Effects of Temperature, Irradiance, and Nutrient Type on the Fragment Growth of Green Tide Alga Cladophora vadorum

(1)

657 Copyright © 2016 The Korean Society of Fisheries and Aquatic Science pISSN:0374-8111, eISSN:2287-8815

서 론

녹조대발생

(green tides)

은 부영양화 환경에서 녹조류의 과 도한 증식을 말하며

(Charlier et al., 2007; Shimada et al., 2008; Zhang et al., 2013),

^이들의^발생^빈도와^{발생해역이}^지 속적으로증가하고있어세계적인환경재해로대두되고있다

(Blomster et al., 2002; Largo et al., 2004; Ye et al., 2011).

^녹 조대발생은 갈파래

(Ulva),

염주말

(Chaetomorpha),

대마디말

(Cladophora),

헛뿌리말

(Rhizoclonium)

속의 해조류에 의해 주로일어나며

(Fletcher, 1996; Taylor et al., 2001; Nelson et al., 2003),

^생태계^구조^변화^및^{생물다양성}^감소를^초래하여^연 안생태계에나쁜영향을미친다

(Nelson and Lee, 2001; Franz and Friedman, 2002).

예를들면

,

녹조대발생은광과공간에대

한경쟁에서열성인해초류

(seagrass bed)

^개체군을^{감소시키고}

(Råberg et al., 2005),

^대발생^해조류의^괴사^및^침전은^해수의 용존산소를감소

(

혹은무산소상태

)

시켜무척추동물

,

어류및

포유류가사멸지대

(dead zone)

^를^{형성하므로}^{종다양성이}^높은

해역이생장속도가빠른소수의일년생종만이존재하는해역 으로바뀐다

(Hallegraeff, 1993; Worm et al., 2001).

^결과적으 로녹조대발생은연안의관광명소파괴

,

^선박의^안전^위협

,

^어 획량감소

,

해면양식등생태적서비스와엄청난경제적피해를 가져오고있다

(Liu et al., 2009; Hu et al., 2010; Ye et al., 2011).

중국

(

^칭다오

)

^에서

2008

^년에 ^대발생한 ^가시파래

(Ulva pro- lifera)

는양적으로

100

^만톤^{이상이었으며}

,

^약

1,000

^억원

(US$

100 million)

^이상의 ^{제거비용이} ^{발생하였으며}

(Wang et al.,

2009),

이후에도어업활동에의한김양식장에착생한갈파래

녹조 대발생종 금발대마디말(Cladophora vadorum)의 절편 생장에 온도, 조도 및 영양염 종류가 미치는 영향

나연주·전다빈·이정록·김영식

¹

·최한길*·남기완

²

원광대학교 생명과학부/환경과학연구소, ¹군산대학교 해양생물공학과, ²부경대학교 자원생물학과

Effects of Temperature, Irradiance, and Nutrient Type on the Fragment Growth of Green Tide Alga Cladophora vadorum

Yeon Ju Na, Da Vine Jeon, Jung Rok Lee, Young Sik Kim

¹

, Han Gil Choi* and Ki Wan Nam

²

Faculty of Biological Science and Institute for Environmental Science, Wonkwang University, Iksan 54538, Korea

1

Department of Marine Biotechnology, Kunsan National University, Kunsan 54150, Korea

2

Department of Marine Biology, Pukyong National University, Busan 48513, Korea

The green macroalga Cladophora vadorum bloomed along the coast at Sangrok Beach, Buan, South Korea, in Sep- tember 2015. To elucidate the cause of bloom, the effects of environmental factors on the vegetative growth of adult fragments were examined. Growth experiments were carried out under different combinations of temperatures and irradiances, and with a single factor of nutrients (nitrogen, phosphorus). The maximal growth of C . vadorum was reported under the combination of 25°C and 100 μmol photons m

^-2

s

^-1

. The species grew under a wide range of N and P concentrations. The growth of C . vadorum peaked at 50 μM PO

₄^3-

, 80 μM NH

₄⁺

, and 100 μM NO

₃^-

. Adult fragments formed holdfasts and new branches within 3 days in culture and became adults, showing polarized growth patterns, in 2 weeks. This is the first report showing the development of numerous bladelets from a segment in Cladophora spe- cies. The present results indicate that Cladophora blooms appear under growth conditions that are favorable in terms of temperatures, irradiance, and nutrients via fragment growth patterns producing rapid holdfasts and many bladelets.

Key words: Cladophora vadorum , Fragmentation, Eutrophication, Temperature, Green tide

This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial Licens (http://creativecommons.org/licenses/by-nc/3.0/) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.

http://dx.doi.org/10.5657/KFAS.2016.0657 Korean J Fish Aquat Sci 49(5) 657-664, October 2016

Received 18 July 2016; Revised 19 September 2016; Accepted 27 September 2016

*Corresponding author: Tel: +82. 63. 850. 6579 Fax: +82. 63. 857. 8837

E-mail address: [email protected]

(2)

류절편과방출된유주자에의해지속적으로대발생이일어나 고있다

(Zhang et al., 2014; Wang et al., 2015).

가시파래에의 한녹조대발생은파래류의분류

,

^생리

,

^생태학적^연구를^촉진시 키는시발점이되었으나

(Zhang et al., 2013),

향후다양한해조 류에의한녹조대발생이예견되므로체계적인관리를위해서 는잠재적인대상종에대한생리및생태학적연구가필요한시 점이다

.

일반적으로

,

녹조대발생원인종은영양염흡수와광합 성효율이좋아서빠른생장을보이는일년생이며

(Peckol et al., 1994; Duarte, 1995; Tan et al., 1999; Merceron et al., 2007;

Nelson et al., 2008; Choi et al., 2010),

^개체군^생장은^현미경 적 세대인 유주자낭

(zoosporangia)

^혹은 ^배우자낭

(gametan-

gia),

그리고성체의절편생장에의해일어나는것으로알려

져있다

(Dan et al., 1997; Deng et al., 2011; Zhang et al., 2013, 2016).

한예로

,

갈파래류인

Ulva mutabilis

와

U. prolifera (=

Enteromorpha prolifera)

의절편은성숙을촉진시켜유주자를 대량으로동시에생성한다고하였으며

(Nordby and Hoxmark, 1972; Dan et al., 1997; Lin et al., 2008),

최근황해에서발생 한

Ulva prolifera

의대발생은절편

(fragment)

^에^의한^무성생식 이중요한메커니즘이라고하였다

(Zhang et al., 2016).

절편재 생

(fragment regeneration)

^은^{이끼깃털말}

(Bryoposis hypnoide)

과녹조대발생종인

Chaetomorpha valida

^의^새로운^개체군^형 성에기여하는것으로확인되었으며

,

이러한절편은인간활동 이나초식자의섭식활동에의해서발생한다고하였다

(Deng et al., 2011).

녹조류대마디말 속

(Cladophora spp.)

에는

214

^종의^사상형 해조류가포함되어있으며

,

^이들은^{조간대에서}^{조하대까지}

,

^그 리고담수에서해수까지세계적인분포를보이는유비쿼터스 종이다

(Dodds and Gudder, 1992; Graham et al., 2009; Guiry and Guiry, 2016).

이러한대마디말류는다양한온도

,

염분

,

조 도와수소이온농도

(pH)

^에^내성을^가지며

(Entwisle, 1989; Tay- lor et al., 2001),

^빠른^영양염^흡수와^생장으로^다양한^지역

(

^미 국

,

캐나다

,

핀란드등

)

에서녹조대발생을일으켰다

(Pitkänen et al., 1997; Vahteri et al., 2000; Higgins et al., 2008).

^{대마디말류} 인

Cladophora vagabunda

의생장은질소

(N, nitrogen)

와인

(P,

phosphorus)

^의^이용^가능성^및^조도와^온도의^{상호작용에}^의해

서결정되며

,

^영양염이^많을수록^개체군^생장은^빠르다고^하였 다

(Peckol et al., 1994).

다른종의대발생에서나타나는것처럼

,

대마디말류에의해생성된해조류매트는부패과정에서악취를 발생시켜관광객감소

(Higgins et al., 2008)

와산소고갈에따 른저서동물의종다양성과생물량을감소시켰다

(Valiela et al., 1997; Lomstein et al., 2006; Balkis et al., 2013).

^{대마디말류} 인수정대마디말

(Cladophora glomerata)

에대한연구는미국 오대호인근에서주로수행되었으며

,

^원인은^용존^인산염과^밀 접한관련이있다고하였다

(Higgins et al., 2008).

최근

,

우리나 라서해안의상록해수욕장인근에서

2015

^년

9

^월에^약

214

^톤의 금발대마디말

(Cladophora vadorum)

^의^대발생이^일어났다

.

^이

로인해경제종인홍조류김의종묘생산에지장을초래하여어 업인의경제적손실을유발시켰으며

, Ha et al. (2016)

은이곳의 해수의총인산염

(0.438 mg L

^-1

)

^이^서해안^평균

(0.046 mg L

^-1

)

^에 비해높게나타남으로써대발생의원인을고농도의인산염이 라고하였다

.

^따라서^본^연구는^우리나라^연안에서^최초로^발생 한금발대마디말대발생의원인을구명하기위하여

,

^온도

,

^조도 와영양염종류가금발대마디말성체의절편생장과재생에어 떠한영향을미치는지를파악하고자하였다

.

재료 및 방법

금발대마디말의엽체는전북부안군상록해수욕장

(34° 60' N, 126° 48' E)

에서

2015

년

9

월에채집되었으며

,

현장해수가담긴 플라스틱샘플병에넣어실험실로운반한후

,

^유화용^붓과^여 과및멸균해수

(0.45 μm)

^로^수회^{세척하였다}

.

^이후

,

^{금발대마디} 말엽체

(3 g)

^를^멸균해수

(100 mL)

^와^함께^파쇄기에^넣고

8,000 rpm

^으로

10 s

^동안^세단한^후^망목

(Ø 0.5 mm)

^으로^여과하고^메 스실린더로침강시켜서실험에필요한

3-4

개의마디를가지는 절편

(fragments)

^을^{확보하였다}

.

성체의 형태와 발생

금발대마디말절편의생장및가근의형성과정을 확인하기 위하여

, 6

^개의^{슬라이드글라스}^조각

(2.5×2.5 cm)

^과

15 mL

^의

PES

배양액

(Provasoli, 1968)

이담긴페트리디쉬

(Ø 9 cm)

에

3 mL

^의^{금발대마디말}^현탁액

(1 mL

^당^약

100

^개^절편

)

^을^접종한 후

, 25℃, 100 µmol photons m

^-2

s

^-1^와

12:12h L:D (Light:Dark)

의광주기로세팅된배양기

(Bionex, Korea)

^에서

2

^달^동안^배양 하였다

.

^배양기간^동안^배양액은

3

^일^간격으로^전량^{교환하였으} 며

,

배양기의광원은형광등이었고조도는디지털조도계

(DX- 200)

^로^{측정하였다}

.

^절편의^{생장패턴과}^기부^생성^등^형태적^변 화는광학현미경

(Olympus BH-2, Japan)

^으로^{관찰하였고}^부착 된디지털카메라

(Canon IXUS 860IS)

^로^{촬영하였다}

. 온도와 조도 영향

온도와조도가금발대마디말의생장에미치는영향을파악하 기위하여

,

^마개가^달린^{배양용기에}

PES

^배지

(5 mL)

^와^현탁액

(1 mL)

^을^넣은^후^각기^다른^온도

(15, 20, 25, 30℃)

^와^조도

(50, 100 μmol photons m

^-2

s

^-1

)

^로^세팅된^{인큐베이터에서}

8

^일^동안 배양하였다

.

^모든^{배양기에서}^광주기는

12:12h L:D

^로^동일하 였으며

,

실험조도는형광등과배양용기의간격을조절하여만 들었다

.

^배양액은

3

^일^간격으로^전량^{교환하였으며}^규조류의^생 장을억제하기위하여

GeO

₂

(5 mgL

^-1

)

^를^배양액에^{첨가하였다}

(Shea and Chopin, 2007).

배양개시전과배양

8

^일^후

,

^{금발대마디말은}^현미경에^부착된 디지털카메라로촬영되었다

.

실험구별로

3

회반복구를두었으 며

,

^{반복구별로}

30

^개체를^무작위로^선택하여

Image J

^프로그램 으로길이를측정하였고평균값을이용하여상대생장률

(RGR,

(3)

relative growth rate)

^을^아래의^식으로^{계산하였다}

(Serisawa et al., 2002).

RGR (% day

^-1

) = 100 (In L

₂

– In L

₁

)/T

₂

–T

₁

L

₂^는^배양^종료^시

, L

₁^은^배양^개시^때의^절편^길이이고

T

₂

–T

₁ 는배양기간

(day)

을나타낸다

.

영양염 종류와 생장

금발대마디말의생장에영양염의종류가미치는영향을파악 하기위하여

,

^먼저^{저영양염해수}

(100 mL)

^가^담긴

3

^개의^비이커 에각기

NaH

₂

PO

₄

(0.142 g)

^을^용해시켜^인산염

stock solution (10 mM)

을

, NH

₄

Cl (0. 540 g)

을녹여암모늄

stock solution (100 mM)

^을

,

^그리고

NaNO

₃

(0.850 g, Sigma Co., USA)

^를^녹 여질산염

stock solution (100 mM)

을만들었다

.

이후

,

저장용 액

(stock solution)

^을^{저영양염해수로}^희석하여^다양한^농도의 인산염

(0, 10, 20, 50, 100 μM),

^암모늄

(0, 5, 10, 40, 80, 100 μM)

과질산염농도

(0, 10, 40, 80, 100, 200 μM)

의배양액을만 들어실험에사용하였다

.

^{저영양염해수}

(low nutrient seawater, OSIL, LNS23, UK)

는질산염

(nitrate),

아질산염

(nitrite),

인산 염

(phosphate)

^의^농도가

<0.1 μM

^이하이고^규산염

(silicate)

^농 도가

<0.3 μM

^이하로^제조된^{인공해수이다}

.

^다양한^인산염

,

^암

모늄과질산염농도를가진배양액

(5 mL)

이담긴배양용기에

금발대마디말절편현탁액

(1 mL)

^을^넣었으며^실험구별

3

^개^반 복구를두었다

.

배양액은

3

일간격으로전량교환하였으며

,

금 발대마디말은

25℃, 100 μmol photons m

^-2

s

^-1^와

12:12h L:D

^로 세팅된배양기에서

6

^일^동안^{배양되었다}

.

^{금발대마디말의}^길이 측정과상대생장률은온도와조도실험과동일한방법으로수 행되었다

.

통계분석

다양한 환경요인

(

^온도

,

^조도

,

^영양염

)

^이 ^{금발대마디말의}^생 장에미치는영향을파악하기 위하여

,

^{통계분석은}

Cochran’s test

로등분산검정

(homogeneity of variances)

을실시하여데 이터의동질성을확인한후

, one-way ANOVA test (

^영양염

)

^와

two–way ANOVA test (

온도

×

조도

)

로금발대마디말의생장 에대한유의차를검정하였다

.

^평균에^대한^유의차가^발견되면

Tukey’s HSD test

^방법으로^사후^검정을^{실시하였으며}

(Sokal and Rohlf, 1995),

데이터분석을위해사용된통계프로그램은

STATISTICA version 7.0

^이었다

.

결 과

성체의 형태와 발생

금발대마디말엽체는황록색으로두갈래로분지된긴실모양 의사상체이며

,

세포의길이는

183.94±5.96 μm (mean ± SE,

n=50 cells)

^였고

,

^직경은

31.28±1.09 μm (n=50)

^로서^길이

/

^직 경의비율은

6.01±0.17 μm

이다

(Fig. 1A, 1B).

금발대마디말 의생장은절편의정단부에서일어났으며

,

^새로^생장한^부위는 배양전에접종된절편에비해세포너비가가늘어

(23.74±0.67 μ m, n=50)

^{구분되었다}

(Fig. 1C).

^{말단부에서는}

3

^일^후에

,

^부착 기가생성되기 시작하였으며

, 2

^주^후에는^발달된^{기부형태를} 보였다

(Fig. 1D, 1E).

배양

4

주후금발대마디말절편의부착기 면적은

0.02±0.00 mm

²^로^{증가하였다}

(Fig. 1F).

^보통^부착기 는말단부에서생성되었지만

,

새롭게생장한정단부에서도형 성되는경우도관찰되었으며

(Fig. 1C),

^많은^부착기를^가진^절 편도있었다

(Fig. 1G).

^약

8

^주^배양한^{금발대마디말의}^기부에서 는다량의가늘고긴엽체가생성되어서로엉켜서생장하였다

(Fig. 1H, 1I).

온도와 조도 영향

온도

-

^조도^생장^실험에서^배양^전^{금발대마디말}^절편의^길이 는

320.79±8.71 μm (mean±SE, n=300 fragments)

^였으며

,

^배 양

8

일후에

556.17-2358.71 μm

로생장하였다

.

조도별엽체 의길이는

1,442.08±178.69 μm (50 μmol photons m

^-2

s

^-1

)

^와

1,624.46±149.67 μm (100 μmol photons m

^-2

s

^-1

)

로생장하여 동일한온도조건에서는고조도에서빠른생장을보이는것으 로나타났다

(F

_1,16

=46.72, P<0.01).

^다양한^온도조건

(15-30℃)

에서금발대마디말은생장하였으며

,

절편의길이는

15℃

에서

762.75±93.50 μm

^로 ^최소였고

25℃

^에서

2,288.81±40.31

μm

로최대로서

, 25℃

에서는다른온도와구별되는빠른생장

을보였고

(P<0.01), 20

과

30℃

^의^실험구^사이에는^유의차가^없 었다

(Tukey test, P＞0.01, Table 1).

^{배양기간에}^{금발대마디말} 의상대생장률은

8.62-32.53 % day

^-1를보였으며

25℃

의

100 μmol photons m

^-2

s

^-1^에서^최대였다

(Fig. 2).

영양염 종류와 생장

배양개시전

,

^{금발대마디말}^절편의^길이는

377.27±9.58 μm

Table 1. Analysis of variance (two-way ANOVA) for the effects of temperature and irradiance on relative growth rate (RGR, % day^-1) of Cladophora vadorum after 8 days in culture

Factors df MS F P

Temperature (T) 3 2330732.5 546.4 < 0.001 Irradiance (I) 1 199290.4 46.7 < 0.001

Interaction 3 37762.5 8.9 < 0.01

Error 16 4265.4

Tukey test (P =0.05)

Temperature 15<20=30<25

Irradiance 50<100

df, dgrees of freedom; MS, mean square; F, F-statistic variance ratio; P, probability.

(4)

(mean ± SE, n=300)

^였으며

,

^배양

6

^일^후

,

^인산염^실험구

(0, 10, 20, 50, 100 μM)

^에서^생장한^절편의^길이는

839.32-978.74 μm

였다

.

금발대마디말절편의상대생장률은

12.74-15.42% day

^-1

로써인산염농도가

50 μM

^인^{실험구에서}^최대였고^고농도

(100

μM)

에서는오히려생장이지연되었다

(Fig. 3A).

사후검정결 과

,

^{금발대마디말의}^{상대생장률은}

3

^개의^인산염^농도

10, 20,

100 μM

^에서는^유의차가^없는^것으로^나타났다

(Tukey HSD

test, P＞0.01).

금발대마디말은

5-100 μM

^의^다양한^암모늄^농도에서^생장하 였으며

, 6

일배양한절편의길이는

826.93-1,019.30 μm

였고상 대생장률은

12.69-16.08% day

^-1^였다

(Fig. 3B).

^{금발대마디말} 의생장은암모늄농도와비례하여증가하였으나최대생장이 일어난

80 μM

^를^정점으로^하여^고농도인

100 μM

^에서는^오히 려감소하는것으로나타났다

(F

_5,12

=104.49, P<0.01).

질산염이 첨가된 배양액에서 금발대마디말 절편의 길이는 배양

6

^일^후에

751.97-1035.34 μm

^였고^{상대생장률은}

11.26- 16.47% day

^-1^였다

(Fig. 3C).

^{금발대마디말의}^생장은^저농도

(0, 5, 10, 40 μM)

^에^비해^고농도

(80, 100 μM)

^에서^빠른^생장을^보 였으나

(F

_6,14

=99.13, P<0.01), 200 μM

^의^{고농도에서는}^오히려 생장이억제되었다

.

사후검정에서금발대마디말의생장은

80

과

100 μM

^에서는^유의차가^없었으나

,

^나머지^실험구에^비해

빠른생장을보였고

,

^저농도^실험구

(0, 5 μM)

^에^비해

10, 40

^및

200 μM

^에서^높은^생장을^보였다

(Tukey test, P＞0.01).

Fig. 1. Development of new filaments of Cladophora vadorum. A: Field-collected materials. B: Cut fragments. C: A developed new filaments (arrow). D: Formation of holdfast. E: A developed holdfast after 2 weeks in culture. F: Holdfast development after 4 weeks. G: Two parts of holdfasts. H: Secondary branches from holdfast after 8 weeks of incubation. I: 8 weeks old cultured fragments. Scale bars are 200 µm (A,G), 100 µm (B-C), 50 μm (D-F), 1 mm (H), 0.2 cm (I).

Fig. 2. Relative growth rate (RGR, % day^-1) of Cladophora vadorum cultured under various temperature and irradiance levels for 8 days. Culture conditions were 34 psu and 12:12h L:D. Data repre- sents mean±SE (n=3 replicates)

0 10 20 30 40

15 20 25 30

RGR (% day

-1

)

Temperature (℃)

50 100 μmol photons m^-2s^-1

0 4 8 12 16 20

0 10 20 50 100

RGR (

% day

-1

)

PO

₄

(μmol/L)

0 4 8 12 16 20

0 5 10 40 80 100

R G R (% day

-1

)

NH

₄

(μmol/L)

0 4 8 12 16 20

0 5 10 40 80 100 200

R G R (% day

-1

)

NO

₃

(μmol/L)

(A)

(B)

(C)

a

b b c b

a

b bc

d

c c

a a

b b c

c b

(5)

녹조대발생종 금발대마디말 성체의 절편 생장

661

고 찰

녹조대발생을일으키는갈파래

,

^염주말과^{대마디말류에}^속하 는종의생장을결정하는가장중요한환경요인은온도와조도 이며

,

이들은다양한온도와조도하에서생존과생장이가능한 것으로알려져있다

(Taylor et al., 2001; Nelson et al., 2008).

^본 연구에서금발대마디말의성체절편은

15℃

에비해상대적으 로고온인

20

^과

25℃

^에서^빠른^생장을^보였는데

, 2015

^년에^상 록해수욕장에서대발생이일어난

8-9

^월의^평균^수온인

25℃

^와 일치하였다

.

또한

,

녹조대발생종인솜대마디말

(Cladophora al-

bida)

^과^{송이가지대마디말}

(C. vagabunda)

^도^최대^생장이

25℃

에서일어난다는

Breeman et al. (2002)

의연구결과와유사하 였다

.

^본^연구에서^{금발대마디말}^절편은^저조도

(50 μmol pho- tons m

^-2

s

^-1

)

에비해고조도인

100 μmol photons m

^-2

s

^-1에서빠 른생장을보였는데

,

^이는^담수인^{오대호에서}^대발생한^수정대 마디말의 최대생장조건

(20℃

^와

120 μmol photons m

^-2

s

^-1

)

^과 유사한생리적특성을보였다

.

또한

,

금발대마디말의성체절 편은

20-30℃

^에서^{상대생장률이}

25-33% day

^-1^로서^세계^최대 규모의대발생종인가시파래의

10-25% day

^-1

(16-26℃, 100- 200 μmol photons m

^-2

s

^-1^에서

)

^에^비해^높게^{나타남으로써}

(Luo et al., 2012),

^{금발대마디말의}^여름철^대발생에^많은^관심과^관 리가필요할것으로생각된다

.

해조류의유성및무성생식은대발생을일으키는종의중요한 메카니즘이며

,

새로운해역에도입된종은엽체의재생

(regen- eration)

^에^의한^{무성생식을}^하는^특성을^가지고^있다

(Maggs and Stegenga, 1999; Boudouresque and Verlaque, 2002; Ny- berg and Wallentinus, 2005).

특히

,

영양번식

(vegetative propa-

gation)

^은^포자^생존이^어려운^{스트레스가}^심한^환경에서^효율

적이며

(Lin et al., 2008),

그중에서엽체의절편에의한재생

(fragment regeneration)

^은^대발생^종의^성숙^촉진^나아가^대량 의유주자방출을유도함으로써대발생의중요한요인으로작 용한다

(Hiraoka et al., 2004; Deng et al., 2011).

이러한절편 재생 형태의녹조대발생은

1992-2000

^년에^핀란드

(

^걸프만

)

^와

2008

년에중국

(

칭다오

)

에서일어난가시파래의대발생과밀접 한관련이있는것으로확인되었다

(Blomster et al., 2002).

^또 한

,

^중국에서^{최대규모의}^대발생을^일으킨^{가시파래는}^다른^갈 파래류

(Ulva intestinalis, U. compressa)

와다르게절편에서수 많은소엽

(blade-let)

^를^{생성하였고}^각^소엽이^한^개체로^발달하 는생장전략을가진다고하였다

(Zhang et al., 2016).

본연구 에서도금발대마디말의성체절편은단기간에부착기를형성 하였고기부에서수많은소엽이생성됨을확인하였으며정단 부에서는빠른극성생장

(polarized growth)

을보였다

.

갈파래 류의절편에서부착기와가지형성은가끔기록되었지만

(Eaton et al., 1966; Lee and Wichroski, 1996; Zhang et al., 2016),

대 마디말류에서의부착기와소엽형성은본연구에서최초로관 찰되었다

.

금발대마디말절편의생장은대조구

(0 μM)

에비해인산염

(10-100 μM),

^암모늄

(5-100 μM),

^혹은^질산염

(5-200 μM)

^이 첨가된실험구에서촉진되었으며

,

최대생장이일어나는영양 염농도는

50 μM (

^인산염

), 80 μM (

^암모늄

)

^과

100 μM (

^질산 염

)

^로서^영양염^종류에^따라^다른^것으로^나타났다

.

^{복술대마디} 말

(Cladophora dalmatica)

의최대생장을위한영양염농도는

10 μM (

^인산염

), 100 μM (

^암모늄

)

^과

800 μM (

^질산염

)

^로서^이 때생장률은

4-8% day

^-1였으며

(Taylor et al., 2001), Cladopho- ra coelothrix

는암모늄

35-70 μM

^에서

10-15% day

^-1^로^빠른^생 장을보였다

(de Paula Silva et al., 2008).

^본^연구에서^금발대마 Fig. 3. Relative growth rate (RGR, % day^-1) of Cladophora vado-

rum grown in PO₄^3-(A), NH₄⁺(B) and NO₃^- (C) for 6 days. Frag- ments were cultured under 25℃, 100 μmol photons m^-2s^-1 and 12:12h L:D. Vertical bars indicate standard errors (n=3 replicates).

Different letters indicate significant group of mean found with the Tukey HSD test.

0 10 20

15 20 25 30

RGR (% day

Temperature (℃)

0 4 8 12 16 20

0 10 20 50 100

RGR (

% day

-1

)

PO

₄

(μmol/L)

0 4 8 12 16 20

0 5 10 40 80 100

R G R (% day

-1

)

NH

₄

(μmol/L)

0 4 8 12 16 20

0 5 10 40 80 100 200

R G R (% day

-1

)

NO

₃

(μmol/L)

(A)

(B)

(C)

a

b b c b

a

b bc

d

c c

a a

b b c

c b

(6)

디말의생장률은

15-17% day

^-1^로서^{복술대마디말}

(4-8% day

^-1

)

과

Cladophora coelothrix (10-15% day

^-1

)

에비해높은생장률 을나타냈다

. 1970

^년에서

1990

^년까지^{오대호에서}^늦가을에^일 어난대마디말류의대발생은 고농도의인산염

(210-421 μM)

때문으로확인되었으며

(Nicholls et al., 2001),

^이외에도^인산 염농도와대마디말의생장

(

^혹은^생물량

)

^은^{정비례하는}^것으로 알려져왔었다

(Higgins et al., 2005a, 2005b).

그러나

, Taylor et al. (2001)

^에^따르면^{복술대마디말은}^인산염

30 μM

^과^고농도의

질산염

100 μM

에서생장이저해되었고

,

본연구에서도금발대

마디말의생장은고농도의인산염

(100 μM),

^암모늄

(100 μM),

질산염

(200 μM)

^의^농도에서^오히려^생장이^억제되는^것이^확

인되었으나생장을억제하는생리적기작에대해서는밝혀져 있지않는상태이다

.

해조류의개체군생장은적절한온도와조도범위에서기하급 수적으로증가하며

(Sousa et al., 2007; Liu et al., 2010),

^대발 생을일으키는녹조류는일반적으로초봄에빠른생장을시작 하고여름에최고조에도달하였으며

,

다양한환경조건에서생 존및생장에대한내성을보였다

(Kim et al., 2004; Liu et al., 2009; Zhao et al., 2011).

금발대마디말은서해안상록해수욕 장에서

2015

^년

8-9

^월에^대발생을^{일으켰는데}^이때^수온과^조도 가최적생장조건이었고

, Ha et al. (2016)

^는^해수의^총^인

(TP)

의농도

(5 μM)

와총질소

(TN)

의농도

(30 μM)

가서해안의다 른해역의해수에비해

10

^배

(

^총^인

)

^와

5

^배

(

^총^질소

)

^가^높은^것을 확인하여

,

대발생의원인을인간활동으로인한영양염의과다 공급으로보고하였다

.

결론적으로

,

^본^연구에서^영양염^농도에^대한^{실내배양의}^결

과는

2015

년의금발대마디말대발생이부영양화가원인이라는

Ha et al. (2016)

^의^결과를^{뒷받침하며}

,

^더불어^영양염^종류

(

^인 산염

,

암모늄

,

질산염

)

와성체의절편생장도대발생과밀접한 관련이있는것으로확인하였다

.

^특히

,

^{실내배양에서}^금발대마 디말성체절편의부착기형성과수많은소엽

(blade-let)

^의^형성 에대한관찰은금발대마디말의생리적특성도대발생을촉진 시키는중요한요인임을밝혔다

.

^{금발대마디말의}^가늘며^긴^엽 체가파도나초식자에의해쉽게절단될수있으며

,

대발생현 장에서부착기를가진엽체는관찰되지않았다는것은이를뒷 받침하고있다

.

^{마지막으로}^{금발대마디말의}^사상형^엽체는^표 면적증대로다른종에비해영양염흡수효율이높았을것으로 생각되며

,

^향후^이러한^{대마디말류의}^대발생에^대한^대책이^필 요할것으로생각된다

.

사 사

이논문은해양수산부의재원으로해양수산생명공학기술개 발사업연구개발비지원에의해수행되었습니다

.

^또한

,

^본^연구 의일부는군산대학교해양생물연구교육센터공간및장비를 활용하여수행되었습니다

.

References

Balkis N, Sivri N, Linda F, Muharrem B, Turgay D and Atakan S. 2013. Excessive growth of Cladophora (Dillwyn) kütz- ing and enteric bacteria in mats in the Southwestern Istanbul coast, Sea of Marmama. IUFS J Biol 72, 43-50.

Blomster J, Bäck S, Fewer DP, Kiirikki M, Lehvo A, Maggs CA and Stanhope MJ. 2002. Novel morphology in Enteromor-

pha (Ulvophyceae) forming green tides. Am J Bot 89, 1756-

1763. http://dx.doi.org/10.3732/ajb.89.11.1756.

Boudouresque CF and Verlaque M. 2002. Biological pollution in the Mediterranean Sea: invasive versus introduced macro- phytes. Mar Pollut Bull 44, 32-38. http://dx.doi.org/10.1016/

S0025-326X(01)00150-3.

Breeman A, Oh YS, Hwang MS and Van Den Hoek C. 2002.

Evolution of temperature responses in the Cladophora

vagabunda complex and the C. alida/sericea complex

(Chlorophyta). Eur J Phycol 37, 45-58. http://dx.doi.org/10.

1017/S0967026201003420.

Charlier RH, Morand P, Finkl CW and Thys A. 2007. Green tides on the Brittany coasts. Environ Res Eng Manage 3, 52- 59. http://dx.doi.org/10.1109/BALTIC.2006.7266128.

Choi TS, Kang EJ, Kim JH and Kim KY. 2010. Effects of salin- ity on growth and nutrient uptake of Ulva pertusa (Chlo- rophyta) from an eelgrass bed. Algae 25, 17–26. http://

dx.doi.org/10.4490/algae.2010.25.1.017.

Dan A, Ohno M and Matuoka M. 1997. Cultivation of the green alga Enteromorpha prolifera using chopped tissue for artifi- cial seeding. Suisan Zoshoku 45, 5-8.

de Paula Silva PH, McBride S, de Nys R and Oaul NA. 2008.

Integrating filamentous green tide algae into tropical pond- based aquaculture. Aquaculture 284, 74-80. http://dx.doi.

org/10.1016/j.aquaculture.2008.07.035.

Deng YY, Tang XR, Huang BX and Ding LP. 2011. Life history of Chaetomorpha valida (Cladophoraceae, Chlorophyta) in culture. Bot Mar 54, 551-556. http://dx.doi.org/10.1515/

BOT.2011.066.

Dodds WK and Gudder DA. 1992. The ecology of Cladophora.

J Phycol 28, 415-427. http://dx.doi.org/10.1111/j.0022- 3646.1992.00415.x.

Duarte C. 1995. Submerged aquatic vegetation in relation to different nutrient regimes. Ophelia 41, 87-112. http://dx.doi.or g/10.1080/00785236.1995.10422039.

Eaton JW, Brown JG and Rouno FE. 1966. Some observations on polarity and regeneration in Enteromorpha. Br Phycol Bull 3, 53-62. http://dx.doi.org/10.1080/00071616600650071.

Entwisle TJ. 1989. Phenology of the Cladophora-Stigeocloni-

um community in two urban creeks of Melbourne. Aust J

Mar Freshwater Res 40, 471-489. http://dx.doi.org/10.1071/

MF9890471.

Fletcher RL. 1996. The British Isles. In: Scharmm W, Nienhuis PH(eds) Marine benthic vegetion: recent changes, the ef-

(7)

fects of eutrophication. Springer, Berlin, pp 150-223.

Franz DR and Friedman I. 2002. Effects of a macroalgal mat (Ulva lactuca) on estuarine sand flat copepods: and ex- perimental study. J Exp Mar Biol Ecol 271, 209-226. http://

dx.doi.org/10.1016/S0022-0981(02)00045-X.

Graham LE, Graham JM and Wilcox LW. 2009. Algae, 2nd ed.

Pearson, San Francisco.

Guiry MD and Guiry GM. 2016. AlgaeBase. World-wide elec- tronic publication, National University of Ireland, Galway.

http://www.algaebase.org.

Ha DS, Yoo HI, Chang SJ and Hwang EK. 2016. Bloom of a filamentous green alga Cldophora vadorum (Areschoug) Kützing and nutrient levels at Shangrok beach, Buan, Ko- rea. Korean J Fish Aquat Sci 49, 241-246. http://dx.doi.

org/10.5657/KFAS.2016.0241.

Hallegraeff GM. 1993. A review of harmful algal blooms and their apparent global increase. Phycologia 32, 79-99. http://

dx.doi.org/10.2216/i0031-8884-32-2-79.1.

Higgins SN, Hecky RE and Guildford SJ. 2005a. Modeling the growth, biomass, and tissue phosphorus concentration of

Cladophora glomerata in eastern Lake Erie: model descrip-

tion and field testing. J Great Lakes Res 31, 439-455. http://

dx.doi.org/10.1016/S0380-1330(05)70275-6.

Higgins SN, Howell TE, Heckky RE, Guildford SJ and Smith RE. 2005b. The wall of green: the status of Cladophora on the northern shores of Lake Erie’s eastern basin, 1995-2002.

J Great Lakes Res 31, 547-563. http://dx.doi.org/10.1016/

S0380-1330(05)70283-5.

Higgins SN, Malkin SY, Howell ET, Guildford SJ, Campbell L, Hiriart-Baer V and Hecky RE. 2008. An ecological re- view of Cladophora glomerata (Chlorophyta) in the Lau- rentian Great Lakes. J Phycol 44, 839-854. http://dx.doi.

org/10.1111/j.1529-8817.2008.00538.x.

Hiraoka M, Ohno M, Kawaguchi S and Yoshida G. 2004.

Crossing test among floating Ulva thalli forming ‘green- tide’ in Japan. Hydrobiologia 512, 239-245. http://dx.doi.

org/10.1023/B:HYDR.0000020332.12641.a2.

Hu C, Li D, Chen C, Ge J, Muller-Karger FE, Liu J, Yu F and He MX. 2010. On the recurrent Ulva prolifera blooms in the Yellow Sea and East China Sea. J Geophys Res 79, 185-194.

http://dx.doi.org/10.1029/2009JC005561.

Kim KY, Choi TS, Kim JH, Han T, Shin HW and Garbary DJ.

2004. Physiological ecology and seasonality of Ulva per-

tusa on a temperate rocky shore. Phycologia 43, 483-492.

http://dx.doi.org/10.2216/i0031-8884-43-4-483.1.

Largo DB, Sembrano J, Hiraoka M and Ohno M. 2004. Taxo- nomic and ecological profile of ‘green tide’ species of Ulva (Ulvales, Chlorophyta) in central Philippines. Hydrobiolo- gia 512, 247-253. http://dx.doi.org/10.1007/978-94-007- 0944-7_32.

Lee TF and Wichroski M. 1996. Polar regeneration in Entero-

morpha prolifera. J Phycol 32, 27.

Lin A, Shen S, Wang J and Yan B. 2008. Reproduction diversity of Enteromorpha prolifera. J Integr Plant Biol 50, 622-629.

http://dx.doi.org/10.1111/j.1744-7909.2008.00647.x.

Liu D, Keesing JK, Xing Q and Shi P. 2009. World’s largest macroalgal bloom caused by expansion of seaweed aquaculture in China. Mar Pollut Bull 58, 888-895. http://dx.doi.

org/10.1016/j.marpolbul.2009.01.013.

Liu D, Keesing JK, Dong Z, Zhen Y, Di B, Shi Y, Fearns P and Shi P. 2010. Recurrence of the world’s largest green-tide in 2009 in Yellow Sea, China: Porphyra yezoensis aquaculture rafts confirmed as nursery for macroalgal blooms. Mar Pol- lut Bull 60, 1423-1432. http://dx.doi.org/10.1016/j.marpolbul.2010.05.015.

Lomstein BA, Guldberg LB, Neubauer AA, Hansen J, Donnelly A, Herbert RA, Viaroli P, Giordani G, Azzoni R, Wit R and Finster K. 2006. Benthic decomposition of Ulva lactusa: a controlled laboratory experiment. Aquat Bot 85, 271-281.

http://dx.doi.org/10.1016/j.aquabot.2006.05.006.

Luo MB, Liu F and Xu ZL. 2012. Growth and nutrient uptake ca- pacity of two co-occurring species, Ulva prolifera and Ulva

linza. Aquat Bot 100, 18-24. http://dx.doi.org/10.1016/j.

aquabot.2012.03.006.

Maggs CA and Stegenga H. 1999. Red algal exotic on North Sea coasts. Helgoländer Meeresun 52, 243-258. http://dx.doi.

org/10.1007/BF02908900.

Merceron M, Antoine V, Auby I and Morand P. 2007. In situ growth potential of the subtidal part of green tide forming

Ulva spp. stocks. Sci Total Environ 384, 293-305. http://

dx.doi.org/10.1016/j.scitotenv.2007.05.007.

Nelson TA and Lee A. 2001. A manipulative experiment dem- onstrates that blooms of the macroalga Ulvaria obscura can reduce eelgrass shoot density. Aquat Bot 71, 149-154. http://

dx.doi.org/10.1016/S0304-3770(01)00183-8.

Nelson TA, Nelson AV, Ribarich H and Tjoelker M. 2003. Sea- sonal patterns in ulvoid algal biomass, productivity, and key environmental factors in the Northeast Pacific. Bot Mar 46, 263-327.

Nelson TA, Haberlin K, Nelson AV, Ribarich H, Hotchkiss R, Van Alstyne KL, Buckingham L, Simunds DJ and Fredrick- son K. 2008. Ecological and physiological controls of species composition in green macroalgal blooms. Ecology 89, 1287-1298. http://dx.doi.org/10.1890/07-0494.1.

Nicholls KH, Hopkins G, Standke SJ and Nakamoto L. 2001.

Trends in total phosphorus in Canadian near-shore waters of the Laurentian Great Lakes: 1976-1999. J Gt Lakes Res 27, 402-422. http://dx.doi.org/10.1016/S0380-1330(01)70656- Nordby Ø and Hoxmark RC. 1972. Changes in cellular param-9.

eters during synchronous meiosis in Ulva mutabilis Føyn.

Exp Cell Res 75, 321-328. http://dx.doi.org/10.1016/0014- 4827(72)90436-3.

Nyberg CD and Wallentinus I. 2005. Can species traits be used