Ni ogen ixa ion,and,di usi e luxes in, he
upwelling egion o ,NW,Ibe ia
Víc o ,Mo ei a<Coello*,,Bea iz,Mou iño<Ca ballido,,Emilio,Ma añón,,Ana,
Fe nández,,Paloma,Chouciño,,E a,Sin es,,Ma a,M.,Va ela,&,An onio,Bode
Session,10.,A mosphe e<Ocean in e ac ion:, ood chains,,
biogeochemis y and,nu ien s
22,July,2016
16:30
2
Modi ied, om Sohm e ,al.,,2011
Wha ,is,Biological,Ni ogen,Fixa ion?
Biological con e sion
N2®NH4+
NH4
+
3
Backg ound:,
e idences,o ,N2 ixa ion,in,N,en iched,en i onmen s
NE,USA,coas
(Mulholland
e ,al.,,2012)
NW,Ibe ia
(Bena ides,
e ,al.,,2011)
W,English,
Channel
(Rees e ,
al.,,2009)
1) To desc ibe he seasonal a iabili y in he magni ude o N2 ixa ion in
he upwelling ecosys em o NW Ibe ia.
2) To quan i y he biogeochemical ele ance o N2 ixa ion as a
mechanism o new ni ogen supply in his sys em.
3) To iden i y he main diazo ophs in he egion du ing aseasonal
cycle.
4
Ou ,goals
5
S udy a ea
Modi ied, om,
Pi che ,e ,al.,,
2010
Downwelling
Upwelling

Me hods
10 samplings (Feb ua y, May, Decembe 2014;Ap il –Decembe 2015):
§
Size< ac iona ed N2 ixa ion a es a 0, 20,40 and 70 mdep h
(15N2up ake echnique, Mon oya e al.1996).
§
Size< ac iona ed P ima y P oduc ion
(14C<up ake incuba ions).
§
Size< ac iona ed Chlo ophyll a
(spec o luo ome ic me hod)
.
§
Nu ien s concen a ion (ni a e, e c.).
§
Diazo ophic communi y composi ion
(ni H PCR amplicons cloned and
sequenced by Illumina® Technology<NGS)
.
§
Mic o u bulence.
6
How,did,we,quan i y,mic o u bulence?
MSS,(Mic o<S uc u e<Tu bulence),p o ile
ISW,Wasse mess echnik,(h p://www.ISW<Wasse .com)
Ve ical,di usi i y,(Kz)
Osbo n,(1980)
ε:(dissipa ion, a e,o , u bulen ,kine ic,ene gy.
N:(B ün Väissälä equency.
7
8
Calcula ion,o ,di usi e, anspo ,o ,
ni a e,ac oss,10<40,m,laye
9
Hyd og aphic,condi ions
16
Ou ,goals
1) To desc ibe he seasonal a iabili y in he magni ude o N2 ixa ion in
he upwelling ecosys em o NW Ibe ia.
2) To quan i y he biogeochemical ele ance o N2 ixa ion as a
mechanism o new ni ogen supply in his sys em.
3) To iden i y he main diazo ophs in he egion du ing aseasonal
cycle.

17
Diazo ophic communi y,(clus e s),
B ay-Cu is simila i y
50%
P incipal Coo dina e Analysis
PERMANOVA by Hyd og aphic condi ions
p- alue < 0.05
18
Diazo ophic communi y,and,en i onmen ,
B ay-Cu is simila i y
50%
P incipal Coo dina e Analysis
19
B ay-Cu is simila i y
50%
N2, ixe s,phylo ypes
P incipal Coo dina e Analysis
20
21
Conclusions
1) Dep h<in eg a ed N2 ixa ion a es anged be ween 0.1 < 15 µmol N m<2d<1 (10
μm size< ac ion dominan )and we e compa able o hose ob ained in he NE
Sub opical A lan ic (NASE).
2) The con ibu ion o N2 ixa ion as a mechanism o new Nsupply, compa ed o
ni a e di usi e luxes, was < 2%.
3) The diazo ophic communi y composi ion exhibi ed a clea seasonal a iabili y
and was domina ed by UCYN<A (mainly unde he mal s a i ica ion
condi ions), ollowed by he e o ophic Bac e ia om Cl. Gammap o eobac e ia
and Ph. Fi micu es (unde mixing condi ions).

22
1< To quan i y mos equen diazo ophs
(UCYN<A and Gammap o eobac e ia).
<
nes ed,PCR
ni H(amplicons
Illumina®,
sequencing
Bioin o ma ics
Composi ion,o , he,diazo ophic
communi y
qPCR,(mos equen diazo ophs)
Fu u e,wo k
2< To quan i y P ymnesiophy a & UCYN<A
symbiosis and o de e mine i s ime<space
dis ibu ion.
Acknowledgmen s:
§
FPU ellowship o V.M. om Spanish Minis y o Educa ion,
Cul u e and Spo s (FPU13/01674).
§
S udy suppo ed by NICANOR p ojec om Xun a de Galicia,
Galician Go e nmen (EM2013/021).
23
Thank you o you a en ion!
Con ac he au ho Víc o Mo ei a:
mo ei a@u igo.es