Photosynthesis-irradiance measurements used to derive P-I relationships and to calculate primary production for each discrete sample. Samples collected aboard Palmer LTER annual cruises off the coast of the Western Antarctic Peninsula, 1991 - 1993.

Photosynthesis-irradiance measurements are used to derive P-I relationships and to calculate primary production for each discrete sample. Blue-green photosynthetron method described by Prezelin et al. (1994) were used to determine photosynthesis irradiance (P-I) relationships for collected samples. Non-linear cureve fits for the P-I data were calculated using the simplex method of Caceci & Cacheris (1984). Curve fitting provided estimates of Pmax (the light saturated rate of photosynthesis) and alpha (the affinity for photosynthesis at light-limited irradiances.