Conservation biology of the smalltooth Conservation biology of the smalltooth sawfish: science to help save the USA's sawfish: science to help save the USA's
first endangered elasmobranchfirst endangered elasmobranch
Tonya Wiley and Beau YeiserCenter for Shark Research
Elasmobranch Conservation Biology Program
What are sawfish?What are sawfish?• Members of the family Members of the family
PristidaePristidae• A type of rayA type of ray• All possess the distinctive All possess the distinctive
toothed rostrum or sawtoothed rostrum or saw• Inhabit tropical and Inhabit tropical and
subtropical coastal, subtropical coastal, estuarine and fresh watersestuarine and fresh waters
• Seven known species, six Seven known species, six in in PristisPristis
• Taxonomy is still confused Taxonomy is still confused and needs revisionand needs revision
• Historically largetooth and Historically largetooth and smalltooth sawfish in the smalltooth sawfish in the USUS
Pristis pectinata Pristis pectinata in US in US waterswaters• Historically common Historically common
from the Mexican from the Mexican border to Carolinasborder to Carolinas
• Summer migrations Summer migrations from Florida and from Florida and Georgia north to Georgia north to Carolinas and Carolinas and Virginia (and Virginia (and sometimes even sometimes even Long Island)Long Island)
The decline of The decline of P. pectinataP. pectinata
• From 1900 to 2000 From 1900 to 2000 the population is the population is estimated to have estimated to have declined in excess of declined in excess of 95%95%
• Extirpated from most Extirpated from most of its historic range, of its historic range, only occurs regularly only occurs regularly in southwest Florida in southwest Florida and Florida Keysand Florida Keys
0
3
6
9
12
15
Year
CP
UE
(lb
/ge
ar
un
its
) Louisiana sawfish abundance
The causes of the The causes of the P. P. pectinata pectinata declinedecline• Mortality in fisheries Mortality in fisheries
(commercial and (commercial and recreational), recreational), especially due to especially due to netsnets
• Loss of important Loss of important nearshore habitat, nearshore habitat, especially for the especially for the juvenilesjuveniles
• Late maturing, Late maturing, produce few youngproduce few young
Male Size at Male Size at MaturityMaturity
Previous data
270 cm (~9 feet)
New data between
320-372 FL
340-395 STL
(~11 feet)
March 2002-Nine Mile Bank
March 2003-Nine Mile Bank
May 2007-East Cape Canal
July 2007-Florida Keys
May 2007-East Cape Canal
The USA’s first endangered The USA’s first endangered elasmobranchelasmobranch
• TOC petitioned for ESA TOC petitioned for ESA listing in 1999listing in 1999
• Status reviewStatus review• April 1, 2003 April 1, 2003 P. pectinata P. pectinata was added to was added to
the US Endangered the US Endangered Species ListSpecies List
• Also:Also:– Protected in Florida Protected in Florida
since 1992since 1992– Critically Endangered Critically Endangered
listing by IUCNlisting by IUCN– Endangered Listing by Endangered Listing by
AFSAFS– CITES Appendix 1CITES Appendix 1
Mote research on Mote research on P. P. pectinatapectinata
• Goal is to provide the Goal is to provide the scientific basis for scientific basis for population recoverypopulation recovery– Determination of Determination of
distribution and distribution and abundanceabundance
– Identification of critical Identification of critical habitathabitat
– Population geneticsPopulation genetics– Population and habitat Population and habitat
modeling modeling
Outreach & EducationOutreach & Education• Ask the public to report Ask the public to report
any captures or any captures or sightings of sawfishsightings of sawfish
• Texas to North CarolinaTexas to North Carolina
• Public can easily identify Public can easily identify sawfish correctlysawfish correctly
• Due to rarity, the public Due to rarity, the public is a good way to sample is a good way to sample a wide area a wide area continuouslycontinuously
Sawfish encounters 1998-Sawfish encounters 1998-20072007
Sawfish encounters 1998-Sawfish encounters 1998-20072007
Size and depth distributionsSize and depth distributions
• Full size range of Full size range of animals reportedanimals reported
• Majority of animals Majority of animals reported are juvenilesreported are juveniles
• Small Small P. pectinataP. pectinata limited to shallow limited to shallow waters (<5m)waters (<5m)
• Larger Larger P. pectinataP. pectinata have a wider depth have a wider depth distributiondistribution
0
10
20
30
40
50
60
Estimated length (cm)
Fre
qu
en
cy
y = 0.0297x - 2.4076
R2 = 0.1345
0
10
20
30
40
50
60
70
80
0 100 200 300 400 500 600
Total length (cm )
De
pth
(m
)
Field SurveysField Surveys
Gillnet and seine Rod and reel
Longline
Spring Juvenile SurveysSpring Juvenile Surveys
•13 sawfish captured
•11 YOY
•2 Immature
•2 new nursery locations (Huston Coves & Bay)
Grocery Creek
Mud Bay
Last Huston Bay
Huston Coves
East Cape Canal
Whitewater Bay
Eagle Key
Habitat use through manual Habitat use through manual trackstracks
Habitat use by juvenile Habitat use by juvenile P. P. pectinatapectinata• Movements are Movements are
strongly influenced by strongly influenced by tide tide
• Remain in very shallow Remain in very shallow water (<50 cm)water (<50 cm)
• Relatively small home Relatively small home range over short range over short periods (days) and periods (days) and often longer periods often longer periods (months)(months)
High tide
Mid tide
Low tide
Habitat use by juvenile Habitat use by juvenile P. P. pectinatapectinata
VR 2 monitoring
1548
1549
1550
1551
4/17/2003 0:00 4/18/2003 0:00 4/19/2003 0:00 4/20/2003 0:00 4/21/2003 0:00 4/22/2003 0:00 4/23/2003 0:00 4/24/2003 0:00 4/25/2003 0:00 4/26/2003 0:00 4/27/2003 0:00 4/28/2003 0:00 4/29/2003 0:00
Time
Sta
tio
n p
rese
nse
Site fidelity studiesSite fidelity studies•Use moored Use moored acoustic listening acoustic listening stations to record stations to record the the presence/absence presence/absence and movements of and movements of sawfishsawfish
Satellite telemetry of large Satellite telemetry of large P. pectinataP. pectinata
• Wildlife Wildlife Computers PAT Computers PAT tags used to tags used to examine longer-examine longer-term term movements of movements of sawfishsawfish
• Archive location, Archive location, depth and temp. depth and temp. data and then data and then send via satellite send via satellite after pop-upafter pop-up
Satellite TaggingSatellite Tagging
Four sawfish:
400 cm TL F - Nov 2006
382 cm TL F - Nov 2006
210 cm TL F - May 2007
330 cm TL M - May 2007
Satellite Tagging-ResultsSatellite Tagging-ResultsDays Since Release
-80
-70
-60
-50
-40
-30
-20
-10
0
0 20 40 60 80 100 120
De
pth
(m
)
06A0532 Released Nov 14 2006 06A0533 Released Nov 15 2006
•Two females
•Data from November 2006 to February 2007
•Similar depth profile
•Data still being analyzed
Starting this Fall…Starting this Fall…
• Monitor the movements, residency time, possible aggregations and habitat use of large sawfish in Everglades National Park and the Florida Keys using BRUVS, and PAT and SPOT tags
BRUV’s
Critical habitat for Critical habitat for P. P. pectinatapectinata
• The next step is to The next step is to determine critical determine critical habitathabitat
• Depth, salinity, Depth, salinity, temperature, temperature, substrate etcsubstrate etc– Juvenile areasJuvenile areas
• PuppingPupping• Growth to maturityGrowth to maturity
– Adult areasAdult areas• FeedingFeeding• MatingMating• AggregationsAggregations• MigrationsMigrations
Critical habitat of Critical habitat of P. P. pectinatapectinata
• Major factors appear Major factors appear to be:to be:– Estuarine areas Estuarine areas
(especially around (especially around river months and lower river months and lower reaches of rivers)reaches of rivers)
– Shallow banks along Shallow banks along mangrove shorelines mangrove shorelines (juveniles)(juveniles)
– Deep channels through Deep channels through shallow areas (adults)shallow areas (adults)
Genetics CollaborationsGenetics Collaborations
• Demian Chapman (Pew Institute for Ocean Science) and Kevin Demian Chapman (Pew Institute for Ocean Science) and Kevin Feldheim (The Field Museum)Feldheim (The Field Museum)
• Objective 1:Objective 1: Determine whether multiple discrete breeding Determine whether multiple discrete breeding populations of sawfish remain in the U.S. that should each be populations of sawfish remain in the U.S. that should each be managed managed independently and locally independently and locally or whether there is only or whether there is only one breeding population that should be managed one breeding population that should be managed as a unit, co-as a unit, co-operatively by federal and state agenciesoperatively by federal and state agencies. (philopatry, . (philopatry, relatedness)relatedness)
• Objective 2:Objective 2: Assess the population history of smalltooth sawfish Assess the population history of smalltooth sawfish in their SW Florida “stronghold” and determine whether they in their SW Florida “stronghold” and determine whether they have suffered a loss of genetic diversity that may compromise have suffered a loss of genetic diversity that may compromise their ability to survive and reproduce in the future.their ability to survive and reproduce in the future.
• Mahmood Shivjy-Nova Southeastern UniversityMahmood Shivjy-Nova Southeastern University• ObjectiveObjective: DNA forensics to identify species of fins and rostra in : DNA forensics to identify species of fins and rostra in
tradetrade
AcknowledgementsAcknowledgements• National Marine Fisheries ServiceNational Marine Fisheries Service• Disney Wildlife Conservation FundDisney Wildlife Conservation Fund• Florida Fish and Wildlife Conservation Florida Fish and Wildlife Conservation
CommissionCommission• Munson FoundationMunson Foundation• Florida Power & LightFlorida Power & Light• National Fish and Wildlife FoundationNational Fish and Wildlife Foundation• National Geographic Conservation TrustNational Geographic Conservation Trust• John Ball Zoo SocietyJohn Ball Zoo Society• Mote Scientific FoundationMote Scientific Foundation