• Title/Summary/Keyword: brackish waters

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Ecosysteme de I′Etang de Berre (Mediterranee nord-occidentale) : Caracteres Generales Physiques, Chimiques et Biologiques

  • Kim, Ki-Tai
    • Korean Journal of Environmental Biology
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    • v.22 no.2
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    • pp.247-258
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    • 2004
  • Climatological, hydrological and planktonical research studies, measurements of primary production and photosynthetic efficiency from December 1976 to December 1978 have been carried out in two brackish lakes: Lake Etang de Berre and Lake Etang de Vaine located in the French Mediterranean coast, in the region of Carry-le-Rouet located on the north-west Mediterranean near Marseilles, and in fresh water inflows from 4 Rivers (Touloubre, Durance, Arc, Durancole) to Lake Etang de Berre. Physico-chemical parameters were measured for this study: water temperature, salinity, density, pH, alcalinity, dissolved oxygen (% saturation), phosphate, nitrate, nitrite, silicate etc. Diverse biological parameters were also studied: photosynthetic pigments, phaeopigments, specific composition and biomass of phytoplankton, primary pelagic production etc. Climatical factors were studied: air-temperature, solar-radiation, evaporation, direction (including strength) of winds, precipitation and freshwater volume of the four rivers. The changes in Lake ‘Etang de Berre’ ecosystem depend on the quality of the water in the Durance River, and on the effects of seawater near the entrance of the Caronte Canal. The water quality of the lake varies horizontally and vertically as a result of atmospheric phenomena, maritime currents and tides. The distribution of water temperatures is generally heterogeneous. Southeasterly winds and the Northeasterly Mistral wind are important in the origins of circulated and mixed water masses. These winds are both frequent and strong. They have, as a result, a great effect on the water environment of Lake Etang de Berre. In theory, the annual precipitation in this region is well over eight times the water mass of the lake. The water of the Durance River flows into Lake Etang de Berre through the EDF Canal, amounting to 90% of the precipitation. However, reduction of rainfall in dry seasons has a serious effect on the hydrological characteristics of the lake. The temperature in the winter is partially caused by the low temperature of fresh water, particularly that of the Durance River. The hydrological season of fresh and brackish water is about one month ahead of the hydrological season of sea water in its vicinity. The salinity of Lake Etang de Berre runs approximately 3$\textperthousand$, except at lower levels and near the entrance to the Caronte Canal. However, when the volume of the Durance River water is reduced in the summer and fall, the salinity rises to 15$\textperthousand$. In the lake, the ratio of fresh water to sea water is six to one (6:1). The large quantities of seston conveyed by rivers, particularly the Durance diversion, strongly reduce the transparency in the brackish waters. Although the amount of sunshine is also notable, transparency is slight because of the large amount of seston, carried chiefly by Tripton in the fresh water of the Durance River. Therefore, photosynthesis generally occurs only in the surface layer. The transparency progressively increases from freshwater to open seawater, as mineral particles sink to the bottom (about 1.7kg $m^{-2}a^{-1}$ on the average in brackish lakes). The concentration of dissolved oxygen and the rate of oxygen saturation in seawater (Carry-le-Rouet) ranged from 5.0 to 6.0 $m\ell$ㆍ.$1^{-1}$, and from 95 to 105%, respectively. The amount of dissolved oxygen in Etang de Berre oscillated between 2.9 and 268.3%. The monographs of phosphate, nitrate, nitrite and silicate were published as a part of a study on the ecology of phytoplankton in these environments. Horizontal and vertical distributions of these nutriments were studied in detail. The recent diversion of the Durance River into Lake Etang de Berre has effected a fundamental change in this formerly marine environment, which has had a great impact in its plankton populations. A total of 182 taxa were identified, including 111 Bacillariophyceae, 44 Chlorophyceae, and 15 Cyanophyceae. The most abundant species are small freshwater algae, mainly Chlorophyceae. The average density is about $10^{8}$ cells $1^{-1}$ in Lake Etang de Berre, and about double that amount in Lake Etang de Vaine. Differences in phytoplankton abundance and composition at the various stations or at various depths are slight. Cell biovolume V (equivalent to true biomass), plasma volume VP (‘useful’ biomass) and, simultaneously. the cell surface area S and S/V ratio through the measurement of cell dimensions were computed as the parameters of phytoplankton productivity and metabolism. Pigment concentrations are generally very high on account of phytoplankton blooms by Cyanophyceae, Chlorophyceae and Cryptophyceae. On the other hand, in freshwaters and marine waters, pigment concentrations are comparatively low and stable, showing slight annual variation. The variations of ATP concentration were closely related to those of chlorophyll a and phytoplankton blooms only in marine waters. The carbon uptake rates ranged between 38 and 1091 mg$Cm^{-2}d^{-1}$, with an average surface value of 256 mg; water-column carbon-uptake rates ranged between 240 and 2310 mg$Cm^{-2}d^{-1}$, with an average of 810, representing 290 mg$Cm^{-2}$, per year 45 000 tons per year of photosynthetized carbon for the whole lake. Gross photosynthetic production measured by the method of Ryther was studied over a 2-year period. The values obtained from marine water(Carry-le-Rouet) ranged from 23 to 2 337 mg$Cm^{-2}d^{-1}$, with a weighted average of 319, representing about 110 gCm$^{-2}$ per year. The values in brakish water (Etang de Berre) ranged from 14 to 1778 mg$Cm^{-2}d^{-1}$, with a weighted average of 682, representing 250 mg$Cm^{-2}$ per year and 38 400 tons per year of photosynthesized carbon for the whole lake.

Systematic Studies on the Cirripeds (Crustacea) from Korea: I. Balanomorph Barnacles (Cirripedia, Thoracica, Balanomorpha)

  • Kim, Il-Hoi;Kim, Hoon-Soo
    • The Korean Journal of Zoology
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    • v.23 no.3
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    • pp.161-194
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    • 1980
  • The authors examined intertidal and sublittoral balanomorph barnacles which were collected from 38 localities in South Korea during the period from 1963 to 1978. 2. Identified and classified materials are composed of 15 species and 2 subspecies, all of which are described, under 10 genera and 5 damilies, of which 2 species and 1 subspecies are new to Korea as follows: Chelonibia patula, Chirona (Striatobalanus) amaryllis, Solidobalanus (Hesperibalanus) hesperius hesperius. 3. As dominant species, Chthamalus challengeri and Tetraclita squamosa japonica are widely distributed in Korea through East Sea, South Sea and Yellow Sea. 4. Balanus albicostatus and B. kondakovi are commonly found in intertidal brackish waters of Yellos Sea and South Sea, whereas, B. trigonus and Megabalanus rosa are typical sublittoral forms.

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New Record of Three Marine Ciliates (Protozoa, Ciliophora) from South Korea

  • Atef Omar;Ji Hye Moon;Jae-Ho Jung
    • Animal Systematics, Evolution and Diversity
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    • v.39 no.1
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    • pp.1-9
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    • 2023
  • During a field survey of Korean marine ciliates, we collected three ciliate species from the eastern coastal waters of the Yellow Sea. Based on the observation of living and protargol and wet silver nitrate stained cells, the ciliates, belonging to the classes Spirotrichea and Oligohymenophorea, were identified as Cardiostomatella vermiformis (Kahl, 1928) Corliss, 1960, Parallelostrombidium paraellipticum Song et al., 2018, and Pleuronema paucisaetosum Pan et al., 2015. Both Parallelostrombidium paraellipticum and Pleuronema paucisaetosum were described only from their type localities, i.e., brackish water, suggesting that they tolerate a broad range of salinity, while Cardiostomatella is marine ciliate and seems to be cosmopolitan. These three species were reported for the first time in Korea. Brief descriptions, remarks to justify their identity and to compare the present isolates with similar taxa, and photomicrographs were provided for the three species.

REARING EXPERIMENT OF COMMON CARP IN BRACKISH WATER (염분함유수에서의 잉어사육시험)

  • KIM In-Bae;JO Jae Yoon;CHOI Jae Young
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.8 no.3
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    • pp.181-184
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    • 1975
  • A aeries of experiments on the tolerance and growth of common carp, about 10 cm long in body length, in brackish water containing salinities of 2 to 20 ppt, were carried out in indoor aquariums. All fish well survived in waters containing salinities up to 12 ppt, when transfered directly from fresh water, and fairly well survived at 15 ppt, when acclimated at lower salinities before putting them into higher salinities. The temperature during the experiments was subjected to the room temperature ranging from $14^{\circ}\;to\;27^{\circ}C$. The food efficiency and growth rate were good both for alive Tubifex and pelletized dry feed at salinities from 2 to 8 ppt, but at 12 ppt the result was very poor for alive Tubifex while, for pellet feed, food efficiency was very good though growth rate was relatively low.

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Isotopic Determination of Terrestrial Food Sources for a Brackish Water Clam Corbicula japonica PRIME in an Estuarine System of Youngil Bay, Korea

  • Lee, Won-Chan;Park, Jin-Il;Choi, Woo-Jeung;Kim, Young-Seop;Lee, Pil-Yong;Kang, Chang-Keun
    • Journal of the korean society of oceanography
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    • v.35 no.1
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    • pp.56-64
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    • 2000
  • The importance of terrestrial organic matter as a food source for a brackish water clam Corbicula japonica was evaluated using stable carbon isotope ratios (${\delta}^{13}$C) in its tissues and potential food resources in an estuarine system of Youngil Bay, Korea. Suspended particulate organic matter (POM) had distinct ${\delta}^{13}$C values from riverine (-31.8 to -27.2%$_o$) to marine waters (-21.0 to -16.6%$_o$). Estuarine macroalgae had a wide ${\delta}^{13}$C range of -22.8 to -15.0%$_o$. The ${\delta}^{13}$C values of riverine POM were more negative than that of riverine phytoplankton (-26.5 to -24.2%$_o$) but similar to that of freshmarsh plant species (-29.1 to -27.5%$_o$ for Phragmites communis and -28.5 to -27.0%$_o$ for Salix gracilistyla), These ${\delta}^{13}$C values suggest that the POM transported by the Hyungsan River is predominantly of terrestrial origin rather than riverine autochthonous sources. The ${\delta}^{13}$C values of Corbicula japonica tissues (-28.7 to -27.2%$_o$) were most similar to values for riverine POM and freshmarsh plants. There was no significant difference in the isotopic composition of the clam individuals. The results indicate a predominant contribution of organic carbon derived from terrestrial and fresmarsh plant detritus to the diet of Corbicula japonica. Our results also confirm previous suggestion that terrestrial organic matter can be incorporated into estuarine food webs although its role is confined to the upper estuarine reaches.

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Pre-monsoon Dynamics of Zooplankton Communityin the Estuary of the Tamjin River, Korea (춘계 탐진강 하구역의 동물플랑크톤 군집 동태)

  • Kim, Saywa
    • Korean Journal of Environmental Biology
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    • v.33 no.1
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    • pp.19-26
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    • 2015
  • Pre-monsoon dynamics of zooplankton community were investigated in the estuary of the Tamjin River flowing into the Doam Bay of the southern coast of Korea. Monthly sampling was carried out to collect zooplankters at five sites in the estuary and the river during the period between March and June 2014. Dissolved oxygen contents were low between $5.0{\sim}7.0mgL^{-1}$ in the estuary and high, 7.0~11.0, in the river. Water temperature increased gradually from 12.0 to $28.0^{\circ}C$ and pH fluctuated between the range 7.4~8.8, respectively. A total of 85 taxa consisted of 25 species of rotifer, 30 kinds of copepod, 8 species of cladoceran, six kinds of aquatic insect larvae, four kinds of decapod and two kinds of Cirripedia larvae and Polychaeta larvae and one kind of Amphipoda, Ispopoda, Appenidicularia, Nematoda and Cnidaria, and Nocticluca scintillans was occurred. Brackish copepods distributed at almost all studied sites with freshwater zooplankters being restricted to upper waters of the river. Monthly succession of Acartia spp. was observed in the estuary with the occurrence of A. hudsonica in March and April then A. omori in May and June. Zooplankton abundance showed to vary from 450 to $87,818ind\;m^{-3}$ due to the explosion of copepodite and copepod nauplius in the estuary. Species diversity indices varied between 0.6~2.3 and generally low in the estuary and high in the river. Sea water input into the river seems to affect the river biota for more than some kilometers of the upper waters of the Tamjin River.

Seasonal Variation in Species Composition of Estuarine Fauna Collected by a Stow Net in the Han River Estuary on the mid-western coast of Korea (한강 하구역 유영생물의 종조성과 계절 변동)

  • Hwang, Sun-Do;Rhow, Jin-Goo
    • The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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    • v.15 no.2
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    • pp.72-85
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    • 2010
  • Seasonal variation in species composition of estuarine fauna in the Han River estuary was determined using monthly samples collected near Ganghwa Island by a bag net from February to December 2009. Total number of species was 86: 54 species of fishes, 16 species of shrimps of crustacean, 12 species of other crustacean such as craps and so on, 3 species of cephalopods and 1 species of jellyfish. Of a total of 86 species, Palaeman carinicauda (32.6%), Acetes japonicus (15.9%), Palaemon gravieri (9.9%), Portunus trituberculatus (7.7%) and Acetes chinensis (6.9%) were predominated in abundance. These 5 crustacean accounted for 73% of total. Abundance, biomass and diversity of Han River estuarine fauna were high in spring and autumn, indicating typical pattern of temperate area. Out of dominant species, the brackish residence species such as Coilia nasus, Chelon haematocheilus, Mugil cephalus, Synechogobius hasta, Lophiogobius ocellicauda, Tridentiger barbatus, Palaeman carinicauda, Palaemon gravieri were collected almost year-round and predominated in abundance. Coastal migratory fauna species such as Coilia mystus, Thryssa hamiltonii, Thryssa adelae, Sardinella zunasi, Engraulis japonicus, Portunus trituberculatus, Acetes japonicus, Collichthys lucidus, Pampus argenteus were most plentiful from spring through autumn. Their adult coastal migratory entered the estuary in spring and large numbers of their juveniles were grew in summer and autumn until moving out to deeper waters for over-wintering, indicating they use estuary as nursing ground. Diadromous fish such as Anguila japonica adults were collected in autumn during their downstream migration. Brackish fauna and crustacean, especially shrimps were predominant, and few contaminant indicator species collected in the Han River estuary, indicating this area maintains the characteristics of natural estuary ecosystem.

The Occurrence of Pseudo-silver eels with Different Silvering Index and Gonadal Development Stages in Anguilla japonica (Anguillidae) from Korean waters (국내에서 채집된 뱀장어 Anguilla japonica (Anguillidae)의 Silvering index와 생식소 발달 단계가 서로 다른 Pseudo-silver eels의 출현)

  • Hong, Yang-Ki;Song, Mi-Young;Park, Hee-Won;Kang, Jung-Ha;Lee, Wan-Ok
    • Korean Journal of Ichthyology
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    • v.29 no.2
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    • pp.94-100
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    • 2017
  • Three pseudo-silver eels (PS1~PS3) were found by analysis of silvering index and biological characteristics of 454 eels, Anguilla japonica, collected from the 9 sites of Korean fresh and brackish waters from September 2014 to August 2015. Two specimens (PS1~PS2) from Lake Soyang and one (PS3) from Geum river estuary were identified as pseudo-silver eel showing a large difference between silvering index and GSI. The external morphology of the pseudo-silver eels were in S2 (late silver eel) stage, but they were classified into Y1 (yellow eel) and Y2 (late yellow eel) stage in GSI, Gut index, Eye index and Y2 stage in gonadal development and mean egg diameter.

Pre-Monsoon Dynamics of Zooplankton Community in the Downstream of the Gagok Stream, Eastward into the East Sea, Korea

  • Kim, Saywa
    • Korean Journal of Environmental Biology
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    • v.33 no.2
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    • pp.223-229
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    • 2015
  • Pre-monsoon dynamics of zooplankton community were investigated in the downstream of the Gagok stream flowing into the East Sea of Korea. Monthly sampling was carried out to collect zooplankters at five sites in the stream during the period between April and July 2014. Dissolved oxygen contents exceeded $7.0mg\;L^{-1}$ all the time. Water temperature was in a range of 15.7 to $24.9^{\circ}C$ and pH 7.4 to 8.8, respectively. A total of 75 taxa consisted of 36 species of rotifers, 16 species of cladocerans, 16 species of copepods, four kinds of aquatic insects, two kinds of decapods and one nematod was occurred. One species of marine copepod and one cladoceran, and one species of brackish rotifer and one copepod distributed at the station located in the stream mouth. Zooplankton abundance showed to vary from 42 to 4202 individuals $m^{-3}$ due to the explosion of aquatic insects and Alona sp. at site 2 located in the downstream in April. Heavy rainfall during the monsoon period seems to decrease the zooplankton abundance caused by diffusion and drifting to the sea. Species diversity indices were generally high between 1.2~2.3 and were recorded to be high at the downstream throughout the study period. With the zooplankton dynamics, the influence of the input of sea waters into the stream seemed to be confined to some hundred meters of the stream mouth facing the East Sea.

Redescriptions of Diophrys appendiculata and D. scutum (Ciliophora: Spirotrichea: Uronychiidae) New to Korea

  • Kwon, Choon-Bong;Lee, Eun-Sun;Shin, Mann-Kyoon
    • Animal Systematics, Evolution and Diversity
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    • v.24 no.2
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    • pp.191-197
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    • 2008
  • Specimens of Diophrys appendiculata (Ehrenberg, ] 838) and D. scutum (Dujardin, 1841) have been collected from the coastal and brackish waters around near Ulsan, during 2004-2007. Diophrys appendiculata and D. scutum are described taxonomically for the first time in Korea. Diagnostic characteristics of these species are as follows. Diophrys appendiculata: size in vivo $43-68{\times}25-50{\mu}m$, adoral zone of membranelles (AZM) covering 43-74% of cell length in impregnated and 46-65% in vivo specimens with 32-47 adoral membranelles (AM). Paroral membrane is slightly curved. Four to five dorsal kinetal (DK) rows are fragmented and anterior and posterior parts of rows densely ciliated. Two macronuclear nodules (Ma) irregular and elongated oval in shape and widely separated. D. scutum: size in vivo $125-225{\times}75-140{\mu}m$, AZM extending to the middle of right border of body and covering 50-60% of cell length with 56-75 AMs. Body shape is typically ovoid with prominent concave margin at right posterio-lateral end, and rather thick and wide longitudinal ridge along lower buccal cavity on ventral side. Two macronuclei shaped like a sausage. five to six dorsal kineties.