Benthic-pelagic coupling in sediment-associated populations of Karenia brevis

Growth, uptake, and assimilation of ammonium, nitrate, and urea, by three strains of Karenia brevis grown under low light

“…It has been suggested that K. brevis may regulate its N physiology to elevate its nocturnal rates of NO 3 À uptake following diurnal exposure to growth saturating levels of light (Sinclair et al, 2006a) or may use nocturnal descent to enhance exposure to other nutrients (Sinclair et al, 2006b). Offshore populations that occur near the sediment-water interface may be exposed to higher concentrations of both reduced and organic nutrients (Jahnke et al, 2005;Sinclair and Kamykowski, 2008). The broad distribution of K. brevis, both within the water column and across the shelf suggests that the N physiology of K. brevis must be understood in a wide variety of environments especially since N is suspected to be one limiting factor to the growth of offshore populations of K. brevis (Hecky and Kilham, 1988;Vargo et al, 2008).…”

Positive feedbacks between bottom-up and top-down controls promote the formation and toxicity of ecosystem disruptive algal blooms: A modeling study

“…One such factor is the vertical migration of K.b. and other dinoflagellates driven by the diel light/dark cycle and varying nutrient concentrations with depth (Kamykowski and Yamazaki, 1997;Sinclair and Kamykowski, 2008). In this diel cycle, dinoflagellates vertically migrate downward at night to access higher nutrient concentrations at depth, and migrate back to near the surface during the day to access light needed for photosynthesis.…”

Influence of daylight surface aggregation behavior on nutrient cycling during a Karenia brevis (Davis) G. Hansen & Ø. Moestrup bloom: Migration to the surface as a nutrient acquisition strategy

“…All of these studies were conducted on relatively high biomass, nearshore, maintenance stage blooms where ambient nutrient concentrations were oligotrophic however. Sinclair and Kamykowski (2013) documented K. brevis cell movement into the sediments in experimental chambers and speculated that K. brevis may access the sediment-water interface offshore, where its flexible photophysiology (Evens et al, 2001;Schaeffer et al, 2007) may confer a competitive advantage in low light environments at depth. McCulloch et al (2013) documented gyroxanthin-containing dinoflagellates, which include K. brevis, across the northwest Florida shelf in near-surface and near-bottom waters which may serve as seed populations during either upwelling or downwelling conditions.…”