Climate Change & Loggerhead Turtles

 

Climate Change & Loggerhead Turtles

A recent long-term study highlights how climate change is reshaping the biology and behaviour of loggerhead turtles. For UPSC aspirants, this topic links directly to Environment & Ecology, Biodiversity, Climate Change, and Conservation Policy.

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🔬 Key Findings of the Study

Species: Loggerhead turtle (Caretta caretta)

Duration: 17 years

Location: Cabo Verde (important Atlantic nesting site)

Published in: Animals journal

Observed Climate-Linked Changes

1️⃣ Earlier Nesting

• Turtles are nesting earlier due to warmer ocean temperatures

2️⃣ Reduced Reproductive Output

• Fewer eggs

• Less frequent breeding

• Breeding cycle shifted from ~2 years → ~4 years

3️⃣ Declining Ocean Productivity

• Satellite chlorophyll estimates show reduced food availability

4️⃣ Shrinking Body Size

• Females becoming smaller

• Smaller females → smaller clutch sizes

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🌊 Why Is This Happening?

Warming Oceans

• Alters marine ecosystems

• Reduces prey abundance

Lower Chlorophyll Levels

• Indicates declining phytoplankton productivity

• Impacts entire marine food chain

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🧠 Important Ecological Concept: “Capital Breeders”

Loggerhead turtles are capital breeders, meaning:

✔ They accumulate energy reserves over years

✔ Use stored energy for reproduction

📌 Climate Impact:

Less food → less stored energy → reduced egg production & breeding frequency

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⚠ Scientific Concern

While earlier nesting may seem adaptive, researchers warn:

❗ Long-term reproductive decline

❗ Population stability may be misleading

❗ Hidden vulnerability despite large nesting numbers

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🛡 Conservation Implications

Traditional Focus

• Protect nesting beaches

Emerging Need

✅ Protect feeding & foraging grounds

✅ Address climate-induced ecosystem degradation

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🌍 Broader Climate Threats to Sea Turtles

1️⃣ Sea Level Rise

• Beach erosion

• Nest inundation

2️⃣ Sand Temperature Rise

• Affects temperature-dependent sex determination (TSD)

• Skewed sex ratios (often more females)

3️⃣ Ocean Ecosystem Changes

• Prey shifts

• Migration disruption

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🧭 Why This Matters for UPSC

📘 Prelims – Environment & Ecology

Key areas:

• Loggerhead turtle species

• Capital breeders

• Chlorophyll as productivity indicator

• Climate impacts on marine fauna

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📗 Mains – GS III

Possible themes:

✔ Climate change & biodiversity

✔ Marine ecosystem disruptions

✔ Conservation strategy shifts

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📙 Essay Topics

• “Climate Change and Silent Ecological Crises”

• “Adaptation vs Survival in the Anthropocene”

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📝 Possible UPSC Questions

Prelims MCQ

Q. The term ‘capital breeders’, sometimes seen in ecology, refers to species that:

A) Breed continuously year-round

B) Depend on stored energy reserves for reproduction

C) Reproduce only once in lifetime

D) Breed only under resource abundance

✅ Answer: B

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Mains GS III

"Discuss the impact of climate change on marine biodiversity with reference to sea turtles."

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🎯 Takeaway for Aspirants

✔ Climate change affects not just weather but species biology

✔ Population numbers alone may hide ecological stress

✔ Conservation must evolve from site-based → ecosystem-based