This curve is below that of Eppley, when that is plotted on the Arrhenius axes, but
the actual quantitative difference is small (see also Goldman 1977). The difference
obviously comes from Eppley’s fitting of an upper envelope (which must be
positioned subjectively) compared to the Goldman–Carpenter approach of fitting a
relation to the central tendency of their data (probably more reliable). Both of these
functions are commonly used in numerical models to characterize the response of
phytoplankton to temperature.
Resting Stages
(^) Many diatoms and dinoflagellates form resting stages (cysts or spores) in response to
unfavorable environmental conditions. Resting spores are more common in centric
diatoms than in pennates (Hasle and Syvertsen 1997). Culture studies show that
diatom resting stages can retain viability for at least two years. Field studies show that
some benthic resting stages remain viable for only a few years, while others remain
viable for decades (McQuoid & Hobson 1996; McQuoid et al. 2002). It is likely that
these resting stages form the seed stock for pelagic phytoplankton blooms when they
are resuspended from the sediment. Wetz et al. (2004) conducted experiments during
the late winter to determine whether samples from the bottom boundary layer in
coastal waters contained viable seed stocks that could serve to initiate a spring bloom.
Growth occurred at light levels that were 40–50% of surface light, indicating that the
resuspended cells could resume growth, but that winter mixing was deep enough to
prevent growth.
(^) Dinoflagellate cysts typically have a different cell wall from actively growing cells,
and often require a period of cold and dark before being able to excyst. At the