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Nutrient retention efficiency, a new ocean metric from plankton respiration and carbon flux

Packard, Theodore T,Osma, Natalia,Fernández-Urruzola, Igor,Maldonado-Uribe, Federico,Martínez, Ico,Tames-Espinosa, Mayte,Romero Kutzner, Vanesa,Bru, Eduardo,Gómez, May · 2015

Abstract

Nutrient retention efficiency (NRE) is a new metric to quantify the capacity of an ocean layer to maintain its nutrients. Conceptually, it is the remineralization of inorganic nutrients associated with respiratory CO2 production (RCO2) within an ocean layer normalized by nutrients fluxing into that layer. It can be expressed as a ratio or a percent. Operationally, below the euphotic zone, it can be calculated either as the ratio, RCO2/(carbon flux) associated with an ocean layer or the inverse of the carbon-flux transfer-efficiency through that layer. Furthermore, it is related to the maximum curvature (b) of the respiration-depth function [RCO2 = (RCO2 )0 z-b]. NRE increases when the absolute value of b increases. NRE associated with microplankton can be calculated from microplankton-ETS depth-profiles. NRE associated with zooplankton can be calculated from zooplankton-ETS depth-profiles. Conceptually total NRE equals the sum of the NREs associated with allplankton fractions. In the Peru upwelling the NRE, associated with the microplankton, displayed a minimum 40 km seaward of the upwelling center over sediments calculated to have high benthic respiration.

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Nutrient retention efficiency, a new ocean metric from plankton respiration and carbon flux

Author: Packard, Theodore T,Osma, Natalia,Fernández-Urruzola, Igor,Maldonado-Uribe, Federico,Martínez, Ico,Tames-Espinosa, Mayte,Romero Kutzner, Vanesa,Bru, Eduardo,Gómez, May
Year: 2015
Source: https://accedacris.ulpgc.es/jspui/bitstream/10553/12910/1/0707474_00000_0000.pdf
Conclusions:
NUTRIENT RETENTION EFFICIENCY, A NEW OCEAN
METRIC FROM PLANKTON RESPIRATION & CARBON FLUX
T.T. Packa d, N. Osma, I. Fe nández-U uzola, F. Maldonado, I. Ma inez, A. He e a, M. Tamés-Espinosa,
V. Rome o-Ku zne , E. B u, M. Gómez
G upo de Eco isiología de los O ganísmos Ma inos (EOMAR). Facul ad de Ciencias del Ma , Uni e sidad de Las Palmas de G an Cana ia, Campus
Uni e si a io de Ta i a, 35017 Las Palmas de G.C., Cana y Islands, Spain. ( edpacka [email protected])
NRE Calcula ion om Respi a ion
NRE is he nu ien emine aliza ion a e
wi hin an ocean laye no malized by
nu ien s en e ing ha laye ia pa icle lux.
Below he eupho ic zone i can be
calcula ed as he in e se o he ca bon- lux
ans e e iciency. Also, i can be calcula ed
om aplank on espi a ion p o ile (and he
Red ield a io). In he eupho ic zone i is
essen ially he espi a ion o p oduc i i y
a io.
Concep ual Basis
F -s = [R /((b+1)(z )b]*[(zs(b+1)] - (z (b+1)]
Box 1.-Ca bon Flux Wo king Equa ion. R is he espi a ion a he
espi a ion maximum, bis he exponen on he powe unc ion, z is he
dep h o he laye h ough which he ca bon will lux, and zsis he bo om
dep h (sea loo ).
Mic oplank on CO2p oduc ion
dec eases e ical pa icle lux
by eleasing DOC & DON!
ABSTRACT Nu ien e en ion e iciency (NRE) is anew me ic o quan i y he capaci y o an ocean laye o main ain i s nu ien s.Concep ually, i is he emine aliza ion
o ino ganic nu ien s associa ed wi h espi a o y CO2p oduc ion (RCO2)wi hin an ocean laye no malized by nu ien s luxing in o ha laye .I can be exp essed as a a io
o ape cen .Ope a ionally, below he eupho ic zone, i can be calcula ed ei he as he a io, RCO2/(ca bon lux) associa ed wi h an ocean laye o he in e se o he
ca bon- lux ans e -e iciency h ough ha laye .Fu he mo e, i is ela ed o he maximum cu a u e (b) o he espi a ion-dep h unc ion [RCO2= (RCO2)0z-b]. NRE
inc eases when he absolu e alue o binc eases.NRE associa ed wi h mic oplank on can be calcula ed om mic oplank on-ETS dep h-p o iles.NRE associa ed wi h
zooplank on can be calcula ed om zooplank on-ETS dep h-p o iles.Concep ually o al NRE equals he sum o he NREs associa ed wi h allplank on ac ions.In he
Pe u upwelling he NRE, associa ed wi h he mic oplank on, displayed aminimum 40 km seawa d o he upwelling cen e o e sedimen s calcula ed o ha e high ben hic
espi a ion.
Fo mazan p oduced om
e azolium (INT) in he ETS
assay “coun s elec ons”.
Reac ion s eng h is p opo ional
o he ed colo .
1. NRE = (R in any ocean laye )/(To al wa e -column R om eupho ic-zone bo om o sea loo .)
2. Exponen (b), he cu a u e o R= (z), con ols pa icle lux & NRE
3. Low wa e column NRE leads o high ben hic espi a ion and ca bon bu ial.
POC, N, P
Flux in
O2
CO2(RCO2)
NH4+(RNH4+)
PO4-(RPO4-)
POC, N, P
Flux ou
EFFICIENCY WITH WHICH PLANKTON MINERALIZE POM
Pe mi s nu ien ecycling! NRE =(∆POM Flux)/(Flux in)
(C -s )1=(d(POC)/dz)
d(CO2)/dz) =
RCO2
(C -s)2
NRE = RCO2/(C -s)1
CUEA C-Line o 15°S Pe u
0
0,5
1
1,5
2
2,5
020 40 60
DEPTH (km)
NRE (R/Fc x 100) S a ion 16 (C14)
Rz= R (z/z )-b
Cu a u e, “b”, is he key o
unde s anding pa icle lux and NRE!
R/V T G THOMPSON (U WASH)