• Journal of Aquaculture
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• v.10 no.2
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• pp.113-121
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• 1997

In order to developed the techniques for artificial seedling production of geoduck clam, Panope japonica, various stimulution for spawning induction and hatching condition were studied. Spawning induction by the air day or UV-irradiation stimulus were not effective. Water temperature stimulus was responsed 15.0~25.0% in May and 10.0% in June. But spawning induction by the gonad incision was highest with 15.0~45.0%. Ammonium hydroxide (NH4OH) stimulus adding in seawater were responsed 15.0% at 8/1000N~10/1000N, and ammonium hyhroxide solution injected in the gonads were responsed 5.0~10.0% at 5/100N~7/100N. The highest fertilization and hatching rate at various water temperature were ranged 74.5~89.2% in 11~$17^{\circ}C, \;84.3~89.5%\;in\;8~14^{\circ}C$, respectively. the highest fertilization rate and hatching rate in various salinity were ranged 72.5~88.5% in 25~$35tetperthousand$, 82.7~86.9% in 30~$35tetperthousand$, respectively. The optimum water temperature and salinity for fertilization and hatching to the 11~14$^{\circ}C$ and 30~$35tetperthousand$, respectively.

• Proceedings of the Korean Environmental Sciences Society Conference
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• 2006.11a
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• pp.283-284
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• 2006

해초지와 해초가 없는 수괴에서 식물플랑크톤의 군집 특성을 비교 분석하기 위하여 해황과 해초지의 규모가 다른 가막만의 원포연안과 여자만의 백일도 주변 해역에서 식물플랑크톤을 채집하고, 수온, 염분, 용존산소, Chlorophyll a와 영양염을 2006년 2월부터 8월까지 조사하였다. 조사 기간동안 해초의 유무에 따른 수온과 염분의 차이는 보이지 않았으나, 용존산소, Chlorophyll a와 영양염 농도는 유의한 차이를 보였다. 또한 거머리말 해초지와 조사 시기에 따른 수온, 염분, 용존산소, Chlorophyll a와 영양염 농도도 유의한 차이를 보였다. 그리고, 원포의 수온은 백일도보다 낮았으나, 염분은 유의하게 높았다. 식물플랑크톤의 현존량과 종조성은 조사 시기에 따라 차이를 보였으며, 현존량은 해초지에서 낮게 나타났다.

• Korean Journal of Environment and Ecology
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• v.13 no.1
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• pp.89-95
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• 1999

본 연구는 임해매립지에서 토양의 화학적 특성을 조사하여 수목식재를 위한 합리적인 토양관리에 관한 자료를 얻고자 수행하였다. 토양조사는 시화매립지의 시흥공단에서 녹지조성 예정지를 중심으로 토지이용별 및 토심별로 실시되었다. 조사지역에서 개흙은 전기전도도와 치환성나트륨 백분율이 높은 염류알칼리성 토양 특징을 갖고있었다. 임해매립지에서 토양 pH 평균값은 7.8~5.7범위이었고, 주거/공단 완충녹지 토양에서 전기전도도와 치환성나트륨 백분율은 각각 3.76Sm-1와 35%로 조사지역 중에 가장 높았다. 토양 50cm 깊이에서 치환성 Na+의 평균함량은 1.76~2.80cmol+/kg으로 조사되었고, 치환성 Na+의 평균함량은 치환성 Ca2+보다는 낮았으나 치환성 Mg2+과 K+보다는 높았다. 토심별 염분농도는 50cm보다 100cm 깊이에서 높게 조사되었으며, 주거/공단 완충녹지는 전토심에서 염분농도가 수목에 영향을 주기에 충분할 정도로 높았다.

• 한국공간정보시스템학회:학술대회논문집
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• 2005.11a
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• pp.251-256
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• 2005

담수와 염수가 적절히 혼합되어있는 만에서는 굴과 가리비 미역 등의 양식업이 활발히 이루어지고 있다. 이러한 바다생물 특히, 미역의 경우는 염분농도가 13psu 이하의 상태가 장시간 유지될 경우 심한 피해를 입는다는 보고가 있다. 그러므로 만에서의 염분분포 파악은 자연환경의 적절한 활용 및 자연재해의 예방적 측면에서 매우 중요하다고 사료되어진다. 본 연구에서는 만에서의 염분분포를 파악하기 위하여 위성영상을 활용하였다. 위성영상은 현지관측이 어려운 홍수기에도 데이터 취득이 가능하며, 대상 지역 전체를 한눈에 볼 수 있는 면분포를 제공한다는 장점이 있다. 본 연구에서 수행한 구체적인 방법은 다음과 같다. 첫째, 위성영상과 탁도와의 높은 상관을 이용하여 위성영상을 탁도 분포로 변환하였다. 둘째, 현지 관측으로부터 얻은 염분과 탁도와의 상관관계를 이용하여 탁도 분포를 염분 분포로 변환하였다. 끝으로, 본 추정수법은 현지관측결과와의 검증을 통하여 타당성을 입증하였다. 결론적으로, 본 수법은 현지관측에 드는 비용절감과, 관측 데이터가 부족한 홍수기의 자연현상 파악등에 그 활용 가치가 있다고 확인되었다.

• Water for future
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• v.25 no.2
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• pp.99-110
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• 1992

A problem of outlet salinity from a stratified fluid with a well developed interface thickness consisting of an upper and lower layer differing slightly in density is considered. Three kinds of apparatus were used for the experimental test and salinity differences between inlet layer and outlet discharge were estimated by the functional relationship using the dimensionless values. For the critical incipient condition of withdrawal of upper layer, Densimetric Froude number is correlated by the inlet diameter and depth ratio in the tank.

• Proceedings of the Korean Society of Fisheries Technology Conference
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• 2001.05a
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• pp.383-384
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• 2001

환경수의 변화중 염분변화는 어체의 삼투압의 변화를 유도하고, 이때 어류는 염분 변화에 대처하기 위하여, 항상성(homeostasis) 유지측면의 삼투압 조절을 한다. 이러한 환경수의 염분변화에 따라 어류는 일정한 체내 삼투압 유지를 위하여 수분과 세포 내 염류 및 영양물질의 농도를 조절하려고 한다. 해산어류의 삼투압 조절기능을 응용하여 담수순화에 관한 연구보고는 숭어에서 수행되어 왔으나(장과 허, 1999; 허와 장, 1999), 다른 어류에 관한 자료는 부족한 실정이다. (중략)

• Proceedings of the Korean Aquaculture Society Conference
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• 2006.05a
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• pp.373-374
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• 2006

• Korean Journal of Fisheries and Aquatic Sciences
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• v.28 no.1
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• pp.87-97
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• 1995

Acute and chronic toxicity of phenol on the mortality, long-term survival and respiration rates of the mysid, Archaeomysis kokuboi adult and juvenile were examined. This experiment was condurted by static bioassay procedure with the different salinity at $25^{\circ}C$ In lethal test, the test animals were exposed to 6 different phenol concentrations to determine $LC_{50}$ and I$LT_{50}$ (median lethal concentration and time) values. The $LC_{50}$ values with the exposure time for the mysid adult ranged from 31.31ppm to 1.49ppm phenol and for the mysid juvenile ranged from 6.90ppm to 0.26ppm in all experimental groups. Mortality was increased with the decrease of salinity, The $96hr-LC_{50}$ values at 16, 24 and $32\%o$ salinity for the mysid adult were 1.49, 2.71 and 4.53ppm phenol, white the values for the mysid juvenile were 0.26, 0.56 and 0.71ppm, respectively. The ratios of $96hr-LC_{50}$ values for the mysid adult to those for the mysid juvenile at 16, 24 and $32\%p$ salinity were 5.73, 4.84 and 6.38, respectively. The mysid juveniles were more sensitive to phenol than the mysid adults. Compared $LT_{50}$ values for the mysid adult with those for the mysid juvenile, the $LT_{50}$ values for the mysid adult ranged from 384.7 to 29.0 hours at 1.7-127ppm phenol concentrations and for the mysid juvenile ranged from 132.2 to 18.7 hours at 0.5~6.Oppm phenol concentrations. The lowest $LT_{50}$ values for the mysid adult and juvenile were showed at the combination of the highest experimental concentration of phenol and the lowest experimental salinity. The mysid juveniles showed lower $LT_{50}$ values than those of adults. The chronic effects of phenol on the mysid at the sublethal effective concentration of phenol were lower in the $32\%o$ salinitr group than 16 or $24\%o$ salinity groups. Oxygen consumption rates of the mysid adult were decreased with the increase of phenol concentration and exposure time, and decreased significantly in lower salinity at the same concentration or phenol.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.21 no.3
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• pp.145-149
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• 1988

The effects of temperatures, salinities and diets on the larvae of the fresh water prawn, Macrobrchium koreana were studied. Survival rates were decreased with increasing salinity concentrations, and the second larval stages were almost died in 48 hours in over $40\%$ sea weter$(13.7\%)$. The intermolt duration of the each stage were shortend with increasing water temperature, and the optimum temperatures of the larvae were from $22^{\circ}C\~26^{\circ}C$ The larvae fed with the meat of Tapes japonicus showed the highest survival rate. When the larvae were fed with the eggyolk powder, all the lauvae died before fourth zoea. Under starved condition moltings were continued up to third zoea.

• Korean Journal of Environmental Agriculture
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• v.22 no.3
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• pp.185-191
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• 2003

The mechanism imparting salt tolerance to crop plants remains still unsolved, although soybean has been classified as a susceptible plant to NaCl. To determine optimum parameters on physiological responses for improving sensitivity of salinity in breeding program, soybean (Glycine max Merr., cv. "Gwan-gan") plants were grown in a greenhouse, treated 20 days after emergence for 7 days with NaCl at 0, 30, 60, and 90mM, corresponding to electric conductivity of 1.2, 4.4, 7.3, and 10.4 dS/m, respectively, and assessed 30 days after treatment. Chlorophyll contents were significantly decreased by NaCl ($0.4{\sim}1.0\;mg/g$) compared to control (1.2 mg/g). Photosynthesis rate by NaCl treatment at $0{\sim}90\;mM$ at flowering stage was ranged from 5.0 (control) to $9.6\;{\mu}mol/m^2/s$. Oxygen for respiration was consumed from 5.4 to $9.7\;{\mu}mol/m^2/s$ so that the ratio of $O_2$ (evolution:consumption) was increased with the increase of NaCl, indicating that $O_2$ consumption seems to go beyond $O_2$ evolution. Water potential of leaf at vegetative stage II was ranged from -0.6 to -1.8 MPa and the highest level was observed at mid-day. Water potential by salt stress was decreased with range of $-2.1{\sim}-2.7MPa$ compared to control. Transpiration was decreased from 17% to 20% by NaCl stress. Water vapor diffusing resistance of intercellular air space was affected significantly, increasing up to $16{\sim}24%$ compared to control by NaCl treatment. Salt-treated soybean tended to accumulate $Na^+$, specially in root, with reduced absorption of N, P, $K^+$, $Ca^{2+}$, and $Mg^{2+}$ contents. Free proline content of soybean leaf as affected by different NaCl concentrations was increased 4.2 times ($184{\sim}434\;{\mu}g/g$) more than control. NaCl also increased activities of nitrate reductase and peroxidase by $28{\sim}161%$ and $3{\sim}22%$, respectively. The results show that physiological characteristics of soybean plants during assay were useful as the best parameters of salt stress or salt tolerance test to improve sensitivity in screening and breeding program among cultivars or germplasms.