The distribution, density and percentage contribution of pack ice seals during ship-board censuses in the marginal sea ice zone beyond the Lazarev Sea in spring 2019 are presented. Adult/juvenile crabeater seals (n = 19), leopard seals (n = 3) and Ross seals (n = 10) were sighted during 582.2 nm of censuses along the ship’s track line in the area bounded by 00°00’–22°E and 56°–60°S. Antarctic fur seals (n = 21) were only encountered on the outer fringes of the pack ice, and Weddell seals were absent due to their primary use of fast ice and inner pack ice habitats close to the coast. Crabeater seal sightings included juveniles (n = 2) and another four groups of 2–3 unclassified crabeater seals, singletons (n = 5), single mothers with pups (n = 3) and a family group (n = 1 triad). Only one leopard seal attended a pup, while no Ross seal pups were located. The survey was likely of insufficient effort, in both extent (north of 60°S) and duration (18 days), to locate seals in considerable numbers this early (late October/early November) in their austral spring breeding season.

Knowledge regarding interactions between predators and their prey is fundamental for understanding underlying links between climate change and ecosystem responses, including predator demographics, in the Southern Ocean. This study reports data on reproductive performance, total population size and diet composition for macaroni and chinstrap penguins breeding at Nyrøysa on Bouvetøya during the summers of 1996–97, 1998–99, 2000–01 and 2007–08. The breeding populations of these two species at Nyrøysa decreased significantly over the study period, with an 80% decline for chinstraps and a 50% decline for macaroni penguins, despite relatively high levels of chick production. During this period macaroni penguins at this site ate a diverse diet, dominated by myctophid fish and two krill species, whereas chinstrap penguins were Antarctic krill specialists. The population changes are probably primarily due to the expanding Antarctic fur seal population, and also to landslides that are the result of increased melting on the island which have destroyed penguin breeding sites. Additional impacts from global warming of the ocean might also be playing a role and could exacerbate the decline in these penguin populations if krill and other prey are negatively impacted in the future in this region. The local chinstrap penguin population would probably be most heavily affected given its narrow feeding niche and small current population size.