ORIGINAL PAPER

Photosynthetic characteristics and UV stress toleranceof Antarctic seaweeds along the depth gradient

Pirjo Huovinen • Ivan Gomez

Received: 14 February 2013 / Revised: 14 May 2013 / Accepted: 27 May 2013 / Published online: 7 June 2013

� Springer-Verlag Berlin Heidelberg 2013

Abstract The photosynthetic characteristics through P-E

curves and the effect of UV radiation on photosynthesis

(measured as rapid adjustment of photochemistry, Fv/Fm)

and DNA damage (as formation of CPDs) were studied in

field specimens of green, red and brown algae collected

from the eulittoral and sublittoral zone of Fildes Peninsula

(King George Island, Antarctic). The content of phenolic

compounds (phlorotannins) and the antioxidant activity

were also studied in seven brown algae from 0 to 40 m

depth. The results indicated that photosynthetic efficiency

(a) was high and did not vary between different species and

depths, while irradiances for saturation (Ek) averaged

55 lmol m-2 s-1 in subtidal and 120 lmol m-2 s-1 in

eulittoral species. The studied species exhibited notable

short-term UV tolerance along the vertical zonation. In

intertidal and shallow water species, decreases in Fv/Fm by

UV radiation were between 0 and 18 %, while in sublittoral

algae, decreases in Fv/Fm varied between 3 and 35 % rel-

ative to PAR treatment. In all species, recovery was high

averaging 84–100 %. The formation of CPDs increased

(15–150 %) under UV exposure, with the highest DNA

damage found in some subtidal species. Phlorotannin

content varied between 29 mg g-1 DW in Ascoseira

mirabilis from 8 m depth and 156 mg g-1 DW in Des-

marestia menziesii from 17 m depth. In general, phloro-

tannin concentrations were constitutively high in deeper

sublittoral brown algae, which were correlated with higher

antioxidant activities of algal extracts and low decreases in

photosynthesis. UV radiation caused a strong decrease in

phlorotannin content in the deep-water Himantothallus

grandifolius, whereas in D. menziesii and Desmarestia

anceps, induction of the synthesis of phlorotannins by UV

radiation was observed. The antioxidant activity was in

general less affected by UV radiation.

Keywords Antarctic � Macroalgae � Phlorotannins �Photosynthetic activity � DNA damage � Antioxidant

activity � UV radiation � Zonation

Introduction

Antarctic seaweeds are shade-adapted organisms exhibiting

an ability to photosynthesize and grow under very low light

in virtue of their high efficiency and low light requirements

for photosynthesis (reviewed by Gomez et al. 2009).

Remarkably, many Antarctic subtidal species such as the red

algae Palmaria decipiens and Iridaea cordata can even

colonize intertidal zones, where they thrive at pools, rocky

crevices and under stones where they experience high irra-

diances (Zielinski 1990; Kloser et al. 1996). In the case of

the large Antarctic brown algae such as Ascoseira mirabilis

and members of Desmarestiales (Desmarestia menziesii, D.

anceps and D. antarctica and Himanthothallus grandifolius)

with Ek values ranging 26–105 lmol m-2 s-1 and domi-

nating at depths of 30–40 m (Weykam et al. 1996; Gomez

et al. 1997), upper limits of distribution can be as shallow as

5 m (Richardson 1979; Drew and Hastings 1992; Kloser

et al. 1994). Apparently, the constitutive high photosyn-

thetic efficiency over a wide-ranging vertical distribution is

functional to the adaptations that allow algae to cope with

the overall low light conditions in winter, and also the

extreme water turbidity due to melting snow, phytoplankton

blooms, fresh water runoff, etc., which impose severe con-

straints to seaweed photosynthesis in spring/summer

P. Huovinen � I. Gomez (&)

Instituto de Ciencias Marinas y Limnologicas, Universidad

Austral de Chile, Casilla 567, Valdivia, Chile

e-mail: igomezo@uach.cl

123

Polar Biol (2013) 36:1319–1332

DOI 10.1007/s00300-013-1351-3

(Kloser et al. 1993; Weykam et al. 1996; Gomez et al. 1997;

Schwarz et al. 2003; Zacher et al. 2009). In contrast, the

capacity to cope with high irradiances in spring/summer has

been developed in response to, e.g., sudden increases in

solar irradiances following the ice breakup in late winter/

spring, when light can penetrate down to 40 m depth largely

exceeding their reported saturating (Ek) and compensation

(Ec) requirements (Gutkowski and Maleszewski 1989;

Schwarz et al. 2003). For example, at Potter Cove, King

George Island, PAR irradiances close to 50 lmol m-2 s-1

at 30 m have been measured (Kloser et al. 1996; Gomez

et al. 1997; Richter et al. 2008).

At eulittoral and shallow subtidal zones up to depths

close to 10 m, algae are exposed not only to high PAR, but

also to harmful levels of UV radiation (Richter et al. 2008).

How do these shade-adapted organisms thus endure high

solar radiation conditions that can be stressful? Despite

some studies focused on vulnerable early stages (Roleda

et al. 2007a, 2008; Zacher et al. 2007a) and macrothalli

from long-term culture conditions (Bischof et al. 1998a;

Rautenberger and Bischof 2006), UV stress tolerance

capacity of field thalli of Antarctic seaweeds is poorly

known. In one of the few studies that addressed the

capacity for in situ photoinhibition of adult phases of

Antarctic seaweeds, Hanelt et al. (1994) indicated that

many littoral species express a downregulation of photo-

synthesis on a daily basis as a response to enhanced solar

radiation at noon. In a recent study comparing the UV

stress tolerance of adult stages and propagules of the

intertidal Antarctic green alga Urospora penicilliformis, it

was found that photosynthesis of both life cycle stages was

resistant to 8-h UV exposure, but spores being relatively

more sensitive to UV-B-induced DNA damage compared

to filamentous macrothalli (Roleda et al. 2009). Studies

conducted in shallow water species from Arctic indicated

that operation of efficient reactive oxygen species (ROS)

scavenging can also be complementary to dissipative or

UV shielding mechanisms in order to endure exposition to

UV radiation in the field (Aguilera et al. 2002). This evi-

dence, not comprehensively addressed on Antarctic sea-

weeds, and the synthesis of UV-absorbing substances (e.g.,

brown algal phlorotannins) can help us to understand the

dual photobiological characteristic of these organisms that

allow them to handle both extremes of incident solar

radiation. Phlorotannins show constitutively high concen-

trations in a variety of Antarctic Desmarestiales, but a

direct relationship with the exposure to UV radiation, and

hence their putative photoprotective role, has not hitherto

been well established (Amsler et al. 2005; Fairhead et al.

2006). However, recent short-term studies on sub-Antarctic

kelps emphasize the importance of phlorotannins as effi-

cient ROS scavengers (Cruces et al. 2012, 2013), which

minimize decreases in photosynthesis and DNA damage in

response to UV stress during low tide (Gomez and

Huovinen 2010).

In the present study we examine (a) to what degree the

physiology (photosynthesis and DNA damage) of adult thalli

of Antarctic seaweeds is impaired in response to UV radia-

tion and whether they exhibit photoprotective mechanisms

(induction of photoprotective substances, antioxidant activ-

ity), and (b) how do these responses vary in eulittoral and

subtidal species. In contrast to the early life stages, enhanced

levels of UV radiation most likely do not cause lethal effects

on adult phases, but will impose severe constraints to phys-

iological performance and resource utilization with conse-

quences for primary production. Based on the evidence that

UV radiation is a key environmental factor determining

seaweed zonation in polar systems (Hanelt et al. 1997a;

Bischof et al. 1998b, Wiencke et al. 2006), we hypothesize

that the expression of individual UV stress mechanisms is

different in seaweeds growing at different depths in the

Antarctic. Thus, this study on algae from the field is aimed to

give insights into the short-term acclimation potential at an

organism level, which can be linked to the ecological field

context in which the mechanisms are operating. This is

particularly relevant when the evidence on direct effects of

climate change (ozone depletion, global warming, etc.) on

polar ecosystems continues to accumulate.

Materials and methods

The seaweed community at Peninsula Fildes

The study was carried out during the austral summer

(February 2010) in the Fildes Bay and Elephant Bay in the

Peninsula Fildes, King George Island (62�120S). The ver-

tical organization of the seaweed community along a gra-

dient from the subtidal to the intertidal zone and the most

relevant ecological scenarios at each depth are shown in

Fig. 1. The lower subtidal from 30 to 10 m is dominated by

the brown algae Himantothallus grandifolius and

Desmarestia anceps, which are strongly shade adapted.

Scattered within these dense forests, it is possible to find

some understory red algae such as Myriogramme mangini,

Phycodrys antarctica and Plocamium sp. Between 20

and 10 m, the diversity increases and species such as

D. menziesii are accompanied by other large brown algae

such as the fucoids Cystosphaera jacquinotii and A. mirabilis.

At this zone, the red algae P. decipiens and Trematocarpus

antarcticus can become abundant. Between 10 m and the

limit with the eulittoral zone, belts of the brown alga

Phaeurus antarcticus and populations of the green alga

Monostroma hariotii are common. Here algae are strongly

disturbed by ice-driven physical processes, e.g., scouring

by grounding icebergs, and at the least down to 2 m depth,

1320 Polar Biol (2013) 36:1319–1332

123

by the seasonal cycle of sea-ice formation (Gambi et al.

1994; Kloser et al. 1994; Smale 2008). In the eulittoral

zone, where tidal range can be close to 2.5 m, the fila-

mentous green algae U. penicilliformis and Ulothrix sp.

occupy unstable substrate conformed by pebbles and

stones. Intertidal pools are populated by the red algae

I. cordata and P. decipiens, the green algae Acrosiphonia

arcta and Ulva sp. and the brown alga Adenocystis utric-

ularis. The upper eulittoral zone is almost exclusively

colonized by the red alga Porphyra endiivifolium and the

green alga Prasiola crispa (Fig. 1). At this level, condi-

tions for algal growth are determined by extreme changes

in physical conditions, especially temperature, solar radi-

ation and wind. During some seasonal periods, the impact

of ice and snow is important, which results in the presence

of algae sheltered in crevices and pools (Kloser et al.

1994). According to our and previous surveys carried out in

other sites along King George Island, this zonation can

vary considerably depending on the geomorphology,

closeness to glaciers, type of substrate, etc. (Ramırez and

Villouta 1984; Zielinski 1990; Kloser et al. 1994, 1996).

Measurement of solar radiation and light environment

Spectral profiles of solar irradiation, both in the air and

under water, were measured with a hyperspectral radiom-

eter RAMSES-ACC2-UV–vis (Trios Optical Sensors,

Oldenburg, Germany). For the air measurements, the

instrument was programmed to record the spectral radia-

tion between 300 and 700 nm each 15 min during several

days in the study period. The daily course of PAR (pho-

tosynthetically active radiation 400–700 nm), UV-A

(315–400 nm) and UV-B (300–315 nm) were finally

calculated. For the underwater depth profiles around noon

(12:00 to 14:00 h), the sensor was submerged at intervals

of 1 m down to a 10 m depth with a minimum of three

measurements per depth. In the study site, intertidal algae

received high levels of PAR (200–600 lmol m-2 s-1),

which exceeds the light requirements for photosynthesis

(Ek) for at least 10 h (Fig. 2B). However, due to the pre-

vailing cloudy conditions, maximal values of UV-B and

UV-A did not surpass 0.2 and 12 W m-2, respectively

(Fig. 2A, B). In the case of the subtidal zone, values at the

subsurface (10 cm) were close to 0.15 and 8 W m-2 of

UV-B and UV-A, while at 10 m, UV-B values decreased to

0.014 and UV-A to 2.2 W m-2 (Fig. 2C, D).

Algal collection and processing

Representative species of green (5), red (8) and brown

algae (8) were collected from the intertidal zone and from

subtidal between 5 and 42 m by scuba diving (Table 1).

After sampling, the specimens were immediately trans-

ferred to the laboratory at Antarctic Station ‘‘Base Julio

Escudero,’’ where they were kept for a maximum of 2 days

in a cool chamber at a temperature around 2 �C with aer-

ation under light/dark cycle (20 h:4 h) corresponding to the

natural conditions at collection site.

Determination of ETR versus light curves

The comparative photosynthetic characteristics of algae

were assessed through electron transport rate (ETR)-based

P-E curves. In the laboratory, algal samples were put in a

dark chamber and irradiated with increasing intensities of

PAR (10 intervals from 0 up to 370 lmol photon m-2 s-1)

Fig. 1 Vertical distribution of

the major seaweeds along the

eulittoral and sublittoral of the

Antarctic coast of Fildes

Peninsula (King George Island,

South Shetlands). The most

important photobiological and

ecological processes at each

depth level are summarized.

This zonation schema can vary

depending on site, is not at scale

and does not include associated

fauna

Polar Biol (2013) 36:1319–1332 1321

123

provided by a pulse amplitude modulation fluorometer

(PAM 2000; Walz, Effeltrich, Germany). ETR was deter-

mined by relating effective quantum yield (UPSII) and the

intensity of the actinic irradiance (Schreiber et al. 1994):

ETR ¼ UPSII � E � A� 0:5

E being the incident irradiance of PAR and A the thallus

absorptance. The factor 0.5 is derived assuming that four of

the eight electrons required to assimilate one CO2 molecule

are supplied by PSII. Absorptance was measured by

placing the algae on a cosine-corrected PAR sensor

(Licor 192 SB, Lincoln, USA), and calculating the light

transmission as:

A ¼ 1� EtE�1o

where Eo is the incident irradiance and Et the irradiance

transmitted beneath the alga. A modified nonlinear function

of Jassby and Platt (1976) was fitted in order to define the

ETR parameters:

ETR ¼ ETRmax � tanh ða� E=ETRmaxÞ

where ETRmax is the maximal ETR, tanh the hyperbolic

tangent function, a the initial slope of the P-E curve (an

indicator of the electron transport efficiency) and E the

incident irradiance. Finally, the saturating point of photo-

synthesis (Ek) was calculated as the quotient between

ETRmax and a.

Experimental exposure to UV radiation and recovery

Two green (A. arcta and M. hariotii), five red (I. cordata,

P. decipiens, P. cartilagineum, P. endiviifolium and

T. antarcticus) and seven brown algal species (A. utricu-

laris, A. mirabilis, C. jacquinotii, D. anceps, D. menziesii,

D. antarctica and H. grandifolius; Table 1) were used in

the experimental work. Algal pieces (6–9) of each species

were exposed to UV ? PAR and PAR treatments for 2 h at

a temperature of 2 �C, followed by a 4-h recovery period

Fig. 2 The light environment at the coastal zone in Fildes Peninsula.

(A) Example of a seaweed community and (B) daily cycle of solar

radiation at a eulittoral exposed site. Dashed area indicates the range

of irradiances at which intertidal algae are saturated (Ek). (C) Subtidal

community dominated by large Desmarestiales (photograph courtesy

of D. Schories) and (D) spectral irradiance at different depths

indicating the prevalence of the biologically relevant wavelengths

1322 Polar Biol (2013) 36:1319–1332

123

under dim light (\5 lmol m-2 s-1). In the exposures, a

combination of UV (Q-Panel-313 and 340 nm fluorescent

tubes, Q-Panel Co., Cleveland, OH) and PAR lamps

(Daylight, Philips, Amsterdam, the Netherlands) were

used. The two irradiation treatments were obtained by the

use of cut-off filters Ultraphan 295 (Digefra, Munich,

Germany; removing wavelengths \295 nm) for

UV ? PAR treatment and Ultraphan 395 (Digefra,

Munich, Germany) for PAR treatment (wavelengths

\395 nm removed). The levels of irradiation were mea-

sured with the radiometer RAMSES and the spectra

weighted using the action spectrum for DNA damage

Table 1 The studied species at Peninsula Fildes, King George Island, indicating their biogeographic and ecological characteristicsa as well as

the collection depth. A detail of physiological measurements carried for each species is also given

Species, authority and abbreviation Biogeographic affinity, morphology,

habitat and collection depth

Measurement and analysisb

(a) Green algae

A. arcta (Dillwyn) J Agardh Amphi-polar; filamentous; crevices

and pools at midlittoral; eulittoral

ETR; Fv/Fm

L. antarctica (Skottsberg) Delepine Endemic; filamentous; deep sublittoral; 42 m ETR

M. hariotii Gain Antarctic/subantarctic; saccate; shallow

sublittoral/intertidal pools; 0.5 m

ETR; Fv/Fm; DNA

Ulothrix sp. Kutzing Antarctic/subantarctic; filamentous; common at

supralittoral; eulittoral

ETR

U. penicilliformis (Roth) Areschoug Amphi-polar; filamentous; abundant at supralittoral;

eulittoral

ETR

(b) Red algae

Callophyllis atrosanguinea

(Hook & Har) Hariot

Antarctic/subantarctic; coarsely branched; deep

sublittoral; 25 m

ETR

I. cordata (Turner) Bory (IC) Antarctic/subantarctic; leathery; broad vertical

distribution; eulittoral

ETR; Fv/Fm; DNA

Gigartina skottsbergii Setchell & Gardner Antarctic/subantarctic; leathery; sublittoral; 20 m ETR

M. mangini (gain) Skottsberg Endemic; foliose; broad vertical distribution in the

sublittoral zone; 25 m

ETR

P. decipiens (Reinsch) Ricker Antarctic/subantarctic; leathery; broad vertical

distribution; eulittoral

ETR; Fv/Fm; DNA

P. cartilagineum (Linnaeus) Dixon Amphi-polar/cold-temperate; finely branched;

sublittoral; 15 m

ETR; Fv/Fm; DNA

P. endiviifolium (A & E. Gepp) Chamberlain Endemic; foliose; upper intertidal zone at exposed

sites; eulittoral

ETR; Fv/Fm; DNA

T. antarcticus (Hariot) Fredericq & Moe Antarctic/subantarctic; leathery; broad vertical

distribution; 20 m

ETR; Fv/Fm; DNA

(c) Brown algae

A. utricularis (Bory) Skottsberg Antarctic/subantarctic; saccate; shallow sublittoral/

intertidal pools; eulittoral

ETR; Fv/Fm; DNA; Phlor; Antiox

A. mirabilis Skottsberg Endemic; leathery; sublittoral from 5 m; 8 m ETR; Fv/Fm; DNA; Phlor

C. jacquinotii (Montagne) Skottsberg Endemic; leathery; sublittoral from 5 m; 25 m ETR; Fv/Fm; DNA; Phlor

D. anceps Montagne Endemic; coarsely branched; dominant at sublittoral

zones; 28 m

ETR; Fv/Fm; DNA; Phlor; Antiox

D. antarctica Moe & Silva Endemic; leathery; sublittoral; 20 m ETR; Fv/Fm; DNA; Phlor; Antiox

D. menziesii J. Agardh Endemic; coarsely branched; dominant at sublittoral

zones; 17 m

ETR; Fv/Fm; DNA; Phlor; Antiox

H. grandifolius (A & E. Gepp) Zinova Endemic; leathery; deeper sublittoral zones: 30 m ETR; Fv/Fm; DNA; Phlor

P. antarcticus Skottsberg Endemic; filamentous; shallow sublittoral; 5 m ETR

a Information compiled from Wiencke and tom Dieck (1990), Luning 1990, Clayton (1994), Wiencke and Clayton (2002)b Fv/Fm; DNA, Phlor; and Antiox were determined in samples exposed to different UV treatments

Polar Biol (2013) 36:1319–1332 1323

123

(Setlow 1974) and photoinhibition of photosynthesis (Jones

and Kok 1966) as normalized to unity at 300 nm. The

experimental levels of UV radiation matched the ranges

measured in situ for this locality and were 0.26 W m-2 for

UV-B and 1.51 W m-2 for UV-A, while the weighted

values for DNA damage and photoinhibition of photosyn-

thesis were 0.08 and 0.47 Wm-2, respectively. The levels

of PAR (13 lmol m-2 s-1 for PAR) were maintained low

to avoid the masking of UV effects. After the exposure and

recovery phase, samples were taken for physiological and

biochemical determinations.

Maximum quantum yield of fluorescence (Fv/Fm)

Fv/Fm, which indicates the ratio of variable to maximal

fluorescence of chlorophyll a of photosystem II (PSII), was

measured with the fluorometer PAM-2000 in algal samples

previously kept in the darkness for 5 min. Inhibition of Fv/

Fm was calculated as the percentage decrease between the

value measured in the PAR ? UV treatment and the value

measured in samples exposed to PAR. Similarly, the

recovery was estimated by comparing the Fv/Fm values of

samples exposed to UV treatment with those from PAR

treatment.

Biochemical analyses

DNA damage

The cyclobutane pyrimidine dimers (CPDs) formed in

response to UV exposures were determined using an

ELISA method (Mori et al. 1991) with modifications

(Gomez and Huovinen 2010). Samples (5 mg) were

homogenized in a mortar with liquid N2. DNA was isolated

using a purification kit (Easy-DNA Kit; Invitrogen) and

quantified with reference to absorbance at 260 nm. Heat-

denatured DNA was applied into microtiter well plates and

dried. The plates were washed with phosphate-buffered

saline with Tween (PBS-T) buffer in order to remove

nonbound DNA and blocked with bovine serum albumin

solution. The blocking solution was removed by washing

with PBS-T. A primary antibody (monoclonal antibodies

MC-062 to recognize CPDs) was added, and the plates

were incubated for 30 min at 37 �C. After washing, the

secondary antibody (monoclonal rabbit antimouse antibody

conjugated with horse radish peroxidase) was added and

incubated for 30 min at 37 �C. 0-Phenylenediamine–H2O2

was used for detection, and the color formation was stop-

ped with 2 M H2SO4. Absorbance at 492 nm in an ELISA

reader was used as relative value of DNA damage. The

percentage increase/decrease in CPDs in algae during

exposure and recovery was compared to those that were

exposed to PAR alone.

Content of phlorotannins in brown algae

Determination of phlorotannins was carried out using the

Folin–Ciocalteu method with modifications as described in

Gomez and Huovinen (2010). The soluble fraction was

analyzed in 10 mg of frozen algal material homogenized

with liquid N2 in a mortar. The extracts were mixed with

1 ml acetone (70 %) and shaken overnight at 4 �C. After

centrifugation (4,000 rpm, 10 min), 250 ll of dH2O,

200 ll of 20 % NaCO3 and 100 ll of 2 N Folin–Ciocalteu

reagent were added to 50 ll of supernatant. The samples

were incubated at room temperature in the darkness for

45 min and centrifuged (5,000 rpm, 3 min). The absor-

bance at 730 nm was measured using a Multiskan Spec-

trum spectrophotometer (Thermo Fisher Scientific Inc.,

Waltham, MA, USA). The content of phlorotannins was

determined using phloroglucinol (Sigma) as a standard.

Based on the calibration curves, the phlorotannin contents

were expressed in dry weight units.

Antioxidant activity in brown algae

The radical scavenging activity of fronds was determined

through the free radical 2,2-diphenyl-1-picrylhydrazyl

(DPPH) scavenging method of Brand-Williams et al.

(1995) modified as described in Cruces et al. (2013). A

150-lM solution of DPPH* in 80 % methanol was added

to 22 ll of sample extract, and the absorbance was mea-

sured at 520 nm using Trolox (6-hydroxy-2,5,7,8-tetra-

methylchroman-2-carboxylic acid) as a standard. The

antiradical activity was defined as lmol Trolox equivalent

on dry weight basis. The changes in the antioxidant activity

were calculated by comparing the initial values (ACc) with

the values after treatment (ACt):

% Radical scavenging ¼ ACt � ACcð ÞAC�1c � 100

Statistical analysis

The variation in physiological parameters (P-E parameters

and responses to UV exposure and recovery) between spe-

cies along the depth gradient was compared by using a

nested ANOVA design, where the levels within species

were regarded as a random factor nested in the fixed two-

level factor depth (eulittoral and sublittoral). Due to that

changes in phlorotannin content and antioxidant activity

after exposure and recovery were assessed only in brown

algae, we used one-way ANOVA to test for differences

between species. In both nested and one-way ANOVA, the

Tukey’s HSD post hoc analysis was used when differences

in means were detected. ANOVA assumptions (homoge-

neity of variances and normal distribution) were examined

using the Levene’s and Shapiro–Wilk W tests, respectively.

1324 Polar Biol (2013) 36:1319–1332

123

The covariation between the different P-E curve parameters

(ETRmax, a and Ek) and the responses of the different

physiological variables after 2-h exposure and 4-h recovery

between the different species were assessed by MANOVA/

MANCOVA analysis with the Wilks’ Lambda as a multi-

variate F. Multivariate homogeneity was tested using Box

M, whereas normality was assessed for each dependent

variable similar as in the univariate ANOVA.

Results

Photosynthetic light requirements

The studied species showed shade-adapted characteristics,

and those collected between 5 and 42 m depth did not show

marked differences in their photosynthetic characteristics.

For intertidal seaweeds, differences between species were

detected (Fig. 3). ETRmax values from P-E curves were

overall higher in the eulittoral species than in those col-

lected from the subtidal zone (p [ 0.0001; nested

ANOVA, Table 2). The intertidal green algae Ulothrix sp.

and A. arcta exhibited the highest ETRmax values close to

35 lmol e- m-2 s-1 (p \ 0.05; HSD), while the lowest

ones were recorded in the deep red alga T. antarcticus

(p \ 0.05 HSD). P. antarcticus, a species common at

shallow subtidal, had the highest ETRmax value (18 lmo-

l e- m-2 s-1) which is comparable to that measured in the

most intertidal species (p [ 0.05; HSD). The initial slope

(a) varied between 10 and 351 (lmol e- m-2 s-1)

(m-2 s-1)-1 in the studied species, but no differences

between the intertidal and subtidal species were detected

(p [ 0.05; nested ANOVA, Table 2; Fig. 3). The light

requirements for saturation of photosynthesis (Ek) were

Fig. 3 Photosynthetic

parameters ETRmax (A), initial

slope (B) and Ek (C) estimated

from electron transport rate

based P–I curves of 22

Antarctic seaweeds collected

from the eulittoral and

sublittoral zone of Fildes

Peninsula. Values are

mean ± S.D. (3–4

measurements)

Polar Biol (2013) 36:1319–1332 1325

123

significantly higher in eulittoral algae compared to sub-

littoral species (p \ 0.0001; nested ANOVA, Table 2;

Fig. 3). Maximal irradiances between 141 and 200

(lmol e- m-2 s-1) were measured in the red algae

M. hariotii and A. arcta (p \ 0.05; HSD post hoc, Fig. 3).

In subtidal species, the lowest light requirements for photo-

synthesis (\30 lmol e- m-2 s-1) were detected in the

algae inhabiting the deeper habitats (e.g., H. grandifolius,

T. antarcticus, Lambia antarctica) (Fig. 3). When the

variation in P-E parameters was analyzed in relation with

the species irrespective of the shore level, a significant

covariation between variables was confirmed (p \ 0.001;

MANOVA; Table 2).

Effects of UV radiation

Exposures to UV radiation caused decreases in maximum

quantum yield (Fv/Fm) which varied in relation with

Table 2 Summary ANOVA/MANOVA results for the differences in

physiological parameters of macroalgae collected at different depths

on King George Island. A nested ANOVA design was used for

P–E curve parameters and the effects of exposure and recovery to UV

radiation (% decrease/increase) on maximal quantum yield of

photosynthesis and CPDs formation (DNA damage). The random

factor species was nested in the fixed factor depth (2 levels: eulittoral

and sublittoral). For percentage changes in phlorotannin content and

antioxidant activity of brown algae, one-way ANOVA was applied.

MANOVA was performed for the covariation between the P–I curve

parameters and the responses after 2-h exposure and 4-h recovery

ETRmax Initial slope (a) Saturating point (Ek)

MS df F MS df F MS df F

(a) P–E curve parameter

Nested ANOVA

Shore level 1,837.6 1 129.4*** 0.010 1 7.3 ns 72,967.3 1 268.9***

Species (nested) 167.4 16 11.8*** 0.014 16 10.3*** 4,459.8 16 16.4***

Error 14.2 53 0.0014 53 271.3 53

MANOVA Wilks value = 0.049; F(3;51) = 14.5**

2-h exposure 4-h recovery

MS df F MS df F

(b) Responses to UV treatments

Fv/Fm

Nested ANOVA

Shore level 1,364.6 1 44.8*** 745.1 1 25.8***

Species (nested) 1,020.5 8 33.5*** 544.5 8 18.8***

Error 30.4 76 28.9 83

MANOVA Wilks value = 0.068; F(3;51) = 22.3**

DNA damage

Nested ANOVA

Shore level 27,671.8 1 626.9*** 1,446.9 1 655.1***

Species (nested) 5,776.3 8 130.8*** 1,311.7 8 593.8***

Error 44.1 39 2.2 40

MANOVA Wilks value = 0.00014; F(2;18) = 346.9***

Phlorotannin content

One-way ANOVA

Between groups (species) 11,095.2 6 1,429.5*** 6,162.3 6 875.6***

Error 7.8 14 7.0 14

MANOVA Wilks value = 0.000004; F(2;12) = 1,123.2***

Antioxidant capacity

One-way ANOVA

Between groups (species) 2,609.0 5 132.0 2,521.8 5 59.7***

Error 19.8 12 42.2 12

MANOVA Wilks value = 0.00092; F(2;10) = 70.0***

*p \ 0.01; **p \ 0.001; ***p \ 0.0001

1326 Polar Biol (2013) 36:1319–1332

123

species and the two major shore levels (p \ 0.0001; nested

ANOVA, Table 2; Fig. 4). Species from eulittoral had

decreases that did not exceed 15 %, while in the sublittoral

brown algae, C. jacquinotii maximal decrease under UV

treatment was close to 35 and 27 % in D. antarctica

(p \ 0.05, HSD; Fig. 4). However, in many species

inhabiting between 20 and 5 m depth and from depths

close to 30 m, the effect of UV treatments was relatively

low and comparable to that in eulittoral species. After 4 h

in dim light, algae exposed to UV radiation recovered

almost completely (84–100 %), especially in some species

collected from the eulittoral, e.g. the red algae P. endi-

viifolium and I. cordata (Fig. 4). The covariation between

exposure and recovery was statistically significant

(p \ 0.001; MANOVA, Table 2).

Damage of DNA after a 2-h exposure to UV radiation

was in general higher in algae collected at deeper locations

compared to eulittoral species (p \ 0.05; nested ANOVA;

Fig. 5). In species such as M. hariotii and P. decipiens,

increases in CPDs were \ 27 % relative to control without

UV radiation. In the case of D. antarctica and Himanto-

thallus grandofolius collected at 20 and 30 m, respectively,

percentage of CPDs increase exceeded 100 % (p \ 0.05,

HSD; Fig. 5). During 4-h recovery in dim light, decreases

in CPDs varied between 3 % in P. decipiens and 35 % in

Plocamium sp. (p \ 0.05, HSD). These variations were

related with the increases in CPDs (p \ 0.0001; MANO-

VA; Table 2).

The content of phlorotannins in seven species of brown

algae was marked by very high values exceeding

100 mg g-1 DW in species such as C. jacquinotii, D.

menziesii and D. anceps (p \ 0.05; one-way ANOVA;

Table 2 and Fig. 6). After a 2-h exposure to UV radiation,

phlorotannins decreased in almost all the species, with the

exception of D. anceps and D. menziesii (p \ 0.05 HSD).

The maximal decrease in phlorotannins between samples

exposed to UV radiation as compared to PAR treatment

was recorded in H. grandifolius (89 %), while in

A. utricularis, the decrease was close to 50 %. These

differences showed also a covariation during the exposure

and recovery periods (p \ 0.05, MANOVA, Table 2).

The antioxidant activity under PAR conditions ranged

between 32 mg TE g-1 DW in A. mirabilis and 101 mg

TE g-1 DW in D. anceps (p \ 0.05, HSD; Fig. 6). In these

species, the scavenging activity was also significantly

reduced in response to the 2-h UV exposure (p \ 0.05,

HSD; one-way ANOVA, Table 2). In the rest of the

Fig. 4 Effect of a 2-h exposure to UV radiation (black circles) and

the corresponding 4-h recovery (open circles) on the maximum

quantum yield (Fv/Fm) in Antarctic seaweeds collected from the

eulittoral and sublittoral zones in Fildes Peninsula. Values are

mean ± S.D. (6–10 measurements) and represent the percentage

reduction in Fv/Fm of UV treatment in relation to PAR exposure.

Species: PE (P. endiviifolium), AU (A. utricularis), AA (A. arcta), IC

(I. cordata), PD (P. decipiens), MH (M. hariotii), AM (A. mirabilis),

PC (Plocamium sp), DM (D. menziesii), DA (D. antarctica), CJ

(C. jacquinotii), DAN (D. anceps), HG (H. grandifolius)

Fig. 5 Effect of a 2-h exposure to UV radiation and the correspond-

ing 4-h recovery on the formation of cyclobutane pyrimidine dimers

(CPDs) in Antarctic seaweeds from the eulittoral and sublittoral zones

in Peninsula Fildes. Values are mean ± S.D. (4–5 measurements) and

represent the percentage variation in CPDs between UV and PAR

treatments. Abbreviations of species names as in Fig. 4

Polar Biol (2013) 36:1319–1332 1327

123

species, the antioxidant capacity was not affected by UV

exposure (p [ 0.05, HSD; Fig. 6). During the recovery

period, variation between samples previously exposed to

UV radiation and those maintained under PAR was similar

(p \ 0.0001; MANOVA, Table 2).

Discussion

Photosynthetic characteristics

The studied Antarctic macroalgae showed in general low

requirements for photosynthesis; however, some differ-

ences between the two major shore levels were found.

Based on the maximum light values measured during the

summer season at the intertidal and subtidal zones (e.g., at

10 m, where PAR was close 170 lmol m-2 s-1), it was

possible to indicate that photosynthesis is not light limited

for several hours during the day (Fig. 2). However, the

initial slope, an indicator of photosynthetic efficiency, was

similarly high in both groups of algae (close to

0.17 lmol m-2 s-1 [lmol m-2 s-1]-1). These results

from chlorophyll fluorescence-based P-E curves confirm

the findings of a survey carried out almost 20 year ago by

Weykam et al. (1996) using polarographic O2 evolution,

revealing a practically uniform high photosynthetic effi-

ciency over a wide range of depths (p [ 0.05) as the

physiological basis explaining the remarkable ability of

these organisms to photosynthesize in changing irradi-

ances. In general, cold-temperate seaweed assemblages, in

particular those inhabiting fjords, have very low light

requirements in order to cope with the episodic diminishing

of light in the water column caused by physical (freshwater

runoff, melting glaciers) or biotic (canopy of kelps, phy-

toplankton blooms) processes (Johansson and Snoeijs

2002; Kjeldstad et al. 2003; Huovinen and Gomez 2011).

This capacity appears to be extreme in some Antarctic

crustose corallines, which grow permanently under sea

ice and are exposed to darkness for up to 4 months at the

Ross Sea, but showing a photobiological potential to

exploit high irradiances during episodic free-ice waters

(Schwarz et al. 2005).

Responses to UV radiation

The results of our study indicated that lower subtidal spe-

cies, such as the brown algae H. grandifolius, D. anceps

and D. menziesii, and the red alga Plocamium sp., have

remarkable UV tolerance. Both decreases in Fv/Fm, a

reliable indicator of photodamage, and the formation of

CPDs (an indicator of DNA damage) were low and similar

to values measured in eulittoral species, showing addi-

tionally high recovery rates when kept under dim light for

4 h. This is surprising since these species are not exposed

commonly to significant UV levels below 20 m depth,

differing in some way with the marked photosynthetic

sensitivity reported for the deep-water Arctic Laminariales

(Hanelt et al. 1997a, b, Bischof et al. 1998b). Clearly these

results reinforce the idea that adult thalli of pseudoperen-

nial algae inhabiting the subtidal zone are less sensitive to

UV radiation than early developmental stages, which has

been well documented for Arctic and Antarctic seaweeds

(Wiencke et al. 2006; Roleda et al. 2007b).

Low requirements for compensation and saturation

allowing a positive carbon balance during periods of active

growth are associated with complex gross morphology and

perennial life strategy (Gomez et al. 1997), which are

functional to tolerate UV stress. In fact, large size and

massive thalli confer advantages not only by improving the

in vivo absorptance spectra of PAR, an essential bio-optical

trait that enables algae to use impoverished wavelengths

incident at deeper habitats (Luning and Dring 1985; Gomez

and Huovinen 2011), but also by magnifying the pathlength

for UV absorption (Caldwell et al. 1983). Thickness as a

mechanism to minimize UV effects, as has been claimed

Fig. 6 Effect of a 2-h UV exposure on (A) the concentration of

phlorotannins and (B) antioxidant activity measured in several brown

algae collected in the eulittoral and sublittoral zone of Fildes

Peninsula. Values are mean ± S.D. (3 measurements) and represent

the percentage variation between UV and PAR treatments

1328 Polar Biol (2013) 36:1319–1332

123

previously to explain the differences in scattering and

transmittance of UV radiation between macro-thalli and

spores (Hanelt et al. 1997b; Roleda et al. 2006, 2007b), is

probably a by-product of morphological adaptations of

large seaweeds associated with substrate occupation,

resistance to drag forces in the water column, escape from

consumers, etc. This idea is confirmed by the findings that

DNA damage was not correlated with thallus thickness in

the present study. Apparently, transmittance and scattering

characteristics of algae (including pigments, phenolic

composition) and not only thickness determine primarily

the susceptibility of algae to DNA damage by UV-B

radiation as has been reported for young sporophytes of

Laminaria (Roleda et al. 2005, 2006). It is reasonable to

argue that leathery and pseudoperennial forms of some

Desmarestiales and Gigartinales that are dominant at

poorly illuminated subtidal regions show enhanced light

absorptance and probably much of their energy is invested

in growth and not in repair and photoprotection.

Eulittoral Antarctic macroalgae show efficient photo-

protective mechanisms, e.g., photoinhibition of photosyn-

thesis, in order to cope with solar radiation (Hanelt et al.

1994). The downregulation of PSII, although triggered

primarily by PAR, has also been invoked to be functional

to minimize the effects of UV radiation in intertidal species

(Bischof et al. 2006). In laboratory exposures, the levels of

PAR generally are low and the ratios of PAR/UV thus do

not match the field situation configuring an experimental

constraint commonly outlined in this type of studies.

However, the results from exposures using artificial UV

conditions can give valuable information on the mecha-

nistic effects of UV radiation as has been reported previ-

ously for lamp-induced photoinhibition of various

Antarctic species (Hanelt et al. 1997c).

In general, Antarctic algae from the eulittoral zone,

normally dominated by smaller morphs than in the subtidal

zone, were tolerant to UV radiation, suggesting that they

are well equipped with efficient mechanism to tolerate high

UV radiation. As was reported previously, not only mac-

rothalli but also early microscopic stages of intertidal

species such as P. endiviifolium, M. hariotii and A. utricularis

show marked tolerance to UV radiation (Zacher et al.

2007a). These algae normally grow not only under

exposure to UV radiation, but also to various changing

environmental factors impacting simultaneously. For

example, it has been reported that P. decipiens, in response

to changes in light, modifies not only its pigment compo-

sition (Luder et al. 2001) but also its membrane lipid

composition that permits a highly efficient light acclima-

tion at low temperatures close to 0 �C (Becker et al. 2010).

In terms of pure optics, monostromatic and optically

translucent thalli of delicate eulittoral species might be

regarded as highly susceptible to UV damage. However,

studies using isolates of the eulittoral green alga Ulva

bulbosa (formerly Enteromorpha bulbosa) revealed a

capacity for high tolerance after short-term exposure to UV

radiation (Bischof et al. 1998a; Rautenberger and Bischof

2006). In many cases, these filamentous green algae are

organized in mats or turf-like formations that can well

minimize the UV injury on the whole organism (Bischof

et al. 2006). In the case of the filamentous green alga

U. penicilliformis, its high insensitivity to UV radiation and

in general, to high solar radiation, apparently is based on an

efficient ultrastructural UV shielding via a dense cell wall,

presence of mucilage and external mineral deposition

(Roleda et al. 2010).

Although not measured in the present study, the

remarkably capacity of shallow and intertidal Antarctic red

algae to tolerate UV radiation can be related with an

enhanced concentration of mycosporine-like amino acids

(MAAs) (Karentz et al. 1991; Hoyer et al. 2002).

Regarding the low formation of CPDs found in our study,

underlying low DNA damage for most of the studied eu-

littoral algae, it is possible to argue that the sunscreen

function of MAAs in conjunction with dissipative mecha-

nisms represent a primary shielding barrier against UV

radiation protecting diverse molecules (Franklin et al.

1999). However, MAAs are multifunctional molecules, and

an antioxidant activity has been reported (Tao et al. 2008;

Coba et al. 2009), similar as that reported for carotenoids of

Chlorophyta (Perez-Rodrıguez et al. 2001) and phlorotan-

nins of Phaeophyceae (see below). These molecules are

active not only against UV radiation but also participate in

ROS scavenging mechanisms that can protect algae from

other stressors prevailing at intertidal zones, e.g. tempera-

ture, desiccation. As in the case of communities chronically

impacted by harsh physical conditions (Bertness et al.

2006), the Antarctic eulittoral system probably is governed

by environmental stress and less by endogenous or biotic

forcing. Hitherto, these presumptions were tested in

establishment stages of one seaweed community in King

George Island, indicating that herbivores alone affect less

the richness and diversity of seaweeds than in interaction

with the physical factors (e.g., UV radiation) (Zacher et al.

2007b). Thus, physiological processes, especially photo-

synthetic characteristics, could be strongly modeled by

environmental gradients.

Brown algal phlorotannins and antioxidant activity

Subtidal species such as D. menziesii, C. jacquinotii and

H. grandifolius have high concentrations of phlorotannins

and corresponded to the ranges previously reported by

Fairhead et al. (2005). In general, these values are signif-

icantly higher than those measured in Arctic/cold-temper-

ate (Dubois and Iken 2012) and sub-Antarctic kelps

Polar Biol (2013) 36:1319–1332 1329

123

(Cruces et al. 2013). In our study, there was a tendency of

lower content of phlorotannins in algae growing at shallow

locations (e.g., A. utricularis, A. mirabilis and D. antarc-

tica). Moreover, a 2-h UV exposure stimulated phlorotan-

nins only in two of the seven studied species. In general,

phlorotannins can form up to 25 % of dry weight (Ragan

and Glombitza 1986) and are present as soluble and cell

wall-bound fractions. Their UV-absorbing properties and

peripheral localization in cells have been related with an

increased tolerance to UV radiation, which has been

demonstrated in various temperate kelps in response to

high UV (Pavia et al. 1997; Swanson and Druehl 2002) and

high CO2 (Swanson and Fox 2007). Recent studies indicate

that phlorotannins reduce photodamage of key physiolog-

ical processes and molecules such as photosynthesis and

DNA in the intertidal kelp Lessonia nigrescens (Gomez

and Huovinen 2010). High levels of phlorotannins have

been correlated with enhanced ROS scavenging activity in

intertidal kelps exposed to high UV doses and metals,

suggesting that these compounds represent primary meta-

bolic anti-stress agents (Huovinen et al. 2010; Cruces et al.

2012). Taking into account that in some sub-Antarctic

seaweeds such as L. nigrescens and Durvillaea antarctica,

induction of phlototannins occurs in short time span

(2–3 h), this pattern observed in the Antarctic brown algae

can suggest that the induction of phlorotannins in response

to UV radiation, at least in algae collected at depths

\10 m, requires longer time periods or alternatively, in

algae with constitutively high levels of phenols, induction

is comparatively lower. In fact, studies carried in D. anceps

and D. menziesii to test the induction of phlorotannins in

response to grazers and UV radiation showed that in situ

exposure to UV for various weeks did not stimulate syn-

thesis of these compounds (Fairhead et al. 2006). Appar-

ently, the high levels of phlorotannins in species normally

not exposed to UV radiation respond to other factors, e.g.,

structural requirements, which have been reported for other

large kelps experiencing rapid growth in short time

(Schoenwaelder 2002; Arnold 2003; Gomez and Huovinen

2010). Considering that Antarctic sublittoral Desmaresti-

ales show considerable herbivore deterrence (Amsler et al.

2005; Fairhead et al. 2005), the high concentrations of

phlorotannins measured in these algae support the idea that

herbivory cannot be ruled out as a major factor explaining

these patterns. The marked decrease in phlorotannins in

response to UV radiation found in H. grandifolius from

30 m suggests a possible damage affecting the synthesis

centers or that soluble phlorotannins (the fraction measured

in this study) was rapidly converted to insoluble phloro-

tannins in order to repair damaged zones of the cell,

especially peripheral membranes (Luder and Clayton 2004;

Cruces et al. 2013).

Consistent with the low UV induction of phlorotannins,

the antioxidant activity of the extracts of brown algae was

not altered by the UV treatments, which suggests that

intrinsically high levels of phlorotannins represent a central

mechanism to prevent cellular damage via ROS. Recent

studies have indicated that high levels of phlorotannins are

correlated with enhanced ROS scavenging activity in kelps

exposed to stressors such as UV radiation and metals,

confirming that these compounds can be regarded as pri-

mary metabolic anti-stress agents (Connan et al. 2006;

Huovinen et al. 2010; Cruces et al. 2012). In Saccharina

latissima, phlorotannins are concentrated in sori where

enhanced antioxidant capacity compared to vegetative

regions was determined (Holzinger et al. 2011). In the

context of environmental stress tolerance, it has been

reported that mechanisms developed by macroalgae, such

as synthesis of protective substances and ROS scavenging

capacity, operate irrespective of the morphology or mor-

pho-functional categories, which have been found in the

Arctic (Aguilera et al. 2002) and cold-temperate species

(Skene 2004; Gomez and Huovinen 2011). According to

our data, although antioxidant activity was only relatively

correlated with phlorotannins contents in subtidal algae, an

association with depth distribution was weak. Thus, we can

speculate that ROS scavenging in species such as

D. menziesii or D. anceps is a general response indepen-

dent on the concentration of phlorotannins and activated in

response to UV radiation when present. In contrast, the

antioxidative responses of eulittoral or shallower species

could be induced.

In conclusion, our findings revealed that Antarctic

macroalgae from the field not only show high photosyn-

thetic efficiency and low light requirements for photosyn-

thesis over a wide depth gradient, but also exhibit notable

UV tolerance along the vertical zonation. The antioxidant

activity is operating along the whole vertical depth gradient

in these communities, which in lower sublittoral algae is

supported by high levels of phlorotannins and permits to

explain the low impact of UV radiation on photosynthesis

and DNA observed in these algae.

Acknowledgments The study was supported by the Grant T-20-09

from Instituto Antartico Chileno (INACH). We thank the technical

assistance of M. Orostegui and C. Rosas in the laboratory analyses.

We are also grateful to D. Schories, I. Garrido, J. Holtheuer and

I. del Moral for field assistance and scuba diving.

References

Aguilera J, Bischof K, Karsten U, Hanelt D, Wiencke C (2002)

Seasonal variation in ecological patterns in macroalgae from an

Arctic fjord. II. Pigment accumulation and biochemical defence

systems against high light stress. Mar Biol 140:1087–1095

1330 Polar Biol (2013) 36:1319–1332

123

Amsler CD, Iken K, McClintock JB, Amsler MO, Peters KJ, Hubbard

JM, Furrow FB, Baker BJ (2005) Comprehensive evaluation of

the palatability and chemical defenses of subtidal macroalgae

from the Antarctic Peninsula. Mar Ecol Prog Ser 294:141–159

Arnold TM (2003) To grow and defend: lack of tradeoffs for brown

algal phlorotannins. Oikos 100:406–408

Becker S, Graeve M, Bischof K (2010) Photosynthesis and lipid

composition of the Antarctic endemic rhodophyte Palmaria

decipiens: effects of changing light and temperature levels. Polar

Biol 33:945–955

Bertness MD, Crain CM, Silliman BR, Bazterrica MC, Reyna MV,

Hildago F, Farina JK (2006) The community structure of western

Atlantic Patagonian rocky shores. Ecol Monogr 76:439–460

Bischof K, Hanelt D, Wiencke C (1998a) UV-radiation can affect

depth-zonation of Antarctic macroalgae. Mar Biol 131:597–605

Bischof K, Hanelt D, Tug H, Karsten U, Brouwer PEM, Wiencke C

(1998b) Acclimation of brown algal photosynthesis to ultraviolet

radiation in Arctic coastal waters (Spitsbergen, Norway). Polar

Biol 20:388–395

Bischof K, Rautenberger R, Brey L, Perez-Llorens JL (2006)

Physiological acclimation to gradients of solar irradiance within

mats of the filamentous green macroalga Chaetomorpha linum

from southern Spain. Mar Ecol Prog Ser 306:165–175

Brand-Williams W, Cuvelier ME, Berset C (1995) Use of a free

radical method to evaluate antioxidant activity. Lebensm Wiss

Technol 28:25–30

Caldwell MM, Robberecht R, Flint SD (1983) Internal filters: prospects

for UV-acclimation in higher plants. Physiol Plant 58:445–450

Connan S, Delisle F, Deslandes E, Ar Gall E (2006) Intra-thallus

phlorotannin content and antioxidant activity in Phaeophyceae of

temperate waters. Bot Mar 49:39–46

Cruces E, Huovinen P, Gomez I (2012) Phlorotannin and antioxidant

responses upon short-term exposure to UV radiation and

elevated temperature in three South Pacific kelps. Photochem

Photobiol 88:58–66

Cruces E, Huovinen P, Gomez I (2013) Interactive effects of UV

radiation and enhanced temperature on photosynthesis, phloro-

tannin induction and antioxidant activities of two sub-Antarctic

brown algae. Mar Biol 160:1–13

de la Coba F, Aguilera J, Figueroa FL, de Galvez MV, Herrera E

(2009) Antioxidant activity of mycosporine-like amino acids

isolated from three red macroalgae and one marine lichen.

J Appl Phycol 21:161–169

Drew EA, Hastings RM (1992) A year-round ecophysiological study

of Himantothallus grandifolius (Desmarestiales, Phaeophyta) at

Signy Island, Antarctica. Phycologia 31:262–277

Dubois A, Iken K (2012) Seasonal variation in kelp phlorotannins in

relation to grazer abundance and environmental variables in the

Alaskan sublittoral zone. Algae 27:9–19

Fairhead VA, Amsler CD, McClintock JB, Baker BJ (2005) Variation

in phlorotannin content within two species of brown macroalgae

(Desmarestia anceps and D. menziesii) from the Western

Antarctic Peninsula. Polar Biol 28:680–686

Fairhead VA, Amsler DA, McClintock JB (2006) Lack of defence or

phlorotannin induction by UV radiation or mesograzers in

Desmarestia anceps and D. menziesii (Phaeophyceae). J Phycol

42:1174–1183

Franklin LA, Yakovleva I, Karsten U, Luning K (1999) Synthesis of

mycosporine-like amino acids in Chondrus crispus (Florideo-

phyceae) and the consequences for sensitivity to ultraviolet B

radiation. J Phycol 35:682–693

Gambi MC, Lorenti M, Russo GF, Scipione MB (1994) Benthic

associations of the shallow hard bottoms off Terra Nova Bay,

Ross Sea: zonation, biomass and population structure. Antarct

Sci 6:449–462

Gomez I, Huovinen P (2010) Induction of phlorotannins during UV

exposure mitigates inhibition of photosynthesis and DNA damage in

the kelp Lessonia nigrescens. Photochem Photobiol 86:1056–1063

Gomez I, Huovinen P (2011) Morpho-functional patterns and

zonation of South Chilean seaweeds: the importance of photo-

synthetic and bio-optical traits. Mar Ecol Prog Ser 422:77–91

Gomez I, Weykam G, Kloser H, Wiencke C (1997) Photosynthetic

light requirements, daily carbon balance and zonation of

sublittoral macroalgae from King George Island (Antarctica).

Mar Ecol Prog Ser 148:281–293

Gomez I, Wulff A, Roleda MY, Huovinen P, Karsten U, Quartino L,

Dunton K, Wiencke C (2009) Light and temperature demands of

marine benthic microalgae and seaweeds in the polar regions.

Bot Mar 52:593–608

Gutkowski R, Maleszewski S (1989) Seasonal changes of the

photosynthetic capacity of the Antarctic macroalga Adenocystis

utricularis (Bory) Skottsberg. Polar Biol 10:145–148

Hanelt D, Jaramillo MJ, Nultsch W, Senger S, Westermeier R (1994)

Photoinhibition as a regulative mechanism of photosynthesis in

marine algae of Antarctica. Ser Cient Inst Antart Chil 44:

67–77

Hanelt D, Wiencke C, Nultsch W (1997a) Influence of UV radiation

on photosynthesis of Arctic macroalgae in the field. J Photochem

Photobiol B Biol 38:40–47

Hanelt D, Wiencke C, Karsten U, Nultsch W (1997b) Photoinhibition

and recovery after high light stress in different developmental

and life-history stages of Laminaria saccharina (Phaeophyta).

J Phycol 33:387–395

Hanelt D, Melchersmann B, Wiencke C, Nultsch W (1997c) Effects

of high light stress on photosynthesis of polar macroalgae in

relation to depth distribution. Mar Ecol Prog Ser 149:255–266

Holzinger A, Di Piazza L, Lutz C, Roleda MY (2011) Sporogenic and

vegetative tissues of Saccharina latissima (Laminariales, Phae-

ophyceae) exhibit distinctive sensitivity to experimentally

enhanced ultraviolet radiation: photosynthetically active radia-

tion ratio. Phycol Res 59:221–235

Hoyer K, Karsten U, Wiencke C (2002) Induction of sunscreen

compounds in Antarctic macroalgae by different radiation

conditions. Mar Biol 141:619–627

Huovinen P, Gomez I (2011) Spectral attenuation of solar radiation in

Patagonian fjord and coastal waters and implications for algal

photobiology. Cont Shelf Res 31:254–259

Huovinen P, Leal P, Gomez I (2010) Interacting effects of copper,

nitrogen and ultraviolet radiation on the physiology of three

south Pacific kelps. Mar Freshw Res 61:330–341

Jassby AD, Platt T (1976) Mathematical formulation of the relation-

ship between photosynthesis and light for phytoplankton. Limnol

Oceonogr 21:540–547

Johansson G, Snoeijs P (2002) Macroalgal photosynthetic responses

to light in relation to thallus morphology and depth zonation.

Mar Ecol Prog Ser 244:63–72

Jones LW, Kok B (1966) Photoinhibition of chloroplast reactions.

I. Kinetics and action spectra. Plant Physiol 41:1037–1043

Karentz D, McEuen FS, Land MC, Dunlap WC (1991) Survey of

mycosporine-like amino acid compounds in Antarctic marine

organisms: potential protection from ultraviolet exposure. Mar

Biol 108:157–166

Kjeldstad B, Frette Ø, Erga SR, Browman HI, Kuhn P, Davis R,

Miller W, Stamnes JJ (2003) UV (280–400 nm) optical prop-

erties in a Norwegian fjord system and an intercomparison of

underwater radiometers. Mar Ecol Prog Ser 256:1–11

Kloser H, Ferreyra G, Schloss I, Mercuri G, Laturnus F, Curtosi A

(1993) Seasonal variation of algal growth conditions in sheltered

Antarctic bays: the example of Potter Cove (King Goerge Island,

South Shetlands). J Mar Syst 4:289–301

Polar Biol (2013) 36:1319–1332 1331

123

Kloser H, Mercuri G, Laturnus F, Quartino ML, Wiencke C (1994)

On the competitive balance of macroalgae at Potter Cove (King

George Island, South Shetlands). Polar Biol 14:11–16

Kloser H, Quartino ML, Wiencke C (1996) Distribution of macro-

algae and macroalgal communities in gradients of physical

conditions in Potter Cove, King George Island, Antarctica.

Hydrobiologia 333:1–17

Luder UH, Clayton MN (2004) Induction of phlorotannins in the

brown macroalga Ecklonia radiata (Laminariales, Phaeophyta)

in response to simulated herbivory—the first microscopic study.

Planta 218:928–937

Luder U, Knoetzel J, Wiencke C (2001) Acclimation of photosyn-

thesis and pigments to seasonally changing light conditions in

the endemic Antarctic red macroalga Palmaria decipiens. Polar

Biol 24:598–603

Luning K, Dring MJ (1985) Action spectra and spectral quantum

yield of photosynthesis in marine macroalgae with thin and thick

thalli. Mar Biol 87:119–129

Mori T, Nakane M, Hattori T, Matsunaga T, Ihara M, Nikaido O

(1991) Simultaneous establishment of monoclonal antibodies

specific for either cyclobutane pyrimidine dimer or (6–4)

photoproduct from the same mouse immunized with ultravio-

let-irradiated DNA. Photochem Photobiol 54:225–232

Pavia H, Cervin G, Lindgren A, Aberg P (1997) Effects of UV-B

radiation and simulated herbivory on phlorotannins in the brown

alga Ascophyllum nodosum. Mar Ecol Prog Ser 157:139–146

Perez-Rodrıguez E, Aguilera J, Gomez I, Figueroa FL (2001) Excretion

of coumarins by the Mediterranean alga Dasycladus vermicularis

in response to environmental stress. Mar Biol 139:633–639

Ragan MA, Glombitza KW (1986) Phlorotannins, brown algal

polyphenols. In: Round FE, Chapman DJ (eds) Progress in

phycological research. Biopress, Bristol, pp 129–241

Ramırez ME, Villouta ES (1984) Distribucion de algas intermareales

en Cabo Melville, Isla Rey Jorge, Shetland del Sur, Territorio

Antartico Chileno. Ser Cient Inst Antart Chil 31:59–166

Rautenberger R, Bischof K (2006) Impact of temperature on UV-

susceptibility of two Ulva (Chlorophyta) species from Antarctic

and Subantarctic regions. Polar Biol 29:988–996

Richardson MG (1979) The distribution of Antarctic marine macroal-

gae related to depth and substrate. Br Antarct Surv Bull 49:1–13

Richter A, Wuttke S, Zacher K (2008) Two years of in situ UV

measurements at the Dallmann Laboratory/Jubany Station. Ber

Polarforsch Meeresforsch 571:12–19

Roleda MY, Hanelt D, Wiencke C (2005) Growth kinetics related to

physiological parameters in young Saccorhiza dermatodea and

Alaria esculenta sporophytes exposed to UV radiation. Polar

Biol 28:539–549

Roleda MY, Wiencke C, Hanelt D (2006) Thallus morphology and

optical characteristics affect growth and DNA damage by UV

radiation in juvenile Arctic Laminaria sporophytes. Planta

223:407–417

Roleda MY, Zacher K, Wulff A, Hanelt D, Wiencke C (2007a)

Photosynthetic performance, DNA damage and repair in gametes

of the endemic Antarctic brown alga Ascoseira mirabilis

exposed to ultraviolet radiation. Austral Ecol 32:917–926

Roleda MY, Wiencke C, Hanelt D, Bischof K (2007b) Sensitivity of

early life stages of macroalgae from the northern hemisphere to

ultraviolet radiation. Photochem Photobiol 83:851–862

Roleda MY, Zacher K, Wulff A, Hanelt D, Wiencke C (2008)

Susceptibility of spores of different ploidy levels from antarctic

Gigartina skottsbergii (Gigartinales, Rhodophyta) to ultraviolet

radiation. Phycologia 47:361–370

Roleda MY, Campana G, Wiencke C, Hanelt D, Quartino ML, Wulff

A (2009) Sensitivity of Antarctic Urospora penicilliformis

(Ulotrichales, Chlorophyta) to ultraviolet radiation is life stage

dependent. J Phycol 45:600–609

Roleda MY, Lutz-Meindl U, Wiencke C, Lutz C (2010) Physiolog-

ical, biochemical, and ultrastructural responses of the green

macroalga Urospora penicilliformis from Arctic Spitsbergen to

UV radiation. Protoplasma 243:105–116

Schoenwaelder MEA (2002) The occurrence and cellular significance

of physodes in brown algae. J Phycol 41:125–139

Schreiber U, Bilger W, Neubauer C (1994) Chlorophyll fluorescence

as a non-intrusive indicator for rapid assessment of in vivo

photosynthesis. Ecol Stud 100:49–70

Schwarz A-M, Hawes I, Andrew N, Norkko A, Cummings V, Thrush

S (2003) Macroalgal photosynthesis near the southern global

limit for growth; Cape Evans, Ross Sea, Antarctica. Polar Biol

26:789–799

Schwarz A-M, Hawes I, Andrew N, Mercer S, Cummings V, Thrush

S (2005) Primary production potential of non-geniculate coral-

line algae at Cape Evans, Ross Sea, Antarctica. Mar Ecol Prog

Ser 294:131–140

Setlow RB (1974) The wavelengths in sunlight effective in producing

skin cancer: a theoretical analysis. Proc Natl Acad Sci USA

71:3363–3366

Skene KR (2004) Key differences in photosynthetic characteristics of

nine species of intertidal macroalgae are related to their position

on the shore. Can J Bot 82:177–184

Smale DA (2008) Continuous benthic community change along a

depth gradient in Antarctic shallows: evidence of patchiness but

not zonation. Polar Biol 31:189–198

Swanson AK, Druehl LD (2002) Induction, exudation and potential

UV protective role of kelp phlorotannins within coastal waters.

Aquat Bot 1578:1–13

Swanson AK, Fox C (2007) Altered kelp (Laminariales) phlorotan-

nins and growth under elevated carbon dioxide and ultraviolet-B

treatments can influence associated intertidal food webs. Glob

Change Biol 13:1696–1709

Tao C, Sugawara T, Maeda S, Wang X, Hirata T (2008) Antioxidative

activities of a mycosporine-like amino acid, porphyra-334. Fish

Sci 74:1166–1172

Weykam G, Gomez I, Wiencke C, Iken K, Kloser H (1996)

Photosynthetic characteristics and C:N ratios of macroalgae

from King George Island (Antarctica). J Exp Mar Biol Ecol

204:1–22

Wiencke C, Roleda MY, Gruber A, Clayton MN, Bischof K (2006)

Susceptibility of zoospores to UV radiation determines upper

depth distribution limit of Arctic kelps: evidence through field

experiments. J Ecol 94:455–463

Zacher K, Roleda MY, Hanelt D, Wiencke C (2007a) UV effects on

photosynthesis and DNA in propagules of three Antarctic

seaweeds (Adenocystis utricularis, Monostroma hariotii and

Porphyra endiviifolium). Planta 225:1505–1516

Zacher K, Wulff A, Molis M, Hanelt D, Wiencke C (2007b)

Ultraviolet radiation and consumer effects on a field-grown

intertidal macroalgal assemblage in Antarctica. Glob Change

Biol 13:1201–1215

Zacher K, Rautenberger R, Hanelt D, Wulff A, Wiencke C (2009)

The abiotic environment of polar marine benthic algae. Bot Mar

52:483–490

Zielinski K (1990) Bottom macroalgae of the Admiralty Bay (King

George Island, Antarctica). Pol Polar Res 11:95–131

1332 Polar Biol (2013) 36:1319–1332

123