The Response Of Penguin Ecology To The Environmental Changes In The Ross Sea,Antarctica,at Different Time Scales

Penguins are an important component of the Southern Ocean ecosystem,and their nesting,breeding,migratory and foraging behaviors are influenced by atmospheric,oceanographic and terrestrial changes at different time scales.The Ross Sea has the largest marine protected area in the world,and studying the response patterns of penguin ecology to environmental changes in this region is of great scientific value for understanding and predicting future trends in the Southern Ocean ecosystem.Inexpressible Island,which has the longest penguin breeding history since the Holocene in the Ross Sea,provides a great convenience for this study.This study integrates a variety of fieldwork and previous research data,and uses multidisciplinary approaches including geochemistry,sedimentology,paleoclimatology,geomorphology,Quaternary geology,and statistics,etc.The results show a penguin subcolonies abandonment event due to a sudden increase in meltwater in the late 19th century,and the effects of oceanographic changes on penguin populations in the Ross Sea at the millennial scale.1.Abandonment of penguin subcolonies in the late 19 century on Inexpressible Island,AntarcticaBased on geochemical data from three ornithogenic profiles on Inexpressible Island,we found the population of some penguin subcolonies increased at the end of the Little Ice Age(LIA).Combined with local topography and surface carcass characteristics,we suggest that intensified streamflow led to the destruction and eventual abandonment of penguin subcolonies in the late 19th century.This study reveals a penguin subcolonies abandonment event in the history on Inexpressible Island due to abrupt climate change,which,combined with previous studies,suggests that this type of event may be more common in the East Antarctica and could have a significant impact on penguin ecology.2.Impacts of Modified Circumpolar Deep Water(MCDW)intrusion on penguin ecology in the Ross Sea over the past 6,000 yearsUsing Cd/P ratios from 13 ornithogenic sediment profiles on Inexpressbile Island as an indicator of MCDW intrusion in the Ross Sea region,the variability of this water body intrusion over the past 6000 years were reconstructed.The intensity of this water body intrusion was weakened at 1.6-2.8 kyr BP,resulting in reduced food supply,increased sea ice,and ultimately reduced penguin populations in the Ross Sea.It is pointed out that changes in oceanographic conditions at the millennial scale may be one of the main drivers of penguin ecology,providing new ideas for studying changes in the Southern Ocean marine ecosystem during the historical period.