• 한국양식학회지
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• 제15권2호
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• pp.79-86
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• 2002

This study is the first attempt to understand the feeding physiology of a sea-urchin larva on a red-tide dinoflagellate. Fifteen day old larvae of S. intermedius capture C. polykrikoides cells by localized reversal of ciliary beats. No failure to transporte the algal cells from theciliated band to mouth and no rejection at the mouth suggest that C. polykrikoides has no feeding deterrence to S. intermedius larvae. The trend obtained for the clearance rate of S. intermedius larvae is similar to that of other sea urchin larvae. Thus, the clearance rate decreased as the algal concentration increased. Maximum clearance rate of S. intermedius on C. polykrikoides was 17.7 $\mu l$/larva/hr. Ingestion rate rapidly increased at lower algal concentrations and saturated at higher concentrations. There was no inhibition in ingestion rate at the highest prey concentration of ca. 3000 cells/ml. Maximum ingestion rate of S. intermedius on C. polykrikoides was 131 ngC/larva/d, which is higher than that reported for the larvae of the mussel Mytilus gal-lotrovincialis, but lower than that of the ciliate Strombidinopsis sp. The grazing rate, calculated by combining the field data on algal abundances with experimental data on ingestion rate, suggests that due to its low abundance, sea urchin Iarva has no significant grazing impact on C. polykrikoides population.

• 한국발생생물학회지:발생과생식
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• 제14권4호
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• pp.225-231
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• 2010

제주도 옹포와 법환 연안에 서식하는 분홍성게의 생식소 발달과 생식주기를 조사하기 위하여 1994년 12월부터 1995년 12월까지 채집된 개체를 대상으로 생식소중량지수(GSI)의 월별 변화, 월별 생식소 발달 단계를 조사하였다. 옹포와 법환 지역에 서식하는 분홍성게의 생식소중량지수의 월별 변화는 유사하였다. 암컷은 옹포와 법환 모두 12월에 각각 $17.8{\pm}4.04$, $13.8{\pm}1.51$로 최고값을 보였고, 수컷도 옹포와 법환 모두 12월에 각각 $15.4{\pm}1.53$, $13.6{\pm}1.32$로 최고값을 나타냈다. 주 산란은 옹포와 법환 수온과 일장 주기가 감소하는 11월~2월에 일어났다. 생식소의 조직학적 관찰 결과, 제주도 옹포와 법환 연안에 서식하는 분홍성게의 암 수 배우자세포 발달 양상은 동시 발달형이고, 년 1회의 산란시기를 갖은 것으로 생각된다.

• 한국수산과학회지
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• 제45권3호
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• pp.262-270
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• 2012

Seaweeds provide habitats in which marine animals can spawn and develop, and serve as a food supply for algaegrazing species such as sea urchins and abalone. Recently, seaweed species have disappeared from coastal ecosystems, leaving barren ground, defined as habitats that have lost their algae forests and where coralline algae containing calcium carbonate components have become encrusted on rocks. The biological causes of barren ground include grazing by herbivores and excessive seaweed harvest. The environmental harm caused by the spread of barren ground includes accelerated eutrophication following the reduction in seaweed, which plays an important role in oceanic purification. In the present study, we identified the relationships between various seaweed species and the occurrence of barren ground. Subtidal benthic macroalgal flora and community structure were observed seasonally on barren ground along vertical transects of rocky shores of Bihwa, Samchuck, and the east coast of Korea from February to November 2006. Fifty-eight seaweed species were identified, including 7 green, 15 brown, and 36 red algae species. There were between 6 and 28 species among seasons. Over the whole study period, average seaweed biomass (g wet wt $m^{-2}$) was 241.90 g, with a seasonal range of 25.26 to 760.34 g. Seaweed biomass declined with increasing seawater depth and ranged between 91.26 and 422.08 g. The vertical distribution of algae was characterized by Undaria pinnatifida and Sargassum honeri at 5 m, S. honeri and U. pinnatifida at 10 m, and U. pinnatifida and Agarum clathratum at 15 m depth. Seasonal patterns in community indices were not found. Community indices showed different patterns along vertical shoreline gradients; the dominance index increased but the richness, evenness, and diversity indices decreased with seawater depth. Sea urchin density was 8 to 24 individ. $m^{-2}$ in Bihwa. These urchin populations had significantly aggregated spatial patterns and recurrent destructive grazing appeared to be occurring.

• 한국수산과학회지
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• 제45권6호
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• pp.686-693
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• 2012

The seaweed community and stomach contents of the dominant herbivorous sea urchins Anthocidaris crassispina and Hemicentrotus pulcherrimus were examined from November 2008 to October 2009, in coastal areas of Tongyeong, Korea. Thirty-five seaweeds including two green, nine brown, and 24 red algae, were found over the study period. Seventeen seaweeds (two green, two brown, and 13 red) and two invertebrates were found in the stomachs of A. crassispina. In H. pulcherrimus, stomach contents were two green, one brown, 11 red seaweeds, and two invertebrates. The shell diameter of A. crassispina and H. pulcherrimus ranged from 22.3 to 62.3 mm and 15.3 to 40.1 mm, respectively. Total body weights ranged from 48.5 to 86.7 g for A. crassispina and from 7.7 to 25.9 g for H. pulcherrimus. The total weight of stomach contents were 5.1 to 25.8 g in A. crassispina and 1.7 to 11.8 g in H. pulcherrimus. The range of gonad weight was 3.6 to 17.0 g in A. crassispina and 0.8 to 4.0 g in H. pulcherrimus. The gonad index (GI) for A. crassispina peaked in July and reached a minimum in December, whereas the GI for H. pulcherrimus was highest in February, and lowest in May.

• 한국환경과학회지
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• 제14권12호
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• pp.1129-1139
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• 2005

A series of experiments was conducted to identify the potential of five phytoplankton species as standard test species for marine ecotoxicological tests. The candidate phytoplankton species are Skeletonema costatum, Heterosigma akashiwo, Prorocentrum micans, Isochrysis galbana, and Tetraselmis suecica. Salinity tolerance and sensitivity on potassium dichromate as a reference material were identified. Toxicity of eleven ocean dumped sewage sludges and four red tide expellent extracts were estimated by the inhibition of population growth rates (PGR) of marine diatom S. costatum, While most species revealed relatively weak tolerance on salinity, T. suecica demonstrated the highest salinity tolerance ranged from $5\~35$ psu and the others $15\~35$ psu. H. akashiwo revealed the highest sensitivity as 72h $IC_{50}$=0.76mg/L and T. suecica the lowest as 72h $IC_{50}$=8.89mg/L on potassium dichromate. Sludge extracts from industrial waste, domestic sewage and livestock farm waste sludge showed high toxicity as 72h $IC_{50}$<$2\%$ and lowest toxicity from filtration bed sludge as 72h $IC_{50}$=$30.50\%$ NOEC (No Observed Effective Concentration) of sludge extract ranged from <$0.4\%$ to $1.6\%$ and this indicated high phytotoxicity of ocean dumped sewage sludge. The test sensitivity of phytoplankton PGR inhibition was much higher than those of marine rotifer Brachionus plicatilis mortality test and bioluminescent inhibition test by marine bacteria Vibrio fischeri, and comparable with the sea urchin (Strongylocentrotus intermedius) fertilization test. As a result the phytotoxicity test using phytoplankton PGR inhibition ($IC_{50}$) must be a useful tool for marine phyto-toxicological evaluation of ocean dumped materials.

• 해양환경안전학회지
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• 제23권4호
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• pp.338-346
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• 2017

이 연구는 2015년 5월부터 12월까지 우리나라 동해안에 위치한 강릉, 울진, 부산 일대에서 천연 해조장 및 서식환경 특성을 분석하였다. 연구기간 동안 출현한 해조류는 총 96종이었으며, 분류군별로는 녹조류 9종, 갈조류 23종, 홍조류 64종이었다. 강릉의 경우, 미끈뼈대그물말(D. divaricata)이 정점별로 $173.2{\sim}613.8g\;m^{-2}$로 가장 높은 생물량을 보였고, 가는보라색우무(S. linearis)가 $360.8{\sim}520.4g\;m^{-2}$, 미역(U. pinnatifida)이 $25.9{\sim}470.8g\;m^{-2}$로 생물량이 높았다. 울진에서는 참곱슬이(P. telfairiae)가 $5.5{\sim}256.2g\;m^{-2}$, 구멍쇠미역(A. clathratum)이 $46.8{\sim}241.5g\;m^{-2}$로 생물량이 높았다. 부산에서 높은 생물량을 보인 해조류는 큰잎모자반(S. coreanum)으로 $388.1{\sim}6,972.4g\;m^{-2}$였고, 감태(E. cava)도 $194.9{\sim}958.5g\;m^{-2}$로 다른 해조류에 비해 상대적으로 높은 생물량을 나타냈다. 생체량 비율의 경우, 강릉에서 0.0 ~ 55.5 %로 평균 19.2 %를 나타내 울진과 부산에 비해 상대적으로 가장 낮았다. 울진에서는 36.8 ~ 73.3 %으로 평균 63.8 %를 보였으며, 부산은 평균 48.5 %였다. 갯녹음 비율은 강릉에서 평균 46.7 %의 비율을 나타냈고, 울진에서는 평균 91.1 %의 높은 비율을 나타냈으며 이번 연구에서 다른 지역에 비해 가장 높은 비율을 보였다. 조식성 동물의 밀도는 강릉에서 평균 6.0 개체/$m^2$로 분석되었고, 울진에서는 7.0 개체/$m^2$를 나타냈으며 부산에서 2.0 개체/$m^2$로 전체 지역 중에서 가장 낮은 조식성 동물 밀도를 보였다. 결론적으로 이전 연구결과와 비교하여 종조성, 출현비율, 밀도는 유사하게 나타났다. 하지만 지구 온난화, 기후변화, 해안개발 등에 의한 물리적, 화학적 오염과 관련하여 지속적인 모니터링 연구가 필요하다고 판단된다.