ETS activity is a good zooplankton biomass proxy

ETS ac i i y is a good zooplank on biomass p oxy M. Gómez, I. Ma inez S. He nández León and T. Packa d Biological Oceanog aphy Labo a o y, 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. In s a ions wi h high alues o chlo ophyll “a” ( igu e 2), (upwelling a ea and s a ions ela ed wi h he cyclonic eddy, igu e 3) zooplank on g ow wi h high me abolic a es. In hese a eas ETS ac i i y co ela es well wi h biomass ( igu es 4 and 5). In coas al s a ions his ela ionship diminishes and is close o Kleibe ’s Law ( igu e 6). O sho e he a io, ETS/Biomass, dec eases o low alues ( igu e 7). In gene al, ega dless o dep h, he upwelling zone has highe ETS/Biomass a ios han ei he he o sho e o insho e. Be ween day and nigh , ( able 1), he e we e no signi ican di e ences in he ETS/Biomass a io in he coas al s a ions. On he o he hand, in he o sho e s a ions, he slope is highe in he nigh , p obably due o he e ical mig a ion o he mesozooplank on communi y. Dep h seems o ha e e y li le impac on he ETS/Biomass a io in he upwelling a ea. Howe e , o sho e he a io a 100-200 m is much lowe han in he su ace laye . This can be seen in wo ypical o sho e ansec (G and H ) see Table II. A e analysing 672 samples, we ind a slope o ETS o Biomass = 1, meaning ha loga i hmic ans o ma ions a e unnecessa y ( igu e 8) King and Packa d (1975) ound he same o zooplank on a he physiological le el, Packa d, e al 1983 and Be dale e al (1995), ound he same esul s in bac e ia cul u es, and Ma ínez e al, 2007, in A emia salina cul u es. ETS ac i i y de ec s biomass well. Kleibe ’s Law, ela ing an o ganism’s biomass (M) wi h i s me abolic a e (R), ollows he allome ic equa ion, R=aM.0.75. I holds o e 20 o de s o magni ude o espi a ion and has gained inc easing impo ance in ecen yea s, because i se es as he basis o he Me abolic Theo y o Ecology. (B own e al, 2004). We ha e p e iously shown ha a he physiological le el, Kleibe ’s law holds o zooplank on (King and Packa d, 1975), bu we do no know i i holds a he ecological le el. To in es iga e his ques ion, zooplank on samples o ETS ac i i y and p o ein, om he no hwes A ican upwelling sys em we e aken in Ma ch o 2006 (CONAFRICA 0603 C uise Figu e 1). These samples included bo h o sho e oceanic, nea sho e upwelling, and zooplank on om en di e en dep hs un il 200 me e s. These samples we e analysed in o al, by size, by dep h, and by di e en egions, o ag eemen wi h Kleibe ’s Law. 064,0755,0 xy 006,0544,0 xy 229,0754,0 xy 094,0823,0 xy 064,0755,0 xy 006,0544,0 xy 229,0754,0 xy 094,0823,0 xy DAY NIGHT Coas al S . O sho e S . Coas al S . O sho e S . y = 0.755x + 0.064 (R2 = 0.578) N = 44 y = 0.544x – 0.006 (R2 = 0.281) N = 143 y = 0.754x – 0.229 (R2 = 0.667) N = 20 y = 0.823x – 0.094 (R2 = 0.553) N = 77 TRANSEC T DEPTH (M) TB 0-100 y = 1.153x – 0.115 (R2=0.68, N= 30) 100-200 y = 1.201x – 0.232 (R2=0.823, N= 40) TC 0-100 y = 0.728x + 0.390 (R2=0.503, N=39) 100-200 y = 0.687x + 0.114 (R2=0.601, N= 41) TD 0-100 y = 1.052x + 0.150 (R2=0.573, N= 39) 100-200 y = 1.112x – 0.102 (R2=0.565, N= 40) TE 0-100 y = 1.036x + 0.003 (R2=0.224, N= 29) 100-200 y = 1.173x – 0.328 (R2=0.731, N= 33) TF 0-100 y = 0.751x + 0.010 (R2=0.469, N=33) 100-200 y = 0.588x + 0.055 (R2=0.5, N=31) TG 0-100 Y = 0.631x +0.075 (R2=0.6, N=29) 100-200 y = 0.231x + 0.107 (R2=0.034, N=29) TH 0-100 y = 0.55x + 0.161 (R2=0.453, N=22) 100-200 y = 0.184x + 0.135 (R2=0.128, N=18) TI 0-100 y = 0.101x + 0.088 (R2=0.016, N= 28) 100-200 y = 0.253x – 0.305 (R2=0.05, N=28) TJ 0-100 y = 0.856x + 0.023 (R2=0.726, N=13) 100-200 y = 0.795x – 0.041 (R2=0.583, N=17) y = 0,7925x + 0,0832 R2 = 0,6425 -1,5 -1 -0,5 0 0,5 1 1,5 2 -1,5 -1 -0,5 0 0,5 1 1,5 2 Biomass (Log mg p o ) Log Φ (µmolO2h-1) COASTAL STATIONS Slope = 0.797 (n =64) y = 0,6441x - 0,0297 R2 = 0,3784 -1,5 -1 -0,5 0 0,5 1 1,5 2 -1,5 -1 -0,5 0 0,5 1 1,5 2 Biomass (L og mgp o ) L og Φ (µmolO2h-1) OFFSHORE STATIONS Slope = 0.644(n = 220) y = 0,8862x + 0,1432 R2 = 0,5254 -1,5 -1 -0,5 0 0,5 1 1,5 2 -1,5 -1 -0,5 0 0,5 1 1,5 2 Biomass (Logmgp o ) Log Φ (µmolO2h-1) Slope = 0.886 (n =248) UPWELLING STATIONS y = 0,9787x - 0,1254 R2 = 0,4771 -1,5 -1 -0,5 0 0,5 1 1,5 2 -1,5 -1 -0,5 0 0,5 1 1,5 2 Biomass (L ogmgp o ) L og Φ (µmolO2h-1) Slope = 0.978 (n = 30) EDDIE STATIONS F om ou esul s and he li e a u e we conclude ha : 1.- In well-nou ished o ganisms (Upwelling and cyclonic eddy a eas) he slope o he log-log plo s o ETS- biomass is nea 1, indica ing a di ec ela ionship. This is in acco dance wi h he esul obse ed in cul u es (Packa d e al, 1983). 2.- In coas al s a ions and in esh zooplank on samples (Packa d and Gómez, 2008), he slope is lowe and close o Kleibe ’s law, indica ing less han well-nou ished condi ions. 3.- In low ood condi ions, as in he o sho e s a ions, he slope is lowe han Kleibe ’s Law. 4.- In gene al, conside ing all he da a, he exponen in he ETS/Biomass ela ionship is close o 1 han i is in Kleibe ’s Law (0,75). This means ha he ETS and biomass a e di ec ly linea ly ela ed and do no ollow he allome ic equa ion and consequen ly do no equi e a loga i hmic ans o ma ion. y = 1,0078x - 0,0689 R2 = 0,6653 -1,5 -1 -0,5 0 0,5 1 1,5 2 -1,5 -1 -0,5 0 0,5 1 1,5 2 Biomass (Log mgp o ) Log Φ (µmolO2h-1) ALL STATIONS Slope = 1.007 (n=672) Packa d e al. (1983) Packa d and Gómez (2008) Tempe a u e Chl ophyll “a” Figu e 1 Figu e 2 Figu e 3 Figu e 4 Figu e 5 Figu e 6 Figu e 7 Figu e 8 Table 1 Table 2