360
ALAlh’ SOUltNIA
b
rhythm and t hc dnyleiigth. Howcwx, the dependence of sexunl and
ikst’Xtlii I reprodiict ion on photoperiod wits (lemonstrated for the diatoms
R t ~ p h ~ u o p y x i s
(Skelc, 1965) and (‘osr.inodiscus (Holmes, 1966), and
I’tki~sclit* ( 1 n(i7, 1 !%8) cxperinicntcd with the effocts of varying regimes
on viirious growth UliiLrtLctc’r’isti(~s of thretb miirine phytopltmkters.
Tlic piirt,i(:1iliir conditions tit Iiigh Iictitucies, where dr%ylength undergoes
consic1er;iblc wiisond c h i i n p , have been faced only with respect to the
inhibition of photosynthesis (stit? above) and zooplankton (Bogorov,
i 946). I’hoto))criodicit,y ti mong benthic micro-algae seems to have
roocivud more iittrntion ( e g . Brucltmayer-Berkenbusch, 1954 ; Castenliolz, 1 !M4 ; ‘I’(h)rgh imd ’rhimann, 1 !)M) ; this problem i
R reviewed
for iilgiw in g:cuoral by ]Iring ( 1970).
l’hytochroiiies iirc tinother challenge. Only quite recently did Lipps
(1973) (lemonstrate a reversible far-red effect’ on the division rate of
four miirine },hytopliuiktt?rs. Otherwise, phytocliromes are mentioned
but t,wic*e in the prcneiit bil)liogrtiphy (Seliger and McEIroy, 1968 ;
Forwiard w c l I h v e n p r t , 1970) and no extraction has been attempted,
njtpnrotitly, from iLny planktonic alga.
H. Ttvnperatzwe
Siticc: tempcvakurt: variations are somewhat buffered in aquatic
erivironnionts wi compared to t6rrestrial ones, this factor might deserve
only little iLtteritioii in most cases. Nevertheless, i t may act indirectly
by originating R s~rr.cttification/rnixing die1 cycle, such as demonstrated
in a lakc ttji Tiilling (1957) and in a coastal marine area by Sournia
(1968).
C. O q q e n , C02, pH
AS ~ t i * l y
its I S U , Morrcn stiited, though ciautiously, that the oxygen
content, of ~ e i i
water incremrs during daytime its an effect of light on
thc ‘’ iinittislculi~s vcrts ”. l’hoiigh physicill processes interfere (Miyake,
I1)48 : Sugiurti, 1!63, 1956 ; Otlum, IgStj), dicl chimges resulting from
respirixtion and photosynthesis may be large enough to provide a means
of e∋itinp diiily production : Odum’s “ diurnal curve method ”,
first cicwloped in fresh waters (Odum, 1956; Otlum and Hoskin, 1958;
I’ttrk ut NI., 1958 ; further refermcrs in Sceley, 1961)) rewived somewhat
sim pli fioc 1 11 ppl i ca tions in I i m no1 ogi rid (l’:dling, 1 957) and ocemograph i -
c d studicbs (Ityt~her et al., 1958 ; ,Jones, 1963 ; Sournia, 1968) ; earlier
Soviet investigations itre listed by ‘Ihlling ( 1 957). I n eutrophic or
coiistal areas, saturation rises commonly from 80- 90% around sunrise
to l l @ 120yo (sometimes considenibly more) in the mid-afternoon ;
compciriitive tliit;r from oligotropliic wi~t~ws i i w lacking.
ALAlh’ SOUltNIA
b
rhythm and t hc dnyleiigth. Howcwx, the dependence of sexunl and
ikst’Xtlii I reprodiict ion on photoperiod wits (lemonstrated for the diatoms
R t ~ p h ~ u o p y x i s
(Skelc, 1965) and (‘osr.inodiscus (Holmes, 1966), and
I’tki~sclit* ( 1 n(i7, 1 !%8) cxperinicntcd with the effocts of varying regimes
on viirious growth UliiLrtLctc’r’isti(~s of thretb miirine phytopltmkters.
Tlic piirt,i(:1iliir conditions tit Iiigh Iictitucies, where dr%ylength undergoes
consic1er;iblc wiisond c h i i n p , have been faced only with respect to the
inhibition of photosynthesis (stit? above) and zooplankton (Bogorov,
i 946). I’hoto))criodicit,y ti mong benthic micro-algae seems to have
roocivud more iittrntion ( e g . Brucltmayer-Berkenbusch, 1954 ; Castenliolz, 1 !M4 ; ‘I’(h)rgh imd ’rhimann, 1 !)M) ; this problem i
R reviewed
for iilgiw in g:cuoral by ]Iring ( 1970).
l’hytochroiiies iirc tinother challenge. Only quite recently did Lipps
(1973) (lemonstrate a reversible far-red effect’ on the division rate of
four miirine },hytopliuiktt?rs. Otherwise, phytocliromes are mentioned
but t,wic*e in the prcneiit bil)liogrtiphy (Seliger and McEIroy, 1968 ;
Forwiard w c l I h v e n p r t , 1970) and no extraction has been attempted,
njtpnrotitly, from iLny planktonic alga.
H. Ttvnperatzwe
Siticc: tempcvakurt: variations are somewhat buffered in aquatic
erivironnionts wi compared to t6rrestrial ones, this factor might deserve
only little iLtteritioii in most cases. Nevertheless, i t may act indirectly
by originating R s~rr.cttification/rnixing die1 cycle, such as demonstrated
in a lakc ttji Tiilling (1957) and in a coastal marine area by Sournia
(1968).
C. O q q e n , C02, pH
AS ~ t i * l y
its I S U , Morrcn stiited, though ciautiously, that the oxygen
content, of ~ e i i
water incremrs during daytime its an effect of light on
thc ‘’ iinittislculi~s vcrts ”. l’hoiigh physicill processes interfere (Miyake,
I1)48 : Sugiurti, 1!63, 1956 ; Otlum, IgStj), dicl chimges resulting from
respirixtion and photosynthesis may be large enough to provide a means
of e∋itinp diiily production : Odum’s “ diurnal curve method ”,
first cicwloped in fresh waters (Odum, 1956; Otlum and Hoskin, 1958;
I’ttrk ut NI., 1958 ; further refermcrs in Sceley, 1961)) rewived somewhat
sim pli fioc 1 11 ppl i ca tions in I i m no1 ogi rid (l’:dling, 1 957) and ocemograph i -
c d studicbs (Ityt~her et al., 1958 ; ,Jones, 1963 ; Sournia, 1968) ; earlier
Soviet investigations itre listed by ‘Ihlling ( 1 957). I n eutrophic or
coiistal areas, saturation rises commonly from 80- 90% around sunrise
to l l @ 120yo (sometimes considenibly more) in the mid-afternoon ;
compciriitive tliit;r from oligotropliic wi~t~ws i i w lacking.