Net production of bacteria passing a 70 micron mesh, or bacteria passing a 1 micron mesh, calculated incorporation of 3H labeled leucine into cell proteins. Method based on microcentrifuge method of Smith, David C., and Farooq Azam. 1992. A simple, economical method for measuring bacterial protein synthesis rates in seawater using 3H-leucine, Marine Microbial Food Webs 6(2):107-114. Nanomolar treatments refer to leucine concentration for calculation of isotopic dilution and necessary leucine concentration to saturate uptake into bacterial cells. For a good example on how to calculate isotopic dilution see Pace. Michael L., and Jonathan J. Cole. Primary and bacterial production in lakes: are they coupled over depth? Plankton Research 16(6):661-672. Sampling Frequency: fortnightly during ice-free season - every 6 weeks during ice-covered season Number of sites: 4