In the larger context of the Western Antarctic Peninsula (WAP) ecosystem, rapid regional warming has fundamentally altered the ecosystem structure and, if trends continue, the northern WAP will soon be characterized by a lack of perennial or summer sea ice, warmer water temperatures, and phytoplankton dominated by smaller cells as opposed to diatoms. These types of conditions were associated with lower prey quality for E. superba, which could have significant ramifications for the rich assemblage of endothermic top predators that make their summer home in the WAP and utilize krill as their main food source.
The krill T. macrura are high in abundance and prey quality, but their small body size, diffuse aggregation behavior, and high wax ester content compared to E. superba might make them an inefficient target prey species.
The krill E. crystallorophias and fish P. antarcticum are also high quality prey, but their ranges are restricted to the South, where summer sea ice still persists.
The myctophid E. antarctica represents a potential, energy rich option for coastal marine predators residing in the North, although this fish species‘ neutral lipid content increased with increasing latitude, also making it a relatively better quality prey in the South.
Read full report here.