Short- and long-term responses of the marine diatom Phaeodactylum tricornutum to spike additions of nitrate at nanomolar levels

Raimbault, Patrick; Gentilhomme, Valérie

doi:10.1016/0022-0981(90)90013-3

Cited by 18 publications

(16 citation statements)

References 29 publications

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“…Removal of baleen whales may have led to a deficit of bioavailable nutrients at the base of the food chain, causing krill populations to decline (Smetacek 2008;Nicol et al 2010). While the overall nutrient contribution of whales may be moderate on a global scale, these nutrients are not added arbitrarily across the ocean but rather are concentrated in the most productive areas, where high background levels of phytoplankton exist that can quickly use such nutrient pulses (Raimbault & Gentilhomme 1990). Southern Ocean sperm whales represent just 3 per cent of the global sperm whale population (Whitehead 2002).…”

Section: Results (A) Sperm Whale Datamentioning

confidence: 99%

Iron defecation by sperm whales stimulates carbon export in the Southern Ocean

Lavery

Roudnew

Gill³

et al. 2010

Proc. R. Soc. B.

131

123

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The iron-limited Southern Ocean plays an important role in regulating atmospheric CO 2 levels. Marine mammal respiration has been proposed to decrease the efficiency of the Southern Ocean biological pump by returning photosynthetically fixed carbon to the atmosphere. Here, we show that by consuming prey at depth and defecating iron-rich liquid faeces into the photic zone, sperm whales ( Physeter macrocephalus ) instead stimulate new primary production and carbon export to the deep ocean. We estimate that Southern Ocean sperm whales defecate 50 tonnes of iron into the photic zone each year. Molar ratios of C export ∶Fe added determined during natural ocean fertilization events are used to estimate the amount of carbon exported to the deep ocean in response to the iron defecated by sperm whales. We find that Southern Ocean sperm whales stimulate the export of 4 × 10 5 tonnes of carbon per year to the deep ocean and respire only 2 × 10 5 tonnes of carbon per year. By enhancing new primary production, the populations of 12 000 sperm whales in the Southern Ocean act as a carbon sink, removing 2 × 10 5 tonnes more carbon from the atmosphere than they add during respiration. The ability of the Southern Ocean to act as a carbon sink may have been diminished by large-scale removal of sperm whales during industrial whaling.

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Section: Results (A) Sperm Whale Datamentioning

confidence: 99%

Iron defecation by sperm whales stimulates carbon export in the Southern Ocean

Lavery

Roudnew

Gill³

et al. 2010

Proc. R. Soc. B.

131

123

View full text Add to dashboard Cite

show abstract

“…Collos 1983, Raimbault & Gentilhomme 1990. However, such estimates will still suffer from the lack of both any adequate model of uptake under non-steady state conditions and any convergent empirical evidence of the effect of a heterogeneous nutrient distribution on phytoplankton uptake and growth.…”

Section: Resultsmentioning

confidence: 99%

Small-scale nutrient patches in tidally mixed coastal waters

Seuront¹,

Gentilhomme²,

Lagadeuc³

2002

Mar. Ecol. Prog. Ser.

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“…Therefore, it does not describe rapid uptake over short periods of time ('surge uptake') during which uptake exceeds assimilation, which has been observed over timescales of seconds to minutes (Raimbault & Gentilhomme 1990, Dortch et al 1991 and even hours (Pedersen 1994). In the terminology of Pedersen (1994), OU kinetics describes 'internally controlled' and 'externally controlled' uptake.…”

Section: Optimal Uptake: Acclimationmentioning

confidence: 99%