No he n Benguela upwelling: D i ing o ces and ecosys em esponses
I. Fe nández-U uzola, A. He e a, L. Pos el, N. Osma, M. Gómez and T. T. Packa d
e abolism o mesozooplank on
ac oss he Benguela upwelling
sys em in e ms o ETS and GDH
ac i i ies
M
Ins i u e o Oceanog aphy and Global Change, Ecophysiology o Plank on G oup, Uni e si y o Las
Palmas de G an Cana ia, Cana y Islands, Spain. E-mail add ess: i e nandez@beca ios.ulpgc.es
INTRODUCTION
Respi a ion in he ocean ecosys ems
Respi a ion is a ubiqui ous p ocess which
cons i u es a key componen in he es ima ion
o he ca bon lux. Howe e , i s magni ude in
ocean ecosys ems emains unce ain (Del
Gio gio and Dua e, 2002) due o he di icul y
on quan i ying in si u espi a ion a es.
They p o ide low da a acquisi ion a es and a e
complica ed by o ganisms manipula ion,
o e c owding and s a a ion (Bidiga e, 1983).
WATER-BOTTLE
INCUBATIONS
Po en ial measu emen s such as ETS a oid hese me hodological a i ac s!!
(I) NH4+ is an in e medi a e p oduc in decomposi ion o o ganic
ma e , which cons i u es he mos educed o m o N.
(II) NH4+ sus ains a global a e age o 80 % o he au ho oph’s
eque imen s (Ha ison, 1992), wi h he mesozooplank on
esponsible o 12 – 23 % (He nández-León, 2008).
Zeh and Kudela (2011)
INTRODUCTION
Impo ance o NH4+ in ma ine sys ems
RECYCLYING
EFFICIENCY
Nu i ional
His o y
(Mille and Roman,
2008; Saba e al., 2009)
Tempe a u e
(Ikeda, 1985)
T ophic
In e ac ions
(Glibe , 1998)
INTRODUCTION
Elec on T anspo Sys em as index o O2 espi a ion
Vmax
INTRODUCTION
Glu ama e dehyd ogenase as index o NH4+ espi a ion
GDH (EC 1.4.1.3) is ound in high le els in plank onic c us aceans (Regnaul , 1987).
I s ole in amino acids ca abolism agues o i s con ol o e a g ea p opo ion o NH4+ exc e ion.
Modi ied om Yuen and Chiew (2010)

INTRODUCTION
Benguela Upwelling Sys em
Namibian coas is cha ac e ized by in ense coas al upwelling associa ed wi h Benguela
cu en . These upwelling a eas p o ide high o ganic p oduc ion linked o phy oplank on
bloom.
Map o sea su ace empe a u e om he MODIS senso on boa d NASA
Aqua sa elli e (3 Feb.2008).
We es ima ed biomass, as well as he
po en ial espi a ion (ETS) and NH4+
exc e ion (GDH) in mesozooplank on
communi y in h ee dep hs along a
ansec wi h di e en oceanog aphic
condi ions o unde s and how a ec
phy oplank on bloom in he zooplank on
me abolism.
MATERIAL AND METHODS
S udy a ea
4 sec ions ac oss he no he n Benguela upwelling sys em: LT1,LT2 and LT3 wi h 12
s a ions, and LT4 wi h 21 s a ions.
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MATERIAL AND METHODS
Expe imen al design
SIZE FRACTIONATION
Da a analysis
Labo a o y wo k a ins i u e
TAXONOMY, BIOMASS and METABOLISM
Mo e han 700 samples we e analyzed o me abolic a es
S o age in c io ials a -80 oC
GDH Ac i i y
(Bidiga e and King, 1981)
ETS Ac i i y
(Packa d e al., 1971)
P o ein
mass
(Low y, 1951)
0
50
100
150
200
250
18:00 18:14 18:28 18:43 18:57 19:12 19:26
Tie e [m]
457N070301, 13-9-2000, 200-75 und 75-25m
ZOOPLANKTON SAMPLING
100-200 μm
200-500 μm
500-1000 μm
> 1000 μm
RESULTS
Global a e ages om he di e en sec ions
The highe biomass alues a e coupled o he upwelled wa e s. ETS ac i i y i s wi h he biomass
pa e n, while GDH ac i i y p esen mo e dispe sion since i oplanc on does no ha e e ec in his
a e. Howe e , he GDH maximum a e is s ill nex o he upwelling.
Biomass
[mg
p o ein
. (m3)-1]
NAM027 NAM025 NAM023 NAM021 NAM019 NAM017 NAM014 NAM009 NAM004 NAM001
--
__
_
• • • • • 4
• 3
50 • • • • • • •
E'
'-'-
5
~
2
Q 100
1
• • •
150 O
500 400
300
200 100 O
Sec ion
Dis ance
[km]
RESULTS
Biomass and enzyme ac i i ies o each “sho ” sec ion
SECTION 1
The e is a bloom on NAM007, which causes high
enzima ic a es in his a ea. This ac i e me abolism
seems o mo e o sho e along he subsupe icial
wa e s, specially o GDH.
SECTIONS 3 and 4
These wo sec ions show a simila pa e n han ha
ound in sec ion one. The bloom is now placed
a ound NAM005 and i sligh ly ex ends o sho e.
SECTION 2
Biomass and ETS ac i i y a e mos ly dis ibu ed in all
he wa e column o NAM009. The la e , howe e ,
p esen s i s maximum be ween 200-75 m. This no
seems o a ec GDH, whose highe ac i i y is in he
su ace wa e s o NAM017 p obably due o a peak o
zooplank on in his egion

RESULTS
Size ac ion con ibu ion o he mean alues in e ms o Biomass
100-200 μm 200-500 μm
500-1000 μm > 1000 μm
All he ac ions p esen high alues onsho e. Howe e , he lowe he size ac ion is, he mo e coupled
is wi h he upwelling. Consequen ly, he mesozooplank on o e 500 μm seems o domina e o sho e,
wi h maximum alues on NAM023 o he highes ac ion.
RESULTS
Size ac ion con ibu ion o he mean alues in e ms o ETS
FRACCIONES INTEGRADAS ETS
100-200 μm 200-500 μm
500-1000 μm > 1000 μm
All he ac ions p esen high alues onsho e. Howe e , he lowe he size ac ion is, he mo e coupled
is wi h he upwelling. Consequen ly, he mesozooplank on o e 500 μm seems o domina e o sho e,
wi h maximum alues on NAM023 o he highes ac ion.
RESULTS
Size ac ion con ibu ion o he mean alues in e ms o GDH
FRACCIONES INTEGRADAS GDH
100-200 μm 200-500 μm
500-1000 μm > 1000 μm
All he ac ions p esen high alues onsho e. Howe e , he lowe he size ac ion is, he mo e coupled
is wi h he upwelling. Consequen ly, he mesozooplank on o e 500 μm seems o domina e o sho e,
wi h maximum alues on NAM023 o he highes ac ion.
RESULTS
Wha does he s a isc ics say?
1. A e he e signi ican di e ences in
ETS, GDH and Biomass be ween DEPTHS? YES!!
(K uskal-Wallis es , p<0.001)
RESULTS
Wha does he s a isc ics say?
2. A e he e signi ican di e ences in ETS,
GDH and Biomass be ween SIZE FRACTIONS? YES!!
(K uskal-Wallis es , p<0.001)

RESULTS
Wha does he s a isc ics say?
YES!!
(Mann-Whi ney es , p<0.001)
3. A e he e signi ican di e ences in ETS, GDH and
Biomass be ween UPWELLED and OFFSHORE WATERS?
RESULTS
Wha does he s a isc ics say?
4. A e he e signi ican di e ences in ETS, GDH
and Biomass be ween DAY/NIGHT SAMPLING? NO!!
(Mann-Whi ney es , p>0.001)
✗
RESULTS
Me abolism and biomass ela ionship: Kleibe ’s law
Fo many yea s i has been accep ed he pa adigm o he Kleibe ´s law,
which s ablish a exponen ial ela ionship be ween biomass and me abolic
a es wi h a coe icien “b” close o 0.75.
Se e al zooplank on s udies show di e en a ios close o o g ea e han
0.75 in op imal eeding condi ions, and below 0.75 when he o ganisms a e
ound in oligo ophic a eas o poo eeding (Gómez e al., 2008; He e a e
al., 2011; Ma ínez, 2007; Packa d and Gómez, 2008).
In his s udy, he coe icien s “b” a e g ea e han 0.75 o ETS and
GDH ac i i ies in bo h upwelling and o sho e a eas.
Me abolic a e = aWb (W=biomass)
RESULTS
Me abolism and biomass ela ionship: Kleibe ’s law
OFFSHORE log ETS = 1.05 log W + 0.68
UPWELLING log ETS = 1.08 log W + 0.67
ETS s Biomass