Assessing the degree of impact from iceberg activities on penguin colonies of Clarence Island
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Abstract: During August and September 2023, three giant icebergs, each bigger than Paris, successively grazed Clarence Island in the northeast of the Antarctic Peninsula, a home to a population of over 100 000 penguins. This incident may serve as a clarion call for the increasing iceberg calving due to global warming and its subsequent impact on the Antarctic ecosystem. Here we investigate this unexpected event and employ historical records and probabilistic analyses of iceberg grounding to assess the degree of impact on penguin colonies of Clarence Island. Among the eleven colonies, there is one with low impact, eight with medium impact, and two with high impact. The low-impact colony, Cape Lloyd, is located in the northern part of the island, while the high-impact colonies, False Ridge and Pink Pool, are in the southeast. The eight medium-impact colonies are distributed along both the eastern and western coasts of the island. This study provides essential support for evaluating the impact of iceberg activity on penguin colonies. We argue that penguin colonies located in areas prone to iceberg drift, such as Clarence Island, may become more vulnerable to the heightened risk of iceberg collisions or groundings in the warming future. Therefore, we hope the public will become more aware of the grave impacts of climate change on penguins and underscore the urgent need for effective conservation strategies.
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Key words:
- iceberg /
- penguin /
- remote sensing /
- extreme events /
- climate change
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Figure 1. Clarence Island and penguin colonies. Orange dots and green triangles represent penguin colonies and krill bases, respectively. Black closed lines indicate contour lines, and the brown regions depict the exposed rock areas on the island. The base map shows the bathymetric features. An inset on the right demonstrates the location of Clarence Island.
Figure 2. Heatmap of the iceberg impact on penguin colonies. The iceberg impact is categorized into three levels: low, medium, and high, corresponding to the blue, gray, and red blocks in the heatmap, respectively. The degree of iceberg impact on penguin colonies is determined by both the iceberg passage frequency (vertical axis) and the iceberg grounding probability (horizontal axis).
Figure 3. Iceberg grazing events, trajectories, and assessment of impact on penguin colonies. a. Iceberg D29B grazes the island on August 3, 2023. b. Iceberg D28 nears the island on August 15, 2023. c. Iceberg D30A grazes the island on September 8, 2023. d. Schematic of a flat iceberg nearing the island. e. Trajectories of the three icebergs from July to September 2023 and average wind speeds for the period. Inset on the left features a Sentinel-2 image from September 8, 2023, showing abundant sea ice fragments. f. Trajectories and origins of icebergs from 1978 to 2023. Iceberg nomenclature is based on the Antarctic quadrant where they were first identified, with sectors delineated counterclockwise as: Area A (0°–90°W), dark green lines; Area B (90°W–180°), light green lines; Area C (180°–90°E), pink lines; Area D (90°E–0°), deep red lines. Light yellow lines indicate icebergs of unknown origin. g. Iceberg impact levels on eleven penguin colonies: red for high impact, yellow for medium impact, and green for low impact. The background displays bathymetric features.
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Arrigo K R, van Dijken G L, Ainley D G, et al. 2002. Ecological impact of a large Antarctic iceberg. Geophysical Research Letters, 29(7): 8, doi: 10.1029/2001GL014160 Budge J S, Long D G. 2018. A comprehensive database for Antarctic iceberg tracking using scatterometer data. IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing, 11(2): 434–442, doi: 10.1109/JSTARS.2017.2784186 Dugger K M, Ainley D G, Lyver P O B, et al. 2010. Survival differences and the effect of environmental instability on breeding dispersal in an Adélie penguin meta-population. Proceedings of the National Academy of Sciences of the United States of America, 107(27): 12375–12380, doi: 10.1073/pnas.1000623107 Duprat L P A M, Bigg G R, Wilton D J. 2016. Enhanced Southern Ocean marine productivity due to fertilization by giant icebergs. Nature Geoscience, 9(3): 219–221, doi: 10.1038/NGEO2633 Fretwell P T, Boutet A, Ratcliffe N. 2023. Record low 2022 Antarctic sea ice led to catastrophic breeding failure of emperor penguins. Communications Earth & Environment, 4(1): 273, doi: 10.1038/s43247-023-00927-x Humphries G R W, Naveen R, Schwaller M, et al. 2017. Mapping application for penguin populations and projected dynamics (MAPPPD): Data and tools for dynamic management and decision support. Polar Record, 53(2): 160–166, doi: 10.1017/S0032247417000055 Jenouvrier S, Holland M, Stroeve J, et al. 2014. Projected continent-wide declines of the emperor penguin under climate change. Nature Climate Change, 4(8): 715–718, doi: 10.1038/nclimate2280 Kooyman G L, Ainley D G, Ballard G, et al. 2007. Effects of giant icebergs on two emperor penguin colonies in the Ross Sea, Antarctica. Antarctic Science, 19(1): 31–38, doi: 10.1017/S0954102007000065 Larue M, Iles D, Labrousse S, et al. 2024. Advances in remote sensing of emperor penguins: first multi-year time series documenting trends in the global population. Proceedings of the Royal Society B: Biological Sciences, 291(2018): 20232067, doi: 10.1098/rspb.2023.2067 Li Tian, Liu Yan, Cheng Xiao, et al. 2017. The effect of seafloor topography in the Southern Ocean on tabular iceberg drifting and grounding. Science China Earth Sciences, 60(4): 697–706, doi: 10.1007/s11430-016-9014-5 Lynch H J, LaRue M A. 2014. First global census of the Adélie Penguin. The Auk, 131(4): 457–466, doi: 10.1642/AUK-14-31.1 Lynnes A S, Reid K, Croxall J P. 2004. Diet and reproductive success of Adélie and chinstrap penguins: Linking response of predators to prey population dynamics. Polar Biology, 27(9): 544–554, doi: 10.1007/s00300-004-0617-1 Moore J C, Gladstone R, Zwinger T, et al. 2018. Geoengineer polar glaciers to slow sea-level rise. Nature, 555(7696): 303–305, doi: 10.1038/d41586-018-03036-4 Qi Mengzhen, Liu Yan, Liu Jiping, et al. 2021. A 15-year Circum-Antarctic iceberg calving dataset derived from continuous satellite observations. Earth System Science Data, 13(9): 4583–4601, doi: 10.5194/essd-13-4583-2021 Sladen W J L. 1953. The adelie penguin. Nature, 171(4361): 952–955, doi: 10.1038/171952a0 Trathan P N, Wienecke B, Barbraud C, et al. 2020. The emperor penguin-Vulnerable to projected rates of warming and sea ice loss. Biological Conservation, 241: 108216, doi: 10.1016/j.biocon.2019.108216 Wilson K J, Turney C S M, Fogwill C J, et al. 2016. The impact of the giant iceberg B09B on population size and breeding success of Adélie penguins in Commonwealth Bay, Antarctica. Antarctic Science, 28(3): 187–193, doi: 10.1017/S0954102015000644 -
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