Seasonal variations of phosphate availability in the SW Pacific Ocean near New Caledonia

Photosynthetic characteristics of Trichodesmium in the southwest Pacific Ocean: importance and significance

“…In the SWP, a critical inorganic phosphate concentration as low as 9 nM was required by Trichodesmium populations for maintaining a significant positive growth rate (Moutin et al 2005). The concentrations of phosphate in that region were observed to be higher than 9 nM in winter and spring, but generally lower than 9 nM in summer and autumn (Van den Broeck et al 2004). Because most Trichodesmium blooms occur in summer, precisely in the period when inorganic phosphate tends to fall below this critical level (Moutin et al 2005), this observation suggests that Trichodesmium would have the capacity to utilize other sources of P, such as dissolved organic phosphate (Mulholland et al 2002).…”

Population dynamics and environmental conditions affecting Trichodesmium spp. (filamentous cyanobacteria) blooms in the south–west lagoon of New Caledonia

“…considering that its two possible sources are phosphorus depleted: runoffs from lateritic soils of this 322 part of New Caledonia (Tenorio et al, 2005) and exchanges with the surrounding oligotrophic ocean 323 (Van Den Broeck et al, 2004). This limitation could explain both the modest trichome density 324 maxima and the low Chl a (< 1 mg m -3 ) concentrations ( Fig.…”

Distribution and rates of nitrogen fixation in the western tropical South Pacific Ocean constrained by nitrogen isotope budgets

“…Attention has consequently shifted to the relatively undersampled Western Tropical 20 South Pacific (WTSP) Ocean, where atmospheric dust fluxes to warm surface waters are higher than in the central and eastern tropical South Pacific (Mahowald et al, 2009), and where surface ocean NO 3 -and PO 4 3-concentrations and ratios are relatively advantageous for diazotrophs (Moutin et al, 2005;Van Den Broeck et al, 2004 blooms of Trichodesmium spp. in the WTSP (Dupouy et al, 2000), consistent with more recent direct observations of elevated Trichodesmium spp.…”