Copepod cultures
Acartia tonsa nauplii were collected from Stony Brook Harbor in July 2004 using a 64 µm mesh plankton net, sorted using a dissecting microscope and placed into 1 or 2 L glass flasks for culturing. Stony Brook Harbor has no history of brown tides and thus copepods collected from this site are presumed naïve to brown tide. During all experimental incubations, copepod cultures were maintained at 22°C and exposed to a 14:10 h light:dark cycle. Natural seawater from Stony Brook Harbor (salinity 27 ppt) was filtered through 0.45 µm filters and used for copepod cultures. Copepods were fed every other day with a 25:25:50 (by culture volume) mixture of I. galbana, T. pseudonana (Cosinodiscophyceae) (3H), and Rhodomonas lens (Cryptophyceae) (CCMP 739), respectively. The latter two algal species were cultured in f/2 medium in the manner described above. Acartia tonsa adults can be cannibalistic when prey abundance is low; therefore, high algal densities were maintained in all flasks.