Long‐term patterns in ecosystem phenology near Palmer Station, Antarctica, from the perspective of the Adélie penguin

• Published in: Ecosphere
• Main Authors: Cimino, Megan A., Conroy, John A., Connors, Elizabeth, Bowman, Jeff, Corso, Andrew, Ducklow, Hugh, Fraser, William, Friedlaender, Ari, Kim, Heather Hyewon, Larsen, Gregory D., Moffat, Carlos, Nichols, Ross, Pallin, Logan, Patterson‐Fraser, Donna, Roberts, Darren, Roberts, Megan, Steinberg, Deborah K., Thibodeau, Patricia, Trinh, Rebecca, Schofield, Oscar, Stammerjohn, Sharon
• Other Authors: National Oceanic and Atmospheric Administration, Office of Polar Programs, Virginia Sea Grant, Virginia Institute of Marine Science
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 2023
• Subjects: Palmer Station; Palmer-Station; Antarc*; Antarctica; Humpback Whale; Sea ice
• Online Access: http://dx.doi.org/10.1002/ecs2.4417; https://onlinelibrary.wiley.com/doi/pdf/10.1002/ecs2.4417; https://onlinelibrary.wiley.com/doi/full-xml/10.1002/ecs2.4417; https://esajournals.onlinelibrary.wiley.com/doi/pdf/10.1002/ecs2.4417

Abstract Climate change is leading to phenological shifts across a wide range of species globally. Polar oceans are hotspots of rapid climate change where sea ice dynamics structure ecosystems and organismal life cycles are attuned to ice seasonality. To anticipate climate change impacts on populations and ecosystem services, it is critical to understand ecosystem phenology to determine species activity patterns, optimal environmental windows for processes like reproduction, and the ramifications of ecological mismatches. Since 1991, the Palmer Antarctica Long‐Term Ecological Research (LTER) program has monitored seasonal dynamics near Palmer Station. Here, we review the species that occupy this region as year‐round residents, seasonal breeders, or periodic visitors. We show that sea ice retreat and increasing photoperiod in the spring trigger a sequence of events from mid‐November to mid‐February, including Adélie penguin clutch initiation, snow melt, calm conditions (low winds and warm air/sea temperature), phytoplankton blooms, shallow mixed layer depths, particulate organic carbon flux, peak humpback whale abundances, nutrient drawdown, and bacterial accumulation. Subsequently, from May to June, snow accumulates, zooplankton indicator species appear, and sea ice advances. The standard deviation in the timing of most events ranged from ~20 to 45 days, which was striking compared with Adélie penguin clutch initiation that varied <1 week. In general, during late sea ice retreat years, events happened later (~5 to >30 days) than mean dates and the variability in timing was low (<20%) compared with early ice retreat years. Statistical models showed the timing of some events were informative predictors (but not sole drivers) of other events. From an Adélie penguin perspective, earlier sea ice retreat and shifts in the timing of suitable conditions or prey characteristics could lead to mismatches, or asynchronies, that ultimately influence chick survival via their mass at fledging. However, more work is ...