Grazing Western Antarctic Peninsula

• Main Authors: Kim S. Bernard A, Deborah K. Steinberg A, Oscar M. E. Schofield B
• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Published: 2012
• Subjects: Antarctic; Antarctic Peninsula; Antarc*; Antarctica; Euphausia superba; Limacina helicina
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.457.3376; http://pal.lternet.edu/docs/bibliography/Public/414lterc.pdf

a b s t r a c t The Western Antarctic Peninsula (WAP) is a region of rapid climate change that is altering plankton community structure. To investigate how these changes may impact carbon and energy transfer in the pelagic food web, grazing rates of the five dominant macrozooplankton species (euphausiids Euphausia superba, Euphausia crystallorophias, and Thysanöessa macrura; the pteropod Limacina helicina, and the salp Salpa thompsoni) in the WAP were measured in January 2009 and 2010 as part of the Palmer Antarctica Long-Term Ecological Research (LTER) study. Measurements were made across the coastal-shelf-offshore and north–south gradients of the LTER survey grid. Highest grazing rates occurred offshore in both years, and in the south during 2009 and north during 2010, all associated with the presence of large localized salp blooms. During both years, E. superba was the major grazer at the coast, while S. thompsoni dominated grazing offshore. L. helicina was an important grazer throughout the study area during both years, but especially so over the shelf during 2009. During 2009, there was little difference in the relative importance of the macrozooplankton grazers along the north–south gradient. The presence of a salp bloom in the north during 2010, though, resulted in a distinct shift in the relative importance of major grazers from the euphausiids and L. helicina in the south to salps in the north.