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,- This paper not to ,be ci ted '''i thout prior reference -to thc nuthors

InternationaJ-Council for thc'Exploration of the Sen

C oHo1979/ L: 15Diological Oceanography Committee

Production Studios in Anteguera Day: a,comparison uith oceanic waters

by

F 0' Real and J~ G'g Braun

Instituto Espaiiol de Oceßnograi'inLaboratorio Oceano~fai'ico de Canarias,Avda o Jose Antonio, 3Santa Cruz de Tenerife'o Islas Canarias'o'

• Summary

As' a-, complement to the studies carried out in Canary ,mters, a:separate private invcstigation lyas carried, out in a~coastal zone, situa­ting al fixed station in thc center of a: small bay (Day of Antequera)~oThis investigation, lvhich includes the majorit)r of facts normally usedin productivity invcstigations, began on the 9 th of Deeember 1974 andfinished on the 15 th of Harch 1976 0 Comparing the values of Antequerawith those simultaneously obtained from oeeanie liaters we can say that

_no definite barrier exists betwecn both ecosystems o naYing observedgreater assimilation numbers,in tbe bay than in the open sea, we areled to believe that in the bay a:greater force of nutrients exists,whieh support a1relatiyely greater prod~ctivity~

Resume: '.

•Comme. complcment aux etudes de productivit6 primnire deyeloppce's

dans les eaux canariennes, on a, effeetue une etude particuliere dansune zone cotiere o Pour cel~ nous avons situe una station fixe au centred'une petite baie (Baie d'Ante9uera)0 Cette etude qui comprend la.plupartdes donnees normalement utilisees dans les rceherches de produetivit6 adebut6 l~ 9 dccembre 1974 et conclut le 15 mars 1976 0 En comparant les,valeurs d'Antequera avec les obtenues sinnltancment dans les; caux ocea­niques on peut dire qu1il n'existe pas une barriere franche entre lesdeux eeosystemes. Ayant observe des valeurs plus hautes d'assimilationdans la-baie, cela nous fait penser qu'il existe dans la meme une plusgrande dynamique des nutrients, ce qui, relativement, supporte une plushaute productivite.

ciftci
Thünen

Introduetion

First studies LInde in ,..aters rouml the Cal1a1'Y Isln11l1s ,~'ith respeetto finding out the basic parm;'letc1's, their relation to plankton prol1ue­tiv1ty levels und thc l1cterminution of tbe CanaT')" marine eeoß~',stem ingeneral, havc sho',-n us, up to nm", tImt an oli[iotrophie situntion cxists,,1th a small quanti ty of nut1'ients in the euphotie ZOlle and lou plnnl\:tonproduetion (exeept du1'ing thc spring blooe) cven as elose to thc shore astl..'o mi1es, (De Leon and Brmm, 1973; Braun, 1971t, 1978 a and b; Braun amIDe Leon, 197h; Braun, Eseanez and De Le6n, 1976; Braun and Real, 1978;neal, De An:ms· and Braun, 197 8 ) 0

,. Bccause of thc proximity to the const of these oligotrophie condi tions,,,'e are dcdicating a, special progrnmne of stlHIy in linters of a bay, l.ryint;i 0 find a disminution of this situntion and also to ohserve ,,'hether thereexist any l1ifferenees bet,,'een oeeanic ,mters und those very near to theshorc, such as tllose be10nging to a bench o

To elnlJ'oratc this progrmmne '''e arc faeed ,.. i th hw main problems. 1)'rhe inexi stence of a shc1f maJ\:es i t praetiea11y iI:1possi1)l~ to obtain aelear barrier bet,..een oeeanie ,..nters and eoastnl \mters o 2) nonnd thcis10no. of Tenerife there are not any places that offer small shelteredbays , ..here ",c ,vould be able to curry out our plans'o TImvever, \\'e decidedon the Antcquera beaeho At this point there is u large eountainous pro-j ection tO\t'ards the North , ..hich protects i t qui te ":ell, and i t is to befound on apart of the island tImt possesses a· small arca of shelf, cspe-

• ;ial1y tm-:ards thc NoE., l:hich is t.he c1irect.ion the Canary Current CO::lCS

.L rom"A permanent station ,ms pluccd in thc center of the bay of coordinates:

282 31,,6'1, und 162 8'1? at a dopth of 15 mcters ''ihich i5 thc normal depthof t.hc lHl~·, registcring a stuuS from thc 9 th Deccmber, 1971i to 15 th Narch,1976., ·(Fie., 1) 0

Naterinl and Hethods

Uater ,ms extracted for analysis in 8 1itre Niskin bottles at 1.11rccdept11s: 0, 5 and 10 meters o Tlle parameters studied and the r:Jcthods uscd"'cre as fol10\ ...s: ternperature (reversing thermor:lCtcrs); sulini ty (neckrnansa1inomcter); oxygcn ('linkIel' method); phospIw.tcs (Nurphy amI Rilc)', 19()2);11i1.rates ('{ood, Anastrong and Riclmrds, 1967); nitri tos (BendscImeiderand Robinson, 1952); silicates (Hullin and Hiley, 1955); rtrnmonium (I~oro­leff, 1969); chlorophyll (SConjuNEscO, 1966); primarJr prouuctivity (51.ec­rJUllli Nielscn, 1952) and zooplankton.,

Incubations of C-llt ' ...cre carried out in~, for approximately 2 - 3.11our5 at about middayo

Results and Discussion

Ternpcrature vnlues are, generally speaking similar ,1'1thin the oolur.mof v:ater, ,dth a sligbt disminution (allmys less tImn a dcgree) in deep"'atcr (Fig" ,,)'0 The greatest contrast ean be notcd in Oetober, ,..ith thcnppearanee in Deecmber, 1975 of an occasional 1.cmperature inversion,possibly duc to a: drop in tcrnperature of surfnce ,mter. At tImt time thc\\leather eonditions ,..ere: adequate for the formation 01 the nfore mentionedinversion'"

In the rnentioned Fig. 2, , ...e have represented the seasonal variationof average valües oi temperature in thc.column of tbc first 10 meters,

-3-

und conparing i t 'vi th average yallleS oi thc first 10 meters simultaneotlslyin occanic ,vat.ers (5 Ini.les to t.lle East of San Anures), similar values eanbc obscn·ed o The details for 'the oecanic station have bcen published moreextensively aa: a~ separate pieee oi 'vork (Drmm, 1978 a) 0

The values of salini.ty at Alltequera and their cornparison 'vi th tImt oioeean salinity are in Fig o 30 Th~general impression is oi similarity,although the' yalues, in occanic 'vaters are slightly superioro '

Thc fCl{ yalues olJtained for oxygcn are giyen in Figo h o EspecialIyhigh valucg; ,dlI be noticed, nlmost nbmys obtaining oversaturation o

Thc phosphates prescnt cxpected Iow vnIucs 0 From lillucteetablcquantities to maximums in spring oi 0.10 pg-at P-PO!.!lo The C01.'l]H:1risonwitll oecanie va1ues cn.n bc observed in Figo h anu tllere exists anex.traordinary similarity in tbc fluctuations, including annual yarintions olIibIler yalucs can be obscrved dllring the spring amI autnnm. 'rhe infom~­

tion gatherell, from Antequera gives tl' yalue in disolveu phosphate 1,,6 tinessuperior to those from thc oceano

In Fig o 5 nitrate concentrations are givcn togcthcr \\'i th an nverageva1ue eomparison of oeean waters o The resu1ts were 1 08 tilJCS superioi tothosc of occanic 1\ntcrs'o

For nitrites (Fig'o 5) the 1m\' yalues obtained are typicn1 oi suriace'inters and comparnblc to occan ,mters o

'{i th respect to silicates (Fig'o 6) higher coneelltrations at Ant.cquerathan at hit;ll sea have boen observed, probably duc to the ljreat proximityoi earth massg All coastal vulues triple oeemi yalues'o

In ammonium, thc Antequera spceifications (FiC;o 6) are similar tothose at high sen., Ah:ays inferior by 1 ug-at N-NII /1.

The chlorophyll ya1nes (figo 7) of 'the beach at Antequera are consis­tently higher, although in a smalIer proportion tlmn the vulues in thcopen sea'Q Novertheless in springtiI:lc, exnctl)~ the opposie happens: Thccoastal yalues are ',,"eak comparcd "'ith the oeeanie ones 0 In general thechlorophyll found in coastal ,mtcrs ,ms 1;..25 times, greater than tlle valucstakcn in the open sen...

Analogously to ,\hat happened 'iith thc chlorophyll, the average val uesof primary productiYity at Antequera are nbm)~s highcr than in oecanic'vaters, exeept· in springtirnc when the productivity in the seu. i5 a littlehigher than that of the beach, (Fig o 8) 0 '\hen ,ve intcgrate t11e information"'0; find tImt tbe production at Antequerij is double tIm.t of the oeeanicwnterso Tberesu1ts expressed in mg C/m-~dny are given in Table I ~itb

an average amuInl content of 159 mg C/m2o day'0

As. for the zooplanl~tonic biornass (Fig o 9) '''hen ,m; compare the valucsat Antcguera ,vi th those of the oceanic station, the former are ah;nyslligller tbetween 1 0 35 and 1 065 times; greater)'" Nevertheless it is~ surpri­sing that on t11e: bench in April, the spring-time peao.k cantt be dctected oIt is possäble that, at this time oi the )'ear, the zooplaru::ton has beentakcn in by the follo\'dng trophic level, ,\1ththe biomass fallinG backinto its steady-statc onee ngain.,

The biomass of thc_zooplankton at -bntcquera has an average yalue C)

of 2 ~38 mg dry ,wight/m':> or 1 0 19 mg C/ro':>" This ":ould mean 17" 85 mg C/m-'i.'It has. bccn noticed that the zooplanl::ton in the Canary Island ,mters

hus a. normal filtering rate of about 15 ml/anima1'odny (Braun, 19711)"Stmlies carried out to find thc eontent of carbon in the' particu1ateorganic material in these ,:atcrs give figures some\\hat superior to 100 mgC/m':> (Braun, 1978 aj neal, De Armas and Brmm, 1978; Dc Armas, 1979).,Supposing tImt this partieulatc orgnnie enrhon is thc basic ava.ilablefoou for thc zooplankton it is possiblc 1.0 obtain for the total of thecOIn...nunity a.verng.c in~estions Rf about 13 rng C/m2 "day. The average primaryproduetivity bcing 159 mg C/m~oday, the ZOOplullliton at Antequera controlsonly 8 % of the primaIj~ prouuction, \~'hich permits a, 92 % sinking oi thesame, ,,,hich serves: as; basic alimentation for the bentonie s:ystem o On thc

I , "

S

5

ßi - 1'1, tcd ncd nÜ ion; 5 .rn

tl " n d, 1 C )1' C, t .l s, i t 1 1 e lJ ti c cl i Iht the :r 10p]; \ - ün:ciCl. 55 C01 tlols 1 0 ~ of C 1 rouuctitn, ut for t üs it is 55<

: io l'l,nsj Cl' t c :t'OOpJ,l ,n . j ~h is to e fu nd in t le first 500J t. s e Jth (J)r< t 19 8 b). J ace' r anee ,,"th e coefficicnts 0 0 8for tf 'rtl tion' 1d 03 for Lru' t tle ai y roduct'on of zoo -to't .nt Iuc'a is st"lllat d at 3 mg C/m2

0 ayoFor oee c, . r5 and eonsi er"ng the i lass of t 1e zoopl -t n

i' IC fir t 500 Letres , the zoo a -tonic pro uetion ,-as stimated toJe 73 J g C/m2

0 d~ (Bra t 19 8 ; ut onsi ering tle oeeanie zoop aD toof 1 Je first 15 metres , 'ie ,\'ou1d 0 tain a dail pro uction of some 2 gC/n2 ('[' _ , ,. ie is somenT at in ri rot !at 0 tain d 0 t 1e eac at. (.

Cone usions

e In the face of the resu1 ts ShOl\Jl. we ma r sum up as fo110'l"s:1) That in the zone stu ied no precise barrier e~'een oeeanic and

coustal ~ ters exists a1though in some of the parame ers re pons~o forthc production of lankt n ~ slight 'ncrcas t in co sta1 raters, eau benoted

2) Tha. in pi' of t is, t he ssirri tion numb rs ihe coast aregenerall r ig er t < those in the open ocean, "Thich in turn sho s agreater force of nutrients -hieh ma r 1.1 relat.ed to terrestrial contri u­tions or to the bot Dm oi t c ay

Ta"') le

() 19 '1

1'1 ' 1975

t")- ') 19/5

6-1 -1975

):2-1:2-197)

15-3 1976

o P -1,.<1 r pr l llC i T' t in Antequera Ba r

1 S

84

19~

~66

I

L

Hean a u 159

, a t.e

-)~-1971I 6 00 2,1(;

• J.:.. '1-19/5 30 7 5,()6

~5-6=1975 11:.50 f) -6

6-1 -1975 4,,05 ~"OO

12- 2-1975 5 .. 12 1,,05

15-3-1976 4 .. 00 2 .. 14

_lcan yalne Z 78

Spatia1 distributionarbon in surface eoastalon the Canary Curren :

cferen~cs

Bel c lUcic er, K o nd R.J 0 Robinson o 1952. A new' spectrop otometriemct od for tlC et 1. jnation of nitrite in sea water o J" aro ResoI :87-93"

Dral1n, J .G o 1974 0 E tlldio relimina so re el grado de f 'ltracion deI700pla {ton cn '<.ßC'-s canarias:o Bo. Inst o Espo Oeeanogr o o. l780

Brau , Jo~o 1978 a o Pro uetion S~dies in Cana Is an waters o 1 0 H~drograp 1)', utri .11.5 al primary pro uetion" leE 0 C'nt 1C ~ < 1a r CUi. r t: U ie11ing aud Li ring Resources 0

Era ,JoG o 1978 b o r 0 nction Studies in ana Is1an waters o 1 0 ~oo-

pI -ton 10l~Ll tiCll o CE 0 S' I osium on the Cana r Curr nt: U 1'c11' g8 ... d Li "i.nb eso rees" ,'0 0 6 0

.urau , J oGo ud "0 De 1 ("'0 1-,7h 0 Tar: [.ciOlles en 1a roe ucci on ri-I a_ ia en (:juns V' 1 (rio r ric ... 1 ~s 0 Bo o I1ISt 0 Espo Oeeanogr 0 ."0 0 17f:

Br~n, JoG o , JoE o Esc( ez and AoR. De Le'n o 1976 0 Obse "aeiones ~Ii

ruic s y biologicas en el ~{ de Af . ca entre ca 0 Ju •.- eabo G lir(Cb Ipona CI -ff; _I' OR 'Jl1E DE S_ A\ED. "J l' C T ro 1973 Bol Inst o

Esp 0 ccanogr.~· 0 0 209

BldlTI, "Go all F o ...<.ca 0 1978 0 A OTll a ison hetfcc'l annopla ton andnet 1.' op1aru.ton in C llLrV I sland ,'aters CES S Ti,posium on theCan, I . Curr nt: l! \'e11ing and Li 'ing Resourec5 0 '0 0. ,630

De Armas, JoD o 1979 Co'· 08ic1on y distr'bl cion de a I ~teria orga1licaen sus ensian ell a~u:ls deI arc.1ipiel<.go canario Tesi l1a l' aeultedde Ci ncias o Tniyersillad .c La. LagUl1c: 0 72 po

De Lean, AgR o and J G Brauno 19730 Cic10 nual e l~ pr duccion pri-rnaria y su rela i6n con los nutrieptes cn aguas canarias Bol o I st G

Fsp. 0 'p<no~r TO 1&-0I~oro eff, r" 1969 G Direet Determination of Am onü:. in .~c.tural ,~. ters

as Iu( opleno1 B.ue ICES C }fo 1969/C:9

lullin, J B o and JoP Ri ey" 19550 The eo10rimetric determination ofsi1ic te ,'it.l sp eial reference to sea and natural ,'aters Anal oChi Acta 12:162-1750

lurph," J and J P" i le,- 9 1962" A modified single solution methodfor t e deterreination of phosphate in natural waters Anal Chim"Acta o 27~31-360

Real, F o J D De Armas and JgG Braun 1978of eh orophy11 ~ and particu1ate organie'aters oi Ca 1ary Is an" lCES- .'1IlpC'si m

Up ·e11ing and Li-in nesourees No. ~~"

SCOR/ .TESCO 1966 Deter~ination of photos.nthetic pigments in sea,·:ater" Nonographs on oeeanograp lic methodolo o 0 Pub 1 Unesco o

Steemann Tielsen E 1952 Use of radiaetire earbon (C 14) for measuringorg nie production in the sea" J o Cons Int E4p10r fer g 18:117-140

''I'"ood tED , F gAoJ·o Armstrollg and F Ag Richards 1967 Determination ofnitrate in sea ,-ater b) cadmium-copper reduetion to nitrite" J larBi01 Ass U K 47:23-31

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