog House Modal Data Analyzed (Mike Russo, NPS)(Mike Russo, NPS)
0
10
20
30
40
50
60
70
1 1.5 2 2.5 3 3.5 4 4.5 5 5.5 6 6.5 7
June
July
August
September
JulyAug
Sept
June
% M
odal S
ize R
ange
% M
odal S
ize R
ange
BooneaBoonea Size Range (mm) Size Range (mm)
Live Live BooneaBoonea Data, Russo Data, Russo 19911991
Near St. Augustine, FLNear St. Augustine, FL
• Our % live results suggest that regardless of collection time, relative ‘numbers’ from month to month are comparable
• Dead Boonea may decrease overall mean size, but the change is minimal in terms of monthly or seasonal modes or means, as rounded by archaeologists
• Mean size in SC suggest dead Boonea are probably ‘recent’ dead and not dead from an extended period from months to years
• Mean dead sizes were smaller from Jan. to June, suggesting they were from that year's cohort • For June-August, mean dead sizes were greater vs. mean lives sizes, suggesting that dead snails are
stragglers from the previous year’s cohort
Preliminary Findings
Recruitment occurs during a very short window in July 06 Recruitment occurs during a very short window in July 06
Individual sample % live values ranged from low Individual sample % live values ranged from low 37%37% (June rep. #2) to a high of (June rep. #2) to a high of 95%95% (Jan. rep. # 2) (Jan. rep. # 2)
Monthly mean (n =3) live %: from low of Monthly mean (n =3) live %: from low of 40%40% (June) to (June) to high of high of 90%90% (Jan.) (Jan.)
Individuals reach max size and population densities in Individuals reach max size and population densities in only a few months, post-hatchingonly a few months, post-hatching
Measurements and monthly sampling appear to explain Measurements and monthly sampling appear to explain our previous seasonal observations for our previous seasonal observations for BooneaBoonea densities densities at our other SC restoration study sites. at our other SC restoration study sites. Encourage others Encourage others to look at to look at BooneaBoonea, even if just live snails!, even if just live snails!
Although Although BooneaBoonea from midden archaeological sampling from midden archaeological sampling efforts cannot distinguish live from dead, our results efforts cannot distinguish live from dead, our results when analyzed using their approach (modal %, etc.) when analyzed using their approach (modal %, etc.) seem to support their assumptions and resultsseem to support their assumptions and results
Signatures for seasons best approach for midden Signatures for seasons best approach for midden samples vs. using monthly datasamples vs. using monthly data
After 9 (out of 13) months of sampling:After 9 (out of 13) months of sampling:
AcknowledgementsSpecial thanks for generous input/efforts:
Virginia Shervette, Mike Russo, Nancy Hadley, Evan Ward, David Bushek, Julie Pai, Darin Jones, Emma Gerald, Michael Hodges, Julie Nelson, Amanda Powers, Lee Taylor, Claudia
Jendron, Donnia Richardson, Mike Yianopoulos & Bill Anderson