Results of a primary productivity study as affected by the type of glass in the culture bottles1

Radiocarbon uptake by Thalassiosira pseudonana was used to compare the effect of bottle type on primary productivity. Three types used in primary productivity studies were considered: standard soda‐lime bottles, commercial Pyrex bottles, and quartz bottles. Transmittance within the ultraviolet region (e.g. 290–320 nm) varied significantly (quartz > Pyrex > Wheaton “800” glass). Measurements of radiocarbon uptake in the three bottle types under white fluorescent lamps alone (4.48 W·m −2 [380–700 nml) were not significantly different. However, when combined with the sunlamp/filter system (0.74 W m −2 [290–320 nm]), there was a significant difference in productivity. The environmentally significant ultraviolet portion of the solar spectrum should be considered when culture bottles are selected for in situ primary productivity studies.