Diamondback Terrapin Population Changes
and GPS Tracking
Presented by: Alexandra Kanonik & Maria Roe

Malaclemys terrapin
● Only species of the family Emydidae
specialized to estuarine habitats
● Sexually dimorphic
○ Females from 15 to 23 cm,
Males 10 to 14 cm
● Keystone species in Jamaica Bay
○ Curbs invertebrate populations
and maintains nutrient
pathways
“your friendly neighborhood turtle”

Celebrating our 20th year of research!
• Aim was to study nesting behavior
and ecology of terrapins by catching
and uniquely marking individuals.
• Research
• Education
• Citizen
Science
Dr. Russell Burke and graduate student Adriana

Many partners and volunteers throughout the years:

2018 was the year for two new regulations giving terrapins more
protections:
● On May 1, 2018 the NYS DEC announced “the closure of the
commercial harvest of terrapins and added the species to the list
of native turtles with no open season”.
● On March 28, 2018 DEC added regulations to “put
forth a requirement for diamondback terrapin
excluder devices on commercial and recreational
crab pots set in near shore harbors, creeks, coves,
rivers and tributaries in New York's Marine and
Coastal Districts”.
Terrapin Excluder Device (TED) on crab pot

“How are terrapins doing”?
What we learned about the Jamaica Bay population
after 20 years of mark-recapture work

Jamaica Bay Nesting Sites

Jamaica Bay Nesting Sites
Ruler’s
Bar
JFK

Current Threats in Jamaica Bay
Habitat destruction
Marsh Loss
Coastal Storms
Predation
Recreational boats
Derelict fishing gear
Pollution

Captures & Recaptures
Females are PIT tagged, measured, examined for
abnormalities, and released at point of capture.
1,078 individual female terrapins marked in
Ruler’s Bar (2003-2018)
● 686 total recaptures
3,130 individuals marked in JFK (2011-2018)
• 1,015 total recaptures

Adult Female Survival
Ruler’s Bar Best Supported Models:
• Resident survival decreasing
from 0.92
• Female survival declined for 2
years post-Hurricane Sandy
JFK Best Supported Model:
• Resident survival constant
over time at 0.92

Major Injuries- Ruler’s Bar Major Injuries
• Damage to 2 or more adjacent costal or
vertebral scutes
• Damage to 3 or more adjacent marginal
scutes
• Missing limbs
• Dislocated limb bones
2.9%
15.6%
17%
17.8% of females in Ruler’s Bar
exhibited major injuries (2009-2018)
• Predominantly shell damage

Major Injuries- Ruler’s Bar
17% of females in Ruler’s Bar
exhibited major injuries (2009-2018)
• Predominantly shell damage
Survival is lower after major injuries
• Persistent infection
• Increased vulnerability to
predators
• Survival of females with little to no injuries: 0.92
• Survival of females with major injuries: 0.88

Female Terrapin first found in 2011 Same exact female found again in 2018!
But...Major Injuries can heal!

Ruler’s Bar Population

JFK Population

Population Movement
Diamondback terrapins exhibit site fidelity
• Minimal interchange between populations
• 11 individuals found in both locations
Evidence of transient individuals found in both Ruler’s Bar and JFK
• 17% of newly tagged terrapins in RB
• 27% of newly tagged terrapins in JFK
Temporary emigrants?
What are their movement patterns?

Next Steps:
Tracking turtles in real-time using GPS transmitters
● Deployed 9 total units this past August
Charging up via solar power.
Relay tower installed at Littoral Society HeadquartersTerrapin model tests fit on to shell

Questions?
Thank You!
Link to our website at: http://jbtr.org/
Link to our Facebook Page at:
Jamaica Bay Terrapin Research and Conservation
https://www.facebook.com/groups/92834779554/Photo credits: Don Riepe, Peter Hyung Yoon & Dexter Raphael
jbtr.org website was created by:nexxite.com