Module 8

Climate Change & Conservation

Most penguin species are in decline. Sea-ice loss, krill collapse, fisheries, marine pollution, and — newly, since 2022 — highly pathogenic avian influenza H5N1 threaten multiple populations simultaneously. Jenouvrier 2014 projected emperor penguin quasi-extinction by 2100 under high-emissions scenarios.

1. Sea-Ice & Emperor Projections

Emperor penguins require stable fast ice for breeding. Jenouvrier 2014 (Nat. Clim. Change) combined a demographic model with CMIP5 sea-ice projections and predicted decline of 19% of colonies by 2100 under RCP4.5 and >80% under RCP8.5. Recent observations (Fretwell 2023 Commun. Earth Environ.) confirmed catastrophic breeding failure at multiple colonies in 2022 due to early ice breakup: entire cohorts of chicks drowned before fledging. The US listed emperor penguins as threatened under the ESA in October 2022.

2. Krill Decline

Antarctic krill (Euphausia superba) underpin the entire Southern Ocean food web. Atkinson 2019 (Nat. Clim. Change) documented a ~50% decline in krill biomass along the Western Antarctic Peninsula over the past four decades. Chinstrap and Adélie penguins, near-obligate krill consumers, have declined correspondingly.

3. H5N1 Avian Influenza

The 2.3.4.4b H5N1 clade reached Antarctic waters in October 2023, causing mass mortality among skuas and elephant seals on South Georgia and South Shetlands. Gentoo and king penguins have tested positive; concern about colony-scale outbreaks in emperor colonies is acute. The immunologically naïve Antarctic fauna has no prior exposure; viral-control options are limited. The situation is being tracked by the Scientific Committee on Antarctic Research (SCAR).

Simulation: Emperor Trajectories

Python

script.py34 lines

import numpy as np, matplotlib
matplotlib.use('Agg')
import matplotlib.pyplot as plt

# Jenouvrier 2014: emperor penguin colony trajectories under RCP4.5 / RCP8.5
years = np.arange(2000, 2101)
N0 = 600_000  # breeding pairs
# Stable 2000-2030 then decline under each scenario
decl_rcp45 = np.where(years < 2030, 0,
                      (years - 2030) * 0.012)   # ~1.2% per yr
decl_rcp85 = np.where(years < 2030, 0,
                      (years - 2030) * 0.030)

N_rcp45 = N0 * np.exp(-decl_rcp45)
N_rcp85 = N0 * np.exp(-decl_rcp85)

fig, ax = plt.subplots(figsize=(12, 6), facecolor='#0a0a1a')
ax.set_facecolor('#111827'); ax.tick_params(colors='#cbd5e1')
for s in ax.spines.values(): s.set_color('#334155')
ax.plot(years, N_rcp45/1000, color='#fbbf24', lw=2.6, label='RCP4.5 (1.2%/yr decline post-2030)')
ax.plot(years, N_rcp85/1000, color='#dc2626', lw=2.6, label='RCP8.5 (3%/yr decline post-2030)')
ax.axhline(10, color='#34d399', ls='--', label='Quasi-extinction threshold')
ax.fill_between(years, 0, N_rcp45/1000, where=(N_rcp45/1000 < 50),
                color='#fbbf24', alpha=0.2)
ax.set_xlabel('Year', color='#cbd5e1')
ax.set_ylabel('Emperor breeding pairs (thousands)', color='#cbd5e1')
ax.set_title('Jenouvrier 2014 emperor penguin projections',
             color='#bae6fd', fontweight='bold')
ax.grid(True, color='#334155', alpha=0.3)
ax.legend(facecolor='#1e293b', edgecolor='#334155', labelcolor='#cbd5e1')
plt.tight_layout()
plt.savefig('output.png', dpi=120, bbox_inches='tight', facecolor='#0a0a1a')
print(f'RCP8.5 2100: emperor breeding pairs ~{N_rcp85[-1]/1000:.0f}k (quasi-extinct)')
print(f'RCP4.5 2100: ~{N_rcp45[-1]/1000:.0f}k (still present but reduced)')

Click Run to execute the Python code

Code will be executed with Python 3 on the server

4. Synthesis of the Course

Penguins are a remarkable evolutionary experiment: flightless aquatic birds that independently reinvented marine-mammal-like physiology, insulation, and acoustic communication. The eight modules traced huddle thermoregulation, fasting biochemistry, hydrodynamic flippers, diving physiology, feather waterproofing, cocktail-party recognition, species diversity, and climate projections. The emperor penguin in particular has become the totemic climate-change species: the penguin whose survival depends on sea ice that is disappearing during the same decade the species is being monitored.

Key References

• Jenouvrier, S. et al. (2014). “Projected continent-wide declines of the emperor penguin under climate change.” Nat. Clim. Change, 4, 715–718.

• Fretwell, P. T. & Boutet, A. (2023). “Unprecedented emperor penguin breeding failure associated with Antarctic sea ice loss.” Commun. Earth Environ., 4, 273.

• Atkinson, A. et al. (2019). “Krill (Euphausia superba) distribution contracts southward during rapid regional warming.” Nat. Clim. Change, 9, 142–147.

• Trathan, P. N. et al. (2015). “Pollution, habitat loss, fishing, and climate change as critical threats to penguins.” Conserv. Biol., 29, 31–41.

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