• Ocean and Polar Research
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• v.26 no.1
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• pp.87-101
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• 2004

This paper delineated the ecology including movement (departure from the rookery and returning to the rookery), egg-laying, and hatch of the penguins occurred in the cold years and a less cold year in the vicinity of King Sejong Station, King George Island off the Antarctic Peninsula. The years of 1988, 1991, 1992, and 1995 were selected as cold years and the year of 2001 was selected as a less cold year based on the mean annual temperature of the years. Gentoo Penguin (Pygoscelis papua) left their rookery in May, meanwhile some remained around the station. They returned in middle-September in the less cold .year, and returned in late-September to early-October in the cold years. Chinstrap Penguin (Pygoscelis antarctica) left their rookery in early-April in the cold years as well as in the less cold year without exception. They returned to the rookery in late-October to early-November in cold years, meanwhile in early-October in the less cold year. This difference in the returning of this bird seems to be related with the exposed sea water, i.e., sea ice condition to feed in the sea. The global warming will lead to the appearance of birds which breed in the Sub-Antarctic. For example, one pair of King Penguin (Aptenodytes patagonicus) was observed in the Maxwell Bay in austral summer. And a pair of snide-like bird was recently observed for the first time in November 2001 at the penguin rookery located in the Barton Peninsula, King George Island. And it will also lead to the disappearance of an Emperor Penguin (Aptenodytes forsteri) which appeared in the full winter when Maxwell Bay and Marian Cove were frozen. It seems that the behaviour of the penguins observed around the station shows the complex effects of the ecology of the birds in combination with the natural environments, which include feeding strategy and areas, animal Instincts, exposed terrain related to weather conditions, and globa1 warming. It is necessary to take further observation and carry out systematic researches on the birds including penguins around the station which show the ecology of the birds as well as the environmental changes.

• Korean Journal of Ecology and Environment
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• v.39 no.1 s.115
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• pp.131-137
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• 2006

Most South Korean lakes are middle/small size artificial reservoirs, which are almost agricultural reservoirs (17,956). A total of 67 species (21 families) were recorded and collected from 65 agricultural reservoirs though field samplings and literature surveys. Dominant species was Pseudorasbora parva (relative abundance 24.5%), and Carassius auratur (41 sites) was the highest frequency. Feeding group of fish communities in the reservoirs was as follows: carnivorous (16.2%), omnivorous (79.5%) and herbivorous fish (4.3%). The number of individuals (P=0.024), species number (P=0.047) and carnivores number (P=0.024) were significantly correlated with reservoir ages. Reservoirs were classified into 3 groups according to feeding patterns of carnivore, omnivore and herbivore groups. The omnivores were dominant group in agricultural reservoirs. Detailed studies on fish community will be a base for the understanding of food web structure and biomanipulation in reservoir systems.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.40 no.5
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• pp.308-314
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• 2007

The feeding habits of Sebastes schlegeli collected from the Tongyeong marine ranching area throughout 2002 were studied. S. schlegeli is a carnivore (piscivore), and consumed mainly fish. Its diet also included a small amount of caridean shrimps, crabs, amphipods, polychaetes, and isopods. The diet of S. schlegeli underwent size-related changes. Small individuals (standard length (SL)<6 cm) fed mainly on fishes, caridean shrimps, and amphipods, and the proportion of fish increased with SL. Large individuals (SL>20 cm) ate fish predominately. The diet of S. schlegeli changes seasonally, and caridean shrimps were consumed mainly from May to July. The dietary breadth index of S. schlegeli varied with SL and season.

• Korean Journal of Ichthyology
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• v.31 no.1
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• pp.39-53
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• 2019

In order to compared the feeding habits of Micropterus salmoides according to the habitat types, the stomach content of a total of 306 M. salmoides were investigated from April to September 2016 in the stream and reservoir. As a result, the highest IRI (Index of relative importance) value in M. salmoides inhibiting the stream and reservoir were identified as fishes. However, the IRI value of crustaceans and insects as well as fishes in M. salmoides inhibiting the reservoir were high, showing a difference in IRI value of M. salmoides inhibiting the stream.

• Journal of Ecology and Environment
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• v.44 no.3
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• pp.143-154
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• 2020

Background: Korean wild boars (Sus scrofa coreanus Heude), because of their adaptability, are a widespread large mammal; however, they sometimes cause problems by invading farms and eating the crops, creating insufficiencies of some foods in South Korea. To understand the diet composition of Korean wild boars according to sex and body size, we collected their feces from Mt. Jeombongsan, Seoraksan National Park, South Korea. The sizes of fecal samples were measured, and genomic DNA was extracted from the samples. We amplified specific loci targeting plants (rbcL and trnL) and animals (COI) to detect the food sources of this omnivore and amplified the ZF and SRY regions to determine the sex. Results: In the wild boar feces, Rosaceae and Bryophyte were the most frequently detected plant food sources at the family level and Diptera and Haplotaxida were the most frequently detected animal food sources at the order level. As a result of sex determination, the sex ratio of wild boars collected in the Mt. Jeombongsan area was approximately 1:1. Our result suggested that there is no significant difference between the diet composition of male and female boars. Based on the average cross-sectional area of the feces, the top 25% were classified into the large body size group and the bottom 25% were classified into the small body size group. The large body size group mainly preferred Actinidiaceae, and the small body size group most frequently consumed Fagaceae. The diet of the large body size group was more diverse than the small body size group. Conclusions: Our results showed that the wild boars preferred Rosaceae, especially Sanguisorba and Filipendula, as plant food sources, and Diptera and Coleoptera of Insecta as animal food sources. Based on the results, the dietary preferences of wild boar appear to be distinguished by not their sex but their body size. Our study could help to elucidate the feeding ecology and population structure of wild boar, as well as address conservation and management issues.

• Ocean and Polar Research
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• v.33 no.1
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• pp.85-97
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• 2011

The tidal flats of Korea today have reduced by 40% in size compared to 1964. To manage this important habitat properly, development of well-organized and nationwide-applicable grading systems is required. There have been several assessment systems proposed previously in Korea, but they are critically flawed in that selected biological indicators are not adequate and grading criteria are obscure and arbitrary. We reviewed the indicators used in these previous evaluation systems (e.g., diversity indices, quantity and quality of benthic macrofauna, halophytes, water birds, etc.) and subsequently proposed new indicators and an improved grading scheme. For the quantitative assessment of macrobenthic community, biomass reflecting production and ecosystem function is recommended over density, which is much less discriminatory among habitats. Of biodiversity indices used, within-, between-habitat and regional biodiversity indices that accurately reflect sampling efforts are suggested. In addition, we proposed to include species rarity, ecosystem engineers, and the ecological quality index ISEP (Inverse function of Shannon-Wiener Evenness Proportion). As for halophytes, their low spatial coverage on benthic habitat suggests that their presence can be used as an ecological indicator of benthic habitat, regardless of their protective status. We stress the need to introduce 1) quantile approach for quantitative indicators (e.g., diversity, biomass, etc.) in relation to grading, 2) presence-absence approach for spatial or aggregate indicators (e.g., boundaries of halophytes and feeding ground of water birds) and 3) benthic habitat mapping that combines all of these indicators.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.32 no.3
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• pp.345-352
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• 1999

The sand dollar, Astriclypeus manni is commonly encountered on a subtidal sand bottom along the coast of Cheju Island. limited information has been reported on their ecology despite their natural abundance. This study reports ecology and an annual reproductive cycle of the sand dollars present at Hamdock, northern coast of Cheju Island. A. manni collected from Hamdock revealed that they are 80 to 200 mm in test diameter. Sediment Brain size analysis indicated that A. manni mostly occurs on medium (particle diameter of 500 $\mu$m) to very find sand (particle diameter of 125 $\mu$m), particularly on fine sand (particle diameter of 250 $\mu$m). Internal morphology and in situ observations on their feeding habit indicated that A. manni is a deposit feeder, feeding on organic debris contained in the sediment around its habitat. A. manni were more frequently observed near Zostrea marina bed where content of organic matter in the sediment is considered to be higher. Gonadal tissues of the male were yellow in color while female gonads appeared to be purple. Fully mature eggs, with a mean diameter of 381 $\mu$m, and sperm were observed from the histological slides of the sand dollars collected in late July to August, suggesting that A. manni spawn during July to August when water temperature reaches 20 to $25^{\circ}C$.

• Korean Journal of Ichthyology
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• v.30 no.1
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• pp.27-35
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• 2018

The activity period and feeding ecology of the Iksookimia yongdokensis were investigated to obtain baseline data for its ecological characteristics in the Chuksan Stream and Gokgang Stream, Gyeongsangbuk-do, Korea from 2015 to 2016. I. yongdokensis were active on cobble, pebble and sand bottom from March to November when the water temperature exceeded $10^{\circ}C$, but tended to overwinter in cobble and pebble during the winter months (December~February) when the water temperature was lower than $10^{\circ}C$. During the day from 9 am to 15 pm, individuals of I. yongdokensis were highly active with a high rate of food consumption. I. yongdokensis activley fed on the surface of stone, pebble and sand as a filter feeder. Their main food sources analyzed with an index of relative importance (IRI) include Chironomidae (54.7%), Branchiopoda (10.1%), Rotatoria (8.7%), Arcellidae (8.6%), Chlorophyceae (6.5%) and Bacillariophyceae (5.1%). Juveniles of I. yongdokensis (total length 20~39 mm) fed on small-sized preys such as Rotatoria, Branchiopoda and Arcellidae, but they exhibited a transition in their prey-size markedly dominated by large-sized preys such as Chironomidae and Ephemeroptera as they grow.

• Korean Journal of Ichthyology
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• v.27 no.4
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• pp.275-283
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• 2015

Habitat characteristics and feeding ecology of Iksookimia pacifica were investigated in this study to provide baseline data for its ecological characteristics in Bukcheon (stream), Goseong-gun, Gangwon-do, Korea. The main inhabit of I. pacifica was found to be sand bottoms of Bb or Bc river type with slow water flow. Based on studies of their habitat preferences according to age, their preference for sand bed was the same. However, their preference for depth and velocity was different. When their age was increased, their depth preference was also increased ($24.9{\pm}17.61cm$ for 0+ year, $69.6{\pm}30.32cm$ for 1+ year, $82.4{\pm}33.30cm$ for 2+ years, and $90.0{\pm}31.55cm$ for $3+{\leq}$ years). The water velocity was found to be 3.8 ~ 4.0 cm/sec for ages between 0+ and 1+ and 6.0 ~ 7.3 cm/sec for ages between 2+ and $3+{\leq}$. They were active on sand from March to November. They would hibernate in sand during the winter season. During the day from 12 pm to 24 am, they were highly active with high food consumption. Their main food sources analyzed with index of relative importance (IRI) include Chironomidae (76.7%), Simuliidae (10.3%), Rotatoria (7.3%), and Arcellidae (2.2%). Their juveniles (total length 20~40 mm) would feed on small-sized preys such as Rotatoria, Copepoda, and Arcellidae. Older I. pacifica would feed on big-sized preys such as Chironomidae and Simuliidae.

• Journal of Ecology and Environment
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• v.31 no.3
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• pp.249-253
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• 2008

We conducted field and laboratory observations of the life histories and fungal hosts of the darkling beetle, Platydema nigroaeneum Motschulsky. P. nigroaeneum, a fungivorous tenebrionid beetle, was a widespread inhabitant of fungi on deciduous trees (Quercus, Salix, Alnus and Carpinus etc.) in Korea. Development from egg to adulthood took $4\sim11$ months in nature and about 66 days in the laboratory at $25.5{\sim}26.1^{\circ}C$ and $63.5\sim64.5%$ relative humidity. Both larvae and adults overwintered in their host fungi or beneath the bark of the host tree near the host fungi. Sporophores of Coriolus $Qu{\acute{e}}let$, Bjerkandera Karst., Daedaleopsis Schroet. and Merulius were common feeding and breeding sites in Korea.