Turtles for the Biology of Reptiles Amphibian Foundation Dr. - - PowerPoint PPT Presentation

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Feb 06, 2024 228 likes •647 views

Turtles for the Biology of Reptiles Amphibian Foundation Dr. Tobias Landberg The Flexible Organism What causes diversity? Responding to challenges at different time scales Behavior Adaptation Plasticity Evolution Where is variation

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Dr. Tobias Landberg

for the Biology of Reptiles

Turtles

Amphibian Foundation

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The Flexible Organism

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What causes diversity?

Responding to challenges at different time scales

Adaptation Behavior Plasticity Evolution

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Where is variation from? P=G+E+G*E

Phenotype Genotype Interaction Environment

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Environment: Behavior

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Environment: Physiological adaptation

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What questions should we ask?

Rhen, T. and Lang, J.W., 1995. Phenotypic plasticity for growth in the common snapping turtle: effects of incubation temperature, clutch, and their interaction. The American Naturalist, 146(5), pp.726-747.

Environment: Developmental plasticity

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What questions should we ask?

Schroeder, A.L., Metzger, K.J., Miller, A. and Rhen, T., 2016. A novel candidate gene for temperature-dependent sex determination in the common snapping turtle. Genetics, 203(1), pp.557-571.

Genotype*Environment Interaction

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Evolution

Lyson, T.R., Schachner, E.R., Botha-Brink, J., Scheyer, T.M., Lambertz, M., Bever, G.S., Rubidge, B.S. and De Queiroz, K., 2014. Origin of the unique ventilatory apparatus of turtles. Nature communications, 5, p.5211.

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Fused ribs Pectoral girdle

Bojanus, 1819

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Volume constraint

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X-ray video during locomotion

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Mitchell & Morehouse, 1863

Anatomy and Physiology of Respiration in the Chelonia "That the locomotive movements may, and perhaps do at times modify the respiratory process, may be taken for granted. That other agents are constantly employed in this function is not less clear…"

Conclusion

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Remote Imaging Study of the Underwater Behavior of Snapping Turtles

Tobias Landberg …with many coauthors Amphibian Foundation

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Snapping turtle of myth and legend Record length 19.5” Record weight 86 pounds

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What are snappers up to?

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Crittercam development & evolution 2008 2015

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Metabolic Hypotheses: Increased underwater activity reduces dive time Increased dive time increases surface time Active underwater behaviors increase surface time

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crittercam deployments 2008-2009 Connecticut

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Success! Field work, research, weather, construction, navigation, diversity, identification, anatomy, physiology, animal care, teamwork, careers, resume writing, boat licenses...

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Jawless?

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Snapping turtle behavior 2008-2014 (14 turtles, ~930 dives, 56+ hours)) Elizabeth DePace Scientific Illustration ’16

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Snapping turtle behavior 2008-2014 (14 turtles)

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Dive duration is affected by behavior

ANCOVA (p<0.001) Rest Trap Burrow Walk Swim Eat

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Surface duration increases with Dive duration

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Surface duration is affected by Dive behavior

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Conclusion

Dive time is limited by active behaviors Surface time increases with dive duration Active behaviors decrease surface time

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Copper Nickel Chromium Lead Mercury Zinc

What’s next? Turtle soup

GRIESBACK, K*; HARTMAN, R; TOBE, S; SCOTT, K; LANDBERG, T Heavy Metal Contaminants in Snapping Turtle Soup from the Philadelphia Area Sunday, Jan. 6, 15:30 (Poster) Central Exhibit Hall P3-92

Ecotoxicology

HARTMAN, R. A.*; GRIESBACK, K.; SCOTT, K. S.; TOBE, S.; LANDBERG, T. Heavy metal contamination of common snapping turtles in the Lower Delaware River watershed 15:30 Central Exhibit Hall P3-89

Blue Heron Nature Preserve

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Heavy Metal Contaminants in Snapping Turtle Soup from the Philadelphia Area

Kiersten Griesback, Ryan A Hartman, Shanan Tobe, Karen S Scott and Tobias Landberg Arcadia University kgriesback@arcadia.edu 

References Abstract Discussion Results Introduction

Snapping turtle soup is a historic dish that remains a menu item in restaurants and taverns in the Philadelphia area. Unfortunately, heavy metals such as iron, lead, mercury and zinc are common in the aquatic environments where these turtles live, and these metals accumulate in turtle tissues through the food web. Though heavy metals negatively affect their reproduction and recruitment, snapping turtles can survive in polluted environments. We examined snapping turtle meat as a food source due to its high potential to transfer acquired heavy metals to the humans that consume it. Samples of snapper soup were acquired from restaurants throughout the lower Delaware River watershed in Pennsylvania (n=40). Meat, fish, and poultry typically contain a level of zinc around 29 ppm, while in vegetables it can be up to 2

ppm. Initial chemical analysis shows that several turtle meat samples contain a level of zinc greater than

these values, and greater than the recommended daily intake value (8 mg per day or 0.11 mg/kg for females and 11 mg per day or 0.14 mg/kg for males). The zinc levels in the samples are not high enough to cause toxicity independently, but combined with other zinc-containing foods consumed in the daily diet, turtle meat can contribute to greater overall zinc levels in the body. High zinc content can cause harmful physiological effects. While our other heavy metal analyses are ongoing, snappers may contain nearly all toxic metals– for which there are no safe levels of consumption. This, combined with ecological data showing that continued harvests of turtle populations for consumption is unsustainable, suggests that snapper soup may be detrimental to both humans and turtles. Keywords: ecotoxicology, bioaccumulation, environmental pollutants, risk assessment

Turtle soup in Philadelphia
Common snapping turtles

○ Chelydra serpentina ○ large size & long lifespan ○ environmental pollutants ○ bioaccumulation of heavy metals

Lower Delaware River Watershed
Harvested wild, USDA farmed & butchered
Null hypothesis: Snapping turtle soup is safe
Predictions: No zinc, mercury, and lead contaminants

Methods

Soup Collection:

30 mile radius of Arcadia

University, PA

frozen
N=9/48

Sample Preparation:

microwave
dissect meat from soup
rinsed & patted dry
35% nitric acid digestion
filtered and diluted to 2%

with deionized water

Zinc contamination:

○ 1/9 samples ○ 3x recommended daily intake (0.11 mg/kg for males and 0.14 mg/kg for females)

Lead & Mercury:

○ 0/9 No detectable levels

Wild turtles:

○ long life spans ○ resilience in pollution ○ low reproduction ○ harvest unsustainable ○ vulnerable to extinction ○ accumulate heavy metals

Future directions:

○ complete sample analysis ○ claws ○ genetics ○ legislation

Mercury (Hg) Analysis Lead (Pb) Analysis Zinc (Zn) Analysis

No Mercury (0/9)
Negative values below

detection limit

Acknowledgements

Special thanks to Dr. Conte at Keystone College who was instrumental in acquiring these data. Also many thanks to Dr. Curotto in Arcadia’s Chemistry department for kind support and Shannon McGrath, Amy Radzelovage, Emily Jerome for their help in the lab and field. (1) Burger, J. & Gibbons, J. (1998). Trace elements in egg contents and egg shells of slider turtles (Trachemys scripta) from the Savannah River site. Archives of Environmental Contamination and Toxicology, 34, 382. (2) Hopkins, B., Willson, J., Hopkins, W. (2013). Mercury exposure is associated with negative effects on turtle reproduction. Environmental Science and Technology, 47(5), 2416-22. (3) Ryan T, Peterman W, Stephens J, Sterrett S. (2014). Movement and habitat use of the snapping turtle in an urban landscape. Urban Ecosystems, 17, 613-623. (4) Tchounwou, P., Yedjou, C., Patlolla, A., Sutton D. (2012). Heavy metal toxicity and the environment. EXS, 101,133-64 (5) Yu, S., Halbrook, R., Sparling, D., Colombo, R. (2011). Metal accumulation and evaluation of effects in a freshwater turtle. Ecotoxicology, 20, 1801–1812. (6) Zinc: Fact Sheet for Health Professionals. (2018). National Institutes of Health. Retrieved from https://

ds.od.nih.gov/factsheets/Zinc-HealthProfessional/
No Lead (0/9)
Negative values below

detection limit

Low Zinc (7/9)
High Zinc (1/9)

Sample Analysis:

ICP-OES, courtesy of Jillian

Conte at Keystone College

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Heavy Metal Contamination of Common Snapping Turtles in the Lower Delaware River Watershed

Ryan A Hartman, Kiersten Griesback, Karen S Scott, Shanan Tobe, Tobias Landberg rhartman@arcadia.edu

Abstract Acknowledgments Discussion Results Methods Introduction

The common snapping turtle (Chelydra serpentina) is a long lived reptile that tolerates tremendous amounts of

pollution. Because of this, they have been used as indicators to monitor toxicity of their environment. The

industrial history of the Philadelphia area as a manufacturer of steel and paper milling led to highly polluted waterways which suggests that the snapping turtles of the region are contaminated with heavy metal pollutants such as zinc, mercury and lead. While zinc is an essential element for humans, there are no known safe levels

f lead consumption. This poses a potential health risk as snapper soup is a Philadelphia regional delicacy

served in restaurants for hundreds of years and trapping turtles for consumption is legal. We examined the heavy metal content of tissue samples of C. serpentina (n= 47 claw clippings from living and additional muscle samples from road-killed turtles) collected in a ~900 square mile area around Philadelphia. Atomic absorption spectroscopy showed detectable heavy metal concentrations in all the samples. As expected, claw tissues of C. serpentina varied dramatically in zinc concentration across sites indicating that local conditions and historical pollution determine metal content. Keratin tissue (AVG= 1351.66μg/g, SD=2292.39μg/g, n=20) showed significantly higher zinc content than muscle (AVG=57.32μg/g, SD=14.59μg/g, n=2). Analysis for lead and mercury are still being investigated. Since turtles throughout the lower Delaware River watershed may have extreme metal concentrations in their tissues, eating turtle flesh from this area may be dangerous to humans in addition to being detrimental to turtle populations already potentially stressed by habitat degradation.  Sample collection

Live Chelydra serpentina, collected by hand
Pennsylvania roads and waterways (n=48)
Keratin was collected from the eight claws
f the hind limbs.
All live specimens were released at their point
f capture shortly after removal.
Muscle tissue was collected from dead

specimens for comparison to its keratin Sample preparation

Weighed
Digested with nitric acid

Apparatus and sample analysis

AA & Vista MPX ICP-OES instrument
Snapping turtle soup is a Philadelphia delicacy.
Chelydra serpentina is a long-lived animal, maturing at 12-15yrs.
Potential for the meat to contain pollutants from their environment

(Bishop et al, 1991; Overman & Krajicek, 1995).

Toxic metals; zinc (Zn), lead (Pb), and mercury (Hg).
Predictions:
Larger, older turtles will show higher concentrations than the smaller,

younger ones (Deprea et al, 2018).

Sites with higher population densities will be more polluted, and will

result in higher levels of metals in turtles that inhabit these areas.

Conclusions:

Zinc in most samples
Several samples showed lead and mercury
Snapping turtles are accumulating pollutants

from their environments in their tissues

Potentially unsafe for human consumption

Hypotheses:

Smaller turtles had higher concentrations of zinc
Reject bioaccumulation hypothesis?
No effect of population density on Zinc levels

Future Directions:

Complete sample
Snapper soup & genetics
Legislation & protection

Zinc (AA)

Decreased with size

(p=0.0153) Mercury (ICP-OES)

One sample exceeds

detection limit Lead (ICP-OES)

Two samples exceed

detection limit Zinc (ICP-OES)

18/31 Samples exceed

detection limit

References

Special thanks to Dr. Jillian Conte at Keystone College who was instrumental in acquiring these data. Also many thanks to Dr. Curotto in Arcadia’s Chemistry department for kind support, and Shannon McGrath, Amy Radzelovage and Emily Jerome for their help in the lab and field. Thanks to the many nature preserves and parks for access and help collecting. Bishop, C.A., Brooks, R.J., Carey, J.H., Ng, P., Norstrom, R.J. and Lean, D.R., 1991. The case for a cause‐effect linkage between environmental contamination and development in eggs of the common snapping turtle (Chelydra s. serpentina) from Ontario, Canada. Journal of Toxicology and Environmental Health, Part A Current Issues, 33(4), pp.521-547. Overmann SR., Krajicek JJ., 1995. Snapping Turtles (Chelydra serpentina) as Biomonitors of Lead   Contamination of the Big River in Missouri's Old Lead Belt. Environmental Toxicology and   Chemistry 14:689–695. Duprea, J., C.J. Hardaway, J. Sneddon, E. Lyonsa, O. E.Christian. 2018.   Determination of selected metals in alligator snapping turtle (Macroclemys temminckii) by inductively coupled plasma-optical emission spectrometry. Microchemical Journal, Volume 137, Pages 27-29. 

Zinc and Population Density

Not affected by population

(p>0.05)

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Conservation Research Bridge Program with Jack Martin, University of San Diego Amphibian Foundation Conservation Research Assistant

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Bridge Program for Conservation Research: A New Route Into the Field

Tobias Landberg* & Mark Mandica, The Amphibian Foundation

What’s a bridge program? Why join a bridge program? Contextualized Instruction Career Development Transition Services Developmental Academic Financial Social When to join a bridge program? Before College During College After College What’s in a bridge program curriculum? Peer Mentoring Field Work Guided Research Creative expression Outreach What’s the problem? Education

While higher education faces declining enrollments in large parts of the country, many young adults are dropping out, transferring or changing majors as they struggle with academic, intellectual, and social challenges of traditional university settings. People who are into amphibian and reptile conservation often have options limited by academic biology programs that may not offer conservation or organismal courses. While some students get opportunities to conduct research as part of their studies, most students can’t get these opportunities as part of formal secondary education. Many realize later in life that they may not have studied the things in college that they cared about most and want to dedicate their lives to. Adults wishing to get experience in conservation research often struggle to find opportunities that will nourish their interests as well as their intellectual and social needs. Bridge programs are tools to help young adults get into a new field. These programs can help students fill gaps in their experience, skills and education stemming from many potential sources in the leaky academic pipeline. We propose our new bridge program as a model of a new tool to train conservation biologists. Our amphibian conservation research bridge program promises to integrate more diversity into the field of conservation by creating a route for people to work with imperiled species in the southeastern United States without first going through the traditional academic path of undergraduate and graduate school.

Abstract

@amphibianfoundation @sciencethegap tobias@amphibianfoundation.org bridge.amphibianfoundation.org

Contacts Website Email Social Media Questions? Access Opportunities Retention Do you want to join us? Students Partners Collaborators Advocates

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Blue Heron Nature Preserve Mill Creek turtle trapping locations

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Conservation Research Bridge Program

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The snapping turtle research team thanks you

Chris Luginbuhl Greg Marshall Kyler Abernathy Tracy Romano Allison Tuttle Jim and Sandra Tripp Elizabeth DePace Kiersten Griesback Ryan Hartman Mark Mandica Jack Martin Sarah Poletti Amphibian Foundation National Geographic Society Mystic Aquarium Tributary Mill Conservancy Connecticut DEEP

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