1/7 #SeaTurtleTalks
"Stranded turtle bones reveal divergent life-history characteristics for critically #endangered #hawksbill #seaturtles inhabiting US waters"
Sometimes🐢wash ashore (strand) dead. Let's talk about what their🦴can tell us about their past life. #TurtleTuesday
2/7
Global #hawksbill pops. declined >80% in the past 100yr. Study of immature🐢was recently identified as🌎priority. Hawksbills typically inhabit🌴coral reefs but juveniles also forage in subtropical US waters➡️Texas & Florida. Yet, little is known about their ecology in the US
3/7
To address this knowledge gap, we studied the growth layers, #stableisotopes & #traceelements in the🦴of 94 US-stranded turtles (1989–2012). This led to new data on:
1⃣ stage duration (oceanic vs. neritic)
2⃣ size-at-age relationships
3⃣ age-at-maturation
4⃣ growth rates
4/7
Key findings:
1⃣ 🦴isotope+element environmental markers = shift from oceanic to neritic life stages @ age 1–3 yr & mean sizes of 23–24 cm SCL, in line with estimates for #hawksbills globally
2⃣ Size-at-age relationships were generally similar to other🐢in the Caribbean…
5/7
3⃣ …yielding age-at-maturation estimates of 15–25 yr (based on min. nesting female SCLs of 69.5–78.8 cm)
4⃣ 🚨Growth rates were much lower for #hawksbills stranded in TX relative to those stranded FL, even after accounting for🐢size & age. Sex & year not key covariates…
6/7
4⃣ ...spatial growth variation may be due to differences in trophic ecology. d15N data for TX🐢are⬆️than would be expected due to only a baseline difference & bulk SIA data suggest distinct isotopic niches. More on this coming soon using #stableisotopes of amino acids #CSIA
7/7
We show the critical info that can be gleaned from integrated analyses of dead, stranded🐢🦴
Learn more in our #openaccess @ESR_IR paper, co-authored by L Avens, (me), LR Goshe, JM Clark, AB Meylan, W Teas, @Donna_J_Shaver, @mgodfreyST, & L Howell doi.org/10.3354/esr011…
I should also add, if you are interested in collecting and studying stranded turtle bones in your neck of the woods and need advice, questions answered, etc. reach out at any time. Always happy to answer Qs or start new collaborations!
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