We would like to make two corrections to our manuscript of errors that have come to light after publication. First, the reported pour size for the Whatman filter used in this study of 0.22 µm should be corrected to be a, "nominal pour size of 0.7 µm". Second, in the discussion we report that U. tumidus has a "planktonic gamete", which is not correct. The gametes of this species are not individually free floating and rather are released in slim clusters. These two corrections we feel do not change the interpretations of our work, but we feel it is important to correct them for scientific accuracy.