Antarctic Science最新文献

A juvenile king penguin (Aptenodytes patagonicus) was sighted at San Martín Station, Marguerite Bay, west of the Antarctic Peninsula (68°07'S, 67°08'W) on 3 February 2020. The animal was apparently healthy. It was uninjured, moving freely between the station buildings. It remained in the area until 27 March, when it was last seen. Numerous king penguin records have been reported in recent years, mostly in the South Shetland Islands. Two chicks have even been recorded hatching on these islands, but there is currently no evidence that king penguins have raised a chick to emancipation successfully. Here we present the most southerly known record of king penguins, the only one farther south than the Antarctic Circle. Coupled with observations from other parts of Antarctica, the information presented here supports previous suggestions by other authors of a southwards expansion of this species specifically in the Antarctic Peninsula region. The presence of this species at numerous Antarctic localities suggests that the known distribution of this penguin could change in the near future in response to climate change.

Advice from avian influenza experts suggests that there is a high risk that highly pathogenic avian influenza will arrive in the Southern Ocean during the austral summers.

Antarctica was once considered biologically isolated, surrounded by oceanic barriers (Fraser et al. 2018). However, floating materials such as kelp rafts (Fraser et al. 2018, Avila et al. 2020), wood (Lewis et al. 2005) and plastics (Avila et al. 2020) are now known to cross these barriers and reach Antarctic shores. Such incursions might enable non-native species (either rafting species themselves or associated hitchhikers) to colonize Antarctica as the climate warms (Avila et al. 2020, Fraser et al. 2020), but whether these species will be able to survive and reproduce in the Antarctic is not yet known. Sea ice is a defining characteristic of Antarctic coastlines, and modelled trajectories of kelp rafts (Fraser et al. 2018) cross-referenced against sea-ice observations (Parkinson 2019) suggest that collisions between rafts and seasonal sea ice occur frequently (Fig. 1a); thus, rafts are expected to be entrained in, on or under sea ice and experience multiple freeze-and-thaw cycles on their journeys to Antarctica. In addition, kelp rafts that reach the Antarctic intertidal will experience temperatures well below 0°C if exposed to the air at low tide. Freezing can cause severe disruptive stress to seaweeds, and ice crystals growing in intercellular spaces can damage cell membranes and cause cell lysis (Eggert 2012). Such damage could affect the buoyancy of kelp tissue and decrease rafting ability. Although some non-native kelp rafts recovered from Antarctic shores appeared to still be reproductively viable, with mature gametes observed in reproductive tissue (Fraser et al. 2018), tissue damage caused by freezing could have widespread effects on the health, function and establishment success of a non-native species traversing the Southern Ocean.

On 15 January 2022, 04h:15 UTC, the volcano Hunga Tonga-Hunga Ha'apai in the south-west Pacific Ocean (20°32'32.37''S, 175°23'38.67''W) erupted in what proved to be the most powerful such event since Krakatau in 1883. Among the many impacts of the eruption, a substantial tsunami propagated throughout the south-west Pacific Ocean. The signatures of the eruption were recorded at a wide range of recording stations globally, including the atmospheric pressure wave, the tsunami itself and, in addition, higher-order responses, such as a tsunami associated with the pressure wave (Carvajal et al. 2022).