TITLE:   Palmer LTER: Relative activities of several bacterial exoenzymes in 
	 the western Antarctic Peninsula during austral summer: Evidence of 
	 sea-ice influence on pelagic bacterial communities
AUTHOR:  James R Christian,  David M Karl
Palmer LTER Contribution #45, ANTJ 1994 Review, Vol 29, No. 5 212-214

In mid-to-late austral summer (Jan 6 - Feb 12) 1994, aboard the R/V
Polar Duke (PD94-01) we surveyed the region south and west of Palmer
Station, along the 300, 400, 500, and 600 lines of the Palmer LTER
sampling grid (Waters and Smith 1992).  Activities of the bacterial
exoenzymes leucine aminopeptidase (LAPase), a-glucosidase (AGase), and
B-glucosidase (BGase) were determined at most stations, following the
methods of Hoppe (1983) and Somville and Billen (1983).  Activities
are detemrined at saturating substrate concentration, and so must be
considered potential activities rather than estimates of activity in
situ.  Activities were also determined in specialized
microenvironments such as pack ice rich in microalgae ("brown ice")
and faecal pellets of the Antarctic krill Euphasia superba Dana.